Typical absence status in adults: diagnostic and syndromic considerations

PURPOSE: To study the electroclinical features of typical absence status (TAS) in adults with syndromes of idiopathic generalized epilepsies (IGEs). METHODS: Twenty-one patients with one or more spells of TAS were identified among 136 consecutive adult patients with IGEs. All patients with TAS had comprehensive electroclinical investigations and EEG or video-EEG recorded absences. RESULTS: TAS occurred in 24.4% of 86 patients who had IGEs with typical absences alone or in combination with other seizures presisting in adult life. The prevalence of TAS appeared to be syndrome related, ranging from as high as 57.1% in perioral myoclonia with absences and 46.2% in "phantom" absences with GTCS to as low as 6.7% in juvenile myoclonic epilepsy. A varying degree of impairment of cognition was the cardinal clinical symptom shared in all TAS, but corresponding syndromes of IGE were often betrayed by other symptoms such as eyelid or perioral myoclonia. In phantom absences with GTCS, TAS was more numerous (p < or = 0.05) and more frequently the first overt seizure type (p = 0.006) than in any other IGE. Only in the syndrome of eyelid myoclonia with absences, TAS was always situation related, mainly as a result of antiepileptic drug discontinuation. CONCLUSIONS: The clinical EEG semiology and prevalence of TAS appear to be syndrome related with the highest prevalence in the syndromes of perioral myoclonia with absences and phantom absences with GTCS (p = 0.0024).     

Vigabatrin and lamotrigin: experiences with 2 new anticonvulsants in the Swiss epilepsy clinic

Vigabatrin and lamotrigine are two new antiepileptic drugs which have recently become available. Vigabatrin is a specific and irreversible inhibitor of the enzyme gamma-amino-butyric-acid (GABA) transferase. Its administration leads to a long lasting increase in GABA, the most important inhibitory neurotransmitter. Vigabatrin is effective in both adults and children in the treatment of partial and especially complex-partial seizures. After add-on in vigabatrin to their therapeutic drug regime in 116 of our own patients, 39% of previously therapy resistant patients reported a reduced seizure frequency of at least 50% and 6% of them became seizure free. In secondarily generalized epilepsies the best results were observed in axial (infantile) spasms. In addition there was some improvement in tonic and convulsive seizures. Single patients showed increased myoclonic and clonic seizures. Initial efficacy was not always maintained during follow-up. In the experience of other authors, vigabatrin is also effective in the treatment of infantile spasms. It is not suitable for the treatment of generalized epilepsies with absences and myoclonic seizures. Most patients tolerate vigabatrin very well, although psychotic episodes are sometimes reported. So far there have been no relevant hepatic or hematological side effects. Lamotrigine is also effective in the treatment of partial seizures, for which it is approved. However, uncontrolled studies and our own experience have shown that it is even more effective in generalized seizures. As add-on therapy in absences and tonic or tonic-clonic seizures, a significant reduction in seizure frequency--in individual cases seizure freedom--can be achieved.(ABSTRACT TRUNCATED AT 250 WORDS)     

Epilepsy and disorders of cortical development in children with congenital cytomegalovirus infection

INTRODUCTION: Neuroimaging and experimental studies have related cytomegalovirus (CMV) to certain neuronal migration disorders. MATERIAL AND METHODS: To define the electroclinical picture of children with epilepsy associated with disorders of cortical development (DCD) and congenital CMV infection, we conducted a clinical, electroencephalographic and neuroradiological study of 10 children with this condition. RESULTS: Eighty per cent of them had dismorphic traits, or malformations outside CNS. All showed other neuroradiological signs (cerebral calcification, white matter damage, porencephaly). Six patients with bihemispheric DCD (agyria-pachigyria, 2; 'poligyria', 1; schizencephaly, 1; bilateral opercular DCD, 2) showed: Tetraparesis, severe or profound mental deficiency, early onset epilepsy (mean age at onset: 11 months) with spasms, tonic seizures, partial seizures, and multifocal paroxysms or unusual diffuse sharp Alfa-Beta EEG activity. One child developed Epilepsia Partialis Continua. Children with bilateral opercular DCD evolved to a continuous spike and wave (SW) electrical status during wakefulness and sleep, linked to a worsening of psychomotor derangement. Four patients with unilateral hemispheric DCD (pachigyric or 'poligyric') showed: Congenital hemiparesis, mild intellectual deficiency, motor seizures (orofacial, hemiclonic, generalized) beginning in the third year of live, atypical absences with focal phenomena, frequent focal rhythmic SW discharges during wakefulness, and continuous SW status during sleep (CSWS). CONCLUSIONS: A wide spectrum of DCD due to congenital CMV infection is documented. Characteristic electroclinical pictures related to the extent and topographical distribution of the DCD are recognized, which may lead to an appropriate diagnosis and prognosis.     

Problematic standards: improving organizational performance through the assess and improve phases

Since 1987, we have diagnosed 10 patients, 4 males and 6 females, aged 2-11 years at the last evaluation, who all met the following criteria of severe myoclonic epilepsy in infancy (SMEI): generalized or unilateral long-lasting febrile clonic seizures in the first year of life; the subsequent appearance of myoclonic seizures and other types of seizure (partial seizures, atypical absences and convulsive status epilepticus); and neuropsychological deterioration for a certain period. Family histories of epilepsy and febrile seizures could be traced in 1 and 3 cases, respectively. None of them had previous personal history of brain insult. Electroencephalographic (EEGic) recordings in febrile seizure stage were normal; and continuous prophylaxis with phenobarbital failed to prevent the recurrence of febrile seizures. EEG studies in myoclonic stage showed generalized spike-and-waves, polyspike-and-waves, focal abnormalities and/or photosensitivity. The seizures were highly resistant to antiepileptic drugs. Our experiences suggested that comedication of valproic acid, clonazepam and carbamazepine may be most effective in treatment of the diverse seizures including myoclonic seizures, myoclonic-tonic-clonic seizures, atypical absences and partial seizures. Myoclonic seizures and atypical absences diminished in parallel to a clear-cut decrease in generalized abnormalities on EEG in 4 cases aged more than 7 years. However, the partial seizures, secondarily generalized seizures and status epilepticus were still present. Further investigations should aim to identify the underlying etiology and to search more effective treatment.     

Idiopathic epilepsy with generalized seizures in early childhood]

Idiopathic epilepsies with generalized seizures of early childhood are based on a genetic predisposition. The onset takes place between the first and fifth years of age, boys are affected more often than girls. Dependent on the clinical symptomatology you have to distinguish: myoclonic seizures; atonic-astatic seizures; myoclonic-astatic seizures; absences; tonic-clonic seizures. In more than half of the cases a combination of these seizures can be observed. The differentiation of epilepsies with generalized seizures of multifocal origin (infantile spasms, Lennox-Gastaut syndrome and Pseudo-Lennox syndrome [atypical benign epilepsy]) may be difficult but is essential. Therapy of choice is valproate, often in combination with ethosuximide (in children with minor seizures) or with kaliumbromide or phenobarbital (in children with tonic-clonic seizures). Generally the prognosis is more unfavourable if epilepsy starts in the first year of life with afebrile and febrile generalized tonic-clonic or clonic seizures, if children are suffering from longlasting states of seizures and if development is disturbed before beginning of epilepsy.     

Ectopic cerebral tissue in the middle ear. A case report

Most idiopathic generalized epilepsies have an onset in childhood or adolescence, with a moderate second incidence peak in the presenium predominantly in women. This study addressed the question of a later onset. The available literature and the records of four personal data sets (two prospective incidence surveys of epileptic seizures, one prevalence study of epilepsy, and one clinical series of individuals with epilepsy) were screened for patients who had experienced a first generalized convulsive seizure with bilateral spike-wave complexes on EEG after 60 years of age. Reports of first idiopathic generalized tonic-clonic seizures occurring after age 60 were extremely rare and none was found in our four cohorts regardless of the methodology involved. Only five case reports were found, all involving a woman. Two had a family history of seizure disorders and two had had at least one seizure earlier in life. Idiopathic generalized epilepsy of late onset, if this condition actually exists, is likely to be the consequence of a genetic predisposition triggered by acquired epileptogenic factors.     

EEG findings in frontal lobe epilepsies

As a group, epilepsies of frontal lobe origin are thought to be poorly localized using surface EEG recordings. This finding may depend on the specific areas of frontal lobe from which the seizures originate or the pathologic substrate. We reviewed the presurgical surface EEGs of patients with frontal lobe epilepsy who underwent epilepsy surgery. The specific area of the frontal lobe where seizures originated was determined by 1) intracranial ictal EEG recordings, or 2) the presence of a structural lesion, identified by imaging studies in patients who achieved complete seizure control following surgery. We differentiated patients whose seizures began in the dorsolateral frontal convexity from those whose seizures began in the medial frontal region, and we correlated EEG findings in the interictal, postictal, and ictal states with seizure semiology, pathologic substrate, and surgical outcome. Four of nine patients had seizures originating in the dorsolateral frontal convexity and five had medial frontal onset seizures. Patients whose seizures originated from the dorsolateral convexity had focal interictal epileptiform abnormalities that localized to the region of seizure onset. Patients whose seizures began in the medial frontal region had either no interictal epileptiform abnormality or had multifocal epileptiform discharges. Patients whose seizures began in the dorsolateral convexity showed focal electrographic seizure activity that was localizing. This rhythmic fast activity did not appear to be substrate-specific. Patients whose seizure onset localized to the medial frontal region did not show focal electrographic seizure at clinical onset. We conclude that the scalp EEG recordings of frontal lobe epilepsies contain features that enable differentiation of seizures originating from two different regions of the frontal lobe.     

Single-chain Fv with manifold N-glycans as bifunctional scaffolds for immunomolecules

PURPOSE: To investigate the significance of cortical pathology of tonic spasms in patients with tuberous sclerosis. METHODS: The subjects were 38 patients with epilepsy associated with tuberous sclerosis. We analyzed ictal EEGs of tonic spasms and partial seizures by means of video-EEG monitoring for a total of 763 tonic spasms in 20 patients and 107 partial seizures in 15 patients. We also investigated the relation between partial seizures and magnetic resonance imaging (MRI) findings of these patients. RESULTS: Ictal EEG patterns of tonic spasms were divided into generalized and focal patterns. Thirteen patients had only generalized patterns, whereas seven had both patterns. In five patients who had focal ictal patterns of tonic spasms and partial seizures, the location of focal patterns corresponded with the location of onset of partial seizures. Focal discharges were seen immediately before, after, and in the middle of tonic spasms in series in 13 patients. The location of focal discharges also corresponded with the location of the onset of partial seizures in 10 of the 13 patients. Regarding partial seizures, four patients had multiple active epileptogenic foci during the same period, and two others had shifting epileptogenic foci with increasing age. CONCLUSIONS: These findings indicate that cortical pathology plays an important role in the occurrence not only of partial seizures but also of tonic spasms in patients with tuberous sclerosis.     

Paediatric pain management--the next step?

Congenital bilateral perisylvian syndrome (CBPS) is a recently described, neuronal migration disorder, characterized by pseudobulbar palsy, epilepsy and mental retardation and bilateral perisylvian dysplasia. A 15-year-old boy was diagnosed with CBPS according to the typical clinical, and magnetic resonance imaging (MRI) features. The patient was suffering from atypical absence seizures, repeating daily in spite of antiepileptic drug therapy, since age 7 years. He had also experienced rare generalized tonic-clonic seizures and complex partial seizures. Neurological examination showed severe restriction of tongue movements, severe dysarthria, dysphagia, facial diplegia, mild pyramidal signs and moderate mental retardation. A computed tomographic (CT) scan demonstrated bilateral perisylvian enlargement. The diagnosis was corrected with MRI after six years. Frequent irregular generalized spike and wave abnormalities and focal sharp and slow waves over the posterior regions of both hemispheres were shown by electroencephalograms (EEG). The patient was treated with Na-Valproate, carbamazepine and lamotrigine but did now show any significant change in seizure frequency in the eight-year follow-up period. Intractable seizures, mental retardation and particularly congenital pseudobulbar palsy suggest this congenital entity. Those patients who exhibit these typically clinical features, must have MRI.     

Anti-viral effect of interferon-alpha on bovine viral diarrhea virus

PURPOSE: Lamotrigine (LTG) is recognised as effective add-on therapy for focal epilepsies, but this is the first double-blind, placebo-controlled, crossover study in treatment-resistant generalised epilepsy. METHODS: The study consisted of 2 x 8-week treatment periods followed by a 4-week washout period. Patients received doses of either 75 or 150 mg daily, depending on their concomitant antiepileptic drugs (AEDs). Long-term continuation was offered at the end of the study with open-label LTG. RESULTS: Five centres in Australia recruited 26 patients who were having absence, myoclonic, or generalized tonic-clonic seizures or a combination of these. Twenty-two patients completed the study. There was a significant reduction in frequency of both tonic-clonic and absence seizure types with LTG. A 350% decrease in seizures was observed for tonic-clonic seizures in 50% of cases and for absence seizures in 33% of evaluable cases. Rash was the only adverse effect causing discontinuation. Twenty-three of 26 opted for open-label LTG, with 20 still receiving LTG for a mean of 26 months. In these 20, 80% had > or =50% seizure reduction and five (25%) were seizure free. CONCLUSIONS: This study shows that LTG is effective add-on therapy in patients with refractory generalised epilepsies. Statistically significant reduction in seizures in both absence and tonic-clonic seizure types was seen even with low doses of LTG.     

Routine microbiological testing in sudden and unexpected infant death

We reviewed 187 depth recorded seizures in 33 patients with non-lesional temporal lobe complex partial seizures. All patients had a minimum of 1 year follow-up following temporal lobectomy. We classified seizure onset pattern as rhythmic activity, attenuation, or repetitive spikes or spike wave complexes. The most common pattern of seizure onset was rhythmic activity and the next most common pattern was repetitive spikes. Seventy-five seizures (49%) had only one seizure onset pattern, and 79 seizures (51%) had a combination of seizure onset patterns. The degree of hippocampal gliosis strongly predicted the type of seizure onset pattern (Chi square = 24.07, 2 d.f., P < 0.01). The rhythmic activity pattern was associated with mild gliosis, and the repetitive spike pattern was associated with severe gliosis. We classified seizure onset as focal or regional based on the number of electrode contacts that were involved by the ictal EEG. A focal seizure onset was associated with an excellent outcome following temporal lobectomy.     

Causes of death and recurrence after surgery for early gastric cancer

The analysis of generalized tonic clonic seizures is usually difficult with scalp EEG due to muscle artifact. We applied Gabor Transform to evaluate 20 seizures from 8 consecutive patients admitted for video-EEG monitoring. We studied the relative intensity ratios of alpha, theta and delta bands over time. In 14/20 events we found a significant decremental activity in the delta band at the onset of the seizure indicating that this is dominated by theta and alpha bands. We conclude that GT is a useful auxiliary tool in the analysis of ictal activity that sheds light on the underlying pathophysiological mechanisms.     

Electroencephalogram and clinical focalities in juvenile myoclonic epilepsy

Partial seizures and asymmetric abnormalities seen on electroencephalogram (EEG) are infrequent in juvenile myoclonic epilepsy, but when present, can lead to a misdiagnosis of partial seizures. We report four patients with juvenile myoclonic epilepsy who had generalized spike or polyspike and wave discharges on EEG in addition to clinical and EEG evidence of focality. The clinical course and response to therapy was similar to that in typical juvenile myoclonic epilepsy.     

Seizures involving the supplementary sensorimotor area in children: a video-EEG analysis

Most reports of supplementary sensorimotor seizures have been of adults with medically refractory epilepsy. Typically, supplementary sensorimotor seizures have onset in childhood. We describe the electroclinical features in 12 children. Cases were selected from an EEG laboratory population in whom video-EEG was performed routinely on all children. Supplementary sensorimotor seizures were diagnosed when there was bilateral tonic posturing of the upper or lower extremities, preserved consciousness, and lack of postictal confusion. Sensory auras were reported by 8 of 9 children aged > 3 years who had daytime seizures. Speech arrest occurred in all patients in whom it could be assessed, and abnormal vocalization was observed in 7 children. Interictal EEGs were often normal (49% of recordings), and ictal EEG changes could be subtle. An etiology was demonstrated in only 2 children, and brain imaging studies were normal in the other 10 patients. Seizures were controlled with antiepileptic drugs (AEDs) in 6 of the 12 children. The clinical manifestations of supplementary sensorimotor seizures in children are similar to those reported in adults; misdiagnosis is common at all ages.     

Association of cerebral palsy with epilepsy

Fifty patients of various types of cerebral palsy were studied to find out an association between cerebral palsy, EEG abnormalities and development quotient. Seventy-six per cent patients had spastic cerebral palsy. Hypotonic cerebral palsy was the next common type (14%). Athetosis and ataxic forms were found to be rare (2% each). Epilepsy was associated with 56% patients. Clinical types of seizures observed were: Generalised tonic-clonic (43%), myoclonic (17.9%), generalised tonic (10.7%), partial simple (10.7%) and partial complex (17.9%). The incidence of seizures was highest in hypotonic type in which 85.7% had epilepsy. Mean developmental quotient of cerebral palsy patients was 34.9% with maximum retardation in hypotonic cerebral palsy (25.14%). Sixty per cent of patients had abnormal EEG, out of these hypotonic patients had maximum (70%) chances of EEG abnormality followed by spastic patients (55%). Developmental retardation was more severe statistically in the patients with abnormal EEG than normal EEG.     

Semiological seizure classification

We propose an epileptic seizure classification based exclusively on ictal semiology. In this semiological seizure classification (SSC), seizures are classified as follows: a. Auras are ictal manifestations having sensory, psychosensory, and experiential symptoms. b. Autonomic seizures are seizures in which the main ictal manifestations are objectively documented autonomic alterations. c. "Dialeptic" seizures have as their main ictal manifestations an alteration of consciousness that is independent of ictal EEG manifestations. The new term "dialeptic" seizure has been coined to differentiate this concept from absence seizures (dialeptic seizures with a generalized ictal EEG) and complex partial seizures (dialeptic seizures with a focal ictal EEG). d. Motor seizures are characterized mainly by motor symptoms and are subclassified as simple or complex. Simple motor seizures are characterized by simple, unnatural movements that can be elicited by electrical stimulation of the primary and supplementary motor area (myoclonic, tonic, clonic and tonic-clonic, versive). Complex motor seizures are characterized by complex motor movements that resemble natural movements but that occur in an inappropriate setting ("automatisms"). e. Special seizures include seizures characterized by "negative" features (atonic, astatic, hypomotor, akinetic, and aphasic seizures). The SSC identifies in detail the somatotopic distribution of the ictal semiology as well as the seizure evolution. The advantages of a pure SSC, as opposed to the current classification of the International League Against Epilepsy (ILAE), which is actually a classification of electroclinical syndromes, are discussed.     

Multilobar polymicrogyria, intractable drop attack seizures, and sleep-related electrical status epilepticus

BACKGROUND AND OBJECTIVE: Patients with cortical malformations often have intractable seizures and are candidates for epilepsy surgery. Within an unselected series of patients with various forms of cortical malformation, nine patients with multilobar polymicrogyria had electrical status epilepticus during sleep (ESES) accompanied by infrequent focal motor seizures. Eight patients also had intractable atonic drop attack seizures. Because ESES usually is accompanied by a good long-term seizure prognosis, the objective of this study was to examine ESES outcome among patients with a structural lesion that is usually highly epileptogenic and has a low seizure remission trend. METHODS: The nine patients had follow-up periods lasting 4 to 19 years. All underwent brain MRI, serial sleep EEG recordings, and cognitive testing during and after ESES. RESULTS: ESES and drop attack seizures appeared between the ages of 2 and 5 years (mean, 4 years) and ceased between the ages of 5 and 12 years (mean, 8 years). At the last visit patients were 8 to 23 years of age (mean, 14.5 years) and were either seizure free or had very infrequent focal motor seizures during sleep. Three patients were free from antiepileptic drugs. In no patient was definite cognitive deterioration apparent after ESES in comparison with earlier evaluations. CONCLUSIONS: Age-related secondary bilateral synchrony underlying ESES may be facilitated in multilobar polymicrogyria. The good seizure outcome contrasts with that usually found in the presence of cortical malformations. For children with polymicrogyria and drop attack seizures, surgical treatment of the epilepsy should be considered cautiously, and sleep EEG recordings should be performed systematically.     

Idiopathic generalized epilepsies with typical absences

Idiopathic generalized epilepsy (IGE) comprises several subsyndromes. These are principally: benign neonatal familial convulsions, benign neonatal convulsions, benign myoclonic epilepsy in infancy, childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, epilepsy with generalised tonic-clonic seizures on awakening. In addition, there are less well-recognized syndromes, such as eyelid myoclonia with absences. The pathophysiology of the IGE syndromes is not fully understood; it is evident that typical absences are the result of abnormal oscillations between the thalamus and cerebral cortex. Genetic studies are in progress to elucidate the biochemical defects underlying the conditions. The clinical and electroencephalographic features of the individual subsyndromes are distinct, but some patients may be difficult to classify into a particular subgroup. A correct syndromic diagnosis is important, as treatment strategies differ for patients with the different forms of IGE, and it is necessary for genetic research.     

Need for electroencephalogram video confirmation of atypical absence seizures in children with Lennox-Gastaut syndrome

Children with childhood epileptic encephalopathy (Lennox-Gastaut syndrome) frequently have both multiple seizure types and nonepileptic stereotyped events that are difficult to differentiate. We hypothesize that electroencephalogram (EEG) video monitoring is essential for correct identification of atypical absence seizures in this population. All video/EEG monitoring records on patients with confirmed Lennox-Gastaut syndrome between September 1992 and December 1996 were reviewed for clinical events and EEG changes. A subset of patients with suspected atypical absence seizures during the video/EEG formed the cohort for analysis. Thirty-eight patients had 48 monitoring periods ranging from 1 to 4 days (mean, 2.2 days). Twenty-six monitoring periods captured suspected atypical absence seizures and formed the study cohort. Suspected atypical absence seizures were epileptic seizures in only 27% (7 of 26) of the study cohort. By contrast, parents reliably and correctly identified tonic, atonic, and tonic-clonic seizures in the study cohort. Reliable diagnosis and subsequent counting of atypical absence seizures in patients with Lennox-Gastaut syndrome cannot be made on the basis of observation and/or history alone. Future outpatient studies of investigational anticonvulsant medications for patients with Lennox-Gastaut syndrome should consider parental counts of atypical absence seizures unreliable. We recommend that video/EEG monitoring be done on all Lennox-Gastaut syndrome patients with suspected atypical absence seizures not controlled by medication.     

Can the age limit for endoscopy be increased in dyspepsia patients who do not have alarm symptoms?

We studied the interictal EEG of 50 epileptic patients (28 males, 22 females) who had parenchymal neurocysticercosis, diagnosed by CAT/MRI of the brain, positive immunological reaction for cysticercosis in cerebral spinal fluid or both. Age ranged from 5 to 61 years old; the mean age of onset was 24.2 +/- 12.2 years. Thirty-six patients had generalized seizures, 13 partial seizures with secondarily generalized seizures, and 1 had complex partial seizures. Twenty-two patients had parenchymal calcifications (inactive form); 21 had parenchymal cysts (active form) and 7 had both. EEG was abnormal in 14 patients (28%): 8 had focal slowing, 3 had focal sharp or spike activity, and 3 had both. The EEG was normal in patients with inactive forms of neurocysticercosis. The EEG was abnormal in 50% of patients with active and mixed forms of neurocystercosis and in 48% of patients with active form only. We conclude that the active forms of neurocysticercosis should be suspected when the EEG is found to be abnormal. In additional, EEG abnormality does not depend on the number of lesions, but rather on location and viability of the cysts, and on host response.