Cognition and dementia in older patients with epilepsy

Melatonin alleviates retinal injury induced by vigabatrin and partially enhances its antiepileptic effects

Structural optimization and combinational use with additive agents might help expand the clinical use of vigabatrin (VGB). Aiming to investigate the combinational effect of melatonin (MLT) on the antiepileptic action and retinal damage of VGB, a rat epilepsy model was induced by intraperitoneal injection of kainic acid (KA) and evaluated via both Racine grading and electroencephalogram (EEG). MLT (5, 10, 20 mg/kg) and VGB (50, 150 mg/kg) were administered intragastrically for 4 weeks, alone or together. The behavioral performance was measured during the remission of seizures via a series of tasks including the open field test (OFT), beam walking test (BW), Y-maze, and novel object recognition test (NOR). The morphological changes of the hippocampus and retina were observed using HE, Nissl, or immunofluorescence staining. Furthermore, the expression of proteins associated with synaptic plasticity and the Wnt/β-catenin/GSK3β signaling pathway were assessed. The results showed that intraperitoneal injection of KA could induce not only seizure, but also long-term behavioral impairments of sense, motion, and learning and memory in rats. Moreover, VGB could alleviate the neuroinflammation and balance the expression of synaptic plasticity and Wnt/β-catenin/GSK3β pathway proteins of epileptic rats. A combination of MLT couldn't enhance the effect of VGB in prolonging the seizure latency but presented an additive effect in alleviating the seizures grading V and improving the behavioral performance in the BW. Crucially, the combination of MLT considerably reduced the retinal cell damage caused by VGB. These results suggested that MLT could be a beneficial combination for VGB in the treatment of epilepsy, which might provide fresh insight into the clinical application of VGB and MLT.

Serum Klotho levels and epilepsy among U.S. adults in the NHANES 2013-2016: a cross-sectional study

The relationship between Klotho and epilepsy is poorly understood. This study aimed to investigate the association between serum Klotho levels and epilepsy. A total of 99,966 individuals who participated in the NHANES from the 2013 to 2016 were initially included. After excluding participants with missing data on serum Klotho concentration (57,286), epilepsy (6) and relevant covariates (6,096), the final sample consisted of 36,578 participants, with a mean age of 59 years. Weighted multivariable logistic regression analyses showed that high serum Klotho levels were negatively associated with the prevalence of epilepsy, with an odds ratio (OR) of 0.74 (95% confidence interval [CI]: 0.64 to 0.86; P < 0.001. The Restricted Cubic Spline analyses (RCS) model showed a non-linear relationship between the serum Klotho levels and epilepsy. Subgroup analysis showed that serum Klotho levels were negatively correlated with epilepsy prevalence in individuals under 65 years of age and in males. Our study suggests that serum Klotho levels were associated with the prevalence of epilepsy. Further large-scale prospective studies and randomized trials are warranted to confirm our findings.

Anti-seizure medication eslicarbazepine affects the synaptic transmission and plasticity in the rat hippocampal synapses

Patients with epilepsy often have various memory and cognitive impairments and it has been observed that the use of anti-seizure medications (ASMs) sometimes worsen the conditions. Understanding the mechanism of action of ASMs on neuronal networks is key towards answering the comorbidities of epilepsy. We used single cell patch clamp experiments and field recordings to investigate the mechanism of action of the ASM, eslicarbazepine acetate (ESL) on excitability and synaptic transmission in the hippocampal synapses. Moreover, we also investigated the effect of ESL on long-term potentiation (LTP) in the hippocampal synapses. We found that ESL reduces the neuronal excitability and sodium channel currents in a concentration dependent manner. As a known sodium channel blocker, the application of ESL was expected to decrease the amplitude of fEPSPs, but surprisingly an increase in the amplitude of fEPSPs was observed in the presence of 50 μM and 100 μM ESL (clinically relevant concentrations). This increase in fEPSPs was due to the antagonistic effect of ESL on adenosine A1 receptors. We also studied the effect of ESL on synaptic plasticity and found that 50 μM and 100 μM ESL impaired the LTP in hippocampal synapses. This study shows the interaction of ESL with Adenosine A1 receptors and its effect on synaptic plasticity. This may explain the complex and varied efficacy as well as side effects of ASMs in patients.

Clinical characteristics and treatment responses of epilepsy in the elderly in northwestern China

OBJECTIVE

To investigate the clinical characteristics and treatment responses of epilepsy in the elderly.

METHODS

Consecutive epilepsy patients (age≥65) who were admitted to the tertiary medical center in northwestern China from 2019 to 2022 and were divided into the early-onset epilepsy (EOE) group and the late-onset epilepsy (LOE) group. Clinical data were analyzed retrospectively, and all patients were followed for one year.

RESULTS

A total of 239 elderly PWE (100 in the EOE group) were enrolled, with ischemic stroke being the primary cause (27.2 %). The proportion of epilepsy due to ischemic stroke was higher in the LOE group compared to the EOE group (33.8 % vs. 27.0 %, p = 0.007). Generalized tonic-clonic seizures (GTCS) were the most common seizure type in elderly PWE (34.7 %) and EOE group (46.0 %). Complex partial seizures (CPS) were the most common seizure type in the LOE group (30.2 %). Hypertension (49.8 %) was the most prevalent comorbidity, and it was more common in the LOE group than in the EOE group (56.8 % vs. 40.0 %, p < 0.05). Of the 207 patients who completed follow-up, 184 were on anti-seizure medications (ASMs) including125 being prescribed a single type of ASM and 59 two or more types. Among patients receiving one type of ASM, more EOE group received traditional ASM (55.6 % vs. 31.0 %), while more LOE group received novel ASM (69.0 % vs. 44.4 %, p = 0.006). More patients receiving two or more type of ASMs were included in the EOE group than in the LOE group (35.9 % vs. 22.6 %, p = 0.036). Seizure freedom was achieved in 61.8 % of the elderly PWE,and the seizure freedom rate was higher in the LOE group than in the EOE group(67.0 % vs51.7 %, p = 0.035).

CONCLUSION

In elderly PWE, there are differences between EOE and LOE across several aspects, including etiology, semiology, and ASMs selection, etc. Furthermore, patients with LOE having a higher likelihood of achieving seizure freedom. Conversely, more patients with EOE need two or more type of ASMs to control their seizures.

Exploring biomarkers of neurodegeneration in epilepsy: Critical insights

The advent of biofluid biomarkers for neurodegenerative disorders has precipitated a surge in recent evidence regarding their role in epilepsy. In this literature review, we examine the diagnostic, prognostic, and therapeutic potential of several biomarkers, including amyloid-beta (Aβ) protein, total (t-tau), phosphorylated tau (p-tau) protein, alpha-synuclein, neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and others in epilepsy. Recent studies highlight mid-life Aβ levels as a risk factor for late-onset epilepsy. Several studies also show that amyloid pathology correlates with cognitive impairment in people with epilepsy (PWE). T-tau and p-tau levels in CSF and serum show diagnostic potential, particularly for temporal lobe epilepsy (TLE). Tau may also have significant prognostic utility in cognition of PWE and status epilepticus. Despite promising findings, larger prospective studies are needed to validate these biomarkers for routine clinical use in older PWE. Mouse models demonstrate tau's association with increased seizure susceptibility and mortality and the association of tau reduction with reduced seizure severity. This further highlights the need to investigate tau-targeting therapies in future studies in older PWE. Recent small-scale retrospective studies link NfL's role in cognitive impairment and status epilepticus, suggest a prognostic role of alpha-synuclein in certain epilepsies, and propose emerging diagnostic and prognostic roles of other biomarkers in epilepsy, including GFAP, cytoskeletal proteins, and S100B. However, larger longitudinal studies are needed to confirm these findings. We propose integrating some of these biomarkers into clinical practice for selected older adults with epilepsy. This integration could improve diagnostic accuracy, prognosticate outcomes, and identify therapeutic targets that may improve seizure control and mitigate the progression of cognitive decline in PWE.

Association Between Smoking and Amnesia in Southwest Iran: A Population-Based Cross-sectional Study

BACKGROUND

Amnesia is a cognitive impairment that manifests as a deficit in the retrieval of previous memories and the acquisition of novel information. Limited research, especially in Iran, exists on the risk factors of amnesia, and smoking might be linked to a greater likelihood of experiencing memory issues and cognitive decline, including amnesia. The aim of this study was to explore the risk factors associated with amnesia and the connection between smoking and amnesia. Study Design: A population-based cross-sectional study.

METHODS

This study was conducted at the baseline of the Hoveyzeh cohort study on adults aged 35-70 years in southwest Iran between 2016 and 2018. The required data on socioeconomic factors, demographic characteristics, history of stroke, history of epilepsy, and history of head trauma were collected from the participants. The relationship between smoking and amnesia was assessed, and multiple logistic regression was employed to account for potential confounding variables.

RESULTS

The mean age of the participants was 48.83±9.20 years, and 39% were male. The overall prevalence of amnesia was 4.2% (95% confidence interval [CI]: 3.8-4.6). The odds of having amnesia were significantly higher in smokers than in nonsmokers (adjusted odds ratio=1.52 [95% CI: 1.21-1.91]). Additionally, several other factors, including age, education level, type of residence, history of stroke, epilepsy, and history of trauma, were associated with amnesia.

CONCLUSION

Our investigations revealed a direct correlation between smoking and amnesia. To gain a more comprehensive understanding of the underlying mechanisms of these associations, it will be imperative to conduct future longitudinal studies.

Epilepsy and Alzheimer disease: New insights and perspectives

Numerous epidemiological and pathophysiological arguments suggest a bidirectional link between late-onset epilepsy and Alzheimer's disease. However, the temporal and causal relationship between the pathophysiological processes underlying these two conditions remains unclear. It is likely that these connections are complex, requiring consideration of various scenarios of causality and reciprocity. In the absence of targeted therapies that effectively address the progression of both diseases, specific measures can be taken to improve patient care. These include screening for cognitive disorders in patients with late-onset epilepsy, detecting subclinical EEG activity in patients with Alzheimer's disease, and identifying and managing cardiovascular risk factors in both populations. Looking ahead, it is evident that global population aging and the potential demographic surge in these two patient groups will necessitate greater efforts to raise awareness and enhance the training of physicians and healthcare professionals in the emerging field of "epileptogeriatrics".

Cognitive dysfunction and its associated factors in patients with epilepsy at referral hospitals in the Amhara region: an institutional-based cross-sectional study

Background

Epilepsy is a multifactorial disease characterized by spontaneous, recurrent seizures and a growing incidence of comorbid conditions such as anxiety, depression, cognitive dysfunction, and sudden unexpected death. Patients with epilepsy often experience cognitive impairment or dysfunction that can negatively affect their quality of life. There is limited research on cognitive dysfunction assessed through the Montreal Cognitive Assessment (MoCA) in the Amhara region, although the MoCA is considered superior to the Mini-Mental State Examination (MMSE). Therefore, this study aimed to assess cognitive dysfunction and identify factors associated with it in patients with epilepsy who were receiving follow-up care at referral hospitals in the Amhara region.

Materials and methods

A multicenter, institutional-based cross-sectional study was conducted among patients with epilepsy who were receiving follow-up care at randomly selected referral hospitals in the Amhara region from January 2024 to July 2024. A total of 355 participants were recruited for the study using a systematic random sampling technique, achieving a response rate of 98%. Cognitive dysfunction was measured using the MoCA. Data were entered with EpiData version 4.7 and then exported into SPSS version 26 for analysis. Multivariable logistic regression analysis was conducted, and a p-value of ≤0.05 was considered statistically significant. The results are presented in text and tables.

Results

The majority of the participants were women (52.1%). The mean age of the study participants was 31 (± 5.4) years. The prevalence of cognitive dysfunction was 29% (95% CI: 25.8, 34.5). Multivariable logistic regression analysis revealed that several factors were statistically significantly associated with cognitive dysfunction. Factors associated with cognitive dysfunction included being a rural resident (adjusted odds ratios (AOR) = 1.21; 95% CI: 1.29, 1.43), having a medical illness (AOR = 2.5; 95% CI: 2.1, 9.1), experiencing generalized seizures (AOR = 1.3; 95% CI: 1.08, 3.1), having a seizure frequency of daily to every other day (AOR = 2; 95% CI: 1.5, 9.2), experiencing seizures for more than 30 years (AOR = 1.5; 95% CI: 1.7, 7.6), and using a combination of anti-seizure drugs (AOR = 2.5; 95% CI: 1.2, 6.2).

Conclusions and recommendations

In this study, a significant proportion of patients with epilepsy receiving follow-up care experienced cognitive dysfunction. Neuropsychological assessment should be emphasized in patients with epilepsy at diagnosis and early follow-up phases of the condition.

Clinical features and outcomes of late-onset epilepsy of unknown etiology: A retrospective study in West China

PURPOSE

Late-onset epilepsy (LOE) usually refers to the development of epilepsy at the age of 50 years or older. Approximately 20 % of LOE cases are diagnosed as late-onset epilepsy of unknown etiology (LOUE) due to a lack of an identifiable cause. The aim of this study was to investigate the clinical features, seizure and cognitive outcomes of patients with LOUE in West China.

METHODS

Patients diagnosed with LOUE at West China Hospital between January 2015 and December 2022 were retrospectively recruited. The seizure and cognitive outcome were followed up for at least 1 year after discharge. Logistic regression models were applied to investigate the risk factors of recurrent seizure and cognitive impairment in patients with LOUE.

RESULTS

We included 286 LOUE patients with a median seizure onset age of 59 years. The most common seizure types were focal to bilateral tonic-clonic seizure (61.9 %) and focal non-motor seizure (37.0 %). Two-hundred and seventy-seven (96.9 %) patients underwent video electroencephalography (VEEG), with seizures recorded in 11.9 % of patients and interictal epileptiform discharges in 58.2 % cases. Majority of the patients (73.4 %) received monotherapy, with levetiracetam, oxcarbazepine and valproate being the most commonly prescribed anti-seizure medications. During the follow-up, 69.1 % of patients achieved seizure-free. Multivariate analysis identified ictal event recorded during VEEG monitoring (OR:0.205, 95 % CI: 0.045-0.932, p = 0.040) and memory impairment (OR:2. 470, 95 % CI: 1.181-5.167, p = 0.016) as significant factors associated with recurrent seizure. Twenty-two patients were classified as cognitive impairment. The onset age (OR:1.095, 95 % CI:1.032-1.162, p = 0.003) and total Fazekas score (OR = 6.770, 95 % CI:1.972-23.241, p = 0.002) were significant risk factors associated with cognitive dysfunction.

CONCLUSION

LOUE is generally a benign form of epilepsy with a high percentage of patients achieving seizure-free status. However, these patients are at a higher risk of memory decline and cognitive dysfunction.

High-frequency oscillations in epileptic and non-epileptic Alzheimer's disease patients and the differential effect of levetiracetam on the oscillations

Alzheimer's disease increases the risk of developing epilepsy together with cognitive decline. Early diagnosis or prediction of parameters associated with epileptic activity can greatly help in managing disease outcomes. Network hyperexcitability is a candidate of interest as a neurophysiological biomarker of Alzheimer's disease. High-frequency oscillations are increasingly recognized as potential biomarkers of hyperexcitability and epileptic activity. However, they have not yet been identified in Alzheimer's disease. In this study, we measured high-frequency oscillations via magnetoencephalography recordings in Alzheimer's disease patients with and without epileptic activity, as part of a Phase 2a randomized, double blind clinical trial of the efficacy of levetiracetam to improve cognitive functions in Alzheimer's disease. To measure the high-frequency oscillations, we used 10-min magnetoencephalography recordings (275-channel and sampling rate 1200-4000 Hz) during awake resting periods in participants with Alzheimer's disease and healthy controls. Recordings from 14 Alzheimer's disease participants, with six having non-epileptic Alzheimer's disease (median age: 60.8, 2 M/4 F), eight having sub-clinical epileptic activity (median age: 54.9, 5 M/3 F) and eight as control (median age: 71, 5 M/3 F), were analysed using two software scripts: Delphos and a custom-made script, for detecting high-frequency oscillations. Levetiracetam 125 mg twice-a-day or placebo was administered for 4 weeks in between two magnetoencephalography recordings, and 4 weeks of washout before switching levetiracetam/placebo phases for each participant. High-frequency oscillations were categorized into ripples (80 to 250 Hz) and fast ripples (250 to 500 Hz). At baseline, Alzheimer's disease participants, both epileptic and non-epileptic had higher rate of ripples and fast ripples than controls in several left/right hemispheric sensor regions (P < 0.05). Additionally, compared to epileptic, non-epileptic had higher rate of ripples in left-frontal, left-temporal and cerebral fissure regions and higher rate of fast ripples in left-frontal regions (P < 0.05). In epileptic type, levetiracetam decreased ripples in bilateral-frontal, bilateral-occipital regions and cerebral fissure, whereas in non-epileptic type, levetiracetam increased both ripples and fast ripples in right central and left parietal regions, and ripples in the right parietal region (P < 0.05). Additionally, we found hemisphere asymmetry in epileptic type, with right temporal/occipital having more high-frequency oscillations than their counterpart region. Overall, Alzheimer's disease had a high level of high-frequency oscillations, with higher numbers observed in non-epileptic type. Levetiracetam decreased high-frequency oscillations in epileptic but increased high-frequency oscillations in non-epileptic. Thus, high-frequency oscillations can function as a biomarker of hyperexcitability in Alzheimer's disease and may be more pathological when asymmetric and coinciding with presence of epileptic activity. Levetiracetam has the potential for treating hyperactivity in patients with epileptic Alzheimer's disease.

Progression of Amyloid Accumulation in Late Adulthood Among People With Childhood-Onset Epilepsy

BACKGROUND AND OBJECTIVES

Previous research has demonstrated increased brain amyloid plaque load in individuals with childhood-onset epilepsy in late middle age. However, the trajectory of this process is not yet known. The aim of this study was to determine whether individuals with a history of childhood-onset epilepsy show progressive brain aging in amyloid accumulation in late adulthood (Turku Adult Childhood-Onset Epilepsy study, TACOE).

METHODS

Adults from a prospective population-based cohort of individuals with childhood-onset epilepsy, originally recruited 1961-1964, together with matched controls, were scanned with [11C]PIB PET twice: after at least 50 years (TACOE-50) and again after at least 55 years (TACOE-55) from the diagnosis.

RESULTS

At TACOE-55, 31.4% (11/36, mean age 63.3 years, 52.8% female) of individuals from the epilepsy group and 11.4% (4/35, 63.1 year, 54.3%) of controls had a visually abnormal [11C]PIB scan (p = 0.039). At TACOE-55, cortical brain [11C]PIB uptakes were higher and increased more from TACOE-50 in the epilepsy compared with the control group (p < 0.05). In voxelwise whole-brain analyses, the epilepsy group showed significantly higher and more widespread brain amyloid accumulation (pFWE < 0.05).

DISCUSSION

The results demonstrate that childhood-onset epilepsy is associated with an earlier age at onset of amyloidosis and greater progressive amyloid accumulation in late adulthood.

Dementia and epilepsy without traumatic brain injury among subjects middle-aged females: a population-based case-control study

Background: Although the association between dementia such as Alzheimer's disease and traumatic brain injury (TBI) is well established, there are significant knowledge gaps with respect to the perspective of dementia and epilepsy without TBI. Objective: We aimed to investigate the relationship between dementia and epilepsy in a population-based study of patients without history of TBI. Methods: This study included a random sample of 30,715 patients with no history of TBI, including 6143 with epilepsy as the study cohort and 24,572 without epilepsy as the comparison cohort. Stratified Cox proportional hazard regression was used to calculate the adjusted hazard ratio (HR), with 95% confidence interval, for the risk of developing dementia in the two cohorts. Results: Patients with epilepsy but no history of TBI had increased risk of dementia (adjusted HR = 1.84). For patients aged 55-64 years, the adjusted HR for dementia was 4.5-fold higher among females in the study cohort than among males. Additionally, this study revealed that risk of dementia among above 75-year population lowest than other age subgroups (adjusted HR = 1.45). Conclusions: The study demonstrated an association between dementia and epilepsy in the patients who had no history of TBI. The effect was pronounced in patients aged 55-64 years, especially in the female population, suggesting that epilepsy needs to be more intensively prevented and controlled in this age group.

Hyperphosphorylated Tau and Cognition in Epilepsy

In light of the growing interest in the bidirectional relationship between epilepsy and dementia, this review aims to provide an overview of the role of hyperphosphorylated tau (pTau) in cognition in human epilepsy. A literature search identified five relevant studies. All of them examined pTau burden in surgical biopsy specimens from patients with temporal lobe epilepsy. The prevalence of pTau reported across the five studies, encompassing a total of 142 patients, ranged from 3.5% to 95%. Findings also varied regarding the location of pTau in the hippocampus and/or temporal cortex. Two of five studies (40%) demonstrated an inverse relationship between pTau burden and cognitive performance, one study with regard to executive functions and the other with regard to naming and verbal short-term memory. The only longitudinal study found a significant link between pTau and cognitive decline in verbal learning and memory, and in part also in naming, from the pre- to the postoperative assessment and from three to 12 months postoperatively. Given the heterogeneity of the study cohorts and the neuropsychological and neuropathological methodologies and findings, no clear picture emerges regarding the association between pTau and cognition in temporal lobe epilepsy. Added to this is the multifactorial etiology of cognitive impairment in epilepsy, including the active epilepsy, the underlying and sometimes dynamic pathology, and anti-seizure medication. Some of these factors may affect pTau expression. Further research should aim to investigate pTau longitudinally and noninvasively on a whole-brain level, using targeted neuropsychological outcome measures and controlling for age and other factors potentially influencing cognitive trajectories in epilepsy.

Late-onset epilepsy and neurodegeneration: intersecting mechanisms or separate entities?

This scientific commentary refers to ‘Late-onset temporal lobe epilepsy: insights from brain atrophy and Alzheimer’s disease biomarkers’ by Ballerini et al. (https://doi.org/10.1093/brain/awae207).

Epileptic Patients with More Clinic Visits Are More Likely to Be Diagnosed with Dementia-A Population-Based Retrospective Cohort Study

OBJECTIVE

This retrospective cohort study assessed dementia risk in epilepsy patients associated with the compliance to epileptic treatment visits.

METHODS

We used Taiwanese insurance claims data to establish an epilepsy cohort (N = 39,216) diagnosed in 2000-2015 and a matched control cohort without epilepsy (N = 156,864), evaluating the incident dementia by the end of 2016.

RESULTS

The dementia incidence was 2.9-fold higher in the epilepsy cohort than in comparisons (4.68 vs. 1.59 per 1000 person-years). Only 9.3% of epilepsy patients were compliant to ≥80% of scheduled treatment visits, but they exhibited a 7.2-fold higher dementia incidence than those without treatment. The contrast was greater in younger patients than in the elderly (20-fold versus 5.5-fold). Dementia incidence increased with the frequency of neurological consultations, peaking in the first year after epilepsy diagnosis.

CONCLUSIONS

Epileptic patients with more clinical visits for active treatment had a higher chance of dementia diagnosis, highlighting the importance of close neurological monitoring post-epilepsy diagnosis to address potential dementia complications.

Safety, tolerability, and efficacy outcomes of the Investigation of Levetiracetam in Alzheimer's disease (ILiAD) study: a pilot, double-blind placebo-controlled crossover trial

OBJECTIVE

To assess whether the antiseizure medication levetiracetam may improve cognition in individuals with Alzheimer's disease who have not previously experienced a seizure.

METHODS

We performed a randomized, double-blind, placebo-controlled crossover pilot study in individuals with mild-to-moderate Alzheimer's disease. Electroencephalography was performed at baseline and those with active epileptiform discharges were excluded. Eligible participants were randomized to placebo for 12 weeks or an active arm of oral levetiracetam (4 weeks up-titration to levetiracetam 500 mg twice daily, 4 weeks maintained on this dose followed by 4 weeks down-titration to nil). Participants then crossed over to the other arm. The primary outcome was change in cognitive function assessed by the Oxford Memory Task, a task sensitive to hippocampal memory binding. Secondary outcomes included tolerability, other neuropsychological scales, and general questionnaires.

RESULTS

Recruitment numbers were severely limited owing to restrictions from the COVID-19 pandemic at the time of the study. Eight participants completed both arms of the study (mean age 68.4 years [SD = 9.2]; 5 females [62.5%]). No participants withdrew from the study and there was no significant difference between reported side effects in the active levetiracetam or placebo arm. Measures of mood and quality of life were also not significantly different between the two arms based on participant or carer reports. In limited data analysis, there was no statistically significant difference between participants in the active levetiracetam and placebo arm on the memory task.

SIGNIFICANCE

This pilot study demonstrates that levetiracetam was well tolerated in individuals with Alzheimer's disease who do not have a history of seizures and has no detrimental effect on mood or quality of life. Larger studies are needed to assess whether levetiracetam may have a positive effect on cognitive function in subsets of individuals with Alzheimer's disease.

PLAIN LANGUAGE SUMMARY

Abnormal electrical activity within the brain, such as is seen in seizures, might contribute to memory problems in people with dementia. We completed a clinical trial to see if an antiseizure medication, levetiracetam, could help with memory difficulties in people with Alzheimer's disease (the most common cause of dementia). In this pilot study, we could not prove whether levetiracetam helped memory function. We did show that the drug is safe and well tolerated in people with dementia who have not had a seizure. This work, therefore, offers a platform for future research exploring antiseizure medications in people with dementia.

Presumed aetiologies and clinical outcomes of non-lesional late-onset epilepsy

BACKGROUND AND PURPOSE

Our objective was to define phenotypes of non-lesional late-onset epilepsy (NLLOE) depending on its presumed aetiology and to determine their seizure and cognitive outcomes at 12 months.

METHODS

In all, 146 newly diagnosed NLLOE patients, >50 years old, were prospectively included and categorized by four presumed aetiological subtypes: neurodegenerative subtype (patients with a diagnosis of neurodegenerative disease) (n = 31), microvascular subtype (patients with three or more cardiovascular risk factors and two or more vascular lesions on MRI) (n = 39), inflammatory subtype (patient meeting international criteria for encephalitis) (n = 9) and unlabelled subtype (all individuals who did not meet the criteria for other subtypes) (n = 67). Cognitive outcome was determined by comparing for each patient the proportion of preserved/altered scores between initial and second neuropsychological assessment.

RESULTS

The neurodegenerative subtype had the most severe cognitive profile at diagnosis with cognitive complaint dating back several years. The microvascular subtype was mainly evaluated through the neurovascular emergency pathway. Their seizures were characterized by transient phasic disorders. Inflammatory subtype patients were the youngest. They presented an acute epilepsy onset with high rate of focal status epilepticus. The unlabelled subtype presented fewer comorbidities with fewer lesions on brain imaging. The neurodegenerative subtype had the worst seizure and cognitive outcomes. In other groups, seizure control was good under antiseizure medication (94.7% seizure-free) and cognitive performance was stabilized or even improved.

CONCLUSION

This new characterization of NLLOE phenotypes raises questions regarding the current International League Against Epilepsy aetiological classification which does not individualize neurodegenerative and microvascular aetiology per se.

Poststroke seizures and epilepsy increase the risk of dementia among stroke survivors: A population-based study

OBJECTIVE

With global aging, the occurrence of stroke and associated outcomes like dementia are on the rise. Seizures and epilepsy are common poststroke complications and have a strong connection to subsequent dementia. This study examines the relationship between poststroke seizures (PSS) or poststroke epilepsy (PSE) and dementia using a national health care database.

METHODS

We conducted a retrospective study using data from the Taiwan National Health Insurance Research Database from 2009 to 2020. We identified acute stroke patients from 2010 to 2015, excluding those with pre-existing neurological conditions. Based on age, sex, stroke severity level, and the year of index stroke, patients with PSS or PSE were matched to those without. The main outcome was incident dementia.

RESULTS

This study included 62 968 patients with an average age of 63 years, with males accounting for 62.9%. Of them, 60.3% had ischemic strokes, and 39.7% had hemorrhagic strokes. After an average follow-up period of 5.2 years, dementia developed in 15.9% of patients who had PSS or PSE, as opposed to 8.4% of those without these conditions. A time-dependent Fine and Gray competing risk analysis showed that PSS and PSE were significantly associated with dementia across all stroke types. Subgroup analyses revealed significantly increased risk of dementia across all age groups (<50, 50-64, and ≥65 years), sexes, and various stroke severity levels. The link between PSS or PSE and dementia was particularly pronounced in men, with a less distinct correlation in women.

SIGNIFICANCE

The risk of incident dementia was higher in patients with PSS or PSE. The potential for therapeutic interventions for seizures and epilepsy to reduce poststroke dementia underscores the importance of seizure screening and treatment in stroke survivors.

Static and dynamic changes in amplitude of Low-Frequency fluctuations in patients with Self-Limited epilepsy with centrotemporal Spikes (SeLECTS): A Resting-State fMRI study

OBJECTIVE

This study aims to explore differences in the static and dynamic amplitude of low-frequency fluctuations (sALFF and dALFF) in resting-state functional MRI (rs-fMRI) data between patients with Benign childhood epilepsy with centrotemporal spikes (SeLECTS) and healthy controls (HCs).

MATERIALS AND METHODS

We recruited 45 patient with SeLECTS and 55 HCs, employing rs-fMRI to assess brain activity. The analysis utilized a two-sample t-test for primary comparisons, supplemented by stratification and matching based on clinical and demographic characteristics to ensure comparability between groups. Post hoc analyses assessed the relationships between sALFF/dALFF alterations and clinical demographics, incorporating statistical adjustments for potential confounders and performing sensitivity analysis to test the robustness of our findings.

RESULTS

Our analysis identified significant differences in sALFF and dALFF between patient with SeLECTS and HCs. Notably, increases in sALFF and dALFF were observed in the right middle temporal gyrus and left superior temporal gyrus among patient with SeLECTS, while a decrease in dALFF was seen in the right cerebellum crus 1. Additionally, a positive correlation was found between abnormal dALFF variability in specific brain regions and various clinical and demographic factors of patient with SeLECTS, with age being one such influential factor.

CONCLUSION

This investigation provides insights into the assessment of local brain activity in SeLECTS through both static and dynamic approaches. It highlights the significance of non-invasive neuroimaging techniques in understanding the complexities of epilepsy syndromes like SeLECTS and emphasizes the need to consider a range of clinical and demographic factors in neuroimaging studies of neurological disorders.

Neuropsychiatry revisited: epilepsy as the borderland between neurology and psychiatry

Since epilepsy is often complicated by psychiatric symptoms, the contributions of psychiatry are indispensable for the care and improvement of the quality of life of individuals with epilepsy. Moreover, the existence of a bidirectional relationship between epilepsy and psychiatric symptoms was recently proposed, based on the evidence that not only are some psychiatric symptoms more likely than others to follow epilepsy, but also that psychiatric symptoms may precede the onset of epilepsy and the presence of psychiatric symptoms may influence the outcome of treatment for seizures. There has also been a gradual accumulation of neurobiological findings related to psychosis, depressive, and anxiety symptoms that are associated with epilepsy with respect to abnormalities in brain networks and neurotransmission. This mini-review focuses on the neuropsychiatric aspects of epilepsy and proposes that a reconsideration of neuropsychiatry in light of epilepsy findings could serve as a bridge between psychiatry and neurology.

Association Between COVID-19 and Neurological Diseases: Evidence from Large-Scale Mendelian Randomization Analysis and Single-Cell RNA Sequencing Analysis

Observational studies have suggested that SARS-CoV-2 infection increases the risk of neurological diseases, but it remains unclear whether the association is causal. The present study aims to evaluate the causal relationships between SARS-CoV-2 infections and neurological diseases and analyzes the potential routes of SARS-CoV-2 entry at the cellular level. We performed Mendelian randomization (MR) analysis with CAUSE method to investigate causal relationship of SARS-CoV-2 infections with neurological diseases. Then, we conducted single-cell RNA sequencing (scRNA-seq) analysis to obtain evidence of potential neuroinvasion routes by measuring SARS-CoV-2 receptor expression in specific cell subtypes. Fast gene set enrichment analysis (fGSEA) was further performed to assess the pathogenesis of related diseases. The results showed that the COVID-19 is causally associated with manic (delta_elpd, - 0.1300, Z-score: - 2.4; P = 0.0082) and epilepsy (delta_elpd: - 2.20, Z-score: - 1.80; P = 0.038). However, no significant effects were observed for COVID-19 on other traits. Moreover, there are 23 cell subtypes identified through the scRNA-seq transcriptomics data of epilepsy, and SARS-CoV-2 receptor TTYH2 was found to be specifically expressed in oligodendrocyte and astrocyte cell subtypes. Furthermore, fGSEA analysis showed that the cell subtypes with receptor-specific expression was related to methylation of lysine 27 on histone H3 (H3K27ME3), neuronal system, aging brain, neurogenesis, and neuron projection. In summary, this study shows causal links between SARS-CoV-2 infections and neurological disorders such as epilepsy and manic, supported by MR and scRNA-seq analysis. These results should be considered in further studies and public health measures on COVID-19 and neurological diseases.

Microglia in Microbiota-Gut-Brain Axis: A Hub in Epilepsy

There is growing concern about the role of the microbiota-gut-brain axis in neurological illnesses, and it makes sense to consider microglia as a critical component of this axis in the context of epilepsy. Microglia, which reside in the central nervous system, are dynamic guardians that monitor brain homeostasis. Microglia receive information from the gut microbiota and function as hubs that may be involved in triggering epileptic seizures. Vagus nerve bridges the communication in the axis. Essential axis signaling molecules, such as gamma-aminobutyric acid, 5-hydroxytryptamin, and short-chain fatty acids, are currently under investigation for their participation in drug-resistant epilepsy (DRE). In this review, we explain how vagus nerve connects the gut microbiota to microglia in the brain and discuss the emerging concepts derived from this interaction. Understanding microbiota-gut-brain axis in epilepsy brings hope for DRE therapies. Future treatments can focus on the modulatory effect of the axis and target microglia in solving DRE.

Detecting and Predicting Cognitive Decline in Individuals with Traumatic Brain Injury: A Longitudinal Telephone-Based Study

Traumatic brain injuries (TBIs) can lead to long-lasting cognitive impairments, and some survivors experience cognitive decline post-recovery. Early detection of decline is important for care planning, and understanding risk factors for decline can elucidate targets for prevention. While neuropsychological testing is the gold standard approach to characterizing cognitive function, there is a need for brief, scalable tools that are capable of detecting clinically significant changes in post-TBI cognition. This study examines whether a clinically significant change can be detected using the Brief Test of Adult Cognition by Telephone (BTACT) in a sample of individuals with chronic TBI and investigates whether potentially modifiable factors are associated with cognitive decline. Ninety participants aged 40 or older with complicated mild-to-severe TBI participated in two telephone-based study visits ∼1 year apart. Demographic, head trauma exposure, comorbid medical conditions, physical, and psychosocial functioning data were collected via self-report. The BTACT, a brief measure of global cognitive function, was used to assess cognitive performance across six domains. A reliable change index for quantifying clinically significant changes in BTACT performance was calculated. Results revealed cognitive decline in 10-27% of participants across various cognitive domains. More specifically, only depressive symptoms, including depressed affect and anhedonia, were significantly associated with cognitive decline after correcting for multiple comparisons using false discovery rate (FDR). Other factors such as the number of blows to the head, male gender, dyspnea, increased anxiety symptoms, seizures, illicit drug use, and fewer cardiovascular comorbidities should be considered hypothesis generating. Importantly, age was not a significant predictor of cognitive decline, which challenges the assumption that cognitive decline is solely related to the natural aging process. It suggests that there are unique factors associated with TBI that impact cognitive function, and these factors can affect individuals across the lifespan. The BTACT is a brief and sensitive tool for identifying clinically meaningful changes in cognitive function over a relatively brief period (i.e., 1 year) in a sample of individuals in the chronic stages of TBI (i.e., x̄ = 6.7 years post-TBI). Thus, the BTACT may be useful in surveillance efforts aimed at understanding and detecting decline, particularly in situations where in-person cognitive screening is impractical or unfeasible. We also identified potentially modifiable targets for the prevention of post-TBI cognitive decline. These findings can offer insights into treatment goals and preventive strategies for individuals at risk for cognitive decline, as well as help to facilitate early identification efforts.

Association of synaptic density and cognitive performance in temporal lobe epilepsy: Humans and animals PET imaging study with [18F]SynVesT-1

AIM

Cognitive impairment is a common comorbidity in individuals with temporal lobe epilepsy (TLE), yet the underlying mechanisms remain unknown. This study explored the putative association between in vivo synaptic loss and cognitive outcomes in TLE patients by PET imaging of synaptic vesicle glycoprotein 2A (SV2A).

METHODS

We enrolled 16 TLE patients and 10 cognitively normal controls. All participants underwent SV2A PET imaging using [18F]SynVesT-1 and cognitive assessment. Lithium chloride-pilocarpine-induced rats with status epilepticus (n = 20) and controls (n = 6) rats received levetiracetam (LEV, specifically binds to SV2A), valproic acid (VPA), or saline for 14 days. Then, synaptic density was quantified by [18F]SynVesT-1 micro-PET/CT. The novel object recognition and Morris water maze tests evaluated TLE-related cognitive function. SV2A expression was examined and confirmed by immunohistochemistry.

RESULTS

Temporal lobe epilepsy patients showed significantly reduced synaptic density in hippocampus, which was associated with cognitive performance. In the rat model of TLE, the expression of SV2A and synaptic density decreased consistently in a wider range of brain regions, including the entorhinal cortex, insula, hippocampus, amygdala, thalamus, and cortex. We treated TLE animal models with LEV or VPA to explore whether synaptic loss contributes to cognitive deficits. It was found that LEV significantly exerted protective effects against brain synaptic deficits and cognitive impairment.

CONCLUSION

This is the first study to link synaptic loss to cognitive deficits in TLE, suggesting [18F]SynVesT-1 PET could be a promising biomarker for monitoring synaptic loss and cognitive dysfunction. LEV might help reverse synaptic deficits and ameliorate learning and memory impairments in TLE patients.

Traumatic Brain Injury, Seizures, and Cognitive Impairment Among Older Adults

Importance

Traumatic brain injury (TBI), seizures, and dementia increase with age. There is a gap in understanding the associations of TBI, seizures, and medications such as antiseizure and antipsychotics with the progression of cognitive impairment across racial and ethnic groups.

Objective

To investigate the association of TBI and seizures with the risk of cognitive impairment among cognitively normal older adults and the role of medications in moderating the association.

Design, Setting, and Participants

This multicenter cohort study was a secondary analysis of the Uniform Data Set collected between June 1, 2005, and June 30, 2020, from the National Alzheimer's Coordination Center. Statistical analysis was performed from February 1 to April 3, 2024. Data were collected from participants from 36 Alzheimer's Disease Research Centers in the US who were 65 years or older at baseline, cognitively normal at baseline (Clinical Dementia Rating of 0 and no impairment based on a presumptive etiologic diagnosis of AD), and had complete information on race and ethnicity, age, sex, educational level, and apolipoprotein E genotype.

Exposure

Health history of TBI, seizures, or both conditions.

Main Outcomes and Measures

Progression to cognitive impairment measured by a Clinical Dementia Rating greater than 0.

Results

Among the cohort of 7180 older adults (median age, 74 years [range, 65-102 years]; 4729 women [65.9%]), 1036 were African American or Black (14.4%), 21 were American Indian or Alaska Native (0.3%), 143 were Asian (2.0%), 332 were Hispanic (4.6%), and 5648 were non-Hispanic White (78.7%); the median educational level was 16.0 years (range, 1.0-29.0 years). After adjustment for selection basis using propensity score weighting, seizure was associated with a 40% higher risk of cognitive impairment (hazard ratio [HR], 1.40; 95% CI, 1.19-1.65), TBI with a 25% higher risk of cognitive impairment (HR, 1.25; 95% CI, 1.17-1.34), and both seizure and TBI were associated with a 57% higher risk (HR, 1.57; 95% CI, 1.23-2.01). The interaction models indicated that Hispanic participants with TBI and seizures had a higher risk of cognitive impairment compared with other racial and ethnic groups. The use of antiseizure medications (HR, 1.23; 95% CI, 0.99-1.53), antidepressants (HR, 1.32; 95% CI, 1.17-1.50), and antipsychotics (HR, 2.15; 95% CI, 1.18-3.89) was associated with a higher risk of cognitive impairment, while anxiolytic, sedative, or hypnotic use (HR, 0.88; 95% CI, 0.83-0.94) was associated with a lower risk.

Conclusions and Relevance

This study highlights the importance of addressing TBI and seizures as risk factors for cognitive impairment among older adults. Addressing the broader social determinants of health and bridging the health divide across various racial and ethnic groups are essential for the comprehensive management and prevention of dementia.

Mechanisms of Neuronal Reactivation in Memory Consolidation: A Perspective from Pathological Conditions

Memory consolidation refers to a process by which labile newly formed memory traces are progressively strengthened into long term memories and become more resistant to interference. Recent work has revealed that spontaneous hippocampal activity during rest, commonly referred to as "offline" activity, plays a critical role in the process of memory consolidation. Hippocampal reactivation occurs during sharp-wave ripples (SWRs), which are events associated with highly synchronous neural firing in the hippocampus and modulation of neural activity in distributed brain regions. Memory consolidation occurs primarily through a coordinated communication between hippocampus and neocortex. Cortical slow oscillations drive the repeated reactivation of hippocampal memory representations together with SWRs and thalamo-cortical spindles, inducing long-lasting cellular and network modifications responsible for memory stabilization.In this review, we aim to comprehensively cover the field of "reactivation and memory consolidation" research by detailing the physiological mechanisms of neuronal reactivation and firing patterns during SWRs and providing a discussion of more recent key findings. Several mechanistic explanations of neuropsychiatric diseases propose that impaired neural replay may underlie some of the symptoms of the disorders. Abnormalities in neuronal reactivation are a common phenomenon and cause pathological impairment in several diseases, such as Alzheimer's disease (AD), epilepsy and schizophrenia. However, the specific pathological changes and mechanisms of reactivation in each disease are different. Recent work has also enlightened some of the underlying pathological mechanisms of neuronal reactivation in these diseases. In this review, we further describe how SWRs, ripples and slow oscillations are affected in Alzheimer's disease, epilepsy, and schizophrenia. We then compare the differences of neuronal reactivation and discuss how different reactivation abnormalities cause pathological changes in these diseases. Aberrant neural reactivation provides insights into disease pathogenesis and may even serve as biomarkers for early disease progression and treatment response.

Structural and functional abnormalities and cognitive profiles in older adults with early-onset and late-onset focal epilepsy

This study aimed to determine the patterns of changes in structure, function, and cognitive ability in early-onset and late-onset older adults with focal epilepsy (OFE). This study first utilized the deformation-based morphometry analysis to identify structural abnormalities, which were used as the seed region to investigate the functional connectivity with the whole brain. Next, a correlation analysis was performed between the altered imaging findings and neuropsychiatry assessments. Finally, the potential role of structural-functional abnormalities in the diagnosis of epilepsy was further explored by using mediation analysis. Compared with healthy controls (n = 28), the area of reduced structural volume was concentrated in the bilateral cerebellum, right thalamus, and right middle cingulate cortex, with frontal, temporal, and occipital lobes also affected in early-onset focal epilepsy (n = 26), while late-onset patients (n = 31) displayed cerebellar, thalamic, and cingulate atrophy. Furthermore, correlation analyses suggest an association between structural abnormalities and cognitive assessments. Dysfunctional connectivity in the cerebellum, cingulate cortex, and frontal gyrus partially mediates the relationship between structural abnormalities and the diagnosis of early-onset focal epilepsy. This study identified structural and functional abnormalities in early-onset and late-onset focal epilepsy and explored characters in cognitive performance. Structural-functional coupling may play a potential role in the diagnosis of epilepsy.

Alzheimer's Disease and Epilepsy: Exploring Shared Pathways and Promising Biomarkers for Future Treatments

Background: Alzheimer's disease (AD) and epilepsy represent two complex neurological disorders with distinct clinical manifestations, yet recent research has highlighted their intricate interplay. This review examines the association between AD and epilepsy, with particular emphasis on late-onset epilepsy of unknown etiology, increasingly acknowledged as a prodrome of AD. It delves into epidemiology, pathogenic mechanisms, clinical features, diagnostic characteristics, treatment strategies, and emerging biomarkers to provide a comprehensive understanding of this relationship. Methods: A comprehensive literature search was conducted, identifying 128 relevant articles published between 2018 and 2024. Results: Findings underscore a bidirectional relationship between AD and epilepsy, indicating shared pathogenic pathways that extend beyond traditional amyloid-beta and Tau protein pathology. These pathways encompass neuroinflammation, synaptic dysfunction, structural and network alterations, as well as molecular mechanisms. Notably, epileptic activity in AD patients may exacerbate cognitive decline, necessitating prompt detection and treatment. Novel biomarkers, such as subclinical epileptiform activity detected via advanced electroencephalographic techniques, offer promise for early diagnosis and targeted interventions. Furthermore, emerging therapeutic approaches targeting shared pathogenic mechanisms hold potential for disease modification in both AD and epilepsy. Conclusions: This review highlights the importance of understanding the relationship between AD and epilepsy, providing insights into future research directions. Clinical data and diagnostic methods are also reviewed, enabling clinicians to implement more effective treatment strategies.

Functional imaging in late-onset epilepsy: A focused review

INTRODUCTION

About 25 % of new-onset epilepsies are diagnosed after age 65. Late-onset epilepsy (LOE) is predicted to become a major healthcare problem in the next 15 years as the global population increases and ages. Neurodegenerative disorders account for 10-20 % of LOE, while over 20 % of these patients have an unknown etiology. Established diagnostic tools such as FDG-PET and novel biomarkers of neurodegeneration including amyloid and tau PET hold a lot of promise in diagnosing and ruling out neurodegenerative disorders in these patients.

METHODS

We conducted a literature search to identify articles involving LOE populations and using one or more functional neuroimaging techniques.

RESULTS

A total of 5 studies were identified through Boolean searching and snowballing. These were highly heterogenous with respect to operational definitions of LOE, analyses and interpretation pipelines.

CONCLUSION

While there is some evidence for feasibility and usefulness of FDG- and Amyloid PET in LOE, methodological heterogeneities in the available literature preclude any notable conclusions. Future research in this field will benefit from a consensus on epilepsy-specific analysis and interpretation guidelines for amyloid and tau PET.

Persistent ∆FosB expression limits recurrent seizure activity and provides neuroprotection in the dentate gyrus of APP mice

Recurrent seizures lead to accumulation of the activity-dependent transcription factor ∆FosB in hippocampal dentate granule cells in both mouse models of epilepsy and mouse models of Alzheimer's disease (AD), which is also associated with increased incidence of seizures. In patients with AD and related mouse models, the degree of ∆FosB accumulation corresponds with increasing severity of cognitive deficits. We previously found that ∆FosB impairs spatial memory in mice by epigenetically regulating expression of target genes such as calbindin that are involved in synaptic plasticity. However, the suppression of calbindin in conditions of neuronal hyperexcitability has been demonstrated to provide neuroprotection to dentate granule cells, indicating that ∆FosB may act over long timescales to coordinate neuroprotective pathways. To test this hypothesis, we used viral-mediated expression of ∆JunD to interfere with ∆FosB signaling over the course of several months in transgenic mice expressing mutant human amyloid precursor protein (APP), which exhibit spontaneous seizures and develop AD-related neuropathology and cognitive deficits. Our results demonstrate that persistent ∆FosB activity acts through discrete modes of hippocampal target gene regulation to modulate neuronal excitability, limit recurrent seizure activity, and provide neuroprotection to hippocampal dentate granule cells in APP mice.

[Risk of epilepsy after a first epileptic seizure with unknown etiology in elderly patients]

AIM

Patients whose epilepsy begins with seizures with unknown etiology in old age have been studied to a limited extent. The aim is to clinically characterise these patients, and predict their risk of developing epilepsy in the long term.

MATERIALS AND METHODS

This is a retrospective observational study of patients over 55 years old experiencing a first epileptic seizure with unknown etiology. The data were collected from their clinical history, including electroencephalogram (EEG) and brain magnetic resonance imaging (MRI) results.

RESULTS

Eighty-seven patients (58.6% male; 71.5 ± 8.1 years) were included. The mean follow-up was 7.3 ± 4.9 years. The most common vascular risk factor was arterial hypertension (77%; n = 67). Focal seizures with altered consciousness were the most frequent type of seizure (44.8%; n = 39), followed by focal seizures evolving to bilateral tonic-clonic seizures (39.1%; n = 34). Brain MRI showed cortical atrophy (50%; n = 42) and signs of small-vessel vascular disease (SVVD) (67.8%; n = 57). Interictal epileptiform EEG abnormalities were observed in 43.7% (n = 38) of the patients, mostly with temporal localisations (94.7%; n = 36). 44.8% (n = 39) had mild cognitive impairment at baseline. Recurrence of seizures, which was observed in 49 patients (56.1%), occurred after a median of 12 months (interquartile range: 4.4-25.9). Finally, 71 patients (81.6%) developed epilepsy.

CONCLUSION

The risk of epilepsy in the long term following a single seizure of unknown etiology in elderly patients is greater than 80%. Arterial hypertension and mild cognitive impairment at baseline are the most common clinical features. Cortical atrophy and the presence of SVVD are frequent in MRI, and routine EEGs do not usually show epileptiform alterations.

Reduced eye gaze fixation during emotion recognition among patients with temporal lobe epilepsy

OBJECTIVES

To investigate the facial scan patterns during emotion recognition (ER) through the dynamic facial expression task and the awareness of social interference test (TASIT) using eye tracking (ET) technology, and to find some ET indicators that can accurately depict the ER process, which is a beneficial supplement to existing ER assessment tools.

METHOD

Ninety-six patients with TLE and 88 healthy controls (HCs) were recruited. All participants watched the dynamic facial expression task and TASIT including a synchronized eye movement recording and recognized the emotion (anger, disgust, happiness, or sadness). The accuracy of ER was recorded. The first fixation time, first fixation duration, dwell time, and fixation count were selected and analyzed.

RESULTS

TLE patients exhibited ER impairment especially for disgust (Z =  - 3.391; p = 0.001) and sadness (Z =  - 3.145; p = 0.002). TLE patients fixated less on the face, as evidenced by the reduced fixation count (Z =  - 2.549; p = 0.011) of the face and a significant decrease in the fixation count rate (Z =  - 1.993; p = 0.046). During the dynamic facial expression task, TLE patients focused less on the eyes, as evidenced by the decreased first fixation duration (Z =  - 4.322; p = 0.000), dwell time (Z =  - 4.083; p = 0.000), and fixation count (Z =  - 3.699; p = 0.000) of the eyes.

CONCLUSION

TLE patients had ER impairment, especially regarding negative emotions, which may be attributable to their reduced fixation on the eyes during ER, and the increased fixation on the mouth could be a compensatory effect to improve ER performance. Eye-tracking technology could provide the process indicators of ER, and is a valuable supplement to traditional ER assessment tasks.

Chronic evoked seizures in young pre-symptomatic APP/PS1 mice induce serotonin changes and accelerate onset of Alzheimer's disease-related neuropathology

OBJECTIVE

Hyperexcitability is intimately linked to Alzheimer's disease (AD) pathology, but the precise timing and contributions of neuronal hyperexcitability to disease progression is unclear. Seizure induction in rodent AD models can uncover new therapeutic targets. Further, investigator-evoked seizures can directly establish how hyperexcitability and AD-associated risk factors influence neuropathological hallmarks and disease course at presymptomatic stages.

METHODS

Corneal kindling is a well-characterized preclinical epilepsy model that allows for precise control of seizure history to pair to subsequent behavioral assessments. 2-3-month-old APP/PS1, PSEN2-N141I, and transgenic control male and female mice were thus sham or corneal kindled for 2 weeks. Seizure-induced changes in glia, serotonin pathway proteins, and amyloid β levels in hippocampus and prefrontal cortex were quantified.

RESULTS

APP/PS1 females were more susceptible to corneal kindling. However, regardless of sex, APP/PS1 mice experienced extensive seizure-induced mortality versus kindled Tg- controls. PSEN2-N141I mice were not negatively affected by corneal kindling. Mortality correlated with a marked downregulation of hippocampal tryptophan hydroxylase 2 and monoamine oxidase A protein expression versus controls; these changes were not detected in PSEN2-N141I mice. Kindled APP/PS1 mice also exhibited soluble amyloid β upregulation and glial reactivity without plaque deposition.

SIGNIFICANCE

Evoked convulsive seizures and neuronal hyperexcitability in pre-symptomatic APP/PS1 mice promoted premature mortality without pathological Aβ plaque deposition, whereas PSEN2-N141I mice were unaffected. Disruptions in serotonin pathway metabolism in APP/PS1 mice was associated with increased glial reactivity without Aβ plaque deposition, demonstrating that neuronal hyperexcitability in early AD causes pathological Aβ overexpression and worsens long-term outcomes through a serotonin-related mechanism.

CCR5 and inflammatory storm

Chemokines and their corresponding receptors play crucial roles in orchestrating inflammatory and immune responses, particularly in the context of pathological conditions disrupting the internal environment. Among these receptors, CCR5 has garnered considerable attention due to its significant involvement in the inflammatory cascade, serving as a pivotal mediator of neuroinflammation and other inflammatory pathways associated with various diseases. However, a notable gap persists in comprehending the intricate mechanisms governing the interplay between CCR5 and its ligands across diverse and intricate inflammatory pathologies. Further exploration is warranted, especially concerning the inflammatory cascade instigated by immune cell infiltration and the precise binding sites within signaling pathways. This study aims to illuminate the regulatory axes modulating signaling pathways in inflammatory cells by providing a comprehensive overview of the pathogenic processes associated with CCR5 and its ligands across various disorders. The primary focus lies on investigating the pathomechanisms associated with CCR5 in disorders related to neuroinflammation, alongside the potential impact of aging on these processes and therapeutic interventions. The discourse culminates in addressing current challenges and envisaging potential future applications, advocating for innovative research endeavors to advance our comprehension of this realm.

Increasing Risk of Dementia Among Patients with Subsequent Epilepsy Within 2 Years Post-Traumatic Brain Injury: A Population-Based Case-Control Study

Background

Although the association between neurodegenerative diseases, such as dementia, and traumatic brain injury (TBI) has long been known, the association between dementia and TBI with epilepsy has been controversial.

Aim

This data-driven population-based study is designed to investigate the association between dementia and epilepsy after TBI within a 2-year period.

Methods

This case-control cohort study was conducted using the Longitudinal Health Insurance Database 2000 (LHID2000). We included 784 individuals ambulatory or hospitalized for TBI with epilepsy from 2001 to 2011, compared with 2992 patients with TBI without epilepsy who were matched for characteristics including sex, age, and healthcare resource use index date. Every participant was followed up for 5 years to ascertain any dementia development. Data were stratified and analyzed using the Cox proportional hazards regression.

Results

Through the 5-year follow-up period, 39 patients (5.21%) with TBI with epilepsy and 55 (1.53%) with TBI without epilepsy developed dementia. TBI with epilepsy was independently associated with a >3.03 times risk of dementia after correcting for age, sex, and comorbidities.

Conclusion

These findings suggest an increased risk of dementia in patients with TBI with epilepsy. Our research recommends that individuals with TBI and epilepsy be monitored more intensively.

Overlapping and distinct phenotypic profiles in Alzheimer's disease and late onset epilepsy: a biologically-based approach

Due to shared hippocampal dysfunction, patients with Alzheimer's dementia and late-onset epilepsy (LOE) report memory decline. Multiple studies have described the epidemiological, pathological, neurophysiological, and behavioral overlap between Alzheimer's Disease and LOE, implying a bi-directional relationship. We describe the neurobiological decline occurring at different spatial in AD and LOE patients, which may explain why their phenotypes overlap and differ. We provide suggestions for clinical recognition of dual presentation and novel approaches for behavioral testing that reflect an "inside-out," or biologically-based approach to testing memory. New memory and language assessments could detect-and treat-memory impairment in AD and LOE at an earlier, actionable stage.

A WORLDWIDE ENIGMA STUDY ON EPILEPSY-RELATED GRAY AND WHITE MATTER COMPROMISE ACROSS THE ADULT LIFESPAN

Objectives

Temporal lobe epilepsy (TLE) is commonly associated with mesiotemporal pathology and widespread alterations of grey and white matter structures. Evidence supports a progressive condition although the temporal evolution of TLE is poorly defined. This ENIGMA-Epilepsy study utilized multimodal magnetic resonance imaging (MRI) data to investigate structural alterations in TLE patients across the adult lifespan. We charted both grey and white matter changes and explored the covariance of age-related alterations in both compartments.

Methods

We studied 769 TLE patients and 885 healthy controls across an age range of 17-73 years, from multiple international sites. To assess potentially non-linear lifespan changes in TLE, we harmonized data and combined median split assessments with cross-sectional sliding window analyses of grey and white matter age-related changes. Covariance analyses examined the coupling of grey and white matter lifespan curves.

Results

In TLE, age was associated with a robust grey matter thickness/volume decline across a broad cortico-subcortical territory, extending beyond the mesiotemporal disease epicentre. White matter changes were also widespread across multiple tracts with peak effects in temporo-limbic fibers. While changes spanned the adult time window, changes accelerated in cortical thickness, subcortical volume, and fractional anisotropy (all decreased), and mean diffusivity (increased) after age 55 years. Covariance analyses revealed strong limbic associations between white matter tracts and subcortical structures with cortical regions.

Conclusions

This study highlights the profound impact of TLE on lifespan changes in grey and white matter structures, with an acceleration of aging-related processes in later decades of life. Our findings motivate future longitudinal studies across the lifespan and emphasize the importance of prompt diagnosis as well as intervention in patients.

European intersocietal recommendations for the biomarker-based diagnosis of neurocognitive disorders

The recent commercialisation of the first disease-modifying drugs for Alzheimer's disease emphasises the need for consensus recommendations on the rational use of biomarkers to diagnose people with suspected neurocognitive disorders in memory clinics. Most available recommendations and guidelines are either disease-centred or biomarker-centred. A European multidisciplinary taskforce consisting of 22 experts from 11 European scientific societies set out to define the first patient-centred diagnostic workflow that aims to prioritise testing for available biomarkers in individuals attending memory clinics. After an extensive literature review, we used a Delphi consensus procedure to identify 11 clinical syndromes, based on clinical history and examination, neuropsychology, blood tests, structural imaging, and, in some cases, EEG. We recommend first-line and, if needed, second-line testing for biomarkers according to the patient's clinical profile and the results of previous biomarker findings. This diagnostic workflow will promote consistency in the diagnosis of neurocognitive disorders across European countries.

High salt diet exacerbates cognitive deficits and neurovascular abnormalities in APP/PS1 mice and induces AD-like changes in wild-type mice

High salt diet (HSD) is a risk factor of hypertension and cardiovascular disease. Although clinical data do not clearly indicate the relationship between HSD and the prevalence of Alzheimer's disease (AD), animal experiments have shown that HSD can cause hyperphosphorylation of tau protein and cognition impairment. However, whether HSD can accelerate the progression of AD by damaging the function of neurovascular unit (NVU) in the brain is unclear. Here, we fed APP/PS1 mice (an AD model) or wild-type mice with HSD and found that the chronic HSD feeding increased the activity of enzymes related to tau phosphorylation, which led to tau hyperphosphorylation in the brain. HSD also aggravated the deposition of Aβ42 in hippocampus and cortex in the APP/PS1 mice but not in the wild-type mice. Simultaneously, HSD caused the microglia proliferation, low expression of Aqp-4, and high expression of CD31 in the wild-type mice, which were accompanied with the loss of pericytes (PCs) and increase in blood brain barrier (BBB) permeability. As a result, wild-type mice fed with HSD performed poorly in Morris Water Maze and object recognition test. In the APP/PS1 mice, HSD feeding for 8 months worsen the cognition and accompanied the loss of PCs, the activation of glia, the increase in BBB permeability, and the acceleration of calcification in the brain. Our data suggested that HSD feeding induced the AD-like pathology in wild-type mice and aggravated the development of AD-like pathology in APP/PS1 mice, which implicated the tau hyperphosphorylation and NVU dysfunction.

Impairments of GABAergic transmission in hippocampus mediate increased susceptibility of epilepsy in the early stage of Alzheimer's disease

BACKGROUND

Patients with Alzheimer's disease (AD) are often co-morbid with unprovoked seizures, making clinical diagnosis and management difficult. Although it has an important role in both AD and epilepsy, abnormal γ-aminobutyric acid (GABA)ergic transmission is recognized only as a compensative change for glutamatergic damage. Neuregulin 1 (NRG1)-ErbB4 signaling can promote GABA release and suppress epileptogenesis, but its effects on cognition in AD are still controversial.

METHODS

Four-month-old APPswe/PS1dE9 mice (APP mice) were used as animal models in the early stage of AD in this study. Acute/chronic chemical-kindling epilepsy models were established with pentylenetetrazol. Electroencephalogram and Racine scores were performed to assess seizures. Behavioral tests were used to assess cognition and emotion. Electrophysiology, western blot and immunofluorescence were performed to detect the alterations in synapses, GABAergic system components and NRG1-ErbB4 signaling. Furthermore, NRG1 was administrated intracerebroventricularly into APP mice and then its antiepileptic and cognitive effects were evaluated.

RESULTS

APP mice had increased susceptibility to epilepsy and resulting hippocampal synaptic damage and cognitive impairment. Electrophysiological analysis revealed decreased GABAergic transmission in the hippocampus. This abnormal GABAergic transmission involved a reduction in the number of parvalbumin interneurons (PV+ Ins) and decreased levels of GABA synthesis and transport. We also found impaired NRG1-ErbB4 signaling which mediated by PV+ Ins loss. And NRG1 administration could effectively reduce seizures and improve cognition in four-month-old APP mice.

CONCLUSION

Our results indicated that abnormal GABAergic transmission mediated hippocampal hyperexcitability, further excitation/inhibition imbalance, and promoted epileptogenesis in the early stage of AD. Appropriate NRG1 administration could down-regulate seizure susceptibility and rescue cognitive function. Our study provided a potential direction for intervening in the co-morbidity of AD and epilepsy.

Association between structural brain MRI abnormalities and epilepsy in older adults

OBJECTIVE

To determine the association between brain MRI abnormalities and incident epilepsy in older adults.

METHODS

Men and women (ages 45-64 years) from the Atherosclerosis Risk in Communities study were followed up from 1987 to 2018 with brain MRI performed between 2011 and 2013. We identified cases of incident late-onset epilepsy (LOE) with onset of seizures occurring after the acquisition of brain MRI. We evaluated the relative pattern of cortical thickness, subcortical volume, and white matter integrity among participants with incident LOE after MRI in comparison with participants without seizures. We examined the association between MRI abnormalities and incident LOE using Cox proportional hazards regression. Models were adjusted for demographics, hypertension, diabetes, smoking, stroke, and dementia status.

RESULTS

Among 1251 participants with brain MRI data, 27 (2.2%) developed LOE after MRI over a median of 6.4 years (25-75 percentile 5.8-6.9) of follow-up. Participants with incident LOE after MRI had higher levels of cortical thinning and white matter microstructural abnormalities before seizure onset compared to those without seizures. In longitudinal analyses, greater number of abnormalities was associated with incident LOE after controlling for demographic factors, risk factors for cardiovascular disease, stroke, and dementia (gray matter: hazard ratio [HR]: 2.3, 95% confidence interval [CI]: 1.0-4.9; white matter diffusivity: HR: 3.0, 95% CI: 1.2-7.3).

INTERPRETATION

This study demonstrates considerable gray and white matter pathology among individuals with LOE, which is present prior to the onset of seizures and provides important insights into the role of neurodegeneration, both of gray and white matter, and the risk of LOE.

Cognitive decline in adult-onset temporal lobe epilepsy: Insights from aetiology

PURPOSE

To identify patients with adult-onset temporal lobe epilepsy (TLE) at risk of developing cognitive decline. Detecting which patients, aetiologies, or factors are most closely related with memory decline would allow us to identify patients that would eventually benefit from more specific treatment.

METHODS

Single centre, retrospective analysis of a prospectively followed-up cohort study, including all patients with the diagnosis of adult-onset TLE during 2013, with a minimum follow-up of five years. Memory and cognitive decline were analysed at 5 years and at last follow-up.

RESULTS

Of 89 initially selected patients, 71 were included. After 5 years, 11/71 (15.5%) patients suffered cognitive decline, of which 1/71 (4%) developed dementia. At last follow-up (range 65-596 m) a total of 34/71 (47.8%) patients were diagnosed with cognitive decline, specifically either memory decline or dementia. Cognitive decline at 5 years was related to: 1. Age at onset: 62.65 years (SD 9.04) in the group with cognitive decline vs 50.33 y. (SD 13.02 in the group without cognitive decline; p=0.004); 2. Onset as status epilepticus (3/6 in patients with memory decline vs 8/65 in patients without cognitive decline; p=0.04); 3. Immune aetiology: 42% compared with unknown (10%) and structural (10%) aetiologies; p=0.036; 4. Hippocampal sclerosis on MRI: 5/11 patients with cognitive decline vs 9/51 patients without cognitive decline; p=0.035. Cognitive decline was not related to seizure frequency, sex, or age (p=0.78; p=0.40; p=0.95, respectively).

CONCLUSIONS

Older age at epilepsy onset, onset as status epilepticus, immune aetiology, and hippocampal sclerosis are risk factors for developing cognitive decline in patients with adult-onset temporal lobe epilepsy.

Pathophysiology to Risk Factor and Therapeutics to Treatment Strategies on Epilepsy

Epilepsy represents a condition in which abnormal neuronal discharges or the hyperexcitability of neurons occur with synchronicity, presenting a significant public health challenge. Prognostic factors, such as etiology, electroencephalogram (EEG) abnormalities, the type and number of seizures before treatment, as well as the initial unsatisfactory effects of medications, are important considerations. Although there are several third-generation antiepileptic drugs currently available, their multiple side effects can negatively affect patient quality of life. The inheritance and etiology of epilepsy are complex, involving multiple underlying genetic and epigenetic mechanisms. Different neurotransmitters play crucial roles in maintaining the normal physiology of different neurons. Dysregulations in neurotransmission, due to abnormal transmitter levels or changes in their receptors, can result in seizures. In this review, we address the roles played by various neurotransmitters and their receptors in the pathophysiology of epilepsy. Furthermore, we extensively explore the neurological mechanisms involved in the development and progression of epilepsy, along with its risk factors. Furthermore, we highlight the new therapeutic targets, along with pharmacological and non-pharmacological strategies currently employed in the treatment of epileptic syndromes, including drug interventions employed in clinical trials related to epilepsy.

The Role of Epileptic Activity in Alzheimer's Disease

Alzheimer's disease (AD) is the most common cause of dementia. Epileptic seizures or epileptic activity have been detected in AD, and people with epilepsy have a higher risk of dementia compared to the general population. This suggests that seizures or epileptic activity might often coexist with AD. It is increasingly evident that epileptic activity or seizures are common but often overlooked comorbidities of AD. However, the causal relationship between seizures, epileptic activity and cognitive decline remains uncertain. Experimental data show that amyloid-β (Aβ) and Tau protein can cause neuronal hyperexcitability and has epileptogenic effects. Neural network hyperexcitation regulates the ratio of Aβ isoforms and is linked to the initiation of AD, indicating a shared mechanism. Clinical studies suggest that cognitive impairment accelerates in AD patients with seizures or epileptic activity. This review discusses the relationship between epileptic seizures and AD, the impact of epileptic activity in AD, and potential treatments.

Protein profiling and assessment of amyloid beta levels in plasma in canine refractory epilepsy

Introduction

The relationship between epilepsy and cognitive dysfunction has been investigated in canines, and memory impairment was prevalent in dogs with epilepsy. Additionally, canines with epilepsy have greater amyloid-β (Aβ) accumulation and neuronal degeneration than healthy controls. The present study investigated plasma Aβ42 levels and performed proteomic profiling in dogs with refractory epilepsy and healthy dogs.

Methods

In total, eight dogs, including four healthy dogs and four dogs with epilepsy, were included in the study. Blood samples were collected to analyze Aβ42 levels and perform proteomic profiling. Changes in the plasma proteomic profiles of dogs were determined by nano liquid chromatography tandem mass spectrometry.

Results and discussion

The plasma Aβ42 level was significantly higher in dogs with epilepsy (99 pg/mL) than in healthy dogs (5.9 pg/mL). In total, 155 proteins were identified, and of these, the expression of 40 proteins was altered in epilepsy. Among these proteins, which are linked to neurodegenerative diseases, 10 (25%) were downregulated in dogs with epilepsy, whereas 12 (30%) were upregulated. The expression of the acute phase proteins haptoglobin and α2-macroglobulin significantly differed between the groups. Complement factor H and ceruloplasmin were only detected in epilepsy dogs, suggesting that neuroinflammation plays a role in epileptic seizures. Gelsolin, which is involved in cellular processes and cytoskeletal organization, was only detected in healthy dogs. Gene Ontology annotation revealed that epilepsy can potentially interfere with biological processes, including cellular processes, localization, and responses to stimuli. Seizures compromised key molecular functions, including catalytic activity, molecular function regulation, and binding. Defense/immunity proteins were most significantly modified during the development of epilepsy. In Kyoto Encyclopedia of Genes and Genomes pathway analysis, complement and coagulation cascades were the most relevant signaling pathways affected by seizures. The findings suggested that haptoglobin, ceruloplasmin, α2-macroglobulin, complement factor H, and gelsolin play roles in canine epilepsy and Aβ levels based on proteomic profiling. These proteins could represent diagnostic biomarkers that, after clinical validation, could be used in veterinary practice as well as proteins relevant to disease response pathways. To determine the precise mechanisms underlying these relationships and their implications in canine epilepsy, additional research is required.

Incidence and risk factors associated with seizures in cerebral amyloid angiopathy

BACKGROUND AND PURPOSE

Cerebral amyloid angiopathy (CAA) is a common cause of intracranial hemorrhage (ICH), which is a risk factor for seizures. The incidence and risk factors of seizures associated with a heterogeneous cohort of CAA patients have not been studied.

METHODS

We conducted a retrospective study of patients with CAA treated at Mayo Clinic Florida between 1 January 2015 and 1 January 2021. CAA was defined using the modified Boston criteria version 2.0. We analyzed electrophysiological and clinical features, and comorbidities including lobar ICH, nontraumatic cortical/convexity subarachnoid hemorrhage (cSAH), superficial siderosis, and inflammation (CAA with inflammation [CAA-ri]). Cognition and mortality were secondary outcomes. Univariate and multivariate analyses were performed to determine risk of seizures relative to clinical presentation.

RESULTS

Two hundred eighty-four patients with CAA were identified, with median follow-up of 35.7 months (interquartile range = 13.5-61.3 months). Fifty-six patients (19.7%) had seizures; in 21 (37.5%) patients, seizures were the index feature leading to CAA diagnosis. Seizures were more frequent in females (p = 0.032) and patients with lobar ICH (p = 0.002), cSAH (p = 0.030), superficial siderosis (p < 0.001), and CAA-ri (p = 0.005), and less common in patients with microhemorrhage (p = 0.006). After controlling for age and sex, lobar ICH (odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.1-4.2), CAA-ri (OR = 3.8, 95% CI = 1.4-10.3), and superficial siderosis (OR = 3.7, 95% CI = 1.9-7.0) were independently associated with higher odds of incident seizures.

CONCLUSIONS

Seizures are common in patients with CAA and are independently associated with lobar ICH, CAA-ri, and superficial siderosis. Our results may be applied to optimize clinical monitoring and management for patients with CAA.

Identification of Factors in Moderate-Severe TBI Related to a Functional Decline in Cognition Decades After Injury

OBJECTIVE

To investigate whether a functional decline in cognitive activities decades after moderate-to-severe traumatic brain injury (m-sTBI) might relate to injury features and/or lifetime health factors, some of which may emerge as consequences of the injury.

DESIGN

Secondary analysis of the TBI Model Systems National Database, a prospective, multi-center, longitudinal study of patients with m-sTBI.

SETTING

TBI Model Systems Centers.

PARTICIPANTS

Included were 732 participants rated on the cognitive subscale of the Functional Independence Measure (FIM Cognitive), a metric for everyday cognitive skills, across 3 time points out to 20 years (visits at 2-, 10-, and 20-year follow-ups; N=732).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

FIM Cognitive Scale. Injury characteristics such as timing and features pertaining to severity and health-related factors (eg, alcohol use, socioeconomic status) were examined to discriminate stable from declining participants on the FIM Cognitive Scale using logistic regression.

RESULTS

At 20 years post-injury, there was a low base rate of FIM Cognitive decline (11%, n=78), with most being stable or having meaningful improvement (89%, n=654). Older age at injury, longer duration of post-traumatic amnesia, and presence of repetitive seizures were significant predictors of FIM Cognitive decline in the final model (area under the curve=0.75), while multiple health-related factors that can represent independent co-morbidities or possible consequences of injury were not.

CONCLUSION(S)

The strongest contributors to reported functional decline in cognitive activities later-in-life were related to acute characteristics of m-sTBI and experiencing post-traumatic seizures. Future studies are needed integrating functional with performance-based cognitive assessments to affirm conclusions and identify the timeline and trajectory of cognitive decline.

The bidirectional relationship between Alzheimer's disease (AD) and epilepsy: A Mendelian randomization study

BACKGROUND

There is a complex, bidirectional relationship between Alzheimer's disease (AD) and epilepsy. However, the causality of this association is unclear, as confounders play a role in this association.

METHODS

We conducted a Mendelian randomization (MR) study to clarify the causal relationship and direction of epilepsy on AD risk. We used publicly available summary statistics to obtain all genetic datasets for the MR analyses. AD and AD-by-proxy and late-onset AD (LOAD) cohorts were included in our study. The epilepsy cohort comprised all epilepsy, generalized epilepsy, focal epilepsy, and its subtypes, as well as some epilepsy syndromes. Next, we conducted validation using another AD cohort.

RESULTS

Two correlations between AD and epilepsy using the inverse variance-weighted (IVW) method are as follows: LOAD and focal epilepsy (ORIVW  = 1.079, pIVW  = .013), focal epilepsy-documented hippocampal sclerosis (HS) and AD (ORIVW  = 1.152, pIVW  = .017). The causal relationship between epilepsy-documented HS and AD has been validated (ORIVW  = 3.994, pIVW  = .027).

CONCLUSIONS

Our MR study provides evidence for a causal relationship between focal epilepsy-documented HS and AD.

Prevalence of dementia in a level 4 university epilepsy center: how big is the problem?

Background

The relationship between epilepsy and dementia is currently a topic of great interest. Our study aimed to determine the prevalence of dementia diagnoses among patients of a large level 4 university epilepsy center.

Methods

In this retrospective monocentric study conducted at the Department of Epileptology of the University Hospital Bonn, we searched for dementia-related terms in a total of 145,501 medical letters from 40,360 adult patients who were seen between 2003 and 2021. Files with at least one hit were selected and analyzed with regard to diagnoses, age, age at epilepsy onset, and the question as to whether epilepsy preceded or followed the dementia diagnosis.

Results

Among the medical letters of 513 patients, dementia-related terms were found. The letters of 12.7% of these patients stated a dementia diagnosis, 6.6% were suspected of having dementia, 4.9% had mild cognitive impairment, and 6.6% had other neurodegenerative diseases without dementia. Taking all 40,360 patients into account, the prevalence of diagnosed or suspected dementia was 0.25%. An older age (≥60 years) and late-onset epilepsy (≥60 years), but not a longer epilepsy duration, increased the odds of dementia by 6.1 (CI 3.5-10.7) and 2.9 (CI 1.7-4.7), respectively. Additionally, vascular, metabolic, inflammatory, and behavioral mood-related comorbidities were commonly observed. Epilepsy tended to precede (23.2%) rather than follow (8.1%) the dementia diagnosis.

Conclusion

Despite the clear limitations of a selection bias and the potential underdiagnosis of dementia and underestimation of its prevalence when relying on the medical letters from a specialized center which rather focuses on epilepsy-related issues, the findings of this study offer valuable insights from the perspective of an epilepsy center. In this setting, the prevalence of dementia in epilepsy is rather low. However, physicians should be aware that the risk of dementia is higher in the elderly, in late-onset epilepsies, and when comorbid risk factors exist. Seizures can also be an early sign of a neurodegenerative disease. Future research should explicitly screen for dementia in patients with epilepsy and stratify them according to their underlying pathologies and comorbidities.