Marja-Liisa Granström

Temporal lobe epilepsy in early childhood

To explore the electroclinical features of temporal lobe epilepsy (TLE) in early childhood, we studied results of video‐EEG and other tests of 14 children aged 16 months to 12 years selected by seizure‐free outcome after temporal lobectomy. Four children had mesiotemporal sclerosis, 1 had cortical dysplasia, and 9 had low‐grade temporal neoplasms. The children had complex partial seizures (CPS) with symptomatology similar to that of adults with TLE, including decreased responsiveness and automatisms. Automatisms tended to be simpler in the younger children, typically limited to lip smacking and fumbling hand gestures. Scalp/sphenoidal EEC showed anterior/inferior temporal interictal sharp waves and unilateral temporal seizure onset in the 4 children with mesiotemporal sclerosis and in the child with cortical dysplasia, but EEG findings in 9 children with low‐grade temporal tumors were complex, including multifo‐cal interictal sharp waves or poorly localized or falsely lateralized EEG seizure onset. In children without tumors, video‐EEG was critical to localization of the epi‐leptogenic zone for resection, but in patients with tumors video‐EEG was less localizing and its main value was to confirm that the reported behaviors were epileptic seizures with semiology typical of temporal lobe onset.

Intelligence of children of epileptic mothers

Intellectual performance was investigated in a group of 148 children of epileptic mothers enrolled in a prospective study during pregnancy, and in 105 control children; 121 of the 148 children (82%) were examined together with the control group at the age of 5 1/2 years. The intelligence of 116 study and 104 control children was assessed by both verbal (Wechsler Preschool and Primary Scale of Intelligence) and nonverbal (Leiter International Performance Scale) methods. The prevalence of mental subnormality among the remaining 32 study children was calculated on the basis of psychologic assessments done outside our study, or school achievement, or both. Of the 148 study group children, 131 had been exposed in utero to antiepileptic drugs, most commonly phenytoin (103 exposed). The prevalence of mental deficiency in the study group (1.4%) was either the same or only slightly elevated in comparison with that in the general population. In the control group, there were no mentally deficient children. The mean intelligence quotients obtained at the 5 1/2-year examination were significantly lower in the study group than in the control group. There was no increased risk of low intelligence attributable to fetal exposure either to antiepileptic drugs below toxic levels or to brief maternal convulsions. In a few cases, there seemed to be a genetic connection between epilepsy in the mother and poor intellectual performance in the child. A high number of minor anomalies was associated with a lower mean intelligence quotient in both the study and the control groups. However, those features previously reported as typical of children of epileptic mothers, and those shown to be associated with phenytoin exposure in a previous phase of this study, did not predict low intelligence in the affected children.

Magnetoencephalography in presurgical evaluation of children with the Landau-Kleffner syndrome

Summary: Purpose: Our aim was (a) to localize the primary epileptogenic cortex for possible multiple subpial transsection in four children with the Landau‐Kleffner syndrome (LKS), and (b) to evaluate the impact of magnetoencephalography (MEG) in the localizing process.

Treatment of infantile spasms : Results of a population-based study with vigabatrin as the first drug for spasms

Summary: Purpose: The efficacy of a protocol consisting of vigabatrin (VGB) as the first and adrenocorticotropic hormone (ACTH) or valproate (VPA) as the second drug was studied in the treatment of newly diagnosed infantile spasms (IS) during 1994 to 1997 in a population‐based design.

Visual Field Constriction in 91 Finnish Children Treated with Vigabatrin

Summary:  Purpose: To study the prevalence and features of visual field constrictions (VFCs) associated with vigabatrin (VGB) in children.

Apparent asynchrony between interictal electric and magnetic spikes

WE recorded simultaneous multichannel electroencephalogram (EEG) and magneto encephalogram (MEG) in four children with partial epilepsy. Sources of averaged spikes were modelled with current dipoles. Of 10 spike averages obtained, three peaked simultaneously in MEG and EEG, and in seven averages, the MEG peak preceded the main EEG peak by 9–40 ms. A small positive early EEG signal coincided with the MEG peak in six asynchronous spikes. The simultaneous MEG and EEG spikes originated within 5–23 mm, while sources of asynchronous peakswere 12–67 mm apart. We conclude that non-identical neurone currents underlie the MEG and EEG signals, and emphasize the importance of modelling early phases of EEG spikes when localizing interictal epileptic zones.

Prediction of perinatal brain damage by cord plasma vasopressin, erythropoietin, and hypoxanthine values

For an assessment of whether cord plasma arginine vasopressin, erythropoietin, and hypoxanthine concentrations are predictors of perinatal brain damage, these concentrations were measured in 62 infants born after preeclampsia of pregnancy, 31 acutely asphyxiated infants, and 38 control infants. Follow-up at 2 years included neurologic examination and the determination of a Bayley mental score. Clear abnormality (death, cerebral palsy, or developmental delay) was found in four infants in the preeclampsia group and five in the asphyxia group; slight abnormality was found in 12 and 6 infants, respectively; and no abnormality was found in the remainder. Neither arginine vasopressin values nor hypoxanthine values predicted adverse outcome in either study group. A high erythropoietin level was found in infants born after preeclampsia regardless of outcome: normal outcome (geometric mean (GM), 102; 95% confidence interval [CI], 69 to 153 mU/ml), slightly abnormal outcome (GM, 100; 95% CI, 37 to 270 mU/ml) or clearly abnormal outcome (GM, 84; 95% CI, 19 to 378 mU/ml). However, asphyxiated infants with clearly abnormal outcome had higher erythropoietin values (GM, 67; 95% CI, 33 to 137 mU/ml; p less than 0.05) than the normal infants (GM, 37; 95% CI, 23 to 59 mU/ml). We conclude that a high erythropoietin level after normal pregnancy, but not after preeclampsia, indicates an increased risk for cerebral palsy or death.

Landau-Kleffner syndrome: epileptic activity in the auditory cortex

The Landau-Kleffner syndrome (LKS) is characterized by electroencephalographic spike discharges and verbal auditory agnosia in previously healthy children. We recorded magnetoencephalographic (MEG) spikes in a patient with LKS, and compared their sources with anatomical information from magnetic resonance imaging. All spikes originated close to the left auditory cortex. The evoked responses were contaminated by spikes in the left auditory area and suppressed in the right--the latter responses recovered when the spikes disappeared. We suggest that unilateral discharges at or near the auditory cortex disrupt auditory discrimination in the affected hemisphere, and lead to suppression of auditory information from the opposite hemisphere, thereby accounting for the two main criteria of LKS.

Parietal epileptic mirror focus detected with a whole-head neuromagnetometer

WHOLE-head magnetoencephalographic recordings revealed two parietal epileptic foci in homotopic areas of the hemispheres. The discharges occurred 17–20 ms later on the left than on the right hemisphere, implying the existence of a left-sided mirror focus. The foci were about 1 cm posterior to the hand primary somatosensory area, identified by evoked response measurements, and thus suggested epileptic activity at the parietal association cortex, in agreement with the observed callosal conduction time.

Monitoring of concentrations of clobazam and norclobazam in serum and saliva of children with epilepsy

Clobazam was added to the previous antiepileptic drug therapy of 90 children suffering from drug resistant epilepsy. Ten patients became seizure free, although four of these later developed tolerance. Thirty-three patients experienced a decrease in seizure frequency, and 24 of these, too, developed tolerance. Forty-four patients showed no change in seizure frequency, and three experienced an increase. The best results were experienced by patients with myoclonic seizures, whereas patients with complex partial seizures usually developed tolerance. The concentrations of clobazam and its active metabolite norclobazam were measured in 251 serum and 57 saliva samples. The group of seizure-free patients had the lowest clobazam and norclobazam concentrations; tolerance was associated with the highest concentrations. Beneficial side effects were associated with low, and adverse effects with high, concentrations of norclobazam. The concentrations of clobazam and norclobazam in saliva correlated with concentrations in serum. Monitoring of serum and salivary concentrations of clobazam and norclobazam is of limited value only, and no therapeutic target range can be given.