Long-term Prognosis and Psychosocial Outcomes after Surgery for MTLE

Memory functioning after hippocampal removal: Does side matter?

To address the memory functioning after medial temporal lobe (MTL) surgery for refractory epilepsy and relationships with the side of the hippocampal removal, 22 patients with pharmaco-resistant epilepsy who had undergone MTL resection (10 right/12 left) at the Salpêtrière Hospital were compared with 21 matched healthy controls. We designed a specific neuropsychological binding memory test that specifically addressed hippocampal cortex functioning, and left-right material-specific lateralization. Our results showed that both left and right mesial temporal lobe removal cause a severe memory impairment, for both verbal and visual material. The removal of left medial temporal lobe causes worse memory impairment than the right removal regardless of the stimuli type (verbal or visual) questioning the theory of the hippocampal material-specific lateralization. The present study provided new evidence for the role of both hippocampus and surrounding cortices in memory-binding whatever the material type and also suggested that a left MTL removal is more deleterious for both verbal and visual episodic memory in comparison with right MTL removal.

Postsurgical outcomes in a cohort of patients with hippocampal sclerosis: Initial experience in a referral epilepsy center in Peru

Mesial temporal lobe epilepsy, one of the most common forms of epilepsy, is often linked with drug resistance. Surgical intervention is a reliable and safe treatment option, though research into postsurgical outcomes in our locality remains limited. We performed a retrospective observational study included 91 patients with mesial temporal lobe epilepsy and hippocampal sclerosis who had undergone anterior temporal lobectomy between 2012 and 2020 at a surgical epilepsy center located in Lima, Peru. Postoperative outcomes were analyzed using bivariate and multivariate analysis based on the Engel classification. We found that after 12 months of follow-up, 78.65% of the 91 patients achieved an Engel IA classification, while 9.09% attained Engel IB classification and 11.24% were designated as Engel II, with only 1.12% classified as Engel IVA. The median QOLIE31 score was 84 (IQR: 75-90), with 74.16% of the participants successfully reintegrating into academic or employment activities. After 24 months, only 68 patients completed the follow-up, with 69.12% achieving an Engel IA classification. Individuals with a secondary education or higher were more likely to achieve an Engel IA classification at 12 months (OR: 5.11; P = 0.005; CI: 1.63-16.01), after adjusting for sex and age. We concluded that most patients exhibited favorable outcomes after 1 year of follow-up. However, lower educational attainment was linked to worse postsurgical outcomes.

The role of the orbitofrontal cortex and insula for prognosis of mesial temporal lobe epilepsy

OBJECTIVE

We investigated the network between the medial temporal lobe (MTL) and extratemporal structures in patients with mesial temporal lobe epilepsy (MTLE) in order to explain the recurrence of MTLE after surgery. This study contributes to our current understanding of MTLE with stereotactic electroencephalography (SEEG).

METHODS

We conducted a retrospective study of SEEG in 20 patients with MTLE in order to observe and analyze the intensity of interictal high-frequency oscillations (HFOs), as well as the dynamic course of coherence connectivity values of the MTL and extratemporal structures during the initial phase of the seizure. The results correlated with the patient prognosis.

RESULTS

First, the presence of HFOs was observed during the interictal period in all 20 patients; these were localized to the MTL in 17 patients and the orbitofrontal cortex in seven patients and the insula in six patients. The better the prognosis, the greater the localization of the HFOs concentration in the MTL structures (p < 0.05). Second, significantly enhanced connectivity of MTL structures with the orbitofrontal cortex and insula was observed in most patients with MTLE, before and after the seizure onset (p < 0.05). Finally, the connectivity between extratemporal structures, such as the orbitofrontal cortex and insula, and MTL structures was significantly stronger in patients who had a worse prognosis than in other patients, before and after seizure onset (p < 0.05).

INTERPRETATION

The epileptogenic network in recurrent MTLE is not limited to MTL structures but is also associated with the orbitofrontal cortex and insula. This can be used as a potential indicator for predicting the prognosis of patients after surgery, providing an important avenue for future clinical evaluation.

Extended follow-up after anterior temporal lobectomy demonstrates seizure recurrence 20+ years postsurgery

OBJECTIVE

Anterior temporal lobectomy (ATL) for medication-resistant localized epilepsy results in ablation or reduction of seizures for most patients. However, some individuals who attain an initial extended period of postsurgical seizure freedom will experience a later seizure recurrence. In this study, we examined the prevalence and some risk factors for late recurrence in an ATL cohort with extensive regular follow-up.

METHODS

Included were 449 patients who underwent ATL at Austin Health, Australia, from 1978 to 2008. Postsurgical follow-up was undertaken 2-3 yearly. Seizure recurrence was tested using Kaplan-Meier analysis, log-rank test, and Cox regression. Late recurrence was qualified as a first disabling seizure >2 years postsurgery. We examined risks within the ATL cohort according to broad pathology groups and tested whether late recurrence differed for the ATL cohort compared to patients who had resections outside the temporal lobe (n = 98).

RESULTS

Median post-ATL follow-up was 22 years (range = .1-38.6), 6% were lost to follow-up, and 12% had died. Probabilities for remaining completely seizure-free after surgery were 51% (95% confidence interval [CI] = 53-63) at 2 postoperative years, 36% (95% CI = 32-41) at 10 years, 32% (95% CI = 27-36) at 20 years, and 30% (95% CI = 25-34) at 25 years. Recurrences were reported up to 23 years postoperatively. Late seizures occurred in all major ATL pathology groups, with increased risk in the "normal" and "distant lesion" groups (p ≤ .03). Comparison between the ATL cohort and patients who underwent extratemporal resection demonstrated similar patterns of late recurrence (p = .74).

SIGNIFICANCE

Some first recurrences were very late, reported decades after ATL. Late recurrences were not unique to any broad ATL pathology group and did not differ according to whether resections were ATL or extratemporal. Reports of these events by patients with residual pathology suggest that potentially epileptogenic abnormalities outside the area of resection may be implicated as one of several possible underlying mechanisms.

Long-term seizure, psychiatric and socioeconomic outcomes after frontal lobe epilepsy surgery

OBJECTIVE

Resective surgery for selected individuals with frontal lobe epilepsy can be effective, although multimodal outcomes are less established than in temporal lobe epilepsy. We describe long-term seizure remission and relapse patterns, psychiatric comorbidity, and socioeconomic outcomes following frontal lobe epilepsy surgery.

METHODS

We reviewed individual data on frontal lobe epilepsy procedures at our center between 1990 and 2020. This included the presurgical evaluation, operative details and annual postoperative seizure and psychiatric outcomes, prospectively recorded in an epilepsy surgery database. Outcome predictors were subjected to multivariable analysis, and rates of seizure freedom were analyzed using Kaplan-Meier methods. We used longitudinal assessment of the Index of Multiple Deprivation to assess change in socioeconomic status over time.

RESULTS

A total of 122 individuals with a median follow-up of seven years were included. Of these, 33 (27 %) had complete seizure freedom following surgery, with a further 13 (11 %) having only auras. Focal MRI abnormality, histopathology (focal cortical dysplasia, cavernoma or dysembryoplastic neuronal epithelial tumor) and fewer anti-seizure medications at the time of surgery were predictive of a favorable outcome; 67 % of those seizure-free for the first 12 months after surgery never experienced a seizure relapse. Thirty-one of 50 who had preoperative psychiatric pathology noticed improved psychiatric symptomatology by two years postoperatively. New psychiatric comorbidity was diagnosed in 15 (13 %). Persistent motor complications occurred in 5 % and dysphasia in 2 %. No significant change in socioeconomic deciles of deprivation was observed after surgery.

SIGNIFICANCE

Favorable long-term seizure, psychiatric and socioeconomic outcomes can be seen following frontal lobe epilepsy surgery. This is a safe and effective treatment that should be offered to suitable individuals early.

Long-term seizure and psychiatric outcomes following laser ablation of mesial temporal structures

OBJECTIVE

Postsurgical seizure outcome following laser interstitial thermal therapy (LiTT) for the management of drug-resistant mesial temporal lobe epilepsy (MTLE) has been limited to 2 years. Furthermore, its impact on presurgical mood and anxiety disorders has not been investigated. The objectives of this study were (1) to identify seizure outcome changes over a period ranging from 18 to 81 months; (2) to investigate the seizure-free rate in the last follow-up year; (3) to identify the variables associated with seizure freedom; and (4) to identify the impact of LiTT on presurgical mood and anxiety disorders.

METHODS

Medical records of all patients who underwent LiTT for MTLE from 2013 to 2019 at the University of Miami Comprehensive Epilepsy Center were retrospectively reviewed. Demographic, epilepsy-related, cognitive, psychiatric, and LiTT-related data were compared between seizure-free (Engel Class I) and non-seizure-free (Engel Class II + III + IV) patients. Statistical analyses included univariate and multivariate stepwise logistic regression analyses.

RESULTS

Forty-eight patients (mean age = 43 ± 14.2 years, range = 21-78) were followed for a mean period of 50 ± 20.7 months (range = 18-81); 29 (60.4%) achieved an Engel Class I outcome, whereas 11 (22.9%) had one to three seizures/year. Seizure-freedom rate decreased from 77.8% to 50% among patients with 24- and >61-month follow-up periods, respectively. In the last follow-up year, 83% of all patients were seizure-free. Seizure freedom was associated with having mesial temporal sclerosis (MTS), no presurgical focal to bilateral tonic-clonic seizures, and no psychopathology in the last follow-up year. Presurgical mood and/or anxiety disorder were identified in 30 patients (62.5%) and remitted after LiTT in 19 (62%).

SIGNIFICANCE

LiTT appears to be a safe and effective surgical option for treatment-resistant MTLE, particularly among patients with MTS. Remission of presurgical mood and anxiety disorders can also result from LiTT.

Surgery procedures in temporal lobe epilepsies

Temporal lobe epilepsy (TLE) is the most common cause of refractory epilepsy amenable for surgical treatment and seizure control. Surgery for TLE is a safe and effective strategy. The seizure-free rate after surgical resection in patients with mesial or neocortical TLE is about 70%. Resective surgery has an advantage over stereotactic radiosurgery in terms of seizure outcomes for mesial TLE patients. Both techniques have similar results for safety, cognitive outcomes, and associated costs. Stereotactic radiosurgery should therefore be seen as an alternative to open surgery for patients with contraindications for or with reluctance to undergo open surgery. Laser interstitial thermal therapy (LITT) has also shown promising results as a curative technique in mesial TLE but needs to be more deeply evaluated. Brain-responsive stimulation represents a palliative treatment option for patients with unilateral or bilateral MTLE who are not candidates for temporal lobectomy or who have failed a prior mesial temporal lobe resection. Overall, despite the expansion of innovative techniques in recent years, resective surgery remains the reference treatment for TLE and should be proposed as the first-line surgical modality. In the future, ultrasound therapies could become a credible therapeutic option for refractory TLE patients.

"Do I still have epilepsy?" Epilepsy identity 15-20 years after anterior temporal lobectomy

OBJECTIVE

Identity is a multifaceted construct, comprising personal identity (sense of being a unique individual) and social identity (the sense-of-self derived from membership of social groups). Social identity involves explicit identification with a group ("I am …") and implicit behaviors or attitudes associated with group membership. Following successful treatment with surgery, patients with epilepsy can undergo a complex and lasting change in personal identity. To date, there has been no research into postoperative social epilepsy identity (SEI). We sought to examine SEI 15-20 years post-surgery, and the relationship between SEI and satisfaction with surgery, psychosocial improvements, mood, and health-related quality of life (HRQoL).

METHODS

Thirty-two patients who underwent anterior temporal lobectomy (ATL; 19 female) were recruited, with a median follow-up of 18 years (interquartile range [IQR] = 2.5). Using a novel interactive online program, we collected data on SEI, satisfaction with surgery, and perceived psychosocial improvements, alongside standardized measures of mood (Neurological Disorders Depressio Inventory-Epilepsy; Patient Health Questionnaire-Generalised Anxiety Disorder-7 item) and HRQoL (Quality of Life in Epilepsy-31 item). Non-parametric analyses were used to analyse the data.

RESULTS

Twenty-five percent of patients were free of disabling seizures since surgery, yet 65% stated they no longer had epilepsy and >90% reported satisfaction with surgery. Explicitly discarding SEI was positively associated with HRQoL at long-term follow-up, over and above seizure outcome. Implicit SEI was expressed as (a) acceptance of epilepsy, (b) a sense of belonging to the epilepsy community, and (c) difficulty disclosing and discussing epilepsy. Difficulty disclosing and discussing epilepsy was associated with increased anxiety and lower HRQoL.

SIGNIFICANCE

At long-term follow-up, over half of our patients reported an explicit change in SEI, which could promote better HRQoL. In contrast, difficulty with disclosure of epilepsy was associated with increased anxiety and reduced HRQoL, possibly reflecting the ongoing effects of stigma. These findings highlight the importance of understanding changes in patient social identity for promoting long-term well-being after surgery.

Focal to bilateral motor seizures in temporal lobe epilepsy during video-EEG monitoring: effects on surgical outcome

The aim of this study was to determine whether the occurrence of focal to bilateral motor seizures in the course of partial drug withdrawal during video-EEG monitoring (FTBMS-M) had a predictive value for seizure recurrence in surgically treated patients with mesial temporal lobe epilepsy (MTLE). We analyzed the outcomes of 59 patients who underwent temporal lobe resection at 12 month postoperative follow up. In total, 48 out of 59 patients were rendered seizure free (81.4%). We analyzed seizure recurrence after surgery with reference to: (i) occurrence of seizures after partial drug withdrawal during video-EEG monitoring (FTBMS-M); (ii) history of secondarily generalized seizures during antiepileptic drug treatment prior to presurgical evaluation (FTBMS-H) and (iii) other possible confounding factors (sex, age, epilepsy duration, side of surgery, presence of hippocampal sclerosis, and history of febrile seizures). We found no differences in the frequency of seizure recurrences between patients with FTBMS-M and patients without FTBMS-M (4/20 vs. 7/39; p = 0.848). Conversely, the frequency of seizure recurrence was significantly higher among the patients with FTBMS-H than among the patients without FTBMS-H (7/20 vs. 4/39; p = 0.021). The predictive value of FTBMS-H for postoperative seizure recurrence was confirmed in logistic regression analysis. We found a statistically significant influence of FTBMS-H on poor outcome after surgery, but not of FTBMS-M or other confounding variables, which suggests that withdrawal seizures do not affect postsurgical seizure control.

Non-invasive, neurotoxic surgery reduces seizures in a rat model of temporal lobe epilepsy

Surgery can be highly effective for treating certain cases of drug resistant epilepsy. The current study tested a novel, non-invasive, surgical strategy for treating seizures in a rat model of temporal lobe epilepsy. The surgical approach uses magnetic resonance-guided, low-intensity focused ultrasound (MRgFUS) in combination with intravenous microbubbles to open the blood-brain barrier (BBB) in a transient and focal manner. During the period of BBB opening, a systemically administered neurotoxin (Quinolinic Acid: QA) that is normally impermeable to the BBB gains access to a targeted area in the brain, destroying neurons where the BBB has been opened. This strategy is termed Precise Intracerebral Non-invasive Guided Surgery (PING). Spontaneous recurrent seizures induced by pilocarpine were monitored behaviorally prior to and after PING or under control conditions. Seizure frequency in untreated animals or animals treated with MRgFUS without QA exhibited expected seizure rate fluctuations frequencies between the monitoring periods. In contrast, animals treated with PING targeting the intermediate-temporal aspect of the hippocampus exhibited substantial reductions in seizure frequency, with convulsive seizures being eliminated entirely in two animals. These findings suggest that PING could provide a useful alternative to invasive surgical interventions for treating drug resistant epilepsy, and perhaps for treating other neurological disorders in which aberrant neural circuitries play a role.

Encephalocele-Associated Drug-Resistant Epilepsy of Adult Onset: Diagnosis, Management, and Outcomes

Epileptogenic encephaloceles, most frequently located in the temporal lobe, are a known lesional cause of focal epilepsy. Data are limited regarding diagnosis, management, and outcomes of patients with epilepsy in the setting of an encephalocele, because the literature mostly comprises case reports, case series, and retrospective studies. We conducted a broad literature review for articles related to encephaloceles and epilepsy regardless of level of evidence. Hence, this review provides a summary of all available literature related to the topic. Thirty-six scientific reports that fulfilled our inclusion criteria were reviewed. Most reported patients presented with focal impaired awareness seizures and/or generalized tonic-clonic seizures. Although most of the encephaloceles were located in the temporal lobe, we found 5 cases of extratemporal encephaloceles causing epilepsy. More patients who underwent either lesionectomy or lobectomy were seizure free at time of follow-up. In the temporal lobe, there is no clear consensus on the appropriate management for epileptic encephaloceles and further studies are warranted to understand the associated factors and long-term outcomes associated with epilepsy secondary to encephaloceles. Reported data suggest that these patients could be manageable with surgical procedures including lesionectomy or lobectomy. In addition, because of data suggesting similar results between procedures, a more conservative surgery with lesionectomy and defect repair rather than a lobectomy may have lower surgical risks and similar seizure freedom.

Initiating an epilepsy surgery program with limited resources in Indonesia

To share the experiences of organizing the epilepsy surgery program in Indonesia. This study was divided into two periods based on the presurgical evaluation method: the first period (1999–2004), when interictal electroencephalogram (EEG) and magnetic resonance imaging (MRI) were used mainly for confirmation, and the second period (2005–2017), when long-term non-invasive and invasive video-EEG was involved in the evaluation. Long-term outcomes were recorded up to December 2019 based on the Engel scale. All 65 surgical recruits in the first period possessed temporal lobe epilepsy (TLE), while 524 patients were treated in the second period. In the first period, 76.8%, 16.1%, and 7.1% of patients with TLE achieved Classes I, II, and III, respectively, and in the second period, 89.4%, 5.5%, and 4.9% achieved Classes I, II, and III, respectively, alongside Class IV, at 0.3%. The overall median survival times for patients with focal impaired awareness seizures (FIAS), focal to bilateral tonic–clonic seizures and generalized tonic–clonic seizures were 9, 11 and 11 years (95% CI: 8.170–9.830, 10.170–11.830, and 7.265–14.735), respectively, with p = 0.04. The utilization of stringent and selective criteria to reserve surgeries is important for a successful epilepsy program with limited resources.

Single-Institutional Experience of Chronic Intracranial Electroencephalography Based on the Combined Usage of Subdural and Depth Electrodes

Implantation of subdural electrodes on the brain surface is still widely performed as one of the “gold standard methods” for the presurgical evaluation of epilepsy. Stereotactic insertion of depth electrodes to the brain can be added to detect brain activities in deep-seated lesions to which surface electrodes are insensitive. This study tried to clarify the efficacy and limitations of combined implantation of subdural and depth electrodes in intractable epilepsy patients. Fifty-three patients with drug-resistant epilepsy underwent combined implantation of subdural and depth electrodes for long-term intracranial electroencephalography (iEEG) before epilepsy surgery. The detectability of early ictal iEEG change (EIIC) were compared between the subdural and depth electrodes. We also examined clinical factors including resection of MRI lesion and EIIC with seizure freedom. Detectability of EIIC showed no significant difference between subdural and depth electrodes. However, the additional depth electrode was useful for detecting EIIC from apparently deep locations, such as the insula and mesial temporal structures, but not in detecting EIIC in patients with ulegyria (glial scar). Total removal of MRI lesion was associated with seizure freedom. Depth electrodes should be carefully used after consideration of the suspected etiology to avoid injudicious usage.

Language lateralization differences between left and right temporal lobe epilepsy as measured by overt word reading fMRI activation and DTI structural connectivity

In cases of brain disease such as temporal lobe epilepsy (TLE), damage may lead to functional reorganization and a shift in language dominance to homolog regions in the other hemisphere. If the effects of TLE on language dominance are hemisphere-focused, then brain regions and connections involved in word reading should be less left-lateralized in left temporal lobe epilepsy (lTLE) than right temporal lobe epilepsy (rTLE) or healthy controls, and the opposite effect should be observed in patients with rTLE. In our study, functional magnetic resonance imaging (fMRI) showed that patients with rTLE had more strongly lateralized left hemisphere (LH) activation than patients with lTLE and healthy controls in language-related brain regions (pars opercularis and fusiform gyrus (FuG)). Corresponding with this difference, diffusion tensor imaging (DTI) found differences in connectivity indicative of patients with lTLE having greater tract integrity than patients with rTLE in the right hemisphere (RH) uncinate fasciculus (UF), inferior longitudinal fasciculus (ILF), and inferior fronto-occipital fasciculus (IFOF) using the network-based statistic analysis method. The UF, ILF, and IFOF tract integrity have previously been associated with lexical (whole-word) processing abilities. Multivariate distance matrix regression provided converging evidence for regions of the IFOF having different connectivity patterns between groups with lTLE and rTLE. This research demonstrates language lateralization differences between patient groups with lTLE and rTLE, and corresponding differences in the connectivity strength of the ILF, IFOF, and UF. This research provides a novel approach to measuring lateralization of language in general, and the fMRI and DTI findings were integral for guiding the neurosurgeons performing the TLE resections. This approach should inform future studies of language lateralization and language reorganization in patients such as those with TLE.

Focal-to-bilateral motor seizures in temporal lobe epilepsy during video-EEG monitoring: effects on surgical outcome

The aim of this study was to determine whether the occurrence of focal-to-bilateral motor seizures in the course of partial drug withdrawal during video-EEG monitoring (FTBMS-M) had a predictive value for seizure recurrence in surgically treated patients with mesial temporal lobe epilepsy (MTLE). We analyzed the outcomes of 59 patients who underwent temporal lobe resection and had postoperative follow-up from 6 to 58 months. In total, 48 out of 59 patients were rendered seizure free (81.4%). We analyzed seizure recurrence after surgery with reference to: (i) occurrence of seizures after partial drug withdrawal during video-EEG monitoring (FTBMS-M); (ii) history of secondarily generalized seizures during antiepileptic drug treatment prior to presurgical evaluation (FTBMS-H) and (iii) other possible confounding factors (sex, age, epilepsy duration, side of surgery, presence of hippocampal sclerosis, and history of febrile seizures). We found no differences in the frequency of seizure recurrences between patients with FTBMS-M and patients without FTBMS-M (4/20 vs. 7/39; p = 0.848). Conversely, the frequency of seizure recurrence was significantly higher among the patients with FTBMS-H than among the patients without FTBMS-H (7/20 vs. 4/39; p = 0.021). The predictive value of FTBMS-H for postoperative seizure recurrence was confirmed in logistic regression analysis. We found a statistically significant influence of FTBMS-H on poor outcome after surgery, but not of FTBMS-M or other confounding variables, which suggests that withdrawal seizures do not affect post-surgical seizure control.

Downregulation of hyperpolarization-activated cyclic nucleotide-gated channels (HCN) in the hippocampus of patients with medial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS)

Changes in the expression of HCN ion channels leading to changes in I_h function and neuronal excitability are considered to be possible mechanisms involved in epileptogenesis in kinds of human epilepsy. In previous animal studies of febrile seizures and temporal lobe epilepsy, changes in the expression of HCN1 and HCN2 channels at different time points and in different parts of the brain were not consistent, suggesting that transcriptional disorders involving HCNs play a crucial role in the epileptogenic process. Therefore, we aimed to assess the transcriptional regulation of HCN channels in Medial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) patients. This study included eight nonhippocampal sclerosis patients and 40 MTLE-HS patients. The mRNA expression of HCN channels was evaluated by qRT-PCR, while the protein expression was quantitatively analyzed by Western blotting. The subcellular localization of HCN channels in the hippocampus was explored by immunofluorescence. We demonstrated that the mRNA and protein expression of HCN1 and HCN2 are downregulated in controls compared to that in MTLE-HS patients. In the hippocampal CA1/CA4 subregion and GCL, in addition to a large decrease in neurons, the expression of HCN1 and HCN2 on neuronal cell membranes was also downregulated in MTLE-HS patients. These findings suggest that the expression of HCN channels are downregulated in MTLE-HS, which indicates that the decline in HCN channels in the hippocampus during chronic epilepsy in MTLE-HS patients leads to the downregulation of I_h current density and function, thereby reducing the inhibitory effect and increasing neuronal excitability and eventually causing disturbances in the electrical activity of neurons.

Laser interstitial thermal therapy after failed anterior temporal lobectomy and amygdalohippocampectomy can improve seizure outcome

Anterior temporal lobectomy and amygdalohippocampectomy (ATL) is the gold standard surgical treatment for drug resistant mesial temporal lobe epilepsy (mTLE). Nevertheless, seizure recurrence after ATL is not uncommon. Insufficient resection of the mesial temporal structures remains one of the most common reasons for ATL failure. Extending the resection leads to improved seizure outcome in a majority of patients. However, repeat craniotomy can be higher risk for the patient and also can be technically challenging due to scarring and altered anatomy. Laser interstitial thermal therapy (LITT) is a novel minimally invasive alternative to ATL, and it has been shown to be safe and effective. However, it is unclear if LITT has a role in managing post-ATL mTLE patients with recurrent seizures and residual epileptogenic structures. LITT is an attractive option for post-ATL patients with residual mesial structures because the surgery is minimally invasive, and it allows precise targeting and real time confirmation of tissue ablation under MRI guidance. We present a case of an mTLE patient with recurrent seizures after ATL who achieved long-term seizure-freedom after successfully undergoing LITT to ablate the residual hippocampus. This approach, if demonstrated to be safe, effective and durable, can benefit select post-ATL mTLE patients.

•

Persistent seizures at long-term follow-up after anterior temporal lobectomy (ATL) is not uncommon.

•

Residual mesial temporal lobe is one of the most common reasons for seizure recurrence after ATL.

•

Laser interstitial thermal therapy (LITT) is a minimally invasive surgery with advantages of intraoperative MRI guidance.

•

LITT can be used to selectively ablate residual mesial temporal structures in post-ATL patients with recurrent seizures.

Atypical language localization in right temporal lobe epilepsy: An fMRI case report

We report a 41- year-old, left-handed patient with drug-resistant right temporal lobe epilepsy (TLE). Presurgical fMRI was conducted to examine whether the patient had language functioning in the right hemisphere given that left-handedness is associated with a higher prevalence of right hemisphere dominance for language. The fMRI results revealed bilateral activation in Broca's and Wernicke's areas and activation of eloquent cortex near the region of planned resection in the right temporal lobe. Due to right temporal language-related activation, the patient underwent an awake right-sided temporal lobectomy with intraoperative language mapping. Intraoperative direct cortical stimulation (DCS) was conducted in the regions corresponding to the fMRI activation, and the patient showed language abnormalities, such as paraphasic errors, and speech arrest. The decision was made to abort the planned anterior temporal lobe procedure, and the patient instead underwent a selective amygdalohippocampectomy via the Sylvian fissure at a later date. Post-operatively the patient was seizure-free with no neurological deficits. Taken together, the results support previous findings of right hemisphere language activation in left-handed individuals, and should be considered in cases in which presurgical localization is conducted for left-hand dominant patients undergoing neurosurgical procedures.

•

The report evaluates evidence for the possibility of right hemisphere language activation in a left-handed right TLE patient

•

The results of the fMRI tasks showed bilateral speech regions, such as left and right Broca's area and Wernicke's area

•

The results support previous findings of right hemisphere language activation in left-handed individuals

•

The report discusses the value of fMRI of language tasks for presurgical planning in epilepsy cases

•

Report highlights how fMRI findings can alter surgical strategy and how intraoperative brain mapping validates these findings

Effects of Non-invasive, Targeted, Neuronal Lesions on Seizures in a Mouse Model of Temporal Lobe Epilepsy

Surgery to treat drug-resistant epilepsy can be quite effective but remains substantially underutilized. A pilot study was undertaken to test the feasibility of using a non-invasive, non-ablative, approach to produce focal neuronal loss to treat seizures in a rodent model of temporal lobe epilepsy. In this study, spontaneous, recurrent seizures were established in a mouse model of pilocarpine-induced status epilepticus. After post-status epilepticus stabilization, baseline behavioral seizures were monitored for 30 d. Non-invasive opening of the blood-brain barrier targeting the hippocampus was then produced by using magnetic resonance-guided, low-intensity focused ultrasound, through which a neurotoxin (quinolinic acid) administered intraperitoneally gained access to the brain parenchyma to produce focal neuronal loss. Behavioral seizures were then monitored for 30 d after this procedure, and brains were subsequently prepared for histologic analysis of the sites of neuronal loss. The average frequency of behavioral seizures in all animals (n = 11) was reduced by 21.2%. Histologic analyses along the longitudinal axis of the hippocampus revealed that most of the animals (n = 8) exhibited neuronal loss located primarily in the intermediate aspect of the hippocampus, while sparing the septal aspect. Two other animals with damage to the intermediate hippocampus also exhibited prominent bilateral damage to the septal aspect of the hippocampus. A final animal had negligible neuronal loss overall. Notably, the site of neuronal loss along the longitudinal axis of the hippocampus influenced seizure outcomes. Animals that did not have bilateral damage to the septal hippocampus displayed a mean decrease in seizure frequency of 27.7%, while those with bilateral damage to the septal hippocampus actually increased seizure frequency by 18.7%. The animal without neuronal loss exhibited an increase in seizure frequency of 19.6%. The findings indicate an overall decrease in seizure frequency in treated animals. And, the site of neuronal loss along the longitudinal axis of the hippocampus appears to play a key role in reducing seizure activity. These pilot data are promising, and they encourage additional and more comprehensive studies examining the effects of targeted, non-invasive, neuronal lesions for the treatment of epilepsy.

A patient-centered approach to understanding long-term psychosocial adjustment and meaning-making, 15 to 20 years after epilepsy surgery

OBJECTIVE

Different psychosocial trajectories have been identified following treatment with epilepsy surgery, as patients adjust to possible changes in seizure frequency and the subsequent impact on their psychosocial functioning. Qualitative research has been key to understanding this adjustment process, particularly in the short-term (2-5 years). Currently, however, there is a lack of qualitative research examining longer-term (>15 years) outcomes, precluding the same rich, detailed understanding of longer-term psychosocial outcomes. Using a grounded theory approach, we explored how patients reflected on and made sense of their adjustment trajectories, 15 to 20 years after surgery. This included the impact of surgery on their sense of self and broader psychosocial functioning.

METHODS

We recruited 40 adult patients who had undergone anterior temporal lobectomy (ATL) 15 to 20 years ago (24 females; 26 left-sided). Median age at habitual seizure onset was 9.7 years (Interquartile range; IQR = 13.8), and at surgery was 31 years (IQR = 12). Median length of follow-up was 18.4 years (IQR = 4.3). Comprehensive one-on-one interviews (median time = 86 min, IQR = 28) were used to elicit patient experiences of their surgery and subsequent psychosocial outcomes. Data were analyzed using a grounded theory inductive-deductive process.

RESULTS

Patient narratives revealed a common process of psychosocial change and meaning-making triggered by surgery, which was often perceived as a major turning point in life. Patients reflected on moving through an early postsurgical period (<5 years) of upheaval and psychological disequilibrium. While this period was often remembered as stressful, difficulties were softened and/or reframed in hindsight. Through this process of reframing and meaning-making, patients were able to reestablish equilibrium and a sense of normality. Differences were evident in how patients navigated the process of meaning-making, and the extent to which they felt surgery had changed their self-identity.

DISCUSSION

We propose a model of postsurgical meaning-making, evident in the narratives of patients who have undergone ATL, providing a new perspective on long-term psychosocial outcomes. This model contributes to our understanding of patient well-being and quality of life, by acknowledging the active role that patients play in seeking to create their own sense of normality after epilepsy surgery.

Diagnostic and prognostic value of noninvasive long-term video-electroencephalographic monitoring in epilepsy surgery: A systematic review and meta-analysis from the E-PILEPSY consortium

OBJECTIVE

The European Union-funded E-PILEPSY network (now continuing within the European Reference Network for rare and complex epilepsies [EpiCARE]) aims to harmonize and optimize presurgical diagnostic procedures by creating and implementing evidence-based guidelines across Europe. The present study evaluates the current evidence on the diagnostic accuracy of long-term video-electroencephalographic monitoring (LTM) in identifying the epileptogenic zone in epilepsy surgery candidates.

METHODS

MEDLINE, Embase, CENTRAL, and ClinicalTrials.gov were searched for relevant articles. First, we used random-effects meta-analytical models to calculate pooled estimates of sensitivity and specificity with respect to postsurgical seizure freedom. In a second phase, we analyzed individual patient data in an exploratory fashion, assessing diagnostic accuracy within lesional and nonlesional temporal lobe epilepsy (TLE) and extratemporal lobe epilepsy (ETLE) patients. We also evaluated seizure freedom rate in the presence of "localizing" or "nonlocalizing" LTM within each group. The quality of evidence was assessed using the QUADAS-2 tool and the GRADE approach.

RESULTS

Ninety-four studies were eligible. Forty-four were included in sensitivity meta-analysis and 34 in specificity meta-analysis. Pooled sensitivity was 0.70 (95% confidence interval [CI] = 0.60-0.80) and specificity was 0.40 (95% CI = 0.27-0.54). Subgroup analysis was based on individual data of 534 patients (41% men). In lesional TLE patients, sensitivity was 0.85 (95% CI = 0.81-0.89) and specificity was -0.19 (95% CI = 0.13-0.28). In lesional ETLE patients, a sensitivity of 0.47 (95% CI = 0.36-0.58) and specificity of 0.35 (95% CI = 0.21-0.53) were observed. In lesional TLE, if LTM was localizing and concordant with resection site, the seizure freedom rate was 247 of 333 (74%), whereas in lesional ETLE it was 34 of 56 (61%). The quality of evidence was assigned as "very low."

SIGNIFICANCE

Long-term video-electroencephalographic monitoring is associated with moderate sensitivity and low specificity in identification of the epileptogenic zone. Sensitivity is remarkably higher in lesional TLE compared to lesional ETLE. Substantial heterogeneity across the studies indicates the need for improved design and quality of reporting.

Systematic review and network meta-analysis of resective surgery for mesial temporal lobe epilepsy

OBJECTIVE

To evaluate the effectiveness of anterior temporal lobectomy (ATL) versus selective amygdalohippocampectomy (SAH) on seizure-free outcome in patients with temporal lobe epilepsy, using both direct and indirect evidence from the literature.

METHODS

MEDLINE, Embase and Cochrane databases were searched for original research articles and systematic reviews comparing ATL versus SAH, and ATL or SAH versus medical management (MM). The outcome was seizure freedom at 12 months of follow-up or longer. Direct pairwise meta-analyses were conducted, followed by a random-effect Bayesian network meta-analysis (NMA) combining direct and indirect evidence.

RESULTS

Twenty-eight articles were included (18 compared ATL vs SAH, 1 compared ATL vs SAH vs MM, 8 compared ATL vs MM, and 1 compared SAH vs MM). Direct pairwise meta-analyses showed no significant differences in seizure-free outcome of ATL versus SAH (OR 1.14, 95% CI 0.93 to 1.39; p=0.201), but the odds of seizure-free outcome were higher for ATL versus MM (OR 29.16, 95% CI 10.44 to 81.50; p<0.00001), and SAH versus MM (OR 28.42, 95% CI 10.17 to 79.39; p<0.00001). NMA also showed that the odds of seizure-free outcome were no different in ATL versus SAH (OR 1.15, 95% credible interval (CrI) 0.84-1.15), but higher for ATL versus MM (OR 27.22, 95% CrI 15.38-27.22), and SAH versus MM (OR 23.57, 95% CrI 12.67-23.57). There were no significant differences between direct and indirect comparisons (all p>0.05).

CONCLUSION

Direct evidence, indirect evidence and NMA did not identify a difference in seizure-free outcome of ATL versus SAH.

The long-term outcomes of epilepsy surgery

Objective

Despite modern anti-epileptic drug treatment, approximately 30% of epilepsies remain medically refractory and for these patients, epilepsy surgery may be a treatment option. There have been numerous studies demonstrating good outcome of epilepsy surgery in the short to median term however, there are a limited number of studies looking at the long-term outcomes. The aim of this study was to ascertain the long-term outcome of resective epilepsy surgery in a large neurosurgery hospital in the U.K.

Methods

This a retrospective analysis of prospectively collected data. We used the 2001 International League Against Epilepsy (ILAE) classification system to classify seizure freedom and Kaplan-Meier survival analysis to estimate the probability of seizure freedom.

Results

We included 284 patients who underwent epilepsy surgery (178 anterior temporal lobe resections, 37 selective amygdalohippocampectomies, 33 temporal lesionectomies, 36 extratemporal lesionectomies), and had a prospective median follow-up of 5 years (range 1–27). Kaplan-Meier estimates showed that 47% (95% CI 40–58) remained seizure free (apart from simple partial seizures) at 5 years and 38% (95% CI 31–45) at 10 years after surgery. 74% (95% CI 69–80) had a greater than 50% seizure reduction at 5 years and 70% (95% CI 64–77) at 10 years. Patients who had an amygdalohippocampectomy were more likely to have seizure recurrence than patients who had an anterior temporal lobe resection (p = 0.006) and temporal lesionectomy (p = 0.029). There was no significant difference between extra temporal and temporal lesionectomies. Hippocampal sclerosis was associated with a good outcome but declined in relative frequency over the years.

Conclusion

The vast majority of patients who were not seizure free experienced at least a substantial and long-lasting reduction in seizure frequency. A positive long-term outcome after epilepsy surgery is possible for many patients and especially those with hippocampal sclerosis or those who had anterior temporal lobe resections.

Psychosocial outcome in epilepsy after extratemporal surgery

OBJECTIVE

Only limited data exist on psychosocial long-term outcome after epilepsy surgery in patients with extratemporal epilepsy. The aim of this study was to investigate psychosocial outcome after extratemporal epilepsy surgery and to assess factors predicting favorable outcome.

METHOD

Sixty-five out of 104 eligible patients who had undergone extratemporal epilepsy surgery at our epilepsy center between 1990 and 2015 (mean age: 42.2. years; 75% of the resections in the frontal lobe) completed a questionnaire asking about seizure status, employment status, marital and living situation, driving status, depressive symptoms, and quality of life (QOL). Follow-up was on average 9.2years after surgery (range: 1-26years).

RESULTS

Thirty-eight (58%) patients were free of disabling seizures (Engel class I), and 28 (43%) have not experienced any seizures after surgery (Engel class IA). Employment rate in the primary labor market remained at 45%, but more patients lost employment (14%) than gained employment (8%). Postoperative employment was predicted by preoperative employment (p=.007), seizure freedom (p=.025), older age at seizure onset (p=.018), younger age at follow-up (p=.035), and female gender (p=.048). Seizure-free patients were more likely to be driving; have a partner, particularly in males; and have lower depressive scores. Quality of life at follow-up was best predicted by employment (p=.012), partnership (p=.025), and seizure freedom (p=.025). In contrast, recurrence of seizures and early seizure onset were associated with poor psychosocial outcome, particularly in men.

CONCLUSION

The study provides support that extratemporal surgery can lead to improved QOL and favorable psychosocial outcome. Seizure freedom is important but not the only determinant of good psychosocial outcome.

Adapting a memory fMRI research protocol in clinical routine: Feasibility and results

OBJECTIVE

The objective of this study was to test the reliability of functional magnetic resonance imaging (fMRI) evaluation of memory function in clinical practice to predict postoperative memory decline in patients with refractory medial temporal lobe epilepsy (MTLE) candidate to surgery.

METHODS

Twenty-six consecutive patients with MTLE who underwent a complete presurgical evaluation were included. All patients underwent fMRI memory study and complete neuropsychological assessment. Lesions consisted in hippocampal sclerosis in 18 patients (12 right and 6 left), dysembryoplastic neuroepithelial tumor (DNET) in 5 cases (4 right, 1 left), epidermoid cyst in one patient (right). Two patients had no lesion (2 left).

RESULTS

Nineteen patients (73%) underwent surgery. The other seven patients (27%) declined surgery, mainly because of the risk of memory deficit. The fMRI procedure correctly predicted both verbal and nonverbal memory postoperative outcome in 13 of the patients (72%), failed to predict a postoperative memory worsening in only two patients (12%), and predicted worsening in three patients (17%) that remained stable (versus 44%, 39%, and 17% with the sole neuropsychological testing). The reliability of the fMRI procedure was not influenced by the type of lesion, the side of the epileptic focus, or the type of preoperative memory profile (typical or atypical).

SIGNIFICANCE

Appearing as a valuable clinical tool to predict postoperative memory outcome, fMRI may add information over and above other available tests.

Factors affecting seizure outcome after epilepsy surgery: an observational series

IMPORTANCE

Surgical treatment can bring seizure remission in people with focal epilepsy but requires careful selection of candidates.

OBJECTIVES

To determine which preoperative factors are associated with postoperative seizure outcome.

DESIGN

We audited seizure outcome of 693 adults who had resective epilepsy surgery between 1990 and 2010 and used survival analysis to detect preoperatively identifiable risk factors of poor seizure outcome.

RESULTS

Seven factors were significantly associated with increased probability of recurrence of seizures with impaired awareness postsurgery: MRI findings (eg, HR adjusted for other variables in the model 2.5; 95% CI 1.6 to 3.8 for normal MRI compared with hippocampal sclerosis), a history of secondarily generalised convulsive seizures (2.3; 95% CI 1.7 to 3.0 for these seizures in the previous year vs never), psychiatric history (1.3; 95% CI 1.1 to 1.7), learning disability (1.8; 95% CI 1.2 to 2.6) and extratemporal (vs temporal) surgery (1.4; 95% CI 1.02, 2.04). People with an older onset of epilepsy had a higher probability of seizure recurrence (1.01; 95% CI 1.00, 1.02) as did those who had used more antiepileptic drugs (1.05; 95% CI 1.01 to 1.09). Combinations of variables associated with seizure recurrence gave overall low probabilities of 5-year seizure freedom (eg, a normal MRI and convulsive seizures in the previous year has a probability of seizure freedom at 5 years of approximately 0.19).

CONCLUSIONS AND RELEVANCE

Readily identified clinical features and investigations are associated with reduced probability of good outcome and need consideration when planning presurgical evaluation.

Predictive coding: A contemporary view on the burden of normality and forced normalization in individuals undergoing epilepsy surgery

Following epilepsy surgery, a good psychosocial outcome is not necessarily contingent on a good seizure outcome. Increasingly, it is believed that "successful" surgery is a combination of both an acceptable and expected seizure status as well as the individual's perception of improvements in quality of life (QOL). The factors that create this optimal outcome remain an ongoing area of research in the epilepsy community. That being said, there have been some major breakthroughs in observing and understanding poor outcomes seen in a subset of postoperative patients with epilepsy. Characteristics of burden of normality and forced normalization are two phenomena that have been evident in cases of poor postoperative outcomes. In this review, we provide a summary of research and concepts used to explain these poor QOL outcomes for a seemingly successful surgery and suggest a contemporary view in understanding the mechanism of forced normalization through understanding the brain as a predictive organ. Using such a predictive coding model together with recommendations of other studies, we suggest the crucial need for a preoperative intervention addressing patient predictions and expectations to optimize on the benefits achievable through epilepsy surgery.

Health-related quality of life and emotional well-being after epilepsy surgery: A prospective, controlled, long-term follow-up

OBJECTIVE

To evaluate health-related quality of life (HRQOL) and emotional well-being in resective epilepsy surgery and nonoperated patients at long-term follow-up.

METHODS

This is a prospective cohort study where patients undergoing presurgical work-up during 1995-1998 completed the Short-Form Health Survey (SF-36) and the Hospital Anxiety and Depression scale (HAD) at baseline, and 2 and 14 years after resective surgery or presurgical evaluation (nonoperated patients). SF-36 scores were compared to a normative population. Proportions of patients reaching HRQOL changes of minimum clinically important difference (MCID) were calculated.

RESULTS

At 14-year follow-up, operated patients scored equal to or better than the normative sample on all SF-36 domains except Social Functioning and Mental Health. Physical component summary (PCS) was better and mental component summary (MCS) was worse than for the normative sample. Nonoperated patients scored worse than the normative sample on five of eight domains, and on PCS and MCS. Change in seizure status from 2 to 14 years did not affect PCS or MCS means. Improvement reaching MCID from baseline to long-term was seen in 50% (PCS) and 47% (MCS) of operated and in 33% (PCS) and 38% (MCS) of nonoperated patients. Worsening was seen in 18% (PCS) and 22% (MCS) of operated and in 38% (PCS) and 38% (MCS) of nonoperated patients. Differences between groups were nonsignificant. HAD scores did not differ between groups, and the numbers of possible or probable cases were low. Patient satisfaction with surgery was higher in operated seizure-free patients. Only 5% of all operated patients considered surgery not to be overall beneficial.

SIGNIFICANCE

At the group level, HRQOL was stable 14 years after surgery compared to after 2 years. Social Functioning and Mental Health were still below, but other domains were similar to the normative sample. Individual patterns did not follow seizure outcome changes, indicating that multiple factors are important for long-term HRQOL.

Effects of surgical side and site on psychological symptoms following epilepsy surgery in adults

This retrospective study examined the potential role of side and site of surgery in psychological symptom change after epilepsy surgery and determined the base rate of psychological change at the individual level. Two-hundred twenty-eight adults completed the Personality Assessment Inventory (PAI) before and after temporal (TLR; n=190) or frontal lobe resection (FLR; n=38). Repeated measures ANOVAs with bootstrapping examined differences in psychological outcome as a function of surgical site separately in patients who underwent left- versus right-sided resections. Individual's PAI score changes were then used to determine the prevalence of clinically meaningful postoperative symptom change. Following left-sided resections, there were significant group-by-time interactions on Somatic Complaints, Anxiety, and Anxiety Related Disorders. There was also a trend in this direction on the Depression scale. TLR patients endorsed greater preoperative symptoms than FLR patients on all of these scales, except the Somatic Complaints scale. After surgery, TLR patients reported symptom improvement on all four scales, while scores of FLR patients remained relatively stable over time. Endorsement of Mania-related symptoms increased in both TLR and FLR groups from pre-to post-surgical testing. Following right-sided resections, both groups endorsed symptom improvements on Somatic Complaints, Anxiety, and Depression scales following surgery. In addition, the TLR group endorsed more Mania-related symptoms than the FLR group regardless of time. Patterns of meaningful change in individual patients were generally consistent with group findings, with the most frequent improvements observed following TLR. However, there were a small subset of patients who reported symptom exacerbation after surgery. Our results suggest that surgical lateralization and localization are important factors in postoperative psychological outcome and highlight the importance of considering psychological change at the individual patient level. Further research is needed to identify potential risk factors for symptom exacerbation to aid in preoperative counseling and identify those patients most in need of postoperative psychological surveillance.

18F-FDG-PET patterns of surgical success and failure in mesial temporal lobe epilepsy

OBJECTIVE

To search for [¹⁸F]-fluorodeoxyglucose (FDG)-PET patterns predictive of long-term prognosis in surgery for drug-resistant mesial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis (HS).

METHODS

We analyzed metabolic data with [¹⁸F]-FDG-PET in 97 patients with MTLE (53 female participants; age range 15-56 years) with unilateral HS (50 left) and compared the metabolic patterns, electroclinical features, and structural atrophy on MRI in patients with the best outcome after anteromesial temporal resection (Engel class IA, completely seizure-free) to those with a non-IA outcome, including suboptimal outcome and failure. Imaging processing was performed with statistical parametric mapping (SPM5).

RESULTS

With a mean follow-up of >6 years (range 2-14 years), 85% of patients achieved a class I outcome, including 45% in class IA. Class IA outcome was associated with a focal anteromesial temporal hypometabolism, whereas non-IA outcome correlated with extratemporal metabolic changes that differed according to the lateralization: ipsilateral mesial frontal and perisylvian hypometabolism in right HS and contralateral fronto-insular hypometabolism and posterior white matter hypermetabolism in left HS. Suboptimal outcome presented a metabolic pattern similar to the best outcome but with a larger involvement of extratemporal areas, including the contralateral side in left HS. Failure was characterized by a mild temporal involvement sparing the hippocampus and relatively high extratemporal hypometabolism on both sides. These findings were concordant with electroclinical features reflecting the organization of the epileptogenic zone but were independent of the structural abnormalities detected on MRI.

CONCLUSIONS

[¹⁸F]-FDG-PET patterns help refine the prognostic factors in MTLE and should be implemented in predictive models for epilepsy surgery.

Management of Adult Onset Seizures

Epilepsy is a common yet heterogeneous disease. As a result, management often requires complex decision making. The ultimate goal of seizure management is for the patient to have no seizures and no considerable adverse effects from the treatment. Antiepileptic drugs are the mainstay of therapy, with more than 20 medications currently approved in the United States. Antiepileptic drug selection requires an understanding of the patient's epilepsy, along with consideration of comorbidities and potential for adverse events. After a patient has failed at least 2 appropriate antiepileptic drugs, they are determined to be medically refractory. At this time, additional therapy, including dietary, device, or surgical treatments, need to be considered, typically at a certified epilepsy center. All these treatments require consideration of the potential for seizure freedom, balanced against potential adverse effects, and can have a positive effect on seizure control and quality of life. This review article discussed the treatment options available for adults with epilepsy, including medical, surgical, dietary, and device therapies.

Long-term outcomes of surgical treatment for epilepsy in adults with regard to seizures, antiepileptic drug treatment and employment

PURPOSE

There is Class I evidence for short-term efficacy of epilepsy surgery from two randomized controlled studies of temporal lobe resection. Long-term outcome studies are observational. The aim of this narrative review was to summarise long-term outcomes taking the study methodology into account.

METHODS

A PubMed search was conducted identifying articles on long-term outcomes of epilepsy surgery in adults with regard to seizures, antiepileptic drug treatment and employment. Definitions of seizure freedom were examined in order to identify the proportions of patients with sustained seizure freedom. The quality of the long-term studies was assessed.

RESULTS

In a number of high-quality studies 40-50% of patients had been continuously free from seizures with impairment of consciousness 10 years after resective surgery, with a higher proportion seizure-free at each annual follow-up. The proportion of seizure-free adults in whom AEDs have been withdrawn varied widely across studies, from 19-63% after around 5 years of seizure freedom. Few long-term vocational outcome studies were identified and results were inconsistent. Some investigators found no postoperative changes, others found decreased employment for patients with continuing seizures, but no change or increased employment for seizure-free patients. Having employment at baseline and postoperative seizure freedom were the strongest predictors of employment after surgery.

CONCLUSIONS

Long-term studies of outcomes after epilepsy surgery are by necessity observational. There is a need for more prospective longitudinal studies of both seizure and non-seizure outcomes, considering individual patient trajectories in order to obtain valid outcome data needed for counselling patients about epilepsy surgery.

Socioeconomic outcome of epilepsy surgery: A controlled national study

PURPOSE

Epilepsy surgery has been a standard treatment for refractory epilepsies that cannot be controlled by standard medical treatment. We aimed to evaluate the health and social consequences of resective surgery relative to controls from a study of national data.

METHODS

Using the Danish National Patient Registry we identified all subjects with an epilepsy diagnosis between 1996 and 2009 and compared them with a group of patients with an epilepsy diagnosis who had had neither epilepsy surgery nor a vagus stimulation diagnosis by the index date, and who were matched by gender, index year for epilepsy diagnosis, and index year for epilepsy surgery. We considered all the health and social information available in the Danish health, medication and social registers. The duration of follow-up was three years.

RESULTS

254 epilepsy patients and 989 controls were analyzed. Surgery patients were more severely affected by their disease as indicated by health care use and social impact before the surgical procedure. Patients who underwent epilepsy surgery had a significantly lower costs associated with the use of medication, outpatient services, inpatient admissions, and accident and emergency visits after surgery. The surgical intervention had no significant effects on social status in terms of occupation and educational level.

CONCLUSION

Although epilepsy surgery was followed by a reduction in inpatient and outpatient health care use, medication and use of accident and emergency facilities, suggesting a positive effect on the epileptic disease, there was no significant effect on social outcome measures.

Predicting the psychosocial outcome of epilepsy surgery: A longitudinal perspective on the 'burden of normality'

Good seizure outcomes and good psychosocial outcomes following epilepsy surgery do not necessarily follow one from the other. This study explored the relationship between several presurgical psychosocial characteristics and postsurgical quality-of-life outcomes. The study aimed to develop the concept of 'the burden of normality' and identify risk factors for a poor psychosocial outcome that could be targeted with ameliorative presurgery cognitive behavioral techniques. Data were collected from 77 epilepsy surgery patients from three UK epilepsy centers and presurgery and postsurgery follow-up data were obtained from 30-34 patients, depending on the measure. Measures were self-report. Postsurgery intervals were determined by the epilepsy surgery care pathway at individual centers. Presurgery poor levels of mental health, poor social functioning, increased belief in illness chronicity, and associating epilepsy with social role limitations were all associated with poor postsurgical quality of life. Adopting an accepting coping strategy presurgery was associated with good postoperative quality of life. Regression analysis showed that a good postsurgical quality of life was positively predicted by a presurgical coping style of being able to make the best of a situation and see challenges in a positive light (i.e., positive reinterpretation and growth from the COPE scale) and negatively predicted by presurgical levels of anxiety. These data are presented as an important step in identifying psychological red flags for an adverse psychosocial outcome to epilepsy surgery, as exemplified by the concept of the 'burden of normality' and specifying targets for preoperative ameliorative psychological advice.

Selective amygdalohippocampectomy via trans-superior temporal gyrus keyhole approach

BACKGROUND

Hippocampal sclerosis is the most common cause of drug-resistant epilepsy amenable for surgical treatment and seizure control. The rationale of the selective amygdalohippocampectomy is to spare cerebral tissue not included in the seizure generator.

METHOD

Describe the selective amygdalohippocampectomy through the trans-superior temporal gyrus keyhole approach.

CONCLUSION

Selective amygdalohippocampectomy for temporal lobe epilepsy is performed when the data (semiology, neuroimaging, electroencephalography) point to the mesial temporal structures. The trans-superior temporal gyrus keyhole approach is a minimally invasive and safe technique that allows disconnection of the temporal stem and resection of temporomesial structures.

Lateralizing value of semiology in medial temporal lobe epilepsy

OBJECTIVES

Analysing the clinical characteristics of seizures constitutes a fundamental aspect of the presurgical evaluation of patients with medial temporal lobe epilepsy and unilateral hippocampal sclerosis (MTLE-HS), the most frequent form of focal epilepsy accessible to surgery. We sought to retrospectively determine whether objective manifestations could have a reliable lateralizing value in a large population of MTLE-HS patients and if their presence could help to identify those patients who would be seizure free after surgery.

MATERIAL AND METHODS

We analysed the frequency and predictive lateralizing value of objective ictal and postictal signs in 391 patients with MTLE-HS (183 left/208 right). Data were derived from chart review and not from blinded videoEEG analysis. Correlation between the presence of reliable lateralizing signs and postoperative outcome was performed in a subgroup of 302 patients who underwent surgery.

RESULTS

Contralateral dystonic posturing was the most frequent and reliable lateralizing sign that correctly lateralized the focus in 96% of patients. Unilateral head/eye deviation was noted in 42% of the patients and predicted unilateral focus in 67%. Ipsilateral postictal nose wiping, contralateral clonus and hypokinesia correctly lateralized the focus in 75%, 81%, respectively, and 100 of patients but were less frequently depicted. Postictal aphasia was a strong lateralizing sign for left MLE-HS. The presence of reliable lateralizing signs was not a predictor of seizure freedom.

CONCLUSION

Seizure semiology is a simple tool that may permit reliable lateralization of the seizure focus in MTLE-HS. The presence of reliable lateralizing signs is not associated with a better postoperative outcome.

Psychosocial factors associated with in postsurgical prognosis of temporal lobe epilepsy related to hippocampal sclerosis

We examined the long-term psychosocial trajectory in a consecutive and homogeneous series of 120 patients followed up for five years after corticoamygdalohippocampectomy (CAH). Evaluation of psychosocial variables at baseline and at five-year follow-up were compared. After five years of CAH, a significant improvement in educational level (p=0.004) and employment status (p<0.001) was observed, although retirement (p<0.001) and divorce (p=0.021) rates increased. In a long-term follow-up, a tendency to have similar QOL profile was observed between Engel classes IA and IB (p>0.05). A more favorable surgical outcome (Engel IA) was related to better psychiatric status (p=0.012). Poor psychosocial adjustment before surgery was the most important predictor of QOL outcome (p<0.05). Patients' trajectory after surgical treatment showed positive effects mainly in those with better seizure outcome. Our results emphasized the influence regarding baseline psychosocial functioning on postoperative psychosocial adjustment. Furthermore, many psychosocial gains and difficulties after surgery may be similar in developing and developed countries.

Long-term seizure and psychosocial outcomes of vagus nerve stimulation for intractable epilepsy

Vagus nerve stimulation (VNS) is a widely used adjunctive treatment option for intractable epilepsy. Most studies have demonstrated short-term seizure outcomes, usually for up to 5 years, and thus far, none have reported psychosocial outcomes in adults. We aimed to assess long-term seizure and psychosocial outcomes in patients with intractable epilepsy on VNS therapy for more than 15 years. We identified patients who had VNS implantation for treatment of intractable epilepsy from 1997 to 2013 at our Comprehensive Epilepsy Program and gathered demographics including age at epilepsy onset and VNS implantation, epilepsy type, number of antiepilepsy drugs (AEDs) and seizure frequency before VNS implantation and at the last clinic visit, and the most recent stimulation parameters from electronic medical records (EMR). Phone surveys were conducted by research assistants from May to November 2014 to determine patients' current seizure frequency and psychosocial metrics, including driving, employment status, and use of antidepressants. Seizure outcomes were based on modified Engel classification (I: seizure-free/rare simple partial seizures; II: >90% seizure reduction (SR), III: 50-90% SR, IV: <50% SR; classes I to III (>50% SR)=favorable outcome). A total of 207 patients underwent VNS implantation, 15 of whom were deceased at the time of the phone survey, and 40 had incomplete data for medical abstraction. Of the remaining 152, 90 (59%) were contacted and completed the survey. Of these, 51% were male, with the mean age at epilepsy onset of 9.4 years (range: birth to 60 years). There were 35 (39%) patients with extratemporal epilepsy, 19 (21%) with temporal, 18 (20%) with symptomatic generalized, 5 (6%) with idiopathic generalized, and 13 (14%) with multiple types. Final VNS settings showed 16 (18%) patients with an output current >2 mA and 14 (16%) with rapid cycling. Of the 80 patients with seizure frequency information, 16 (20%) had a modified Engel class I outcome, 14 (18%) had class II, 24 (30%) had class III, and 26 (33%) had class IV. Eighty percent said having VNS was worthwhile. Among the 90 patients, 43 patients were ≥ 18 years old without developmental delay in whom psychosocial outcomes were further analyzed. There was a decrease in the number of patients driving (31% vs 14%, p=0.052) and working (44% vs 35%, p=0.285) and an increase in the number of patients using antidepressant medication (14% vs 28%, p=0.057) at the time of survey compared to before VNS. In this subset, patients with >50% SR (60%) were taking significantly fewer AEDs at the time of survey compared to patients with unfavorable outcomes (median: 3 vs 4, p=0.045). The associations of >50% SR with the psychosocial outcomes of driving, employment, and antidepressant use were not significant, although 77% of this subset said VNS was worthwhile. This is the first study that assesses both seizure and psychosocial outcomes, and demonstrates favorable seizure outcomes of >50% SR in 68% of patients and seizure freedom in 20% of patients. A large majority of patients (80%) considered VNS therapy worthwhile regardless of epilepsy type and psychosocial outcomes.

Assessment of driving outcomes after epilepsy surgery

INTRODUCTION

Driving is an important factor contributing to good quality of life in patients with epilepsy. Little work has been undertaken to explore the details of driving experience alone in this patient population. We assessed the driving status of our patients prior to and following surgery for epilepsy. We also sought to determine what associations exist between patient characteristics and postoperative driving status.

METHODS

The participants were selected from those adult patients with epilepsy who have required surgical treatment at our home institution between 2006 and 2010. Each participant received a questionnaire asking about driving and seizure status before and after surgery. The surveys were distributed using a modified Dillman approach. Perioperative patient data were obtained from the electronic medical record system in addition to a previously assembled epilepsy database from the Neurology Department at our institution. Independent variables were analyzed to look for significant associations with driving outcomes.

RESULTS

One hundred forty eligible patients were included in the survey population; 78 patients returned a questionnaire for a response rate of 55.7%. Eighty percent of patients experienced driving as a regular part of life at some point prior to surgery. At the time of the questionnaire distribution, 68% of patients had returned to regular driving. Demographic characteristics did not play a significant role in whether or not the patient had a favorable driving outcome after surgery. However, patients who had a history of driving on a regular basis prior to surgery and those who had an Engel Class I outcome after surgery had significantly higher rates of good driving outcomes. Also, patients with an unfavorable preoperative driving status were more likely to have a favorable driving outcome after surgery if they had an Engel Class I outcome. Patients in whom intracranial electroencephalography (EEG) was utilized prior to resection had worse driving outcomes.

CONCLUSIONS

A surprisingly high percentage of patients with epilepsy have experienced driving on a regular basis prior to surgery. We can assume that most patients were not driving immediately prior to surgery, given the fact that they had progressed to requiring surgery for treatment of their epilepsy. Thus, a driving rate of 68% after surgery can be considered good. We found that a patient's preoperative driving history, the use of intracranial EEG before surgical resection, and Engel classification were significant predictors of postoperative driving outcomes. These data provide patients with assistance in preoperative counseling. More investigation needs to be completed in other patient variables - such as seizure types, magnetic resonance imaging (MRI) findings, and patient motivators for driving - as possible predictors of driving outcomes.

Prospective and longitudinal long-term employment outcomes after resective epilepsy surgery

Objective:

To investigate long-term employment outcomes after resective epilepsy surgery in a national population-based cohort of adults.

Methods:

In the Swedish National Epilepsy Surgery Register, all adults who were operated with resective epilepsy surgery from 1995 to 2010 were identified. Two-year follow-up was available for 473/496, 5-year follow-up for 220/240, 10-year follow-up for 240/278, and 15-year follow-up for 85/109 patients.

Results:

There were no significant changes in employment outcome over time at group level, but for those with full-time employment at baseline, 79%, 79%, 57%, and 47% of seizure-free patients were in full-time work at 2-, 5-, 10-, and 15-year follow-up, compared to patients with benefits at baseline, where 16%, 27%, 31%, and 33% of seizure-free patients worked full time at these time points (p = 0.018 at 10 years). More patients with full-time work had ability to drive, a family of their own, and higher educational status than patients in part-time work or on benefits. Univariate predictors for employment at long term were having employment preoperatively, higher education, favorable seizure outcome, male sex, and younger age at surgery. Multivariate predictors were having employment preoperatively, favorable seizure outcome, and younger age.

Conclusions:

The best vocational outcomes occurred in seizure-free patients who were employed or students at baseline, which may reflect a higher general psychosocial level of function. Younger age also predicted better employment outcomes and it therefore seems plausible that early referral for surgery could contribute to better vocational outcomes.

Brain tumors in children with refractory seizures—a long-term follow-up study after epilepsy surgery

PURPOSE

Epilepsy surgery is an established treatment option for medically refractory epilepsy. Brain tumors, besides dysplasias, vascular malformations, and other lesions, can cause refractory epilepsy. Long-term epilepsy-associated brain tumors, even though mostly benign, are neoplastic lesions and thus have to be considered as both epileptic and oncological lesions.

METHODS

We retrospectively analyzed epileptological and oncological long-term follow-up (FU) in pediatric patients who underwent brain surgery for refractory epilepsy and whose histology showed a tumor as underlying cause (n = 107, mean FU 119 months).

RESULTS

At last available outcome, 82.2% of patients were seizure free (International League Against Epilepsy (ILAE) class 1) and seizure outcome was stable over more than 14 years. Fifty-four percent of the patients were without anti-epileptic drugs (AEDs) at last available outcome; 96.2% of the tumors were classified WHO grade I and II and 3.7% were malignant (WHO grade III). Adjuvant treatment was administered in 5.7%; 2.9% had relapse and one patient died (tumor-related mortality = 1.4%). After surgery, 91% of the patients attended regular school/university and/or professional training.

CONCLUSIONS

This study shows that epileptological outcome within this group is promising and stable and oncological outcome has a very good prognosis. However, oncological FU must not be dismissed as a small percentage of patients who suffer from malignant tumors and adjuvant treatment, relapse, and mortality have to be considered.

Features of scalp EEG in unilateral mesial temporal lobe epilepsy due to hippocampal sclerosis: Determining factors and predictive value for epilepsy surgery

OBJECTIVE

To investigate determining factors of the ictal scalp EEG pattern at seizure onset and its predictive value for postsurgical outcome in people with unilateral MTLE due to hippocampal sclerosis (MTLE-HS).

METHODS

Review of consecutive people with chronic MTLE-HS undergoing presurgical video-EEG telemetry. Exclusion criteria were additional epileptogenic lesions or seizure generators or compromised EEG traces at seizure-onset. Mixed linear or logistic regression models were used.

RESULTS

Inclusion of 63 patients with 219 seizures with a favorable outcome (no seizures or auras only) in 43 patients at last follow-up. Rhythmic activity at seizure-onset (RA) had a frequency of 4.7±1.5/s (range 1-8/s), mostly localized in the anterior temporal region. Postsurgical seizure outcome was not associated with any clinical or electrophysiological feature. RA in the delta-band was more often observed with shorter epilepsy duration (p=0.002).

CONCLUSIONS

RA on scalp EEG gets faster with increasing epilepsy duration, possibly via time-dependent alterations of epileptogenic networks. Neither the frequency of RA nor other EEG-features appeared to predict postsurgical seizure outcome.

SIGNIFICANCE

The results challenge the view that if patients with apparent MTLE display RA in the delta-band, seizure-onset in neocortical structures rather than in temporo-mesial tissue should be considered and further investigations should be prompted.