Reading epilepsy with absences, television-induced seizures, and pattern sensitivity.

A 14-year-old right-handed girl suffering from absence seizures from age 6 began to have reflex seizures elicited by reading and watching television when she was 13. Neurophysiological studies showed pattern sensitivity and photo-sensitivity. VEPs, obtained with flash and pattern reversal stimulation, were normal. This atypical form of reading epilepsy suggests an interaction of pattern vision and cognitive functions as precipitating stimuli in reflex seizures.

[Continuous localized EEG discharge during sleep in children without neuropsychological problems]. / Décharges EEG localisées continues pendant le sommeil chez des enfants sans troubles neuropsychiques.

After having reported continuous localized EEG discharge during slow sleep (CLEDS) in six children with congenital encephalopathy, we observed a similar EEG picture in six children free from both neuropsychological and neuroradiological defects. They suffered from partial idiopathic epilepsy; five presented a familial disposition towards febrile seizures. Continuous paroxysmal activity during sleep was observed from 4.8 yrs to 4.11 yrs (mean age: 4.9 yrs). Spontaneous remission of CLEDS was observed in three cases after 2-25 months, but one or more relapses occurred in two cases, and five children are still suffering from CLEDS. Seizures were controlled by drugs in all cases. Deterioration of intelligence level, although not severe, was observed in one case, after 24 months of CLEDS.

[Continuous localized EEG discharges during sleep in children]. / Décharges EEG localisées continues pendant le sommeil chez l'enfant.

Continuous generalized spike-and-wave complexes occurring during slow-sleep were first observed in some children by Patry et al. (1971). A general review of the reported cases was made by Tassinari et al. (1984). We have observed a new clinical-EEGraphic picture. Spikes and spike-and-wave complexes localized to one hemisphere were recorded during at least 85% non-REM sleep both in 3 quadriplegic and in 3 hemiplegic mentally retarded children, aged from 2 years and 10 months to 11 years (mean age: 5 years and 2 months). Cyclic organization of sleep was almost normal. Wake EEG showed an epileptic focus. Brain CT showed midline defect and brain atrophy in quadriplegic patients, and a wide temporal-parietal porencephalic cyst in hemiplegic patients. This EEGraphic pattern was associated with a more pronounced mental impairment: neuropsychological improvement was observed in 2 cases, when continuous sleep discharges disappeared. As aforesaid, this picture seems to be related either to hemispheric or to midline brain defects. In our cases, sleep phase organization could be examined, while continuous generalized discharges occurring during sleep do not allow such a study.

Unilateral photoconvulsive response in agenesis of the corpus callosum.

An 11-year-old female presented with the unusual coexistence of self-induced photogenic epilepsy and an atypical epileptiform ictal EEG pattern evoked by intermittent photic stimulation. The EEG showed irregular 2.5-4 Hz spike-wave and polyspike-wave complexes, strictly localized on the left hemisphere, and associated with impairment of consciousness and myoclonic jerking of the contralateral side of the body. A computer tomographic scan showed agenesis of the corpus callosum. According to the literature on corpus callosum section in uncontrolled epilepsies, we hypothesize that in our patient the agenesis of the corpus callosum probably prevented the generalization of the ictal EEG pattern evoked by intermittent photic stimulation.

Electroclinical features in children and adolescents with epilepsy and/or migraine, and occipital epileptiform EEG abnormalities.

This study attempted to better define clinical and EEG features for differential diagnosis between epilepsy and migraine in children with occipital epileptiform EEG abnormalities. We studied 126 children (57 males, 69 females; age 4-18 years) suffering from epilepsy (63), migraine (43) or both (20). Patients were selected because of the presence of epileptiform abnormalities in the occipital regions on their EEG at rest. Differences among groups were statistically analyzed (Pearson chi square; ANOVA) for sex, age at onset of seizures and migrainous attacks, family history, ictal signs and symptoms, EEG at rest (unilateral vs bilateral distribution of epileptiform abnormalities), and EEG during Hyperventilation (HV) and Intermittent Photic Stimulation (IPS). Significant differences were found in family history, ictal signs and symptoms, EEG at rest and during activation tests. A family history of epilepsy, visual symptoms such as colored hallucinations and micro/macropsias, frequently associated with clinical signs in the visual system (eye deviation, nystagmus), unilateral EEG abnormalities, and abnormal response to IPS were closely related to diagnosis of epilepsy. On the other hand, a family history of migraine, visual symptoms such as amaurosis and scotomata, without evident clinical signs, bilateral EEG abnormalities, and no changes during IPS were significantly related to migraine. In conclusion, these clinical and EEG differences should be considered in the differential diagnosis between epilepsy and migraine in children with occipital epileptiform EEG abnormalities.

Neuropsychological correlates of subclinical paroxysmal EEG activity in children with epilepsy. 2: Quantitative aspects.

Altered cognitive functioning has often been reported in patients with epilepsy. In our study we looked for quantitative correlation between the recurrence of Subclinical Spike-and-Wave Discharges (SSWD) during EEG recording, the scores on the intelligence test (WISC) and the electro-clinical characteristics of 29 epileptic children with subclinical discharges of generalized spike-and-wave complexes. In our sample we found a below-normal mean IQ, with greater impairment on performance than on verbal tasks. No clear quantitative correlation was found between the weighted scores on the various subtests and the "time density" of the spike-and-wave complexes. These findings suggest that the SSWD interfere with cognitive development (mainly with visuo-spatial and sensorimotor coordination abilities) and selectively impair some of the functions involved in the cognitive processes.

Neuropsychological correlates of subclinical paroxysmal EEG activity in children with epilepsy. 1: Qualitative features (generalized and focal abnormalities).

The cognitive deficit often associated with epilepsy is attributable to the presence and interaction of several factors but whether recurrent subclinical spike-wave discharges interfere with cognitive development is not yet clear. In the present study, the presence of subclinical discharges proved to be significantly associated with lower than average Full-Scale Intelligence Quotient (IQ), Verbal IQ and Performance IQ scores (Wechsler Intelligence Scale for Children) in comparison with patients not presenting EEG abnormalities during test. These findings confirm the adverse effect both of generalized and focal EEG epileptiform abnormalities, even if unaccompanied by overt seizures.

Visual evoked potentials in infants of diabetic mothers: relations to clinical and metabolic status during pregnancy and delivery.

OBJECTIVE: To evaluate Visual Evoked Potentials (VEPs) and psychomotor development of infants of diabetic mothers (IDMs) in relation to clinical and metabolic data during pregnancy and delivery. METHODS: VEPs and psychomotor development (Brunet-Lézine) were analysed in 40 two-month-old IDMs (21 males, 19 females), 24 from mothers with type-1 diabetes, 13 gestational diabetes, and 3 type-2 diabetes. Normative VEP data were obtained from 63 age matched controls. RESULTS: VEP latencies were significantly longer in IDMs than in controls (O1 wave IV=197.9+/-35.5 vs 155.3+/-30.3; P<0.001; O2 wave IV=200.2+/-33.8 vs 155.6+/-29.0; P<0.001). The mean developmental quotient was normal. In IDMs with type-1 diabetes delayed VEPs were related to increased weight during pregnancy (r 0.516; P 0.009), 1st trimester fasting blood glucose (r 0.458; P 0.037), insulin requirement during the 2nd (r 0.441; P 0.035) and 3rd trimester (r 0.422; P 0.039); in IDMs with gestational diabetes, VEP latency showed negative relation to Apgar scores (r -0.748; P 0.008). CONCLUSIONS: IDMs have delayed VEPs, which may possibly be related to poor metabolic control in pre-gestational diabetes, and to delivery complications in gestational diabetes. SIGNIFICANCE: IDMs show subtle neurophysiologic changes detectable by VEPs.

Effects of chronic high serum levels of phenobarbital on evoked potentials in epileptic children.

We studied VEP and BAEP in 8 epileptic children with chronic high serum levels of phenobarbital. Records were obtained when the drug serum level was more than 40 mg/l and repeated when serum concentration was within the normal range. During the periods of high levels, P2 latency of the VEP was abnormally increased in all cases but one. The mean P2 latency decreased according to the reduction of the serum level of phenobarbital (139.6 msec vs. 110.1 msec, P = 0.002), and a significant regression coefficient (r = 0.546, P = 0.0271) was also noted between P2 latency and drug serum concentration. BAEPs were normal in all cases but one, who had a coexisting high level of phenytoin. All these findings suggest that the pharmacological effect of phenobarbital may be detected by VEPs and may result in delay of the P2 component.

Familial occurrence of benign myoclonus of early infancy.

Three cases of benign myoclonus of early infancy (BMEI) were observed in the same family. Previously, only sporadic cases have been reported. Electroencephalogram (EEG) recordings were consistently normal, and the affected girls had normal neurological development. Therapy was not administered and the episodes spontaneously disappeared within the first months of life. While etiological mechanisms of BMEI are still unknown, a hereditary mechanism is now hypothesized on the basis of these cases.

Outcome after discontinuation of antiepileptic drug therapy in children with epilepsy.

We studied recurrence risks and predictive factors of relapse after antiepileptic drug (AED) discontinuation in a prospective analysis of 425 children with epilepsy who had not had a seizure for at least 2 years (follow-up after withdrawal 1.6-12 years, mean 8 years). Factors closely related by multivariate analysis to relapse were neurologic abnormalities, mental retardation, seizure type (infantile spasms, absence seizures), and appearance or persistence of EEG abnormalities during the course of the illness and before discontinuation. When multivariate analysis was performed to evaluate outcome of patients with a first relapse (isolated vs. multiple relapses), the variables closely related to a poor prognosis were etiologic factors, first relapse characterized by more than one seizure in a 24-h period, seizure-free period less than 4 years, unchanged seizure type at first relapse, more than one AED for seizure control, and abnormal EEG before the first relapse. In itself, resumption of therapy did not influence outcome. At the study cutoff point, 88% of patients with relapse were again seizure-free. We conclude that AEDs can safely be discontinued if predictive factors are considered to individualize the risk of relapse for each patient.

Pattern-sensitive epilepsy: genetic aspects in two families.

We report two families in which five members (three in one and two in the other) suffer from pattern-sensitive epilepsy. In all affected members seizures were induced by environmental visual patterned stimuli. Diagnosis was confirmed by neurophysiological studies, including EEG with pattern and intermittent light stimulation and visual evoked potentials. The role of genetic aspects and the relationship between this form of reflex seizures and photosensitive epilepsy are emphasized.

Pattern sensitivity and photosensitivity in epileptic children with visually induced seizures.

We evaluated photosensitivity and pattern sensitivity in 74 epileptic children (38 males, 36 females aged 4.4-19 years; mean age 11.9 years) with reflex seizures induced by environmental visual stimuli and analyzed clinical and EEG characteristics of patients according to type of sensitivity. Standard procedures of visual stimulation were used in all cases. Seven children were excluded because of poor cooperation (3) or no activation (4). Fifty-one percent of the remaining 67 patients showed sensitivity to both light and pattern, whereas 33% showed photosensitivity and 16% showed pattern sensitivity. Generalized abnormalities were more frequently elicited by intermittent light stimulation than by pattern (73 vs. 36%, p < 0.001). Significant differences in clinical and EEG findings were noted among patients according to their sensitivity to light or/and pattern. In particular, pattern-sensitivity patients without photosensitivity had a higher occurrence of localization-related symptomatic epilepsies, neurologic abnormalities, and epileptiform EEG abnormalities, mainly focal, at rest.

Genetic aspects of nonconvulsive status epilepticus.

We studied the occurrence of seizure disorders within the immediate family in 3 groups of probands: (1) 64 epileptic children with nonconvulsive status epilepticus (NCSE); (2) 454 epileptic children who have had no episodes of NCSE; (3) 306 healthy children, matched for age and sex. Recurrence of seizures among relatives of epileptic probands without NCSE was significantly higher than among the general population, both in generalized and partial epilepsies. We also observed an increased incidence of convulsions among the relatives of probands with NCSE and the general population; no differences were noted between epileptic children with or without NCSE. These data support the hypothesis that genetic factors play an important role in the etiology of seizure disorders in children with NCSE.

Responsiveness of the visual system in childhood migraine studied by means of VEPs.

We have tried to ascertain whether the increased visual evoked potential (VEP) amplitude found in adult migraineurs is present also in children with migraine. We investigated 43 children, 26 male and 17 female, with a mean age of 11.4 years, 24 with common and 19 with classic migraine, and compared them with a control group of 20 children, 11 male and 9 female, with a mean age of 9.7 years. Flash and pattern reversal VEPs were recorded in both groups, and the study was carried out in the pain-free interval between attacks. The children with migraine showed a significant (p less than 0.01) increase in VEP amplitude on flash stimulation but not on pattern reversal. There were no differences between classic and common migraine. The abnormal responsiveness of the visual system seems to be related to variations in light intensity rather than to spatial contrasts.

Self-induced pattern-sensitive epilepsy in childhood.

We studied five children (1 boy and 4 girls) with self-induced pattern-sensitive epilepsy. All patients had refractory epilepsy with multiform, though mainly myoclonic, seizures and medium grade to severe mental retardation. Spontaneously self-induced seizures were documented in all cases by EEG. All the patients underwent full neurophysiological assessment (baseline EEG recording, with activation: eyelid closed, hyperventilation, ILS, EEG during the randomized presentation of 3 types of spatial structured stimuli, VEP-F and VEP-PR). The pattern that triggered the EEG anomalies was highly specific and selective for each patient. Clinical seizures were reproduced by the same patterns as the ones used by the patients to bring on the seizures at will. Authors stress the importance of identifying such peculiar type of epilepsy and of attempting adequate treatment.