Sleep EEG and developmental dysphasia: lack of a consistent relationship with paroxysmal EEG activity during sleep

In order to clarify the relationship between developmental dysphasia and EEG abnormalities, paroxysmal activities during sleep were studied in a series of 24 children with expressive developmental dysphasia (mean age 8 years) and compared to a control group of 39 children (mean age 9 years). The children of both groups were selected excluding cases with prior history of neurological disease or epilepsy. In the control group, 37 children had normal sleep EEG while 2 children had paroxysmal abnormalities. In the dysphasic group, epileptic abnormalities were observed in 9 cases, rare in 4 cases and frequent in 5 cases (density: 2.5 to 66.2% of total sleep time). Nevertheless, paroxysmal abnormalities did not reach the frequency described in the Landau-Kleffner syndrome, and it is unlikely that EEG abnormalities could have produced dysphasia.

[Agrypnia (organic insomnia)]

The word agrypnia, ie, organic insomnia, was first used to describe a patient with a Morvan fibrillary chorea, which is an ill-delineated syndrome. This review considers the experimental insomnia created by raphe nuclei, anterior hypothalamic, or thalamic lesions. There are some papers reporting REM and non-REM sleep reduction in man after vascular, traumatic or degenerative lesion of the pons. There is only one case of agrypnia due to a bilateral stereotatic thalamic injury. Infectious agrypnia (trypanosomiasis, Von Economo) may exist but has not been documented by polygraphic means. Fatal familial insomnia induces a precocious agrypnia and leads to death with vegetative and motor disturbances. It is associated with an abnormal prion-protein which may interfere with gabaergic synapses. Finally agrypnia in humans corresponds to either lesionnal or infra microscopic synaptic prion linked disorders.

[Sleep and intra-ictal epileptic electroencephalographic activities]

From this review it appears that the slow wave sleep (SWS) increases the mean density of electroencephalographic paroxysmal activities (PA) whatever the epileptic syndrome. This pattern is not marked according to a bell curve among the epileptic population: about half the patients exhibit few or no PA during SWS, 20% show an increase during waking and another 20% during SWS. Begnin epilepsy with centro-temporal spikes is associated with an important sleep PA increase. In partial epilepsy, stage 3 and 4 sleep should increase the PA transmission. In children, a large increase in PA during SWS defines the continuous spike-wave during sleep syndrome, which is also observed in the syndrome of acquired aphasia with epilepsy of Landau-Kleffner; both conditions raise the issue of the neuropsychological consequences of the sleep PA. The sleep effect on the various epileptic models is analysed, showing a mean increase in PA during SWS and during transition between sleep and waking. This evidence is in agreement with the fact that during light sleep thalamocortical loops are functioning with an oscillatory pattern which facilitates PA expression. More hypothetic is the effect of sleep on the discharge rate of epileptic focus and on the cortical diffusion of the epileptic discharges. Gaba certainly participates in the thalamic influence, but its role on PA by the cortical and brain stem inhibition is speculative. Noradrenaline and acetylcholine, implicated in waking, reduce PA activity. Interindividual variations suggest that each epileptic has his own pathological neuronal organisation in which cortex and thalamocortical connexions are variously sensitive to the neurotransmitters implicated in sleep and waking.

Isolated motor control dysfunction related to progressive multifocal leukoencephalopathy during AIDS with normal MRI

We describe the case of a human immunodeficiency virus-infected 34-year-old man with progressive multifocal leukoencephalopathy (PML). His case displayed unusual features, including a bizarre movement disorder, predominant involvement of the subcortical U fibers on neuropathologic examination, and the absence of MRI abnormalities suggestive of PML. Anatomic-clinical correlations are discussed.

[Progressive supranuclear paralysis. Quantification of dopamine D2 receptors using radionuclide tomography]

Progressive supranuclear palsy (PSP) may sometimes be misdiagnosed as Parkinson's disease in its early stages, hence an early positive diagnosis of PSP based on dopamine D2 receptor density could be extremely valuable. In the present case report, the absence of dopamine D2 receptors was clearly demonstrated in the striatum using 123I-iodobenzamide (IBZM) tomoscintigraphy. This illustrates the potential use of IBZM tomoscintigraphy to identify Parkinson-like's disease presenting with decreased dopamine D2 receptor density; and hence to predict L-Dopa effectiveness. Further studies are needed to evaluate the vaue of IBZM tomoscintigraphy in the different Parkinson's like diseases.

[The influence of sleep on abnormal waking movements]

Sleep decreases considerably the abnormal movements seen during waking in the degenerative extra-pyramidal diseases. However, the electrophysiologic recordings reveal that muscular contractions are not completely abolished. This decrease parallels the reduction of the waking system which act likely as a non-specific system of amplification. One can notice that sleep modifies the characteristics of the parkinsonian tremor and that some palatal myoclonias persist during sleep.

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.

Influence of lateral gaze on electroencephalographic spectral power

The effects of maintaining lateral gaze (as opposed to looking straight ahead) on electroencephalographic spectral power were tested in 12 right handed male subjects during eye opening (EO) and eye closure (EC). Our working hypothesis, based on Kinsbourne's paradigm, was that maintaining right lateral gaze activates the left hemisphere while maintaining left lateral gaze activates the right hemisphere, this activation resulting in a reduction in the spectral power over the hemisphere in question. Results showed that the variations in spectral power involved mainly the alpha frequency band. In the EC condition, the results were consistent with our working hypothesis: right lateral gaze produced a marked reduction in left hemispheric spectral power. In the EO condition, alpha power was constantly higher in the right hemisphere whether lateral gaze was maintained to the right or to the left. This can possibly be due to an attentional effect. Results are discussed with regard of the type of alpha rhythm and of the activation of cortical oculomotor centres. They shed light on the controversy concerning the existence of specific EEG correlates of cognitive activity, which preferentially involve each of the cerebral hemispheres.

[Amineptin dependence and iatrogenic acne. Review of the literature apropos of a case]

We relate the case of a drug addict of 31 years old whose dependence to the amineptine got complicated with severe acne-like lesions, as it sometimes happens. Compared, with teenage acne, severe acne can be distinguished by its late out break, its monstrous nature and its larger surface area. Amineptine has been found (or its metabolites) in the plasma, the urine. The treatment consists in the stopping of the drug addiction, combined with the prescription of isotretinoin.

Influence of lateralized neuropsychological activities with and without sensorimotor components on EEG spectral power (alpha-rhythm)

Spectral analysis of the EEG (alpha-rhythm) was studied in 8 young right-handed men who underwent 6 experimental tasks which were compared with rest, and included two pure motor activities using only the right and then the left hand, two pure neuropsychological tasks, and two "mixed" tasks with both neurophysiological and motor activities. The electrophysiological parameters studied were the log of spectral power and an asymmetry index (RP-LP)/(RP + LP). In order to demonstrate lateralization of the EEG, one must associate lateralized motor and neuropsychological tasks (which are supposed to preferentially involve one of the cerebral hemispheres). These results may reconcile apparently divergent views published in the literature with respect to lateralized EEG modifications associated with cognitive activities.

Two mesencephalic lacunar infarcts presenting as Claude's syndrome and pure motor hemiparesis

Two exceptional cases of mesencephalic lacunar infarcts located both in the anterior vascular territory are reported. In patient 1, the infarct selectively involved the red nucleus, thus resulting in a Claude's syndrome. In patient 2, the lesion was limited to the external 2/3 of the cerebral peduncle, and was responsible for a pure motor hemiplegia (PMH). CT scan easily demonstrated the lesion in both cases. Claude's syndrome is very unusual, and PMH has only been reported once before in a mesencephalic infarct. The reasons why these lesions are so uncommon are discussed.

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.

[Sleep in neurologic diseases]

Neurological diseases may induce alterations in sleep which are difficult to interpret owing to the multiple interferences introduced by treatments, associated somatic symptoms and time-related changes in causal lesions. The consequences of vascular or traumatic lesions observed in man confirm the data obtained from experimental lesions created in animals, thereby throwing some light on the roles played by the cerebral cortex, the thalamus and the brain stem nuclei. In degenerative diseases polygraphic recordings show subclinical signs of extension which are exceptionally specific of any particular type of degeneration. In epileptic patients recordings have determined the distribution of intercritical activities in the various waking and sleep stages: an increase of the activities during sleep appears to be a fairly independent constitutional feature. To sum up, one may say that the various sleep and waking control systems may be diversely affected by diseases of the nervous system. States of vigilance modulate some critical pathologies, such as epilepsy, according to modalities and a physiopathology that have not yet been fully elucidated.

The influence of vigilance states on paroxysmal EEG activities and clinical seizures in children

We studied the relationships between clinical variables and those related to the states of vigilance in 18 cases of benign partial epilepsy with centro-temporal spike-waves, 22 cases of definite symptomatic partial epilepsy, and 16 cases of undetermined partial epilepsy. The time of day during which the seizures appeared and the paroxysmal activity densities during non-REM and REM sleep are not distributed differently among the 3 electro-clinical types. However, the benign epilepsy with centro-temporal spikes group had more patients with sleep-sensitive paroxysmal activities. Patients who mainly had nocturnal seizures were found to have more frequent generalized seizures and a greater sleep-sensitive paroxysmal activity. Three cases demonstrated continuous spike-waves during sleep. The patients who had little or no paroxysmal activity during sleep were the youngest. This study illustrates that sleep-sensitive seizures and paroxysmal activities are not specific to benign childhood epilepsy with centro-temporal spikes, and that seizures and paroxysmal activities are two manifestations associated with epilepsy, affected in different ways by states of vigilance.