Side-to-side axial movements. Adding a new sign to the asymmetry of the clonic phase and asymmetric seizure termination in differentiating primary and secondarily generalised tonic-clonic seizures.

AIM: To study new semiological signs which help distinguish between primary and secondarily generalised tonic-clonic seizures (GTCS). METHODS: We retrospectively studied 86 GTCS, 13 primary and 73 secondary, in 58 patients who underwent video-EEG (vEEG) evaluation in our epilepsy monitoring unit. Eleven patients had generalised epilepsy and 47 focal epilepsy. Two expert epileptologists, blinded to diagnosis, examined the vEEGs independently for the presence of five semiological signs. RESULTS: Asymmetry of limb movements in clonic phase, side-to-side axial movements, and asymmetric seizure termination occurred more frequently (p<0.05) in secondary GTCS compared to primary GTCS. Combining asymmetry of limb movements in clonic phase and side-to-side axial movements provided the greatest value in differentiating secondary GTCS from primary GTCS. CONCLUSION: Careful examination of GTCS seizure semiology can help differentiate primary from secondary GTCS. The semiological sign of side-to-side axial movements, which has not previously been studied in this context, may add to existing literature of semiological signs and be of value for the evaluation of surgical patients in the epilepsy monitoring unit. In the out-patient setting, a clear history of these signs may help guide drug treatment choices.

Modern technology calls for a modern approach to classification of epileptic seizures and the epilepsies.

In the last 10-15 years the ILAE Commission on Classification and Terminology has been presenting proposals to modernize the current ILAE Classification of Epileptic Seizures and Epilepsies. These proposals were discussed extensively in a series of articles published recently in Epilepsia and Epilepsy Currents. There is almost universal consensus that the availability of new diagnostic techniques as also of a modern understanding of epilepsy calls for a complete revision of the Classification of Epileptic Seizures and Epilepsies. Unfortunately, however, the Commission is still not prepared to take a bold step ahead and completely revisit our approach to classification of epileptic seizures and epilepsies. In this manuscript we critically analyze the current proposals of the Commission and make suggestions for a classification system that reflects modern diagnostic techniques and our current understanding of epilepsy.

Lateralization of interictal EEG findings.

Several reports indicate that interictal epileptiform discharges (IED) may be more likely to occur over the left cerebral hemisphere than over the right. The objective of our study was to determine the frequency and type of IED on routine and multihour EEGs in a tertiary epilepsy center to estimate the frequency of left-sided versus right-sided IED and to determine interictal spike distribution pattern differences between adult and pediatric epilepsy patients. The current study retrospectively reviewed 31,207 EEGs (25,793 routine EEGs and 5414 multihour EEGs) recorded on 24,003 patients during the period from 1993 to 2003. All EEGs were read according to a systematic EEG classification system. Every patient was considered only once by including the first abnormal EEG. Regional unilateral or bilateral IEDs were recorded in 1707 patients (7%). Regional unilateral or bilateral slow was recorded in 2297 patients (9.6%). Left-sided regional IED were seen in 828 patients and accounted for 58% of all unilateral IED. Left-sided slow was seen in 1389 patients and accounted for 65% of all unilateral slow. Lateralization of slow was due to intermittent slow, whereas continuous slow involved both hemispheres equally. There was no lateralization difference in benign focal epileptiform discharges of childhood. Lateralization shows a tendency toward greater left-sided lateralization of interictal findings with aging. Benign focal epileptiform discharges were only seen under the age of 20 years old. Regional IEDs were seen in approximately 7% of patients and slowing occurs in 10% of patients. Both abnormalities were seen more frequently in the left hemisphere. Age adjusted analysis of the data revealed that this left-sided predominance was mildly increased in adults as compared with pediatric patients.

Ipsilateral blinking seizures during left fronto-temporal ictal pattern on scalp EEG.

We report an infant with left eye blinking seizures accompanying a left (ipsilateral) fronto-temporal scalp EEG ictal pattern. The epileptogenic lesion was a left frontal encephalomalacia along the ventriculo-peritoneal shunt tract. The shunt was inserted for treatment of communicating hydrocephalus. This case illustrates the lateralizing value of the ictal blinking. Review of the literature suggests that seizures with unilateral blinking are likely to be produced by activation of ipsilateral trigeminal fibers innervating subdural intracranial structures and pial vessels in temporal and frontal lobes. Ipsilateral blinking could also be produced by activation of the ipsilateral cerebellar hemisphere.

Fluctuating Kluver-Bucy syndrome in a child with epilepsy due to bilateral anterior temporal congenital malformations.

An 11-year-old boy with epilepsy due to congenital bilateral anterior temporal lobe malformations presented with fluctuating Kluver-Bucy syndrome (KBS). Since the age of 2, he had experienced clusters of three or four daily complex partial seizures over 2-3 days in a month, followed by a seizure-free interval of 3-4 weeks. During the seizure-free period, the patient exhibited hyperorality, sniffing, irritability alternating with placidity, anxiety, unsolicited sexual gestures, and unusual calmness after eating. KBS features escalated up to the onset of the seizure cluster, and remitted after the seizures. Brain MRI revealed bilateral anterior temporal cortical dysplasia with enlarged and dysmorphic amygdalar-hippocampal complex. Brain [(18)F]fluorodeoxyglucose positron emission tomography PET showed bilateral anterior and mesial temporal hypometabolism. Video/EEG monitoring revealed independent right and left temporal lobe seizures. This is the first reported case of KBS due to congenital bitemporal malformations. Also, KBS behavior phenotype in this patient fluctuated, with escalation during the seizure-free period and remission induced by the monthly seizure cluster. This fluctuating pattern could represent forced normalization.

Detection of epileptiform activity by human interpreters: blinded comparison between electroencephalography and magnetoencephalography.

PURPOSE: Objectively to evaluate whether independent spike detection by human interpreters is clinically valid in magnetoencephalography (MEG) and to characterize detection differences between MEG and scalp electroencephalography (EEG). METHODS: We simultaneously recorded scalp EEG and MEG data from 43 patients with intractable focal epilepsy. Raw EEG and MEG waveforms were reviewed independently by two experienced epileptologists, one for EEG and one for MEG, blinded to the other modality and to the clinical information. The number and localization of spikes detected by EEG and/or MEG were compared in relation to clinical diagnosis based on postoperative seizure freedom. RESULTS: Interictal spikes were captured in both EEG and MEG in 31, in MEG alone in eight, in EEG alone in one, and in neither modality in three patients. The number of detections ranged widely with no statistical difference between modalities. A median of 25.7% of total spikes was detectable by both modalities. Spike localization was similarly consistent with the epilepsy diagnosis in 85.2% (EEG) and 78.1% (MEG) of the patients. Inaccurate localization occurred only in those cases with very few spikes detected, especially when the detections were in one modality alone. CONCLUSIONS: Interictal epileptiform discharges are easily perceived in MEG. Independent spike identification in MEG can provide clinical results comparable, but not superior, to EEG. Many spikes were seen in only one modality or the other; therefore the use of both EEG and MEG may provide additional information.