PubMed Health⌕ Search

Biomedical subjects

A Autret

Publications and source records attributed to A Autret.

At least 19 recordsLinked to original sources
PubMed1992

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.

Adult↗
PubMed1992

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.

Adolescent↗
PubMed1991

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.

Adult↗
PubMed1991

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.

Aged↗
PubMed1991

[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.

Acne Vulgaris↗
PubMed1990

[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.

Brain Injuries↗
PubMed1990

[Unusual headaches].

Cluster headache, ice pick headache, cough and effort headaches, and headaches related to sexual activity are unusual forms of headaches which are not treated elsewhere in this Revue du Praticien. They are briefly described.

Cluster Headache↗
PubMed1990

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.

Adolescent↗
PubMed1990

Influence of lateralized sensorimotor and neuropsychological activities on electroencephalographic spectral power.

In order to test the effect of 'lateralized' sensorimotor and neuropsychological activities on EEG spectral power (P), we recorded EEGs over the right and left central regions with 3 different derivations C5P3/C6P4, C5Cz/C6Cz, and C5 ears-linked (EL)/C6EL in 14 young, right-handed men who underwent ten 2 min sequences including 4 during rest (3 with eyes closed (EC), 1 with eyes open (EO], and 6 during tasks reputed to involve preferentially the left (Le) or the right (Ri) hemisphere, i.e., pure left and pure right motor activity of the hand (EC), pure neuropsychological tasks consisting in lexical followed by spatial form analysis and finally mixed (neuropsychological and motor) EC tasks consisting in writing followed by left hand object recognition. Three spectral parameters P, log P and asymmetry index AI = (P Ri-P Le)/(P Ri + P Le) were calculated in 5 frequency bands theta, alpha 1, alpha 2, alpha 3 and beta 1. We observed a relationship between task complexity and P reduction on both hemispheres which was greater during rest, less during motor activity and least during mixed motor and neuropsychological activities; during EC activities more specifically involving the left hemisphere, only the comparison between rest and mixed sequences was significant. During EC activities involving the right hemisphere, both motor and mixed sequences were significantly different from rest sequences. In addition, during the EO sequences, P was usually greater than during rest. As compared to rest conditions, the AI increased during sequences preferentially involving the left hemisphere and decreased during preferentially right hemisphere activities.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

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.

Adult↗
PubMed1990

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.

Aphasia↗
PubMed1990

Cicletanine and hypertensive retinopathy.

The aim of the present work was to study the activity of a new antihypertensive drug, a synthetic furopyridine, cicletanine, upon hypertensive morphological lesions of the retina. The stroke-prone spontaneously hypertensive rat strain (SHR-SP), known to develop hypertensive retinopathy, was a particularly suitable material in this view. The experiment was carried out in 39 rats (SHR-SP/A3N Iffa Credo), initially at the age of 11 weeks, divided into 3 groups: one as control group, the other two treated orally with 100 and 150 mg/kg cicletanine, respectively. All rats had free access to tap water containing 1% NaCl. For 46 days, blood pressure, body weight and death rate were recorded, then the rats were sacrificed. The eyes were removed, the posterior pole collected and fixed with Trump's liquid for transmission electron microscopy. In the control group, the capillaries showed marked hypertensive lesions. Multivesicular bodies were found in the different layers, particularly in the innermost layers; photoreceptor impairments could also be observed. In contrast to this group, both cicletanine-treated groups showed only rare and minimal lesions.

Administration, Oral↗
PubMed1989

Cerebellar hemangioblastoma and primary hyperparathyroidism.

The authors report the case of a 52-year-old woman presenting with cerebellar hemangioblastoma and primary hyperparathyroidism. It is the second reported case involving this new association. The relationship between these two tumors is discussed.

Cerebellar Neoplasms↗