Potential of cannabinoids as treatments for autism spectrum disorders

Current treatments for autism spectrum disorders (ASD) are limited in efficacy and are often associated with substantial side effects. These medications typically ameliorate problem behaviors associated with ASD, but do not target core symptom domains. As a result, there is a significant amount of research underway for development of novel experimental therapeutics. Endocannabinoids are arachidonic acid-derived lipid neuromodulators, which, in combination with their receptors and associated metabolic enzymes, constitute the endocannabinoid (EC) system. Cannabinoid signaling may be involved in the social impairment and repetitive behaviors observed in those with ASD. In this review, we discuss a possible role of the EC system in excitatory-inhibitory (E-I) imbalance and immune dysregulation in ASD. Novel treatments for the core symptom domains of ASD are needed and phytocannabinoids could be useful experimental therapeutics for core symptoms and associated domains.

3T MRI Whole-Brain Microscopy Discrimination of Subcortical Anatomy, Part 2: Basal Forebrain

BACKGROUND AND PURPOSE

The basal forebrain contains multiple structures of great interest to emerging functional neurosurgery applications, yet many neuroradiologists are unfamiliar with this neuroanatomy because it is not resolved with current clinical MR imaging.

MATERIALS AND METHODS

We applied an optimized TSE T2 sequence to washed whole postmortem brain samples (n = 13) to demonstrate and characterize the detailed anatomy of the basal forebrain using a clinical 3T MR imaging scanner. We measured the size of selected internal myelinated pathways and measured subthalamic nucleus size, oblique orientation, and position relative to the intercommissural point.

RESULTS

We identified most basal ganglia and diencephalon structures using serial axial, coronal, and sagittal planes relative to the intercommissural plane. Specific oblique image orientations demonstrated the positions and anatomic relationships for selected structures of interest to functional neurosurgery. We observed only 0.2- to 0.3-mm right-left differences in the anteroposterior and superoinferior length of the subthalamic nucleus (P = .084 and .047, respectively). Individual variability for the subthalamic nucleus was greatest for angulation within the sagittal plane (range, 15°-37°), transverse dimension (range, 2-6.7 mm), and most inferior border (range, 4-7 mm below the intercommissural plane).

CONCLUSIONS

Direct identification of basal forebrain structures in multiple planes using the TSE T2 sequence makes this challenging neuroanatomy more accessible to practicing neuroradiologists. This protocol can be used to better define individual variations relevant to functional neurosurgical targeting and validate/complement advanced MR imaging methods being developed for direct visualization of these structures in living patients.

Simulating human sleep spindle MEG and EEG from ion channel and circuit level dynamics

BACKGROUND

Although they form a unitary phenomenon, the relationship between extracranial M/EEG and transmembrane ion flows is understood only as a general principle rather than as a well-articulated and quantified causal chain.

METHOD

We present an integrated multiscale model, consisting of a neural simulation of thalamus and cortex during stage N2 sleep and a biophysical model projecting cortical current densities to M/EEG fields. Sleep spindles were generated through the interactions of local and distant network connections and intrinsic currents within thalamocortical circuits. 32,652 cortical neurons were mapped onto the cortical surface reconstructed from subjects' MRI, interconnected based on geodesic distances, and scaled-up to current dipole densities based on laminar recordings in humans. MRIs were used to generate a quasi-static electromagnetic model enabling simulated cortical activity to be projected to the M/EEG sensors.

RESULTS

The simulated M/EEG spindles were similar in amplitude and topography to empirical examples in the same subjects. Simulated spindles with more core-dominant activity were more MEG weighted.

COMPARISON WITH EXISTING METHODS

Previous models lacked either spindle-generating thalamic neural dynamics or whole head biophysical modeling; the framework presented here is the first to simultaneously capture these disparate scales.

CONCLUSIONS

This multiscale model provides a platform for the principled quantitative integration of existing information relevant to the generation of sleep spindles, and allows the implications of future findings to be explored. It provides a proof of principle for a methodological framework allowing large-scale integrative brain oscillations to be understood in terms of their underlying channels and synapses.

3T MRI Whole-Brain Microscopy Discrimination of Subcortical Anatomy, Part 1: Brain Stem

BACKGROUND AND PURPOSE

The brain stem is compactly organized with life-sustaining sensorimotor and autonomic structures that can be affected by numerous pathologies but can be difficult to resolve on conventional MR imaging.

MATERIALS AND METHODS

We applied an optimized TSE T2 sequence to washed postmortem brain samples to reveal exquisite and reproducible brain stem anatomic MR imaging contrast comparable with histologic atlases. This resource-efficient approach can be performed across multiple whole-brain samples with relatively short acquisition times (2 hours per imaging plane) using clinical 3T MR imaging systems.

RESULTS

We identified most brain stem structures at 7 canonical axial levels. Multiplanar or oblique planes illustrate the 3D course and spatial relationships of major brain stem white matter pathways. Measurements of the relative position, course, and cross-sectional area of these pathways across multiple samples allow estimation of pathway location in other samples or clinical subjects. Possible structure-function asymmetries in these pathways will require further study-that is, the cross-sectional area of the left corticospinal tract in the midpons appeared 20% larger (n = 13 brains, P < .10).

CONCLUSIONS

Compared with traditional atlases, multiplanar MR imaging contrast has advantages for learning and retaining brain stem anatomy for clinicians and trainees. Direct TSE MR imaging sequence discrimination of brain stem anatomy can help validate other MR imaging contrasts, such as diffusion tractography, or serve as a structural template for extracting quantitative MR imaging data in future postmortem investigations.

Review: The past, present and future challenges in epilepsy-related and sudden deaths and biobanking

Awareness and research on epilepsy-related deaths (ERD), in particular Sudden Unexpected Death in Epilepsy (SUDEP), have exponentially increased over the last two decades. Most publications have focused on guidelines that inform clinicians dealing with these deaths, educating patients, potential risk factors and mechanisms. There is a relative paucity of information available for pathologists who conduct these autopsies regarding appropriate post mortem practice and investigations. As we move from recognizing SUDEP as the most common form of ERD toward in-depth investigations into its causes and prevention, health professionals involved with these autopsies and post mortem procedure must remain fully informed. Systematizing a more comprehensive and consistent practice of examining these cases will facilitate (i) more precise determination of cause of death, (ii) identification of SUDEP for improved epidemiological surveillance (the first step for an intervention study), and (iii) biobanking and cell-based research. This article reviews how pathologists and healthcare professionals have approached ERD, current practices, logistical problems and areas to improve and harmonize. The main neuropathology, cardiac and genetic findings in SUDEP are outlined, providing a framework for best practices, integration of clinical, pathological and molecular genetic investigations in SUDEP, and ultimately prevention.

De novo loss of function mutations in KIAA2022 are associated with epilepsy and neurodevelopmental delay in females

Intellectual disability (ID) affects about 3% of the population and has a male gender bias. Of at least 700 genes currently linked to ID, more than 100 have been identified on the X chromosome, including KIAA2022. KIAA2022 is located on Xq13.3 and is expressed in the developing brain. The protein product of KIAA2022, X‐linked Intellectual Disability Protein Related to Neurite Extension (XPN), is developmentally regulated and is involved in neuronal migration and cell adhesion. The clinical manifestations of loss‐of‐function KIAA2022 mutations have been described previously in 15 males, born from unaffected carrier mothers, but few females. Using whole‐exome sequencing, we identified a cohort of five unrelated female patients with de novo probably gene damaging variants in KIAA2022 and core phenotypic features of ID, developmental delay, epilepsy refractory to treatment, and impaired language, of similar severity as reported for male counterparts. This study supports KIAA2022 as a novel cause of X‐linked dominant ID, and broadens the phenotype for KIAA2022 mutations.

MRI characterization and longitudinal study of focal cerebellar lesions in a young tuberous sclerosis cohort

BACKGROUND AND PURPOSE

There are few articles characterizing cerebellar lesions in patients with TSC and no published series documenting longitudinal evaluation of these lesions, to our knowledge. Recent suggestion of a correlation between autism and cerebellar lesions in patients with TSC heightens the importance of understanding these lesions. Our purpose was to characterize cerebellar lesions in a cohort of young patients with TSC with specific interest in assessing longitudinal changes.

MATERIALS AND METHODS

We retrospectively reviewed MR images from 145 pediatric and young adult patients with tuberous sclerosis (mean age, 7.6 years). A number of imaging characteristics of cerebellar tubers were recorded, and patients were evaluated for SGAs. Patients with follow-up scans >3 months from the original scan were further analyzed for longitudinal tuber characterization.

RESULTS

There were 24.1% of patients with focal cerebellar lesions; 52.4% of patients with cerebellar lesions demonstrated change in imaging characteristics during longitudinal analysis. Fifty-one percent of the lesions were enhanced after gadolinium administration. Twenty percent of the patients with cerebellar lesions had pathologically confirmed SGAs compared with the incidence of 11% in the 145 patients with TSC reviewed.

CONCLUSIONS

In our large cohort of young patients with TSC, cerebellar tubers were common and 52% of patients had tubers that changed with time. A higher percentage of patients with cerebellar lesions developed SGAs than patients with TSC without cerebellar lesions. Because this is the first reported longitudinal study of cerebellar lesions in TSC, further investigation may provide additional insight into TSC pathology and associated clinical manifestations, such as autism, developmental delay, and seizures.

Long-term association between seizure outcome and depression after resective epilepsy surgery

OBJECTIVE

This study explored the association between long-term epilepsy surgery outcome and changes in depressive symptoms.

METHODS

Adults were enrolled between 1996 and 2001 in a multicenter prospective study to evaluate outcomes of resective epilepsy surgery. The extent of depressive symptoms and depression case status (none, mild, or moderate/severe) were assessed using the Beck Depression Inventory (BDI) preoperatively and 3, 12, 24, 48, and 60 months postoperatively. A mixed-model repeated-measures analysis was performed, adjusting for covariates of seizure location, gender, age, race, education, and seizure control.

RESULTS

Of the total 373 subjects, 256 were evaluated at baseline and 5 years after surgery. At baseline, 164 (64.1%) were not depressed, 34 (13.3%) were mildly depressed, and 58 (22.7%) had moderate to severe depression. After 5 years, 198 (77.3%) were not depressed, 20 (7.8%) were mildly depressed, and 38 (14.8%) were moderately to severely depressed. Five years after surgery, the reduction in mean change from baseline in BDI score was greater in subjects with excellent seizure control than in the fair and poor seizure control groups (p = 0.0006 and p = 0.02 respectively). Those with good seizure control had a greater reduction in BDI score than the poor seizure control group (p = 0.02) and borderline significant reduction compared with the fair seizure control group (p = 0.055).

CONCLUSION

Although study participants had initial improvement in depressive symptoms, on average, after resective surgery, only patients with good or excellent seizure control had sustained long-term improvement in mood.

Abnormalities of cortical thickness in postictal psychosis

Postictal psychosis (PIP), the occurrence of psychotic episodes following a seizure, is a common and serious comorbidity in patients with epilepsy. Yet, the anatomical correlates remain poorly defined. Here, we used quantitative MRI morphometry to identify structural abnormalities in the cortex of patients with PIP relative to patients with epilepsy without PIP and age- and gender-matched normal healthy controls. Comparison of patients with epilepsy and PIP with patients with epilepsy without PIP revealed increased cortical thickness in the right lateral prefrontal cortex, right anterior cingulate cortex, and right middle temporal gyrus. The PIP group was distinguished from the EC and NC groups by thicker cortex in the right rostral anterior cingulate cortex and thinner cortex in the right angular gyrus and the left middle temporal region. Findings indicate that PIP is associated with thickening of the right anterior cingulate cortex, which may serve as a marker for patients at risk for developing PIP.

Historical perspectives and definitions of the postictal state

The postictal state and its features were recognized by physicians from Babylonian times through to the advent of modern neurology in the late 19th century. Among varied descriptions and definitions lies one of the best known and still used eponyms in medicine, Todd's paralysis. Despite a relative lack of biological insight, many key observations were made in an era mostly devoid of treatments for epilepsy.

Hyperfamiliarity for faces

OBJECTIVE

To report 4 cases of hyperfamiliarity for faces (HFF) and review 5 previously reported cases.

METHODS

We identified cases of HFF from PubMed search and references in prior reports.

RESULTS

Three of our 4 cases had pathologic findings that were most extensive in the left temporal lobe. HFF occurred after a tonic-clonic seizure (cases 1 and 3), during simple partial seizures (case 2), and in the setting of an increase in simple partial seizure frequency but not during seizures (case 4). All 9 cases were adults with 1 or more seizures; symptoms first occurred after seizures in 5 cases and during seizures in 1 case. Ictal symptoms lasted from seconds to minutes and from 2 days to more than 7 years in the other 6 cases. The duration of HFF was not associated with the presence or extent of a structural lesion. While in several cases HFF appears to result from a postictal Todd paralysis, the mechanism underlying persistent cases is uncertain.

CONCLUSIONS

This modality (visual)-specific and stimulus (face)-specific syndrome is associated with diverse structural, functional imaging, and neurophysiologic findings. Lesions are more often left-sided and involve the temporal lobe. Epilepsy and seizures were present in all 9 cases, suggesting a pathophysiologic relationship, which likely varies among cases. Although only reported in 9 patients, HFF is probably much more common than it is diagnosed.

Reliable change indices and regression-based measures for the Rey-Osterreith Complex Figure test in partial epilepsy patients

The Rey-Osterreith Complex Figure (ROCF) is commonly used in evaluations of patients undergoing epilepsy surgery. We assessed test-retest performance on ROCF in 30 partial epilepsy patients (mean interval = 33.7 months) to derive reliable change indices (RCIs) and regression-based measures for change. ROCF reproductions were rescored by three raters (IRR Copy: 0.963; Delayed Recall: 0.986). The derived adjusted RC (90% CI) cutoff values for the ROCF Copy were (<or=-6.5, >or=8.4) and were (<or=-6.8, >or=10.0) for the Delayed Recall. Results from regression-based analyses were negative, using age, education, seizure duration, and age of onset, whereas a baseline score was a significant predictor of a follow-up score. The results provide a means to evaluate long-term outcome in epilepsy patients using the ROCF.

Epilepsy surgery in tuberous sclerosis complex: early predictive elements and outcome

AIM

The aim of the study was to evaluate the surgical treatment of epilepsy and detection of possible early surgery predictive elements in patients with tuberous sclerosis complex (TSC).

MATERIALS AND METHODS

Forty-two TSC patients with epilepsy were selected and divided into two main groups: definite and fruste forms. Definite forms were divided into different groups: patients with pharmacologically controlled epilepsy, patients with pharmacoresistant epilepsy excluded from surgery after an extensive presurgical assessment, and patients with a pharmacoresistant epilepsy who underwent surgery. We compared the definite TSC groups to identify elements that predict surgical candidacy. Second, we compared all operated patients to assess surgical outcome.

CONCLUSION

We found several factors that could predict a surgical intervention even if identification of patients with refractory epilepsy who can benefit from surgery is an evolving process. Also, several positive factors for good surgical outcome were identified. Patients with the fruste form had excellent surgical outcome.

Expectations prior to epilepsy surgery: an exploratory comparison of men and women

Although the clinical goal of resective epilepsy surgery is seizure freedom, patients have a wide set of expectations for this invasive procedure. The goal of this study was to evaluate potential gender differences in expectations among patients undergoing resective epilepsy surgery. Ratings of the importance of 12 potential impacts ("expectations") of resective surgery were analyzed in a seven-center cohort study including 389 adults aged 16 and older who underwent resective epilepsy surgery. Men and women both ranked anticipated changes in driving and memory as the most important presurgical expectations. Women rated driving, physical activity limitations, and economic worries as less important, and fatigue and pregnancy concerns as more important than did men (p's< or =0.05). Exploratory factor analysis indicated a different pattern of associations among the 12 importance items for men and women. Whether gender differences in presurgical values are associated with outcomes needs exploration.

Effects of vagus nerve stimulation on cardiovascular regulation in patients with epilepsy

OBJECTIVE

To evaluate the impact of vagus nerve stimulation (VNS) on heart rate and blood pressure (BP) modulation in epilepsy patients.

MATERIAL AND METHODS

Twenty-one epilepsy patients with VNS were tested during on (60 s) and off (5 min) phases. We monitored BP, RR intervals (RRI) and respiration. Spectral analysis was performed in low- (LF: 0.04-0.15 Hz) and high-frequency bands (HF: 0.15-0.5 Hz). For coherences above 0.5, we calculated the LF transfer function between systolic BP and RRI, and the HF transfer function gain and phase between RRI and respiration. Differences between the on and off phases were evaluated using Wilcoxon test.

RESULTS

VNS did not change RRI and BP values. The LF power of BP and the LF and HF power of RRI increased significantly. There was a slight change in the RRI/BP LF gain and the RRI/respiration HF gain (ns). The HF phase between RRI and respiration decreased significantly.

CONCLUSIONS

Our findings show that VNS influences both sympathetic and parasympathetic cardiovascular modulation. However, our results also show that VNS does not negatively influence autonomic cardiovascular regulation.

Levetiracetam has no acute effects on brain gamma-aminobutyric acid levels

OBJECTIVE

The mechanism of action of levetiracetam (LEV), an antiepileptic drug, is related to a novel binding site, SV2, but LEV acts on GABA-A receptors. The objective of the study described here was to determine if LEV modulates brain GABA in vivo.

METHODS

Concentrations of cerebral GABA and serum LEV were obtained in seven healthy individuals using 1H magnetic resonance spectroscopy at baseline and 3 and 6 hours following oral administration of 1 g of LEV.

RESULTS

Brain cerebral GABA acutely concentrations did not change from baseline.

CONCLUSION

The results indicate that LEV does not increase human cerebral GABA concentrations acutely in healthy individuals.

A subcortical network of dysfunction in TLE measured by magnetic resonance spectroscopy

OBJECTIVE

The goal of this work was to evaluate the relationship between neuronal injury/loss in the hippocampus, thalamus, and putamen in temporal lobe epilepsy (TLE) patients using (1)H magnetic resonance spectroscopic imaging.

METHODS

(1)H spectroscopic images from the hippocampus and thalamus of controls and patients with TLE were acquired at 4 T. The spectroscopic imaging data were reconstructed using an automated voxel-shifting method based on anatomic landmarks providing four, six, and three loci for the hippocampus, thalamus, and putamen, respectively. For correlation analysis, the hippocampal and striatal loci were averaged to provide single estimates of the entire structure, whereas the thalamus was divided into two regions, an anterior and posterior measure, using the average of three loci each.

RESULTS

The ratio of N-acetyl aspartate to creatine (NAA/Cr), a measure of neuronal injury/loss, was significantly reduced in both the ipsilateral and contralateral hippocampi and thalami. NAA/Cr in the ipsilateral hippocampus was significantly correlated with the ipsilateral and contralateral anterior and posterior thalami, putamen, and contralateral hippocampus. In control subjects, the hippocampi were only correlated with each other.

CONCLUSIONS

The data demonstrate that there is significant neuronal injury/loss in both the ipsilateral and contralateral thalami in temporal lobe epilepsy patients, with greater impairment in the anterior portions of the ipsilateral thalamus. The degree of injury/loss in the ipsilateral and contralateral thalamus and putamen is directly correlated with that of the ipsilateral hippocampus. This is consistent with the hypothesis that the impairment and damage associated with recurrent seizures as measured by N-acetyl aspartate originating in the hippocampus results in injury and impairment in other subcortical structures.

Auras are frequent in idiopathic generalized epilepsy

The occurrence of an aura is often considered evidence of a partial rather than an idiopathic generalized epilepsy syndrome. The authors examined this hypothesis by prospectively recording reports of auras by patients being admitted for video-EEG monitoring. Auras were equally common (70%) among patients with idiopathic generalized epilepsy as they were among those with localization-related epilepsy. Presence of an aura is not a reliable indicator of localization-related epilepsy.

Optimal evaluation of digital electroencephalograms

Currently available digital EEG equipment provides considerably greater opportunities for clinical data analysis than is generally appreciated especially when appropriate software is used. Data from 7 different laboratories that had been obtained for routine diagnostic evaluations on 7 different EEG instruments and stored on compact disks were investigated. Since the instruments do not filter the data at input, ultra slow activity down to 0.01 Hz is currently being recorded but the attenuation factor is instrument dependent. Nevertheless, relevant clinical information is potentially available in these data and needs to be explored. Several examples in regard to epilepsy are presented. Determination of seizure onset may depend on the frequencies that are examined. The use of appropriate filter settings and viewing windows for the clinical question to be answered is stressed. Differentiation between simple and complex spike wave discharges, as well as spread of spikes, can readily be achieved by expanding the time base to 1 or 2 seconds and placing a cursor on the peak of the negative spike. Latencies in the millisecond range can then become apparent. EEGs co-registered with MEG should be evaluated with the same software in order to allow an adequate assessment of the similarities and differences between electrical and magnetic activity. An example of a comparison of EEG, planar gradiometers and magnetometers for an averaged spike is shown.

Changes in depression and anxiety after resective surgery for epilepsy

OBJECTIVE

To determine changes in depression and anxiety after resective surgery.

METHODS

Data from subjects enrolled in a prospective multicenter study of resective epilepsy surgery were reviewed with the Beck Psychiatric Symptoms Scales (Beck Depression Inventory [BDI] and Beck Anxiety Inventory [BAI]) and Composite International Diagnostic Interview (CIDI) up to a 24-month period. chi2 analyses were used to correlate proportions.

RESULTS

A total of 358 presurgical BDI and 360 BAI results were reviewed. Moderate and severe levels of depression were reported in 22.1% of patients, and similar levels of anxiety were reported by 24.7%. Postoperative rates of depression and anxiety declined at the 3-, 12-, and 24-month follow-up periods. At the 24-month follow-up, moderate to severe levels of depression symptoms were reported in 17.6 and 14.7% of the patients who continued to have postoperative seizures. Moderate to severe depression and anxiety were found in 8.2% of those who were seizure-free. There was no relationship, prior to surgery, between the presence or absence of depression and anxiety and the laterality or location of the seizure onset. There were no significant relationships between depression or anxiety at 24-month follow-up and the laterality or location of the surgery.

CONCLUSIONS

Depression and anxiety in patients with refractory epilepsy significantly improve after epilepsy surgery, especially in those who are seizure-free. Neither the lateralization nor the localization of the seizure focus or surgery was associated with the risk of affective symptoms at baseline or after surgery.

Adult-onset epilepsy in focal cortical dysplasia of Taylor type

Focal cortical dysplasia of Taylor type (FCDT) usually presents with seizures at an early age, whereas adult onset of epilepsy is uncommon. We reviewed the medical records of 213 patients with FCDT. In 21 patients (10%), age at seizure onset ranged from 18 to 55 years (mean 25.3). The outcome of seizures in patients with FCDT and adult-onset epilepsy seems favorable vs childhood-onset seizures.

Use of the Brief Visuospatial Memory Test-Revised (BVMT-R) in neuropsychological evaluation of epilepsy surgery candidates

Many commonly used measures of figural reproduction have been found to be relatively insensitive to the effects of right temporal lobe dysfunction. More positive findings are present in studies using measures of figural learning over repeated trials. This study examined the use of a commercially available measure of figural learning in a sample of epilepsy patients undergoing presurgical neuropsychological testing. The Brief Visuospatial Memory Test-Revised (BVMT-R) was administered to 47 subjects undergoing comprehensive presurgical workups with video and EEG monitoring. Groups with left (N = 25) and right (N = 22) temporal lobe seizures did not differ on BVMT-R measures of learning, delayed recall, or yes/no recognition. Approximately 29% of the sample exhibited "impaired" performance in comparison to published norms. The results of receiver operating curve analyses revealed little discrimination in performance between groups. The BVMT-R does not appear to have the sensitivity required for assessing nonverbal memory in this population.

Depression but not seizure frequency predicts quality of life in treatment-resistant epilepsy

BACKGROUND

The two-thirds of patients with epilepsy who become seizure-free have a quality of life (QOL) similar to the general population. The major treatment challenge is patients with refractory epilepsy. Whereas neurologists typically focus on seizure reduction in the treatment of these patients, results of studies relating seizure frequency to QOL are conflicting. As depression is associated with reduced QOL in epilepsy and antiepileptic medications (AEDs) can cause depression, it is important to determine the relative roles of depression and seizure frequency in QOL in refractory epilepsy.

METHODS

Prospective evaluation was conducted of patients with refractory epilepsy being admitted to an inpatient video-EEG monitoring unit. The impact of clinical variables (age, sex, marital status, seizure frequency, duration and type of seizure disorder, seizure localization, number of AEDs, depression) on QOL was analyzed.

RESULTS

Depression was a powerful predictor of QOL (n = 122, beta = -35.8, p < 0.0001). No other variable predicted QOL. Depression was common (54%), severe (19% with suicidal thoughts), underdiagnosed (37%), and largely untreated (17% on antidepressants).

CONCLUSIONS

Treatment of depression may be inadequately prioritized in the management of intractable epilepsy.

A double-blind, placebo-controlled study of remacemide hydrochloride in patients with refractory epilepsy following pre-surgical assessment

This multicentre, randomised, double-blind, placebo-controlled, parallel-group study investigated the efficacy, safety and pharmacokinetics of remacemide hydrochloride in adult patients ( n= 59) with refractory epilepsy, undergoing reduced or discontinued antiepileptic drug (AED) usage, as part of an evaluation for epilepsy surgery. On discontinuation or reduction of maintenance AEDs, patients received remacemide hydrochloride, up to 600 mg daily, or placebo, for up to ten days or until they experienced a fourth complex partial (CPS) or a generalised tonic-clonic (GTC) seizure. Pre- and post-study blood and urine samples were taken for analysis. Remacemide hydrochloride showed a significantly ( P= 0.045) longer median time to fourth seizure compared with placebo (6.8 vs. 3.8 days). Median nine-day seizure counts were significantly ( P= 0.0327) lower with remacemide hydrochloride than placebo (6.2 vs. 12.8). Eleven remacemide hydrochloride patients and six placebo patients completed ten days' treatment. Remacemide and desglycinyl metabolite levels were lower in patients receiving concomitant carbamazepine or phenytoin than in those receiving non-inducing AEDs or remacemide hydrochloride alone. No serious adverse events occurred; all patients receiving remacemide hydrochloride completed the study. Remacemide hydrochloride was well tolerated and showed significant therapeutic activity in this patient population.

Nondominant hemisphere lesions and conversion nonepileptic seizures

To explore the hypothesis that lateralized hemispheric dysfunction may contribute to the development of conversion symptoms, the authors studied frequency of unilateral cerebral physiological or structural abnormalities in 79 consecutive patients with conversion nonepileptic seizures (C-NES), who were also compared with two groups of epilepsy patients without C-NES. Sixty (76%) of the C-NES patients had unilateral cerebral abnormalities on neuroimaging, of which 85% were structural. Ictal or interictal epileptiform abnormalities on EEG were found in 78% of C-NES patients and focal slowing in another 10%. Fifty (63%) of the C-NES patients had both structural and epileptiform abnormalities. Among the 60 with unilateral abnormalities, 43 (71%) had right hemisphere structural lesions or physiologic dysfunctions (C-NES>non-C-NES, P<0.02). This study supports prior studies and clinical observations that cerebral dysfunction can contribute to the pathogenesis of conversion disorder, and that nondominant hemisphere dysfunction may play a greater role.

Decrease of sympathetic cardiovascular modulation after temporal lobe epilepsy surgery

In temporal lobe epilepsy (TLE), there is evidence of ictal and interictal autonomic dysregulation, predominantly with sympathetic overactivity. The effects of TLE surgery on autonomic cardiovascular control and on baroreflex sensitivity (BRS) have not been studied. To evaluate such effects, we monitored heart rate (HR), systolic blood pressure (BP(sys)) and respiration in 18 TLE patients 3-4 months before and after TLE surgery. We used Blackman-Tukey spectral analysis to assess sympathetic and parasympathetic modulation as powers of HR and BP(sys) oscillations in the low frequency (LF, 0.04-0.15 Hz) and high frequency (HF, 0.15-0.5 Hz) bands. BRS was determined as the LF transfer function gain between BP and HR. After surgery, HR, BP(sys), respiration and HF powers remained unchanged, while LF powers of HR (1.57 +/- 1.54 bpm(2)) and BP(sys) (2.19 +/- 1.34 mmHg(2)) and BRS (0.68 +/- 0.31 bpm/mmHg) were smaller than pre-surgical LF powers of HR (3.87 +/- 3.26 bpm(2)) and BP(sys) (4.80 +/- 3.84 mmHg(2)) and BRS (1.12 +/- 0.39 bpm/mmHg; P < 0.05). After TLE surgery, there is a reduction of sympathetic cardiovascular modulation and BRS that might result from decreased influences of interictal epileptogenic discharges on brain areas involved in cardiovascular autonomic control. TLE surgery seems to stabilize the cardiovascular control in epilepsy patients by reducing the risk of sympathetically mediated tachyarrhythmias and excessive bradycardiac counter-regulation, both of which might be relevant for the pathophysiology of sudden unexpected death in epilepsy patients (SUDEP). Thus, TLE surgery might contribute to reducing the risk of SUDEP.

Premorbid psychiatric risk factors for postictal psychosis

Postictal psychosis (PIP) is a common and clinically significant sequela of inpatient epilepsy monitoring. A series of 622 patients with complex partial epilepsy undergoing video-EEG evaluations as candidates for epilepsy surgery were evaluated, by structured psychiatric interview, for individual and family psychiatric histories, depression, anxiety, and features of personality disorders. No patient had psychotic symptoms at baseline. Twenty-nine developed a PIP episode during monitoring. The a priori hypotheses were that patients with PIP would have higher baseline schizotypal and paranoid personality ratings and a greater prevalence of histories of psychiatric treatment and family history of psychotic illness. However, only a higher prevalence of mood disorder among first- and second-degree relatives distinguished the patients who developed PIP on logistic regression analyses (odds ratio=3.49, P=0.001). Possible mechanisms linking vulnerability toward mood disorders and the development of psychotic symptoms in epilepsy are discussed.

Adult-onset idiopathic generalized epilepsy: clinical and behavioral features

PURPOSE

To identify and define clinical and behavioral features of patients with adult-onset idiopathic generalized epilepsy (IGE).

METHODS

We reviewed the charts of 313 IGE patients at the NYU Comprehensive Epilepsy Center over the past 5 years to identify patients with adult onset (18 years old or older). We excluded patients with childhood or adolescent symptoms that suggested absence, myoclonic, or tonic-clonic seizures, as well as those with a history of significant head injury or other known causes of localization-related epilepsy.

RESULTS

Forty-two (13.4%) patients had a clear onset of IGE in adulthood; average age of onset was early 20s (mean, 23.8 years; range, 18-55 years). Twenty-one patients had adult myoclonic epilepsy (AME, 50%), and three had generalized tonic-clonic seizures on awakening (GTCS-A, 7%). More than two thirds (n=30) are well controlled with current antiepileptic drugs (AEDs), and almost 90% are currently employed (n=37). One third were diagnosed and treated for mental disorders, including depression (n=12), anxiety (n=7), obsessive-compulsive personality disorder (n=2), and postictal psychosis (n=1).

CONCLUSIONS

Adult-onset IGE is associated with a good prognosis. An association may exist between psychological disorders, psychotropic medication, and level of seizure control in adults with IGE.

Progression of postictal to interictal psychosis

PURPOSE

To describe a case series of patients with both postictal psychosis (PIP) and chronic interictal psychosis (IIP).

METHODS

We retrospectively reviewed the records of 43 patients with PIP from a comprehensive epilepsy center to find evidence of both PIP and IIP in the same patient.

RESULTS

Six (13.9%) of the 43 patients met all the criteria for both PIP and IIP. Five of our six patients had multiple documented PIPs before they became chronically psychotic. The range of length of time between PIP and IIP was 7 to 96 months. Postictal and interictal psychotic behavior was similar or identical in five of six cases.

CONCLUSIONS

The results of this study suggest a progression from PIP to IIP: there is a similarity between the symptoms of the two psychoses, a history of multiple PIPs before the first IIP, and a period of months to years between PIP and IIP onset.

Late seizure recurrence after multiple subpial transections

We studied long-term outcome (range, 28-89 months; mean, 56 months) after multiple subpial transections (MSTs) for medically refractory epilepsy. Forty-three (79.6%) of 54 patients had a consistent significant reduction in seizure frequency, and 27 (50%) of the 54 were either entirely seizure free or virtually so. However, 10 (18.6%) patients sustained an increase in seizure frequency several years after surgery, after showing initial postoperative improvement. This suggests that late seizure recurrence is a more important problem in cases in which MST has been performed than for pure resections.

Alcohol and marijuana: effects on epilepsy and use by patients with epilepsy

We review the safety of alcohol or marijuana use by patients with epilepsy. Alcohol intake in small amounts (one to two drinks per day) usually does not increase seizure frequency or significantly affect serum levels of antiepileptic drugs (AEDs). Adult patients with epilepsy should therefore be allowed to consume alcohol in limited amounts. However, exceptions may include patients with a history of alcohol or substance abuse, or those with a history of alcohol-related seizures. The most serious risk of seizures in connection with alcohol use is withdrawal. Alcohol withdrawal lowers the seizure threshold, an effect that may be related to alcohol dose, rapidity of withdrawal, and chronicity of exposure. Individuals who chronically abuse alcohol are at significantly increased risk of developing seizures, which can occur during withdrawal or intoxication. Alcohol abuse predisposes to medical and metabolic disorders that can lower the seizure threshold or cause symptoms that mimic seizures. Therefore, in evaluating a seizure in a patient who is inebriated or has abused alcohol, one must carefully investigate to determine the cause. Animal and human research on the effects of marijuana on seizure activity are inconclusive. There are currently insufficient data to determine whether occasional or chronic marijuana use influences seizure frequency. Some evidence suggests that marijuana and its active cannabinoids have antiepileptic effects, but these may be specific to partial or tonic-clonic seizures. In some animal models, marijuana or its constituents can lower the seizure threshold. Preliminary, uncontrolled clinical studies suggest that cannabidiol may have antiepileptic effects in humans. Marijuana use can transiently impair short-term memory, and like alcohol use, may increase noncompliance with AEDs. Marijuana use or withdrawal could potentially trigger seizures in susceptible patients.

Late seizure recurrence after multiple subpial transections

We studied long-term outcome (range, 28-89 months; mean, 56 months) after multiple subpial transections (MST) for medically refractory epilepsy. Forty-three (79.6%) of 54 patients had a consistent significant reduction in seizure frequency, and 27 (50%) of the 54 were either entirely seizure free or virtually so. However, 10 (18.5%) patients sustained an increase in seizure frequency several years after surgery, after showing initial postoperative improvement. This suggests that late seizure recurrence is a more important problem in cases in which MST has been performed than for pure resections.

Bilateral resective epilepsy surgery in a child with tuberous sclerosis: case report

OBJECTIVE AND IMPORTANCE

Surgical intervention can reduce the burden of seizures in selected patients with tuberous sclerosis and medically refractory epilepsy.

CLINICAL PRESENTATION

A child presented with tuberous sclerosis and severe epilepsy beginning in the first month of life and delayed development before 1 year of age. Video-electroencephalographic monitoring at the age of 1 year revealed a left temporal seizure focus. Repeat videoelectroencephalography at 2 years of age revealed a right posterior quadrant seizure focus. Bilateral subdural electrodes were placed, confirming independent seizure onsets from the right parietal area (overlying a tuber) and prominent interictal activity over the left superior temporal region.

INTERVENTION

The right parietal focus was resected, and electrodes were maintained over the left temporal focus. After right parietal resection, ictal discharges were recorded over the left temporal region; a corticectomy was performed 2 days later. No tonicoclonic or complex partial seizures have occurred during a follow-up period of more than 24 months. Simple partial motor seizures involving the right foot have been reduced by more than 80%, and other simple partial seizures have been eliminated. Postoperatively, there has been marked improvement in the patient's cognitive and motor developmental status.

CONCLUSION

In selected patients with bilateral seizure foci involving separate lobes, aggressive bilateral surgery can be safe and effective.

Hemispheric influence on autonomic modulation and baroreflex sensitivity

Several studies suggest hemispheric lateralization of autonomic cardiovascular control. There is controversy regarding which hemisphere dominates sympathetic or parasympathetic activity. Hemispheric influences on baroreflex sensitivity (BRS) have not yet been evaluated. To determine hemispheric autonomic control in epilepsy patients, we assessed cardiovascular and baroreflex modulation before and during hemispheric inactivation. For 15 patients with drug-refractory epilepsy, we analyzed autonomic heart rate (HR) and blood pressure (BP) modulation and BRS before and during left and right intracarotid amobarbital procedure (IAP). After Blackman-Tukey spectral analysis, we calculated the low-frequency (LF: 0.04-0.15 Hz) and high-frequency (HF: 0.15-0.5 Hz) power of HR and BP as well as BRS as the LF transfer function gain between BP and HR. Right hemispheric inactivation induced a significant decrease of BP and an increase of HF power of HR and BP (p < 0.05). Left inactivation increased HR, BP, and LF power of both signals and decreased BRS by nearly 30% (p < 0.05). The results confirm previous IAP studies showing sympathetic lateralization in the right hemisphere and, moreover, demonstrate parasympathetic predominance and up-regulation of BRS in the left hemisphere. In epilepsy patients, unilateral electrical activity might derange autonomic balance between both hemispheres and contribute to cardiovascular dysregulation and sudden fatalities.

Psychotropic medication use in patients with epilepsy: effect on seizure frequency

Physicians are often reluctant to use psychotropic medications in epilepsy patients with psychiatric disorders because of concern over the potential risk for lowering seizure threshold. This study assesses retrospectively the impact of psychotropic medications on seizure frequency in 57 patients seen consecutively at an epilepsy center. During psychotropic drug therapy, seizure frequency decreased in 33% of patients, was unchanged in 44%, and increased in 23%. Mean seizure frequency was not statistically different between pre-treatment and treatment periods (t = 0.23, df = 56). Simultaneous adjustments in antiepileptic drug regimen could not account for the findings. Results support the position that psychotropic medications, introduced slowly in low to moderate doses, can be safely used in epilepsy patients with comorbid psychiatric pathology during the regular course of clinical care.

Safety and efficacy of standard and new antiepileptic drugs

Knowledge about the comparative safety and efficacy of standard and new antiepileptic drugs (AEDs) is limited. Medications are selected on the basis of seizure type and epilepsy syndrome, adverse effect profiles, and cost. However, there are few data comparing the efficacy of the new AEDs for the treatment of recent-onset versus refractory partial seizures, simple versus complex partial seizures, frontal versus temporal lobe seizures, or other relevant clinical types. Few studies compare new AEDs. The next best approach has been the use of meta-analyses and compilation of data from clinical trials, which allow interstudy comparisons to define broad and rough comparative estimates. These analyses, however, do not define clear differences in the safety and efficacy of the new AEDs because of differences in study populations. The new AEDs have expanded our arsenal against seizures. As a group, they have favorable safety and efficacy profiles. The challenge is to define the differences in terms of clinical significance.

Monoamine neurotransmitters in resected hippocampal subparcellations from neocortical and mesial temporal lobe epilepsy patients: in situ microvoltammetric studies

It is known that epilepsy patients diagnosed with neocortical temporal lobe epilepsy (NTLE), differ from those diagnosed with mesial temporal lobe epilepsy (MTLE), e.g., in hippocampal (HPC) pathology. In the present studies, we tested the hypothesis that NTLE and MTLE subtypes of human epilepsy might differ in regards to their HPC monoamine neurochemistry. Monoamine neurotransmitters were studied in separate signals and within s with semiderivative microvoltammetry, used in combination with stearate indicator, Ag-AgCl reference and stainless steel auxiliary microelectrodes. Anterior HPC specimens from the patients' epileptogenic zone, defined by electrocorticography, were resected neurosurgically from 13 consecutive patients with intractable temporal lobe epilepsy. Four patients were diagnosed with NTLE and nine with MTLE. The criteria for the diagnosis of NTLE versus MTLE was absence versus presence of HPC sclerosis, respectively, based on MRI examination of resected tissue. In addition, NTLE patients demonstrated seizure onset in anterolateral temporal neocortex on electroencephalography (EEG). HPC subparcellations studied were: (a) Granular Cells of the Dentate Gyrus (DG), (b) Polymorphic Layer of DG and (c) Pyramidal Layer: subfields, CA1 and CA2. Dopamine (DA), serotonin (5-HT), norepinephrine (NE) and ascorbic acid (AA) (co-factor in DA to NE synthesis), exhibited separate and characteristic half-wave potentials in millivolts. Each half-wave potential, i.e., the potential at which maximum current was generated, was experimentally established in vitro. Concentrations of neurotransmitters found in HPC subparcellations were interpolated from calibration curves derived in vitro from electrochemical detection of monoamines and AA in saline phosphate buffer. Significant differences between subtypes in concentration of monoamines were analyzed by the Mann Whitney rank sum test and those differences in probability distribution of monoamines were analyzed by the Fisher Exact test; in each case, P<0.01 was the criteria selected for determining statistical significance. DA concentrations were higher in NTLE compared with MTLE in each HPC subparcellation [P=0.037, 0.024 and 0.007, respectively (P<0.01)] and DA occurred more frequently in NTLE in the Pyramidal Layer [P=0.077 (P<0.01)]. AA was present in one NTLE patient. NE concentrations were higher in MTLE vs. NTLE in each subparcellation [P=0.012, 0.067 and 0.07, respectively (P<0.01)] and NE occurred more frequently in MTLE in Granular Cells of DG and Pyramidal Layer [P=0.052 and 0.014, respectively (P<0.01)]. In MTLE, NE concentrations in the CA1 subfield of the Pyramidal Layer were decreased vs. the CA2 subfield [P=0.063 (P<0.01)]. Serotonin was found in every HPC subparcellation of each subtype but 5-HT concentrations were higher in NTLE vs. MTLE in the Granular Cells of DG and the Pyramidal Layer (CA1 subfield) [P=0.076 and 0.095, respectively (P<0.01)]. Thus, this preliminary study showed that marked differences in HPC monoamine neurochemistry occurred in NTLE patients as compared with MTLE patients.

Wada testing in pediatric patients by use of propofol anesthesia

BACKGROUND AND PURPOSE

Wada testing may provide important information for surgical planning in pediatric patients with medically refractory epilepsy, but it is often not used because of the difficulties in performing the angiographic portion of the procedure in conscious children. We reviewed our experience using propofol, a short-acting IV administered anesthetic agent, for pediatric patients undergoing Wada testing.

METHODS

In a retrospective review of Wada tests performed on patients younger than 18 years, we identified 24 cases in which propofol anesthesia was used. We reviewed the medical records of these patients, with particular reference to dose of propofol, physiological parameters during anesthesia, and adequacy of neuropsychological testing after emergence from anesthesia.

RESULTS

Patients ranged in age from 6 to 16 years (mean age, 12.5 years). Propofol induced mild reductions in blood pressure (12.4% for systolic and 13.9% for diastolic blood pressure) and heart rate (mean reduction of 4.7%), which did not require specific treatment in any patient. Recovery from anesthesia was smooth and rapid, allowing initiation of Wada testing within 15 to 25 minutes of cessation of propofol. Wada testing was successfully accomplished in all patients.

CONCLUSION

Propofol provided rapid induction of anesthesia, was administered without endotracheal intubation, and did not cause substantial changes in cardiorespiratory parameters. Propofol anesthesia allowed controlled angiography among patients as young as 6 years and did not interfere with neuropsychological testing.

Brief report: Adolescents' attitudes toward epilepsy: further validation of the Child Attitude Toward Illness Scale (CATIS)

OBJECTIVE

To examine adolescents' attitudes toward having epilepsy using the Child Attitude Toward Illness Scale (CATIS) and to provide further psychometric validation of the scale in this population.

METHODS

Participants were 197 adolescents aged 11 to 17 years who completed the CATIS at two points and two external validation scales. Test-retest and internal consistency reliability and construct validity were computed. Analysis of variance was used to examine differences in attitudes according to gender, age, and epilepsy severity.

RESULTS

Girls, older adolescents, and those with more severe epilepsy had more negative attitudes toward having epilepsy than boys, younger adolescents, and those with moderate or mild epilepsy, respectively. Psychometric analyses yielded excellent internal consistency reliability and good test-retest reliability. The CATIS was moderately correlated with self-esteem and mastery, supporting its construct validity.

CONCLUSIONS

The CATIS is a useful and psychometrically sound tool to assess adolescents' attitudes toward having chronic illness.

Emotional outbursts and post-traumatic stress disorder during intracarotid amobarbital procedure

Severe emotional outbursts (SEOs) during intracarotid amobarbital procedures (IAP) rarely jeopardize preoperative language and memory testing. Four of four patients (100%) with outbursts had experienced significant emotional trauma (three were raped and one witnessed a decapitation), compared with 26 of 546 patients (4.8%) without outbursts (chi2 = 69.8, p < 0. 0001). Evocative injections were ipsilateral to seizure focus. IAP may disrupt emotional balance in some traumatized patients. Counseling may prevent SEOs.