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Objective To characterize photoparoxysmal EEG response (PPR) using a standardized protocol of intermittent photic stimulation (IPS) and standardized definitions for PPR, classified into six types. Methods Using the SCORE system (Standardized Computer-Based Organized Reporting of EEG) we prospectively built a large database of standardized EEG annotations. In this study, we extracted the features related to PPR from the structured dataset consisting of 10,671 EEG recordings with IPS, from 7,188 patients. Results The standardized IPS protocol elicited PPR in 375 recordings (3.5%), in 288 patients (4%), with a preponderance among young (11–20 years) and female patients (67%). PPR was persistent in patients with multiple recordings. The most frequent type of PPR was activation of preexisting epileptogenic area (58%), followed by generalized-PPR limited to the stimulus train (22%). We could not find any recording with self-sustained posterior response. Seizures were elicited in 27% of patients with PPR, most often myoclonic seizures and absences, in patients with self-sustained generalized PPR. Conclusions The most common type of PPR was accentuation of preexisting epileptogenic area. Self-sustained posterior response could not be documented. Self-sustained generalized-PPR had the highest association with seizures. Significance Using standardized stimulation protocol and definitions for PPR types, IPS provides high diagnostic yield.

OBJECTIVE: To investigate whether Posterior Dominant Rhythm (PDR) can be reliably assessed in sleep-EEG recordings and to investigate the diagnostic yield of standard-wake and sleep-recordings.METHODS: EEG recordings of 303 consecutive patients aged 18-88 years were analyzed. All patients had both standard-wake and sleep-recordings, including patients who had abnormal standard recordings. Melatonin was used in 6% of sleep EEGs, and sleep deprivation in 94%. The mean duration of sleep was 41 min. We measured the PDR frequency in standard and sleep-recordings, both before and after sleep. We compared the diagnostic yield of standard-wake and sleep EEG recordings.RESULTS: Compared to standard EEG, sleep-recordings showed a significantly lower PDR frequency, both when measured before and after sleep (p CONCLUSIONS: PDR is significantly slower in the wake periods of sleep-recordings, compared to standard wake recordings.SIGNIFICANCE: Sleep and standard wake recordings are complementary.

Purpose: To assess whether injuries occur more often in an Epilepsy Monitoring Unit (EMU) where portable EEG amplifiers are used, and where patients can freely move within a large area during the monitoring.Methods: Patients were monitored at the Danish Epilepsy Center, in an EMU specifically designed for this purpose, and they were under continuous surveillance by personnel dedicated to the EMU. Adverse events (AEs) - including injuries, were prospectively noted, as part of the safety policy of the hospital. Other data were retrospectively extracted from the electronic database, for a 5-year period (January 2012-December 2016).Results: 976 patients were admitted to the EMU. Falls occurred in 19 patients (1.9%) but none of them resulted in injury. Only one serious AE occurred: a patient had a convulsive status epilepticus, which did not respond to first-line treatment in the EMU and was transferred to the intensive care unit. The rate of AEs were similar or lower than previously reported by other centers, where the mobility of the patients had been restricted during monitoring.Conclusion: In an EMU specially designed for this,purpose, where patients are under continuous surveillance by personnel dedicated to the EMU, injuries can be avoided even when the mobility of the patients is not restricted. (C) 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

To investigate whether extending the 10-20 array with 6 electrodes in the inferior temporal chain and constructing computed montages increases the diagnostic value of ictal EEG activity originating in the temporal lobe. In addition, the accuracy of computer-assisted spectral source analysis was investigated.Forty EEG samples were reviewed by 7 EEG experts in various montages (longitudinal and transversal bipolar, common average, source derivation, source montage, current source density, and reference-free montages) using 2 electrode arrays (10-20 and the extended one). Spectral source analysis used source montage to calculate density spectral array, defining the earliest oscillatory onset. From this, phase maps were calculated for localization. The reference standard was the decision of the multidisciplinary epilepsy surgery team on the seizure onset zone. Clinical performance was compared with the double banana (longitudinal bipolar montage, 10-20 array).Adding the inferior temporal electrode chain, computed montages (reference free, common average, and source derivation), and voltage maps significantly increased the sensitivity. Phase maps had the highest sensitivity and identified ictal activity at earlier time-point than visual inspection. There was no significant difference concerning specificity.The findings advocate for the use of these digital EEG technology-derived analysis methods in clinical practice.

Purpose The aim of this study was to assess how frequently prodromes occur in an adult patient group from a tertiary referral epilepsy centre and to investigate the EEG changes during the prodromes. Methods 578 consecutive patients were interviewed on subjective phenomena, experiences heralding the seizures, for at least 30min before the start of the seizure. EEGs were recorded during the prodromes. Results Ten out of 490 included patients had prodromes (2%). We were able to record EEG during prodromes in 6 patients. Three patients had EEG changes corresponding to nonconvulsive status epilepticus. Three patients had unrevealing EEG recordings during prodromes. Conclusion Our results suggest that at least in a part of the patients, the prodromes are actually ictal phenomena, and should be treated as nonconvulsive status epilepticus.

The interictal epileptiform discharges (IEDs) consist of a fast component (FC; spike or sharp-wave) followed by a slow-wave component (SC). Our purpose was to assess the intra-individual variance, the diagnostic significance and the effect of sleep on the SC. Ninety-nine EEG recordings from 50 consecutive patients with IEDs were analysed. We measured the duration (ms) of the SC (SC-duration), while the amplitude of the SC was divided by the amplitude of the FC yielding a normalized value (SC/FC amplitude-ratio). Intra-individual, intra- and inter-recording coefficients of variation (CV) were calculated for the SC-duration and SC/FC amplitude-ratio. The correlation with the diagnosis, and the effect of sleep was analysed. The SC-duration and the SC/FC amplitude-ratio had low CV (

Background – Ketogenic diet (KD) is an effective treatment for pharmacoresistant epilepsy: more than half of the patients show a greater than 50% reduction in seizures. Objective – To identify clinical or electroencephalogram (EEG) variables predicting the response to KD. Methods – Clinical and EEG data were retrospectively analysed from 50 consecutive patients treated by KD for severe, pharmacoresistant epilepsy. Most of the patients (70%) had retarded mental and motor development. Results – Three months after the start of the KD two-thirds (33) of the patients were responders (had a more than 50% reduction in seizure frequency). The presence of epileptiform EEG discharges in the temporal region correlated with an unfavourable response (P = 0.03). The presence of bilateral synchronous epileptiform discharges, and the presence of complex partial seizures approached significance but all other variables did not. Conclusions – Our results further support that KD is efficient in a wide variety of epileptic patients with a broad range of EEG features. However, patients with epileptiform discharges in the temporal region are less likely to achieve therapeutic response.

Inpatient long-term video-EEG monitoring (LTM) is an important diagnostic tool for patients with seizures and other paroxysmal behavioural events. The main referral categories are diagnosis (epileptic versus non-epileptic disorder), seizure classification and presurgical evaluation. The diagnostic usefulness of the LTM varies considerably (19–75%) depending on how this was defined and on the selection of the patients. The purpose of this study was to assess the diagnostic usefulness and the necessary duration of the LTM for the referral groups, in patients extensively investigated before the monitoring. An LTM was considered diagnostically useful when it provided previously not reported, clinically relevant information on the paroxysmal event. For the presurgical group, reaching a decision concerning surgery was an additional requirement.We reviewed data from 234 consecutive LTM-sessions (221 patients) over a 2-year period. In 44% of the cases the LTM was diagnostically useful. There were no significant differences concerning diagnostic usefulness among the main referral groups: diagnostic (41%), classification (41%) and presurgical (55%). Diagnostic usefulness did not differ among the age groups either. The duration of the successful LTM-sessions was significantly longer in the presurgical group (mean: 3.5 days) than in the diagnostic and classification groups (2.4 and 2.3 days, respectively). We conclude that LTM is a valuable diagnostic tool even in patients extensively investigated before the monitoring, and is equally effective in the referral and age groups. However, patients referred for presurgical evaluation need considerably longer LTM, and this should be taken into account when planning the resources and calculating the costs.

The frequency distribution of different types of epilepsy (according to the classification model of the International League against Epilepsy) concerning 402 children is reported. The investigation showed a moderate preponderance of partial as against generalized epilepsies. Elemental and complex symptomatology were about equally frequent. As regards generalized epilepsies, the petit mal group was considerably smaller than most often reported previously; conversely, myoclonic-astatic epilepsy (Lennox-Gastaut's syndrome) was more frequently encountered. The definitory criteria and the concept of the Lennox-Gastaut Syndrome are discussed. 91.8 % of the whole pediatric population (age less than 15 years at time of investigation) could be categorized according to the classification model. This, in agreement with earlier investigations on this subject, shows the contemporary international classification model to be useful and relevant.

The relative frequency of different types of epilepsy in accordance with the International Classification of Epilepsies is reported, concerning 1,508 consecutive outpatients with epilepsy, who at the time of investigation were at age 15 years and above. The investigation showed a marked preponderance for partial epilepsies as against generalized epilepsies; partial epilepsies with complex symptomatology were especially frequent, contributing by more than one third of all cases.

Objectives – To study the risk of teratogenicity in infants of women with epilepsy. Material and methods – Prospective data from 1996 to 2000 comprised 147 pregnancies. The most frequent antiepileptic drugs (AEDs) used were lamotrigine (LTG) 35% (n = 51), oxcarbazepine (OXC) 25% (n = 37) and valproate (VPA) 20% (n = 30). Seventy-four per cent (n = 109) received monotherapy. Folic acid supplementation was taken during first trimester by 118 patients (80%). Results – The overall risk of malformations among newborns in the AED-exposed group was 3.1% (n = 4). Two children were born with multiple malformations (VPA monotherapy), two children had ventricular septal defects (one OXC monotherapy, and one OXC and LTG). The risk of malformations was 2.0% in women treated with LTG and 6.7% in women treated with VPA (NS). Conclusion – Despite the small number of cases in the study these data indicate that treatment with LTG during pregnancy might be relatively safe. Larger prospective studies are needed to obtain adequate power for statistical analysis.

This is the first in vivo demonstration of an association between endogenous neurotransmitter release and conscious experience. Using 11C-raclopride PET we demonstrated increased endogenous dopamine release in the ventral striatum during Yoga Nidra meditation. Yoga Nidra is characterized by a depressed level of desire for action, associated with decreased blood flow in prefrontal, cerebellar and subcortical regions, structures thought to be organized in open loops subserving executive control. In the striatum, dopamine modulates excitatory glutamatergic synapses of the projections from the frontal cortex to striatal neurons, which in turn project back to the frontal cortex via the pallidum and ventral thalamus. The present study was designed to investigate whether endogenous dopamine release increases during loss of executive control in meditation. Participants underwent two 11C-raclopride PET scans: one while attending to speech with eyes closed, and one during active meditation. The tracer competes with endogenous dopamine for access to dopamine D2 receptors predominantly found in the basal ganglia. During meditation, 11C-raclopride binding in ventral striatum decreased by 7.9%. This corresponds to a 65% increase in endogenous dopamine release. The reduced raclopride binding correlated significantly with a concomitant increase in EEG theta activity, a characteristic feature of meditation. All participants reported a decreased desire for action during meditation, along with heightened sensory imagery. The level of gratification and the depth of relaxation did not differ between the attention and meditation conditions. Here we show increased striatal dopamine release during meditation associated with the experience of reduced readiness for action. It is suggested that being in the conscious state of meditation causes a suppression of cortico-striatal glutamatergic transmission. To our knowledge this is the first time in vivo evidence has been provided for regulation of conscious states at a synaptic level.

This paper introduces a method for tracking patients under video surveillance based on a color marker system. The patients are not restricted in their movements, which requires a tracking system that can overcome non-ideal scenes e.g. occlusions, very fast movements, lighting issues and other moving objects. The suggested marker system consists of twelve unique markers that are located at each joint. By using a color marker system, each marker (if visible) can be found in every frame disregarding the possibility that it was occluded in the previous frame, compared to other tracking systems.

Background The duration of electroencephalography (EEG) recordings varies widely among laboratories. Although several recommendations had been published, there are no previous studies directly addressing this. Aims of the study To assess the effect of the recording duration on detection of EEG abnormalities in a tertiary referral centre for epilepsy. Methods We have reviewed 1005 EEG recordings and determined the shortest recording duration necessary to identify interictal EEG abnormalities. Results Standard, awake recordings shorter than 20 min yielded a significantly lower incidence of abnormal findings as compared to longer recordings. Although there was an increase in the diagnostic yield from 30 to 180 min recording duration, this failed to reach the level of significance. For sleep recordings, there was no significant increase in the diagnostic yield beyond 30 min. Conclusions Our results provide evidence for recommending at least 20 min recording duration for standard awake EEGs and 30 min for sleep EEG recordings. As data were derived from patients referred to our epilepsy centre, the results are only valid for epilepsy-related indications.

Medication withdrawal (MW) is an important method of provoking seizures and activating epileptiform EEG activity during the diagnostic work-up of patients evaluated for epilepsy surgery. Previously it was suggested that MW might influence the seizure-type and activate cortical areas otherwise not producing epileptiform discharges, leading to a false localization of the irritative zone. In order to investigate this we reviewed 42 consecutive cases of MW, of 36 patients, during a 3-year period. We compared seizure frequency, seizure-types and the localization of interictal epileptiform discharges before and after MW. Seizure frequency was significantly higher after MW. In the whole group we found an increase in seizure propagation: the proportion of the complex partial seizures and secondarily generalised seizures increased, while the proportion of the simple partial seizures decreased following MW. In one-third of the patients the interictal EEGs after the MW were different from those recorded before the MW. However, in these discordant cases the EEG findings after the MW (and not before the MW) were concordant with the seizure onset zone and the lesional zone. We conclude that MW is an effective and reliable seizure provoking method, and it does not lead to false localization of the irritative zone.

The aim of the study was to evaluate the sensitivity, specificity and the predictive values of repeated serum prolactin measurements in relation to epileptic seizures versus pseudoseizures. The method used was prospective measuring of serum prolactin from blood samples drawn (1) 15 min after seizure and (2) 2 hr after the first sample. Two parameters were used: the absolute maximal level; and the relative rise in blood level. In the study 38 had epilepsy (simple or complex partial seizures with or without secondary generalisation); and 20 had pseudo-epileptic seizures. In all cases, the diagnoses were made independent of the prolactin levels. In 30/38 (79%) of epilepsy patients and 17/20 (85%) of pseudoseizure patients, the diagnoses were corroborated by intensive EEG monitoring (video or cassette telemetry). There was a statistically significant rise in prolactin levels in both groups (p < 0.0001 and

The electroencephalography (EEG) signal has a high complexity, and the process of extracting clinically relevant features is achieved by visual analysis of the recordings. The interobserver agreement in EEG interpretation is only moderate. This is partly due to the method of reporting the findings in free-text format. The purpose of our endeavor was to create a computer-based system for EEG assessment and reporting, where the physicians would construct the reports by choosing from predefined elements for each relevant EEG feature, as well as the clinical phenomena (for video-EEG recordings). A working group of EEG experts took part in consensus workshops in Dianalund, Denmark, in 2010 and 2011. The faculty was approved by the Commission on European Affairs of the International League Against Epilepsy (ILAE). The working group produced a consensus proposal that went through a pan-European review process, organized by the European Chapter of the International Federation of Clinical Neurophysiology. The Standardised Computer-based Organised Reporting of EEG (SCORE) software was constructed based on the terms and features of the consensus statement and it was tested in the clinical practice. The main elements of SCORE are the following: personal data of the patient, referral data, recording conditions, modulators, background activity, drowsiness and sleep, interictal findings, "episodes" (clinical or subclinical events), physiologic patterns, patterns of uncertain significance, artifacts, polygraphic channels, and diagnostic significance. The following specific aspects of the neonatal EEGs are scored: alertness, temporal organization, and spatial organization. For each EEG finding, relevant features are scored using predefined terms. Definitions are provided for all EEG terms and features. SCORE can potentially improve the quality of EEG assessment and reporting; it will help incorporate the results of computer-assisted analysis into the report, it will make possible the build-up of a multinational database, and it will help in training young neurophysiologists.

NARCOLEPSY WITH CATAPLEXY (NC) IS CAUSED BY ALMOST COMPLETE LOSS OF HYPOCRETIN (OREXIN) NEURONS IN THE HYPOTHALAMUS. THESE NEURONS produce the sleep-wake and REM sleep-regulating neuropeptides hypocretin-1 and hypocretin-2 (orexin-A and orexin-B).1, 2 Several studies have detected a low level of hypocretin-1 in the cerebrospinal fluid (CSF hcrt-1) in the majority of NC patients as well as in some patients with narcolepsy without cataplexy (NwC). Thus, determination of CSF hcrt-1 may be of diagnostic value for narcolepsy, and it has been included as a diagnostic tool in the current International Classification of Sleep Disorders (ICSD-2).3 However, the prevalence of low CSF hcrt-1 seems to vary greatly between studied populations: 77%4 to 94%5 in NC patients and 11%6 to 38%7 in NwC patients. This may reflect true between-population differences, but this is difficult to determine mainly because of different study definitions of low and normal CSF hcrt-1 levels and the great inter-assay variability of the CSF hcrt-1 radioimmunoassay. Hypocretin-deficient patients often carry the HLA-DQB1*0602-allele,8 so different HLA-DQB1*0602 frequencies in the study populations might also contribute to the variation observed. Direct extrapolation of study results from different sleep laboratories has therefore not yet been possible. Hence, the ICSD-2 criterion for low CSF hcrt-1 still needs to be validated in different populations. We aimed to (1) characterize the relationship between the clinical profile, the paraclinical profile (sleep investigations, HLA-type), and the ICSD-2 criterion for low CSF hcrt-1 (< 30% of normal mean) in a Danish population consisting of patients with narcolepsy with or without cataplexy, other hypersomnias, neurological disorders, and normal controls; and (2) recalculate the CSF hcrt-1 results of all eligible NC and NwC populations (identified by MEDLINE search) according to the ICSD-2 criterion for low CSF hcrt-1 (< 30% of normal mean), and then directly compare all study results.

Transient suppression of the motor cortex and of the speech areas cause well-described postictal phenomena following seizures involving the respective cortical areas. Pain is a rare symptom in epileptic seizures. We present a patient with painful tonic seizures in the left leg. The amplitude of the cortical component of the somatosensory evoked potential following stimulation of the left tibial nerve was reduced immediately after the seizure. Our findings suggest that the excitability of the sensory cortex is transiently reduced following a seizure involving the somatosensory area.

Publisher Summary This chapter inspects the case of a woman suffering from idiopathic generalized epilepsy with some features of juvenile myoclonic epilepsy. Her seizures had begun when she was 12 years with generalized tonic–clonic seizures and, allegedly, psychomotor seizures that were not further described. Seizures usually occurred just after awakening. Video-EEG recording showed innumerable generalized bursts of 4–6 Hz spike–polyspike-waves, each burst lasting 1–2 seconds and accompanied by a slight lapse of consciousness and upward deviation of the eyes with blinking, but no clonic movements in the extremities. She was initially treated with carbamazepine and then with phenytoin, but treatment was changed to valproate because of side effects and insufficient seizure control. Valproate was reasonably effective, but because of unacceptable weight gain, her treatment was changed to a combination of lamotrigine and vigabatrin. After the video-EEG, valproate was re-instituted, and ethosuximide was subsequently added, with much improved seizure control. Because of recurrent problems with weight gain, valproate was replaced by lamotrigine. This patient's aura-like phenomena with strong autonomic components had obviously been misinterpreted as evidence of focal seizures. Furthermore, several normal EEGs despite prolonged monitoring made a diagnosis of idiopathic generalized epilepsy less likely, until a rather short but intensive session of video-EEG monitoring together with the history led to the correct classification of her seizure types and epilepsy syndrome.

Epilepsy in dogs is often difficult to medically control, resulting in premature death of dogs with epilepsy. However, the risks of premature death are not known.Dogs with epilepsy have an increased risk of premature death as compared to a general population of dogs.Sixty-three dogs diagnosed with epilepsy between 1993 and 1996 were included in this study.A prospective longitudinal study of the population was performed from the diagnosis of epilepsy until the time of euthanasia, death, or a maximum of 12 years to investigate mortality and risk factors. Information about sex, onset, type, frequency, and control of seizures, remission of epilepsy, death, cause of death, and owner's perspective was collected and analyzed.The median age at death of dogs was 7.0 years. The life span of dogs in which euthanasia or death was directly caused by their epileptic condition was significantly shorter as compared with epileptic dogs that were euthanized because of other causes (P = .001). The median number of years that a dog lived with epilepsy was 2.3 years. Females lived longer with epilepsy than males (P = .036). Seizure type (primary generalized versus focal seizures) was not significantly associated with survival time. The remission rate of epilepsy (spontaneous remission and remission with treatment) was 15%.The diagnosis of epilepsy implies an increased risk of premature death. The prognosis for dogs with epilepsy is dependent on a combination of veterinary expertise, therapeutic success, and the owner's motivation.

Epilepsy surgery is done in order to obtain seizure freedom or to reduce the number of epileptic seizures in selected patients not responding to medical treatment. Few Danish children have had this treatment, most probably because of some restrictions imposed by The Danish National Health Board. We present the results of the first 22 Danish children who have had epilepsy surgery.All children up to the age of 15 operated from January 1st 1996 to May 1st 2002 are included. According to the guidelines of The Danish National Health Board, 17 children have been operated abroad because the epileptic focus was extratemporal or intracranial EEG-monitoring was necessary. Follow-up varied from five years and six months to one month.At the time of the operation, all children had a long-lasting medical intractable epilepsy. 18 children had daily seizures and 15 were mentally retarded. Multi-lobar resection was performed in ten, hemispherectomy in three and lobar resection in eight children. Total seizure-free outcome was seen in 12 children, whereas three only had simple partial seizures (totally 68 per cent). The remaining children had at least a 50 per cent seizure reduction. On an average, the cognitive function was unchanged one year after the surgery. The majority of the parents stated that the behaviour of the child had improved on one or more specific issues. One mother stated that to a certain degree she regretted the operation. In four children, an unexpected complication was registered (slight hemiparesis and a hemianopsia).The results documented that epilepsy surgery is effective for selected children in spite of long-lasting severe epilepsy. In order to alleviate the consequences of severe epilepsy it is, however, important to refer the patients early. There seems to be a need for more and early referrals for childhood epilepsy surgery in Denmark.

The purpose of this study was to investigate the prevalence and selected risk factors of epilepsy, the proportion of dogs with epilepsy in remission, and the types of seizures in Danish Labrador Retrievers. A prospective cross-sectional study of epilepsy was conducted in 1999-2000. The study was carried out in 2 phases in a reference population consisting of 29,602 individuals. In phase 1, 550 dogs were selected by random sampling stratified by year of birth. A telephone interview was used to identify dogs with possible epilepsy. In phase 2, dogs judged during phase 1 as possibly suffering from epilepsy were further subjected to physical and neurologic examination, CBC, blood chemistry, and a questionnaire on seizure phenomenology. Seventeen dogs were diagnosed with epilepsy, yielding a prevalence of 3.1% (95% CI 1.6-4.6%) in the Danish population of Labrador Retrievers. A diagnosis of epilepsy was 6 times more probable in dogs4 years (born before 1995) than in younger dogs (born between 1995 and 1999) (P = .004, relative risk = 6.5). No significant difference in risk between genders was observed, nor could any effect of neutering be proven statistically. The frequencies of primary generalized seizures and partial seizures (with or without secondary generalization) were 24 and 70%, respectively. The type of seizures could not be classified in 6%. In conclusion, the 3.1% prevalence of epilepsy in Danish Labrador Retrievers is higher than the 1% prevalence of epilepsy described in the general canine population, establishing that this breed is at increased risk.

The aim of the present prospective study was to evaluate changes in plasma GABA concentration in relation to clinical response during vigabatrin treatment of epilepsy. We studied 29 patients with uncontrolled partial-onset seizures during open add-on vigabatrin treatment and measured plasma GABA and vigabatrin concentrations by a sensitive HPLC method. Following short-term treatment 17 out of 28 patients had a seizure reduction of50% (responders). After long-term treatment 16 out of 22 patients were responders. There was no difference between responders and nonresponders regarding pretreatment seizure frequency, treatment duration, vigabatrin dose, or plasma vigabatrin concentration. Responders had a significant (p0.001) increase in mean plasma GABA both after short-term (from 0.380 to 0.530 nmol/ml; mean increase: 48%) and after long-term (from 0.392 to 0.618 nmol/ml; mean increase: 71%) vigabatrin treatment, whilst nonresponders had no significant changes in GABA levels. However, since plasma GABA increased in a subgroup of nonresponders, mean plasma GABA levels did not differ between responders and nonresponders. Although plasma GABA increased significantly in the responder but not in the nonresponder group during vigabatrin treatment of patients with epilepsy, it does not seem to be a reliable marker of individual clinical response to vigabatrin treatment.

W8.2 SCORE: an overview of the software H. Aurlien1, S. Beniczky2, A. Fuglsang-Frederiksen3, A. Martinsda-Silva4, E. Trinka5, G. Visser6, G. Rubboli7, H. Hjalgrim2, H. Stefan8, I. Rosen9, J. Zarubova10, J. Dobesberger5, J. Alving2, K.V. Andersen11, M. Fabricius11, M.D. Atkins2, M. Neufeld12, P. Plouin13, P. Marusic10, R. Lees14, R. Pressler15, R. Hopfengartner8, J.C. Brogger2, R. Mameniskiene16, W. van Emde Boas17, P. Wolf2 1Department of Neurology, University of Bergen, Norway, 2Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark, 3Department of Clinical Neurophysiology, University of Aarhus, Denmark, 4Neurological Department, University of Porto, Portugal, 5Department of Neurology, Paracelsus Medical University, Salzburg, Austria, 6Department of Clinical Neurophysiology, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands, 7Department of Neurological Sciences, University of Bologna, Italy, 8University Hospital Erlangen, Epilepsy Center, Neurological Clinic, Erlangen, Germany, 9Department of Clinical Neurophysiology, University of Lund, Sweden, 10Neurology Department, Charles University, Prague, Czech Republic, 11Department of Clinical Neurophysiology, Glostrup Hospital, University of Copenhagen, Denmark, 12EEG and Epilepsy Unit, Department of Neurology, Tel-Aviv Sourasky Medical Center, Israel, 13Clinical Neurophysiology Department, Hopital Saint-Vincent de Paul, Paris, France, 14Department of Clinical Neurophysiology, Helsinki University, Finland, 15Great Ormond Street Hospital for Children, NHS Trust, London, England, UK, 16Department of Neurology, Vilnius University Santariskiu Klinikos Hospital, Lithuania, 17Dutch Epilepsy Clinics Foundation, S.E.I.N., Heemstede, The Netherlands

Chromosome studies were performed on both bone-marrow cells and peripheral blood lymphocytes from ten patients with epilepsy, treated with diphenylhydantoin alone. There was no evidence of chromosome damage. Furthermore, the bone-marrow smears from five of the patients were studied for the presence of micronuclei. There was no increase in the number of micronuclei compared with control persons. Conflicting results about the cytogenetic effect of diphenylhydantoin have appeared in the literature. It is emphasized that, in studies on the chromosome-damaging effect of chemical agents in man, bone-marrow cells seem to be most indicative of the conditions in vivo.

PURPOSE: To investigate whether hyperventilation (HV) for 5min increases the diagnostic yield of electroencephalography (EEG) compared to 3min HV.METHODS: data were evaluated from 1084 consecutive patients, from three European centres, referred to EEG on suspicion of epilepsy. Seizures and interictal EEG abnormalities precipitated during the first 3min and during the last 2min of the HV period (totally 5min) were determined.RESULTS: Eight hundred seventy-seven patients (81%) completed 5min HV. Seizures were precipitated during the first 3min of HV in 21 patients, and during the last 2min in four more patients. Interictal EEG abnormalities were precipitated in the first 3min of HV in 16 patients, and during the last 2min in 7 more patients. Psychogenic nonepileptic seizures occurred in eight patients during the first 3min of HV and in two more patients during the last 2min. No adverse events occurred during the last 2min of HV, but eight patients (1%) stopped HV during the last 2min because they were not able to hyperventilate further.CONCLUSION: 16% of seizures and 30% of interictal EEG abnormalities triggered by HV occurred during the last 2min of HV, suggesting the clinical usefulness of prolonged hyperventilation for 5min. The vast majority of patients (99%) who are able to hyperventilate for 3min can complete 5min HV, without additional adverse events.

In 30 patients, who were all comatose as a result of cerebral anoxia after cardiac arrest, at least one EEG with activity in the alpha frequency range was recorded. Regionally the activity of the above mentioned characteristic was often diffusely distributed or most pronounced occipitally, whereas a tendency to affect other regions was rarely observed. In 50% of the patients, where more than one EEG was recorded, the 'alpha' rhythm was still present in the following record. Only one of the patients survived, and even so, with considerable mental defects. In 4 patients the level of consciousness improved, but 3 of them never reached a definite level of cortical function and died as a result of cerebral anoxia.

— 12 patients with absence epilepsy were treated with alternatively 1 or 3 daily doses of sodium valproate (VPA) in a double-blind cross-over design. Seizure frequency, EEG paroxysmal activity, clinical side-effects and laboratory findings were assessed for both treatment periods. There was no statistically significant difference between the 2 dosage schedules, and the simplicity of monodose treatment is an important factor in good patient compliance. The apparent discrepancy between plasma half-life and biological action of VPA is discussed.

– A 47-year-old man with a typical obstructive sleep apnea syndrome (OSAS) secondary to a large oral cyst is reported. Although the patient also had a nasal septum deviation with narrowed air passage, removal of the cyst resulted in complete and lasting relief from clinical symptoms despite persisting sleep apnea and unchanged arousal reaction in the EEG. The concurrent mechanisms of OSAS in the present case are discussed, and the importance of searching for a curable underlying disorder in clinical overt OSAS is emphasized.