Excessively elevated C-reactive protein after surgery for temporal lobe epilepsy

Objective

We present a series of 87 patients who underwent anteromesial temporal lobe resections for therapy refractory temporal lobe epilepsy. In addition to seizure outcome, we observed excessively elevated CRP-levels in this patient population.

Methods

We followed 87 patients (m = 39, f = 48; mean age 33.73 ± 12.92, range 5–67 years) who underwent surgery between July 2003 and November 2011. Seizure outcome was classified in all patients according to the ILAE-classification by Wieser et al. (mean follow-up: 38.72 months). CRP levels were measured in 59 patients of the epilepsy surgery group and in a control group of 44 consecutive patients with supratentorial tumors (22 glioblastomas, 22 meningiomas).

Results

Clinical benefit was seen in 96.6% of the patients (ILAE classes 1–4), 80.5% were completely seizure free (ILAE class 1). Post-OP CRP values were significantly higher in the epilepsy group (n = 59; mean CRP peak value: 100.86 mg/l, range: 16–258 mg/l) compared to the control group (n = 44; mean CRP peak value: 36.85 mg/l, range: 0.4–233 mg/l) (p < 0.001), but the correlation of mean CRP value and mean temperature peak is weak (r = 0.31).

Conclusions

Seizure outcome after surgery for temporal lobe epilepsy was excellent, CRP levels were excessively elevated in these patients in the absence of clinical infection and significantly higher compared to resections of supratentorial lesions.     

Inter-ictal spike detection using a database of smart templates

Objective

Visual analysis of EEG is time consuming and suffers from inter-observer variability. Assisted automated analysis helps by summarizing key aspects for the reviewer and providing consistent feedback. Our objective is to design an accurate and robust system for the detection of inter-ictal epileptiform discharges (IEDs) in scalp EEG.

Methods

IED Templates are extracted from the raw data of an EEG training set. By construction, the templates are given the ability to learn by searching for other IEDs within the training set using a time-shifted correlation. True and false detections are remembered and classifiers are trained for improving future predictions. During detection, trained templates search for IEDs in the new EEG. Overlapping detections from all templates are grouped and form one IED. Certainty values are added based on the reliability of the templates involved.

Results

For evaluation, 2160 templates were used on an evaluation dataset of 15 continuous recordings containing 241 IEDs (0.79/min). Sensitivities up to 0.99 (7.24 fp/min) were reached. To reduce false detections, higher certainty thresholds led to a mean sensitivity of 0.90 with 2.36 fp/min.

Conclusion

By using many templates, this technique is less vulnerable to variations in spike morphology. A certainty value for each detection allows the system to present findings in a more efficient manner and simplifies the review process.

Significance

Automated spike detection can assist in visual interpretation of the EEG which may lead to faster review times.     

Slow spindles’ cortical generators overlap with the epileptogenic zone in temporal epileptic patients: An electrical source imaging study

Objective

To determine whether temporal epileptic patients and normal volunteers display similar sleep spindles’ cortical generators as determined by electrical source imaging (ESI), and whether such generators overlap in epilepsy patients with the epileptogenic zone identified by ESI.

Methods

Twelve healthy subjects and twelve temporal lobe pharmaco-resistant epileptic patients underwent a 256-channel EEG recording during a daytime nap. Sleep spindles were analyzed off line, distinguishing slow (10–12 Hz) and fast (12–14 Hz) ones, and the final averaged signal was projected onto a MNI (Montreal Neurological Institute) space to localize cortical generators. The same procedure was performed for averaged epileptic spikes, obtaining their cortical source. Intra- and inter-group statistical analyses were conducted.

Results

Multiple, concomitant generators were detected in both populations for slow and fast spindles. Slow spindles in epileptics displayed higher source amplitude in comparison to healthy volunteers (Z = 0.001), as well as a preferential localization over the affected temporal cortices (p = 0.039). Interestingly, at least one of slow spindles’ generators overlapped with the epileptogenic zone.

Conclusion

Slow spindles, but not fast ones, in temporal epilepsy are mainly generated by the affected temporal lobe.

Significance

These results point to the strict relation between sleep and epilepsy and to the possible cognitive implications of spikes arising from memory-encoding brain structures.     

Is interictal EEG activity a biomarker for mood disorders in temporal lobe epilepsy?

Objective

Psychiatric comorbidities are frequent in temporal lobe epilepsy (TLE), and symptoms of these comorbidities may be related to epilepsy activity. Here we evaluated interictal EEG activity in TLE patients with or without psychiatric comorbidities.

Methods

A cohort study of 78 patients with TLE, with evaluation of wake/sleep interictal scalp EEG. All subjects were submitted to a psychiatric structured clinical interview (SCID) for the diagnosis of lifetime psychiatric comorbidities. Three major diagnostic categories were studied: mood disorders, anxiety disorders, and psychosis. We then evaluated differences in interictal EEG activity between patients with and without these psychiatric comorbidities.

Results

Infrequent EEG interictal spikes, defined as less than one event per minute, were significantly associated with mood disorders in TLE (p = 0.02).

Conclusions

Low intensity seizure disorder has been associated with a decrease in interictal EEG discharges and with an increase in psychiatric symptoms in TLE, a phenomenon known as forced normalization. In our study, we observed a low interictal spike frequency on EEG in TLE patients with mood disorders.

Significance

A low spike index might be a neurophysiological marker for depression in temporal lobe epilepsy.     

Consideration of epilepsy surgery in adults should be independent of age

Objectives

Epilepsy surgery is performed less frequently in persons over 45 years of age than in younger individuals, probably reflecting biases among patients, referring physicians and neurologists.

Methods

We report on a clinically heterogenous cohort of patients aged 45 years or older who underwent epilepsy surgery for medically intractable epilepsy.

Results

Over a 15-year period, 42 patients with a mean duration of epilepsy of 27.3 years underwent elective surgery. The mean follow-up period was 48 months. Thirty-two patients had an Engel class I outcome, of which 23 were totally seizure-free (Ia). Six patients had a class II outcome (rare disabling seizures), one had a class III outcome (worthwhile improvement), and three had a class IV outcome (no worthwhile improvement). The majority of patients reported an improved quality of life and satisfaction with the epilepsy surgery. A subjective improvement in cognition was reported in 7 patients while a decline was reported in 10 patients. New neuropsychiatric difficulties were reported in three patients while three patients reported improved anxiety after surgery. Only one patient became newly employed after surgery while 23 returned to driving. Permanent complications occurred in four patients (thalamic infarct during a Wada test (n = 1) and asymptomatic visual field defect (n = 3)).

Conclusions

We report a favorable outcome from epilepsy surgery in a large series of older adults and conclude that age per se is not a contraindication to epilepsy surgery. We emphasize the lack of correlation between outcome from surgery and pre-operative duration of epilepsy.     

Seizure outcomes of lesionectomy in pediatric lesional epilepsy with brain tumor – Single institute experience

Purpose

To determine the clinical characteristics, surgical strategy, and outcome in pediatric lesional epilepsy patients younger than 5 years of age undergoing surgery in a single institute.

Method

Retrospective data were collected and analyzed on patients younger than 5 years of age who underwent lesionectomy for lesional epilepsy at single institute from January 2001 to August 2010. Fourteen pediatric lesional epilepsy patients were enrolled in this study. Engel classification was used to classify seizure outcome.

Results

Median preoperative seizure period was 1 month (range, 1–21). Median post-operative follow up period was 35 months (range 13–84). Ten patients who underwent gross total resection of tumor showed Engel class Ia seizure outcome without any antiepileptic drug (AED). Subtotal resection was performed in four patients to avoid eloquent area injury. Two of these four patients with subtotal removal became seizure-free (Engel class Ia) without AED, while two were in Engel class Ib with AED medication. There was no significant surgical morbidity or mortality.

Conclusion

Lesionectomy in children younger than 5 years of age is relatively safe and effective in controlling seizures. Short preoperative seizure periods and total removal of tumor might be associated with good outcome. Therefore, early and complete lesionectomy alone may help allow for seizure freedom and optimal brain development in pediatric patients.     

Seizure control and side-effect profile after switching adult epileptic patients from standard to extended-release divalproex sodium

Objectives

To assess changes in seizure frequency, medication side-effects (especially tremor) and formulation preference after switching patients overnight from immediate-release to extended-release divalproex sodium.

Methods

Prospective evaluation of consecutive adult outpatients at an urban public hospital who were followed for 6 months after switching drug formulations. Seizure frequency was estimated from patient self-reports. Medication side-effects were monitored with a structured interview (tremor, fatigue, GI upset, hair loss), physician exam (nystagmus, tremor), a drawing test (tremor) and a specific 25-item questionnaire assessing the impact of tremor on activities of daily living.

Results

Forty-seven patients were included in the study but six patients were either lost to follow-up or had insufficient data. Seizure frequency and side-effect profile did not change significantly after switching drug formulations. However, patients had significant subjective improvement in their tremor with the extended-release formulation as assessed by the 25-item questionnaire (p = 0.009 at 3 months and p = 0.04 at 6 months); other measures of tremor severity showed no change during the 6-month follow-up period. Most patients (71%) preferred the extended-release formulation.

Conclusion

Patients with epilepsy can be switched overnight from standard to extended-release divalproex sodium, without significant change in seizure frequency and drug side-effect profile. Most patients prefer the extended-release formulation, in part due to subjective decrease in tremor during daily activities.     

Usefulness of a simple sleep-deprived EEG protocol for epilepsy diagnosis in de novo subjects

Objective

In case series concerning the role of EEG after sleep deprivation (SD-EEG) in epilepsy, patients’ features and protocols vary dramatically from one report to another. In this study, we assessed the usefulness of a simple SD-EEG method in well characterized patients.

Methods

Among the 963 adult subjects submitted to SD-EEG at our Center, in the period 2003–2010, we retrospectively selected for analysis only those: (1) evaluated for suspected epileptic seizures; (2) with a normal/non-specific baseline EEG; (3) still drug-free at the time of SD-EEG; (4) with an MRI analysis; (5) with at least 1 year follow-up. SD-EEG consisted in SD from 2:00 AM and laboratory EEG from 8:00 AM to 10:30 AM. We analyzed epileptic interictal abnormalities (IIAs) and their correlations with patients’ features.

Results

Epilepsy was confirmed in 131 patients. SD-EEG showed IIAs in 41.2% of all patients with epilepsy, and a 91.1% specificity for epilepsy diagnosis; IIAs types observed during SD-EEG are different in generalized versus focal epilepsies; for focal epilepsies, the IIAs yield in SD-EEG is higher than in second routine EEG.

Conclusions

This simple SD-EEG protocol is very useful in de novo patients with suspected seizures.

Significance

This study sheds new light on the role of SD-EEG in specific epilepsy populations.     

Surgery for perirolandic epilepsy: Epileptogenic cortex resection guided by chronic intracranial electroencephalography and electric cortical stimulation mapping

Subject

The objective of this study was to assess outcome with regard to seizure status and neurological function in patients undergoing resective surgery involving the perirolandic area.

Method

All 15 patients who underwent perirolandic cortical resection between October 2006 and September 2007 at the Comprehensive Epilepsy Centre of Beijing Xuanwu Hospital were included in the study. The locations of functional cortical areas, ictal onset zones and epileptogenic lesions were mapped by chronic intracranial EEG recordings and electric cortical stimulation. Seizure outcome was determined using the modified classification of Engel and colleagues. Motor and sensory deficits were monitored.

Results

At last follow-up 5 patients (33%) were in Engel class I, 4 (27%) were in class II, 3 (20%) were in class III, and 3 (20%) were in class IV. Nine patients suffered immediate functional deficits; 8 of these recovered completely within 2 weeks to 3 months of surgery. One had mild persistent loss of finger motor control.

Conclusion

After accurate presurgical evaluation using invasive recordings and functional brain mapping, epileptogenic cortical resection can give excellent results and few deficits in patients with perirolandic epilepsy.     

Sleep and psychological health during early recovery from critical illness: An observational study

Introduction

Intensive care patients often report sleep disruption in ICU and during recovery from critical illness.

Objectives

To assess: (i) patients' self-reported sleep quality in ICU, on the hospital ward after transfer from ICU and two and six months after hospital discharge; (ii) whether patients who report sleep disruption in ICU continue to report sleep disruption in recovery and (iii) whether prehospital insomnia, experiences in intensive care, quality of life and psychological health are associated with sleep disruption six months after hospital discharge.

Methods

Patients completed self-report measures on sleep quality at five time points: prior to hospitalization, in ICU, the hospital ward, two months and six months after hospital discharge, their intensive care experiences two months after discharge and psychological health and quality of life six months after discharge.

Results

Patients (n = 222) were aged (mean ± SD) 57.2 ± 17.2 years, 35% female, had mean ICU stay of 5 ± 6 days and BMI of 26 ± 5. Over half the participants (57%) reported poor sleep at six months; for 10% this was at all time points after ICU admission. Prehospitalization insomnia (p = .0005), sleep quality on the ward (p = .006), anxiety (p = .002), and mental (p = .0005) and physical health (p = .0005) were independently associated with poorer sleep quality in survivors six months after ICU treatment.

Conclusions

Sleep is a significant issue for more than half of survivors 6 months after ICU treatment. Some influencing factors, such as hospital sleep quality, anxiety, physical health and mental health, are potentially modifiable and should be targeted in recovery programs.     

Very high frequency oscillations (over 1000 Hz) in human epilepsy

Objective

High frequency oscillations (HFO) of 100–500 Hz have been reported in epileptic human brain. However, the questions of how fast these oscillations can reach, and which frequency range is clinically important remain unanswered. We recorded interictal and ictal very high frequency oscillations (VHFO) of 1000–2500 Hz by subdural electrodes using 10 kHz sampling rate. We describe the characteristics of VHFO, and discuss their underlying mechanism and clinical significance.

Methods

Five patients with neocortical epilepsy were studied. All patients underwent intracranial EEG monitoring with subdural electrodes. EEG recording with sampling rate of 10 kHz was conducted. Histopathology revealed malformation of cortical development in all cases.

Results

In four of five patients, very high frequency activities of 1000–2500 Hz were detected in highly localized cortical regions (one to four electrodes in individual patient). We named these activities “very high frequency oscillations (VHFO)”. Interictally, VHFO appeared intermittently, and were interrupted by spikes. Sustained VHFO without spikes appeared around the start of seizures.

Conclusions

Both interictal and ictal VHFO can be recorded by subdural electrodes. Compared to HFO previously reported, VHFO have much higher frequency, more restricted distribution, smaller amplitude, and different timing of onset.

Significance

Recording of VHFO may be useful for identifying the epileptogenic zone.     

Optimal timing and differential significance of postoperative awake and sleep EEG to predict seizure outcome after temporal lobectomy

Objective

To evaluate the prognostic value of postoperative EEGs to estimate post anterior temporal lobectomy (ATL) seizure outcome.

Significance of triphasic waves in patients with acute encephalopathy: A nine-year cohort study

Objective

Triphasic waves (TWs) are a frequent electroencephalography (EEG) finding in encephalopathy, yet their origin and prognostic significance are not well understood. The aim of this study was to determine the clinical and EEG characteristics in encephalopathic patients with TWs. We hypothesized that specific EEG characteristics are predictive of outcome.

Methods

Consecutive adult encephalopathic patients with TWs on EEG and neuroimaging were included. EEG analysis included semiquantitative evaluation of TWs, background activity, and EEG reactivity. The study endpoint was death.

Results

Over a nine-year period, 105 patients with TWs were included. Common abnormalities on neuroimaging were white matter lesions (60%) and cerebral atrophy (59%). Pathologic conditions included infections (56%), renal (50%) and liver insufficiency (12%), and respiratory failure (20%). Mortality was 20%. Absent EEG background reactivity and respiratory failure were independently associated with death (OR 3.73, 95%CI 1.08–12.80, p = 0.037 and OR 6.47, 95%CI 1.98–21.12, p = 0.02).

Conclusions

These results suggest that TWs are a marker of structural brain disease coupled with toxic-metabolic perturbations, and that etiologies or underlying pathologies were not predictive for outcome while non-reactive EEG was independently associated with death.

Significance

In contrast to clinical, EEG and neuroimaging findings, non-reactive EEG patterns predicted death in encephalopathic patients with TWs.     

Outcome of lesionectomy in medically refractory epilepsy due to non-mesial temporal sclerosis (non-MTS) lesions

Objectives

To analyze the seizure outcome of lesionectomy for refractory epilepsy secondary to non-mesial temporal sclerosis (non-MTS) lesions.

Methods

Sixty-eight patients with non-MTS lesions (M:F = 42:26; age at onset: 11.7 ± 9.6 years; age at surgery: 21.1 ± 9.4 years), who underwent lesionectomy for refractory epilepsy were analyzed. The age at onset, frequency/type of seizure, MRI findings, video-EEG, histopathology and Engel's grading at 1 year/last follow up were recorded.

Results

The duration of epilepsy at surgery was 9.9 ± 6.9 years. The location of lesions were: temporal: 41 (60.3%); frontal: 21 (30.9%); parietal: 6 (8.8%). The type of lesionectomies performed were temporal 41 (60.3%), extra-temporal: 25 (36.8%), temporo-frontal and temporo-parietal: 1 (1.5%) patient each. The histopathological diagnosis were neoplastic: 32 (47.1%), cortical dysplasia: 19 (27.9%), other focal lesions: 17 (25%). At mean follow up of 2.9 ± 2.1 years (median: 2.6 years), outcome was – Engel's class I: 43 (63.2%), IIa: 14 (20.6%), III: 7 (10.3%), IV: 4 (5.9%). Good seizure control (Engel's class I/IIa) was achieved in 57 (83.8%) patients. The good prognostic markers included temporal seizures, extended lesionectomy and AEDs after surgery while poor prognostic marker was gliotic lesion on histopathology.

Conclusion

Following lesionectomy due to non-MTS lesions, seizure freedom (Engel I) was noted in about 63.2% of patients, which is comparable to other series and reiterates the effectiveness of lesionectomy for seizure control.     

The EEG response to photic stimulation is not increased in alcohol-related seizures

Objective

To investigate the occipital EEG response to 18 and 24 Hz photic stimulation (the H-response) in alcohol-related seizures (ARS).

Method

Twenty-two ARS patients, 15 of whom had a withdrawal seizure (WS) were compared with patients with recent seizures of other causes: 21 patients with epilepsy, and 30 Alcohol Use Disorders Identification Test (AUDIT) negative patients with other seizures. EEG from 37 out-patients with epilepsy and 79 sciatica patents served as patient-controls. The spectral amplitude around 18 and 24 Hz and a new photic H-ratio (24/18 Hz relative amplitude) was calculated.

Results

The H-ratio was significantly reduced in the ARS group compared to the sciatica group. H-ratio reduction correlated with the AUDIT score in ARS patients (p = 0.02). No differences between WS and non-WS patients were found for H-response variables.

Conclusion

A dose–response relationship between AUDIT and the photic response H-ratio was observed in ARS patients. The EEG-driving response to 24 Hz flashes was not increased in ARS.

Significance

The relative decrease in 24 Hz photic response in ARS reflected drinking severity. The H-ratio is a candidate biomarker for ARS on the group level, although the moderate effect size precludes its use in individual patients.     

Epilepsy in children with periventricular leukomalacia

Objective

We aimed to analyze the development of epilepsy in a patient group with periventricular leukomalacia followed at a tertiary pediatric neurology center.

Patients and methods

The study included 108 children aged between 2 and 8 years with radiologically proven periventricular leukomalacia who had been regularly observed at the Istanbul University, Istanbul Faculty of Medicine, Department of Pediatrics, Pediatric Neurology outpatient clinic between January 2006 and December 2011.

Results

Neonatal seizures were reported in 22 patients (20.3%), 14 of whom developed epilepsy. A significant correlation was found between neonatal seizures and prematurity and newborn asphyxia (p = 0.013 and p = 0.010, respectively). Epilepsy developed in 35 patients (32.4%), history of neonatal seizures and more severe loss of white matter, periventricular hyperintensity and corpus callosum involvement were found to be correlated with epilepsy (p = 0.001, p = 0.004, p = 0.016, and p = 0.004, respectively). The most common seizure pattern observed was generalized tonic clonic seizures (n = 13) and complex partial seizures (n = 11). Those with focal EEG findings had a significantly better neurodevelopmental and cognitive level than those with multifocal/generalized EEG findings (p = 0.024). Seizures continued with varying frequency in 14 epileptic patients (40%) despite antiepileptic treatment.

Conclusion

Almost a third of patients with periventricular leukomalacia develop epilepsy that can be intractable in substantial part. Neonatal seizures and severe MRI findings are important clues that can indicate the development of epilepsy in these patients.     

Uncovered primary seizure foci in Lennox-Gastaut syndrome after corpus callosotomy

Purpose

Corpus callosotomy (CC) is a palliative surgical procedure to control atonic, tonic, or generalized tonic-clonic seizure in Lennox-Gastaut syndrome (LGS). Here, we report patients with LGS who underwent resective surgery, following CC better delineating the presumed seizure foci localized in one hemisphere.

Methods

We retrospectively reviewed seven patients with LGS who underwent CC and subsequent cortical resection. The median follow-up duration after lobectomy was 20 months (range, 15-54 months) and three patients had follow-up periods over 24 months. The findings of video electroencephalography (EEG) monitoring, structural and functional neuroimagings were compared between pre- and post-CC.

Results

Four patients had Engel class I and one patient had Engel class II outcomes following cortical resection; post-CC, compared to pre-CC, showed better localized ictal/interictal epileptiform discharges in the unilateral frontal area in two patients, in the unilateral parieto-temporo-occipital areas in one patient and in the unilateral fronto-temporal areas in the remaining two patients. Two patients had Engel Class III outcome following cortical resection; post-CC EEG continued to show multifocal epileptiform discharges but predominantly arising from a unilateral frontal area. Following CC, positron emission tomography showed localized glucose hypometabolism of which location was concordant with post-CC EEG abnormalities in all patient. Similarly, ictal/interictal single photon emission computed tomography also showed localized abnormalities concordant with post-CC EEG abnormalities in five of the six patients. Pathological assessment revealed cortical dysplasia in six patients, whereas no pathological abnormality was found in the remaining patient, who obtained Engel Class I outcome following cortical resection.

Conclusion

CC could change EEG findings, glucose metabolisms and cerebral blood flows, and it is sometimes helpful in delineating the primary seizure focus in patients with LGS.     

Outcome and complications of chronically implanted subdural electrodes for the treatment of medically resistant epilepsy

Background

Surgery for medically resistant epilepsy is safe and effective. However, when noninvasive techniques are insufficient, then consideration is given to invasive electrocorticography (EcoG).

Objective

The aim of the study was to analyze results and complications of subdural electrodes placement in the treatment of intractable epilepsy.

Methods

Ninety-one consecutive patients who underwent placement of subdural electrodes (1999-2010) were considered for this study. All patients underwent a standardized pre-operative evaluation. Invasive subdural electrode placement was considered when there were inadequate ictal recordings, there was discordance between EEG and neuroimaging or the epileptogenic zone was localized near eloquent cortex.

Results

Resective epilepsy surgery was performed in 70/91 patients (76.9%). Twenty-four out of seventy (34.3%) who underwent surgical resection were seizure-free (CL-I) at last follow-up. A statistical evaluation revealed a very strong trend for patients with positive lesional pre-operative MRI to have improved outcomes compared to normal brain MRI population (p = .028). There were 10 surgical related complications (11%), but no mortality or permanent morbidity. Statistical analysis demonstrated that placement of a subdural grid in any combination was statistically significant (p = .01) for surgical complications.

Conclusions

Invasive monitoring is a useful and necessary technique for the surgical treatment of intractable epilepsy. Careful surveillance is required during the monitoring period especially when the patient has undergone large subdural grid placement. A good working hypothesis can minimize complications and achieve better outcomes.     

Reduced fronto-cortical brain connectivity during NREM sleep in Asperger syndrome: An EEG spectral and phase coherence study

Objective

To investigate whether sleep macrostructure and EEG power spectral density and coherence during NREM sleep are different in Asperger syndrome (AS) compared to typically developing children and adolescents.

Methods

Standard all night EEG sleep parameters were obtained from 18 un-medicated subjects with AS and 14 controls (age range: 7.5–21.5 years) after one adaptation night. Spectral, and phase coherence measures were computed for multiple frequency bands during NREM sleep.

Results

Sleep latency and wake after sleep onset were increased in AS. Absolute power spectrum density (PSD) was significantly reduced in AS in the alpha, sigma, beta and gamma bands and in all 10 EEG derivations. Relative PSD showed a significant increase in delta and a decrease in the sigma band for frontal, and in beta for centro-temporal derivations. Intrahemispheric coherence measures were markedly lower in AS in the frontal areas, and the right hemisphere over all EEG channels. The most prominent reduction in intrahemispheric coherence was observed over the fronto-central areas in delta, theta, alpha and sigma EEG frequency bands.

Conclusion

EEG power spectra and coherence during NREM sleep, in particular in fronto-cortical derivations are different in AS compared to typically developing children and adolescents.

Significance

Quantitative analysis of the EEG during NREM sleep supports the hypothesis of frontal dysfunction in AS.