Spectral analysis of the EEG (alpha rhythm) and activity in the left hemisphere: the effects of lateral gaze.

This study tests the effect of maintaining right and left lateral gaze during a writing task which preferentially implicates the left hemisphere using an asymmetry parameter calculated from the spectral power of the alpha rhythm (RP-LP/RP + LP) in a right-handed patient undergoing the same experimental regimen nine times. A six derivation EEG was recorded. Maintaining left lateral gaze (toward the active hemisphere) removes the lateralization found during writing while staring straight ahead whereas maintaining right lateral gaze (toward the side opposite the active hemisphere) results in slightly lower values which are however, not significantly different from those obtained during staring straight ahead. This study adds an electrophysiologic aspect to Kinsbournes's paradigm on gaze position and hemispheric activation.

ERP evidence of developmental changes in processing of faces.

OBJECTIVES: There is disagreement in the behavioural literature, as to whether face processing undergoes qualitative or quantitative change with age. METHODS: We studied event-related potentials (ERPs) associated with facial processing in 48 children (4-14 years) and 12 adults. Five categories of stimuli were presented: faces, cars, scrambled faces, scrambled cars, butterflies. The butterflies were targets (P = 12%); the other stimulus categories were equally represented and all were non-targets. RESULTS: An N170 was recorded only to the faces at posterior temporal sites and in adults it was largest at T6'. This component was seen across age groups, but at steadily increasing latencies in younger children. Age-related increases in N170 amplitude were found at T6'. In children under 12 years of age, the frontal P170 was not reliably seen. CONCLUSION: This study suggests that the underlying neural basis associated with processing faces matures in a gradual, quantitative manner throughout childhood.

A note on the occurrence of unusual electroencephalographic sleep patterns in selected normal children.

Polysomnographic recordings were performed in 50 children free from any familial or personal history of seizure or neurologic diseases to evaluate the frequency of epileptiform and unusual electroencephalographic patterns in a normal population. A 9-year-old boy exhibited focal spikes that became bilateral with a density of 24% to 32% during slow wave sleep, and another boy showed a few spikes during slow wave sleep. In seven cases, 14- and 6-Hz rhythms were recorded, mostly in rapid eye movement sleep. A right rhythmic and temporal discharge was observed in one girl. Epileptiform electroencephalographic patterns are not infrequent, and 14- and 6-Hz rhythms during rapid eye movement sleep are common in normal children.

[Emergency electroencephalography during perinatal cerebral intensive care: indications and results]. / Electroencéphalogramme en urgence au cours de la souffrance cérébrale périnatale: indications et résultats.

The main contribution of EEG during intensive care in infants with hypoxic-ischemic encephalopathy is i) to help determine whether infants with subtle clinical manifestations present with epileptic seizures, ii) to determine whether paralyzed or heavily sedated infants present with convulsive phenomena, iii) to assess the therapeutical response to anticonvulsants, 4) to contribute, in combination with ultrasound scanning, to diagnostic evaluation of the severity of lesions, and to provide valuable prognostic informations via the analysis of the background activity, as normal EEG is highly predictive of normal outcome, whereas various abnormal EEG features are constantly associated with subsequent major neurological abnormalities or death. These EEG features are readily available from a very early stage and may both precede and be prognostically more sensitive than information obtained from ultrasound. Recording of neonatal electroencephalogram requires awareness of the normal development of electroencephalographic features in the newborn, skilled technicians, and experienced readers of EEG tracings.

Are frequent spike-waves during non-REM sleep in relation with an acquired neuro-psychological deficit in epileptic children?

In a population of 11 children with frequent spike waves during non REM sleep who had no neurological symptoms between birth and their first symptom, 3 groups were compared according to their neuropsychological performances. In the first group, the children had no intellectual deficit, in the second group, they had an acquired aphasia as in the Landau-Kleffner syndrome and in the third they had severe behavioural disorder and mental deterioration. The non REM sleep paroxysmic activity density tended to be highest in the third group, variable in the second group and moderate in the first group, and their topography was always generalized in the acute phase in groups II and III but asymmetrical in group I. The EEG anomalies disappeared during adolescence but in group II and III children a moderate to severe delay in school work persisted.

[Emergency EEG and brain injuries]. / EEG en urgence et traumatisme crânien.

The aim of this study is to review indications for emergency EEG in case of brain trauma. The authors emphasize the indication of emergency EEG for the diagnosis of either cerebral death or early post traumatic seizures, and for the monitoring of intensive neurological treatments. Emergency EEG and diagnosis of cerebral death has been reviewed in another issue of this journal. Diagnosis of early post-traumatic seizures may be difficult in case of cranial trauma in either the presence or the absence of coma. Emergency EEG help guide the diagnosis of electrical signs of seizures, thus indicating that treatment with antiepileptic drugs is advisable. Severe post-traumatic coma requires barbiturate impregnation and moderate hypothermia. In this last case, emergency EEG is essential for the monitoring of pharmacological treatments. The authors conclude that continuous EEG monitoring could in the future substitute for standard EEG recorded in emergency.

[Acute reversible pan-dysautonomia: effect of erythromycin on gastrointestinal involvement]. / Pan-dysautonomie aiguë réversible: effet de l'érythromycine sur l'atteinte gastro-intestinale.

We describe a case of acute autonomic neuropathy in an 18-year-old woman. Gut dysfunction was sufficiently severe for the patient to undergo laparotomy for suspected mechanical-intestinal obstruction before the diagnosis was made. Apart from the gut, other organs affected included the pupils, sweat and lachrymal glands. Cardiovascular autonomic function tests showed the involvement of sympathetic adrenergic nerves. Small bowel barium X-ray showed resolution of gastric stasis and emergence of jejunum dilatation during intravenous administration of erythromycin but this treatment did not eliminate intestinal obstructive symptoms. The patient had an incomplete recovery in 3 months. Erythromycin might have therapeutic value in patients with intestinal motility dysfunction in acute dysautonomia.

[Intracerebral hematoma in gamma-angio-encephalography]. / Les hématomes intracérébraux en gamma-angio-encéphalographie

The radionuclide angiography, of gamma-angio-encephalography (gamma-A.E.G.), a non invasive method, is able to bring specific information for the diagnosis of intracerbral hematoma (I.C.H.). In 25 out of 32 verified cases of I.C.H. the rapid sequential imaging shows from the arterocapillary time a deeply seated avascular area, which is a quite different aspect from the defect observed in ischemic A.C.V., or malignant tumors. The transit curves confirm the regional of circulating blood pool.

Effect of salbutamol, a putative cerebral beta agonist on sleep stages and interictal epileptic discharges.

The effects of Salbutamol 1.5 mg in 250 ml dextrose solution was tested on 14 epileptic patients following a double blind cross-over design. Sleep parameters and interictal paroxysmal activities density were measured. No seizures were encountered during the experiment. No modification of either sleep parameters (duration of sleep stages, latency of sleep and paradoxical sleep, duration of sleep cycles and awaking) or density of P. A. during waking state, on stage I, II, III and IV and paradoxical sleep were observed. In other respects, 5 patients had no P. A. during polygraphic sessions. They exhibited a longer duration of paradoxical sleep and a shorter duration of awaking than the 9 other patients with P. A. So with the dosage used here no implication of central beta-adrenoceptors in sleep mechanisms and production of epileptic activity are suggested.