Distinctive sleep complaints and polysomnographic findings in antibody subgroups of autoimmune limbic encephalitis.

INTRODUCTION: Sleep disturbances are being increasingly recognized in association with autoimmune encephalitis (AIE). We investigated the prevalence of sleep-related symptoms and polysomnographic features of patients with AIE and the long-term outcomes in these patients in a multi-center, prospective study from Turkey. METHODS: We prospectively evaluated patients with definite AIE in a common database including demographics, AIE-related and sleep-related symptomatology. Maximum and latest modified Rankin scores (mRS) and Liverpool Outcome Score (LOS) were noted. RESULTS: Of 142 patients, 87 patients (61.3%) fulfilled the criteria for definite AIE (mean age, 46.8+18.8 years; 51.7% women; mean disease duration, 21.0+38.4 months). 78.9% of patients had at least one or more new onset or worsened sleep-related symptomatology: insomnia (55.3%), excessive daytime sleepiness (EDS, 28.0%), sleep apnea (18.7%), REM sleep behavior disorder (RBD, 17.3%), restless legs syndrome (10.7%) and oneiric stupor (9.3%). Sleep efficiency, N3 and REM sleep were decreased and N1 sleep was increased in patients with Ab[+] AIE. LOS points were highest in those with insomnia and sleep apnea, and lowest in those with EDS, RBD and oneiric stupor. RBD and sleep apnea were more common in anti-LG1 Ab[+] group than anti-NMDAR Ab[+] group. Index of periodic leg movements was highest in anti-LG1 Ab[+] group. Patients with EDS and oneiric stupor had more common memory problems. Maximum and latest mRS scores were positively correlated with EDS and oneiric stupor. EDS, RBD and oneiric stupor were negatively correlated with LOS points. CONCLUSION: Our study emphasizes the presence and importance of early diagnosis of sleep disturbances in AIE in regard to their deteriorative influences on disease prognosis.

Recovery function of somatosensory evoked potentials in juvenile myoclonic epilepsy.

Objective: We analysed the recovery function of somatosensory evoked potentials (SEPs) in juvenile myoclonic epilepsy (JME) patients. We hypothesized that there may be disinhibition in the recovery of SEPs at 20-100 ms intervals in JME patients. Methods: We recorded SEPs and SEP recovery in 19 consecutive patients with JME admitted for a routine follow-up examination, and in a control group composed of 13 healthy subjects who were similar to the patient group regarding age and sex. The recovery function of SEPs was examined using paired stimuli at 30, 40, 60, and 100 ms intervals. Results: The amplitudes of N20-P25 and P25-N33 components were higher in patients with JME. Ten patients had high-amplitude SEPs. By paired stimulation, there was inhibition of SEPs in both groups. The mean recovery percentages of N20-P25 and P25-N33 components at 30, 40, 60, and 100 ms were not different between healthy subjects and patients with JME. Conclusions: The recovery function of SEP is normal in JME even in the presence of high-amplitude SEPs.

Improved decision-making and psychophysiological responses in mesial temporal lobe epilepsy after anterior temporal lobectomy.

The somatic marker hypothesis is an influential model of human decision-making postulating that somatic feedback to the brain enhances decision-making in ambiguous circumstances, i.e. when the probabilities of various outcomes are unknown. The somatic feedback can be measured as autonomic responses, which are regulated by the amygdala. The failure to evoke this somatic feedback, which occurs in patients with amygdala lesions, impairs decision-making. The purpose of this study was to investigate the decision-making behaviour of mesial temporal lobe epilepsy patients with pre- and post-epilepsy surgery to ascertain whether the decision-making abilities of groups can be explained by means of the generation of somatic feedback responses. The preoperative group comprised 32 patients with mesial temporal lobe epilepsy due to hippocampal sclerosis, while the postoperative group comprised 23 patients who had undergone anterior temporal lobectomy. The age and gender-matched control group consisted of 30 healthy participants. Decision-making performances were assessed and skin resistance responses were measured simultaneously. The findings of this study reveal that the decision-making performance of preoperative patients with unilateral mesial temporal lobe epilepsy was impaired under conditions of ambiguity, i.e. they did not generate somatic feedback responses before making decisions around ambiguous outcomes, and produced significantly poor scores overall based on a decision-making task. In addition, the resection of epileptogenic limbic structures positively affected the generation of somatic feedback responses, as demonstrated by the significant difference between the magnitudes of autonomic responses of the pre- and post-operative groups. The findings of the study validate the contribution of mesial temporal lobe structures to decision-making behaviour, and also point to the importance of examining the connectivity patterns between the neural structures involved in the decision-making network.

Compatibility of MRI and FDG-PET findings with histopathological results in patients with focal cortical dysplasia.

PURPOSE: The present study aimed to determine if the specific characteristics of fluorodeoxyglucose-positron emission tomography (FDG-PET) analyses of the FCD subgroups were compatible with the magnetic resonance imaging (MRI) and clinical findings of the patients in these subgroups. METHODS: This study included 71 patients who had a presurgical evaluation workup performed due to drug-resistant seizures, who underwent epilepsy surgery, and who were histopathologically diagnosed with FCD. Relationships involving MRI and FDG-PET findings and clinical data from pathological subgroups and patients were assessed. RESULTS: According to the International League Against Epilepsy (ILAE) classifications of FCD, 28 of the patients were type I and 43 were type II. FCD was visible on the MRI scans of 53 patients, and a majority of this group was classified as type II FCD (n=34). Of these 53 patients, FCD was located in the temporal area of 21 patients, the extratemporal area of 29 patients. Of the patients who exhibited FDG-PET hypometabolism (PET-positive), 23 were classified as temporal, 17 as frontal, 11 showed involvement of the posterior cortex. The age of seizure onset was younger in PET-positive patients (p=0.032), and histopathological analyses revealed that 23 patients had type I FCD and 30 patients had type II FCD. CONCLUSION: PET scans reveal a lesion by showing hypometabolism in patients who have refractory epilepsy and an early age of onset with FCD. The lesions of MRI-negative/PET-positive FCD patients tend to be localized in the temporal lobe and that FCD may be localized in the frontal lobe of MRI-negative/PET-negative patients. However, the histopathological examinations of MRI-positive/PET-positive, MRI-negative/PET-positive, and MRI-negative/PET-negative patients did not exhibit a particular histopathological subtype.

Epilepsy Surgery in Children with Lesional Partial Epilepsies.

AIM: Surgery for epilepsy is a significant treatment alternative with favorable outcomes in the pediatric age group. In this study we present the surgical outcomes of pediatric population referred to our center. MATERIAL AND METHODS: The clinical data of 126 patients (≤18 years) with lesional partial epilepsies operated in our center between 1995- 2011 were evaluated retrospectively. Parameters investigated were gender, age at seizure onset, duration of epilepsy, etiology, type and location of operation and outcome. Seizure outcome was classified according to Engel's classification. RESULTS: The study group consisted of 70 males (55,6%) and 56 females (44.4%). The most common etiology was malformation of cortical development followed by tumors and hippocampal sclerosis. Overall 73.8% of patients had Engel I, 13.5% Engel II and 11.9% Engel III+IV postoperative seizure outcome. CONCLUSION: The results of our pediatric patients who underwent surgery were similar to previous reports in the literature. The seriousness of the clinical picture should tempt physicians to refer the patients as soon as possible to avoid long term complications like epileptic encephalopathies and the side effects of antiepileptic drugs during the development of the young brains.

Enhanced blink reflex recovery in juvenile myoclonic epilepsy.

Juvenile myoclonic epilepsy (JME), which has been attributed to the dysfunction of cortico-thalamic pathway, has been considered to be one of the system epilepsies. However, electrophysiological and functional neuroimaging techniques have revealed the functional involvement of various parts of the central nervous system, also. Here, we aimed to analyze the role of brainstem circuits in JME by using the blink reflex recovery cycle (BRrc). Electrophysiological recordings of 18 JME patients together with age and gender matched 18 healthy subjects were made during single and paired supraorbital stimulation. Constant current paired stimuli were delivered at interstimulus intervals (ISI) of 200 and 400ms. Amplitudes of R2 responses were measured on the non-dominant side, and percentages of the recovery cycles were calculated. All participants had normal and similar R1 and R2 components of blink reflex (BR). At ISI of 400ms, R2 recoveries were significantly higher in the JME group compared to healthy subjects (p=0.040). There was no correlation between R2-BRrc and ages of JME patients, disease duration and daily dosage of valproic acid. We suggest that in JME, the integrity of BR circuit is preserved while the excitability of the brainstem BR circuitry is enhanced.

Presentation of an unusual patient with Lafora disease.

Lafora disease is a rare, fatal, autosomal recessive progressive myoclonic epilepsy. The condition is characterised by seizures, myoclonus and dementia. In this case report, a patient who presented with generalised tonic-clonic seizures at the age of 30 is discussed. Until the age of 48, the patient did not have myoclonic jerks or ataxia clinically, but had well controlled seizures. He developed dementia and late extrapyramidal signs. Axillary skin biopsy revealed typical Lafora inclusion bodies. Genetic analysis showed a mutation in the EMP2B gene. To our knowledge, this is the first description of a patient suffering from a Lafora disease without disabling myoclonus and ataxia but rather rare seizures, extrapyramidal signs, and dementia.

No effects of the gonadal hormones on photoparoxysmal EEG responses in idiopathic generalised epilepsy.

PURPOSE: It is accepted that the estradiol hormone is proconvulsant and progesterone is anti-convulsant. In this study the effects of gonadal hormones on photoparoxysmal responses on EEG in idiopathic generalised epilepsy were researched. METHOD: Twenty-two women with photosensitive idiopathic generalised epilepsy having regular menstrual cycles were recruited into the study. Patients presenting photoparoxysmal responses were selected from routine EEG recordings. Blood samples were taken on day 14 (E) and 25 (P) of the menstrual cycle to confirm E and P peaks. An EEG recording was performed for each patient on E and P days. RESULT: No statistically significant differences were monitored with respect to frequency, duration of the photoparoxysmal responses on E and P peaks days (p>0.05). COMMENT: In this study no correlation could be demonstrated among menstrual cycle and photoparoxysmal responses.

Visual field defects in selective amygdalohippocampectomy for hippocampal sclerosis: the fate of Meyer's loop during the transsylvian approach to the temporal horn.

OBJECTIVE: Meyer's loop, the most vulnerable part of the optic radiations during approaches to the temporomedial region, extends to the tip of the temporal horn and is often encountered in epilepsy surgery. The risk of damaging Meyer's loop during transsylvian selective amygdalohippocampectomy peaks while accessing the temporal horn through its roof by opening the inferior limiting sulcus of the insula. In this prospective study, we sought to evaluate and identify the incidence of visual field deficits in a homogeneous group of patients who had temporal lobe epilepsy with hippocampal sclerosis and who underwent transsylvian selective amygdalohippocampectomy. METHODS: We studied 30 patients who were referred for epilepsy surgery for intractable complex partial and/or secondary generalized seizures and evaluated according to a noninvasive protocol. All patients underwent selective amygdalohippocampectomy for temporal lobe epilepsy with hippocampal sclerosis using the standard transsylvian approach. Visual field deficits were examined preoperatively in 30 patients, by either a confrontation method (n = 18) or standard Goldmann perimetry (n = 12) and postoperatively in all patients using standard Humphrey digital perimetry. RESULTS: Visual field examination was normal in all patients before surgery. Humphrey perimetric measurement revealed visual field deficits in 11 patients (36.6%) after surgery. CONCLUSION: We have shown that there is a considerable risk of having visual field deficits after standard transsylvian selective amygdalohippocampectomy owing to the interruption of the anterior bundle of the optic radiation fibers, which most likely occurs while opening the temporal horn through the inferior limiting sulcus of the insula.