Showing papers in "Neurophysiologie Clinique-clinical Neurophysiology in 1995"
TL;DR: Sleep efficiency was nearly always poor with a high percentage of wakefulness after sleep onset (WASO) and increased number of arousals, and REM sleep was often reduced and in some cases incompletely defined as far as its microstructural aspects.
Abstract: Summary Twenty-one patients affected by extrapyramidal disorders were polygraphically recorded during spontaneous nocturnal sleep for two consecutive nights to assess their sleep and movement patterns. The patients (pts) sample included: Gilles de La Tourette syndrome (TS, nine pts), neuroacanthocytosis (NA, six pts) and Huntington's chorea (HC, six pts). Sleep recording included C3/A2, 01/A2, ROC/LOC, submental EMG, EKG, nasal airflow thoracoabdominal respirogram, bilateral anterior tibialis and other EMGs, in relation to the individual distribution of the abnormal movements. According to our observations, abnormal movements always decreased but never ceased completely during sleep. Sleep efficiency (SE) was nearly always poor with a high percentage of wakefulness after sleep onset (WASO) and increased number of arousals. REM sleep was often reduced and in some cases (3 TS pts) incompletely defined as far as its microstructural aspects. Slow wave sleep (SWS) was reduced in HC, normal in NA, and increased in all TS patients with the exception of the two adult subjects more severely affected, while the percentage of stage 2 was not affected. Spindling was increased in NA, HC and in the two most severely affected adult TS patients.
87 citations
TL;DR: The present paper finds that shift work is associated with severe sleepiness on the night shift and to some extent on the morning shift, at least as severe as that seen in hypersomnia.
Abstract: The present paper finds that shift work is associated with severe sleepiness on the night shift and to some extent on the morning shift. This sleepiness is at least as severe as that seen in hypersomnia and is associated with a strongly increased risk of accidents. The reason for night shift sleepiness is work at the circadian nadir, extended periods of wakefulness, and truncated sleep. Much of the sleepiness in shift work may be predicted using a quantitative model.
79 citations
TL;DR: An improved method of EEG processing, strict criteria for patients selection, and comparison with behavioral data suggest that patients suffering from migraine without aura between attacks require more time for automatic and/or voluntary processes.
Abstract: "Oddball" paradigm studies of auditory P300 have yielded conflicting results in migraine. We therefore undertook an additional study of auditory event-related potentials (ERPs) using an improved method of EEG processing, strict criteria for patients selection, and comparison with behavioral data. Twenty-one healthy subjects were compared to 20 patients suffering from migraine without aura between attacks. Migraine patients differed significantly from control subjects on several parameters: shorter latency of N1 (Cz) evoked by standard stimuli, longer latencies of both P3a and P3b (Pz) evoked by target stimuli, longer interval between N1 and P3b (Cz), smaller P3b (Cz) amplitude, longer reaction time (RT), higher number of errors (false alarm and/or omissions) and higher mean score on Plutchik-Van Praag's (PVP) inventory for depression. Errors were significantly correlated with RT and PVP scores. From a behavioral perspective, these results may suggest that patients suffering from migraine without aura between attacks display a higher level of arousal and more superficial attention, but require more time for automatic and/or voluntary processes. According to the inverted U-shaped relationship between performance and arousal, these patients may have difficulties in adjusting their attention level to perform a task in a optimal way.
52 citations
TL;DR: C-Fos expression was considerably increased in regions involved in the regulation of arousal states, such as the locus coeruleus (noradrenergic neurons) and the medial preoptic area (non-GABAergic neurons), and it was demonstrated that c-fos expression in this region is causally involved in sleep regulation.
Abstract: We have recently demonstrated that c-fos expression is strongly induced by both spontaneous and forced wakefulness in many brain regions. c-Fos expression was considerably increased in regions involved in the regulation of arousal states, such as the locus coeruleus (noradrenergic neurons) and the medial preoptic area (non-GABAergic neurons). With c-fos antisense injection in the medial preoptic area, we demonstrated that c-fos expression in this region is causally involved in sleep regulation. c-Fos expression in other areas, such as the cerebral cortex and the hippocampus, may be related to the functional consequences of prolonged wakefulness and to the need of sleep. Further work should explore the mechanisms leading to changes in the expression of c-fos, and possibly of its target genes, during the sleep-wake cycle.
45 citations
TL;DR: When initially normal, motor potentials evoked by transcranial magnetic stimulation had a significant predictive value for long-term functional outcome, whereas SEP and SSR did not.
Abstract: A prospective 3-month follow-up examination was carried out in 12 patients with supratentorial stroke. Motor evoked potentials (MEP), somatosensory evoked potentials (SEP) and sympathetic skin responses (SSR) were performed 1-7 days, 30 days and 3 months after stroke. The functional outcome measured by a daily activity index (Barthel index) was assessed 3 months after the stroke. There was a significant correlation between SEP and MEP results obtained for the first week and recovery of sensation and motility 3 months later. When initially normal, motor potentials evoked by transcranial magnetic stimulation had a significant predictive value for long-term functional outcome, whereas SEP and SSR did not. SSR present at the initial stage was correlated with the state of consciousness.
38 citations
TL;DR: Exogenous MLT is able to influence the endogenous secretion of the hormone according to a phase response curve, and plays the role of an endogenous zeitgeber on core temperature or sleep-wake cycle.
Abstract: Melatonin (MLT) is a methoxyindole secreted principally by the pineal gland. It is synthesized at night under normal environmental conditions. The endogenous rhythm of secretion is generated by the suprachiasmatic nuclei and activated by the light/dark cycle. Light is able to both suppress or activate melatonin production on the light schedule. The nycthohemeral rhythm of this hormone can be determined by repeated measurements of plasma or saliva MLT or urine sulfatoxy-MLT, the main hepatic metabolite. Melatonin can be considered as the output (the hand) of the endogenous clock. Since the regulating system follows a central and sympathetic nervous pathway, an abnormality at any level could unspecifically modify the MLT secretion, especially in patients with sympathalgia or dysautonomia. Melatonin plays the role of an endogenous zeitgeber on core temperature or sleep-wake cycle. Exogenous MLT is able to influence the endogenous secretion of the hormone according to a phase response curve. There are practical implications for this property in situations when biological rhythms are disturbed (jet-lag syndrome, delayed sleep phase syndrome, insomnia in blind people, shift-work, insomnia in elderly people). Improvement of pharmaceutical forms (controlled release preparations) or development of MLT analogs could lead to decisive progress.
26 citations
TL;DR: The case of a child presenting with numerous stroke-like episodes associated with EPC which, despite therapy, were not controlled and aggravated the clinical condition of the patient.
Abstract: Summary There are few reports in the literature dealing with the association between mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and epilepsia partialis continua (EPC) in children. We report the case of a child presenting with numerous stroke-like episodes associated with EPC which, despite therapy, were not controlled and aggravated the clinical condition of our patient. We present the neuroradiological, biochemical, genetic and muscle biopsy findings, and EEG characteristics, with attention to polygraphic recordings which were done during wake and sleep periods. We consider the correlation with other possible etiological factors relating to EPC and in particular co-involvement of the basal ganglia as a cause of EPC in our patient.
20 citations
TL;DR: In this paper, the authors retrospectively evaluated the EEG performed at their first referral in 56 consecutive JME patients first seen between 1986 and 1992 (26 M, 30 F, aged 12-53, mean 24.4, with onset of JME at age 10-33, mean 14.3).
Abstract: Atypical clinical and/or EEG presentation may complicate the diagnosis of juvenile myoclonic epilepsy (JME). To assess the sensitivity of a standard EEG recording, we retrospectively evaluated the EEG performed at their first referral in 56 consecutive JME patients first seen between 1986 and 1992 (26 M, 30 F, aged 12-53, mean 24.4, with onset of JME at age 10-33, mean 14.3). The diagnosis had been made in none of these patients prior to referral, and was often confirmed only during follow-up. A 20-minute standard EEG was recorded, including hyperventilation (HV) and intermittent light stimulation (ILS). This EEG was normal in 15 cases (27%), showing aspecific or misleading changes in 11 cases (20%) and typical changes in only 30 cases (54%). The baseline EEG was normal in 25 (45%), atypical in 11 (20%), and typical for JME in only 20 (35%). HV and ILS yielded 37 and 39 normal, 10 and 7 aspecific and 9 and 10 specific findings, respectively. A single standard EEG without activation may thus be inconclusive or misleading for the diagnosis of JME in more than 50% of newly referred patients.
16 citations
TL;DR: A protocol using the combination of small naps, and administration of a pharmacological aid to counteract the effects of amphetamines and amphetamine-like substances and eugregoric substances is described.
Abstract: Prolonged sleep deprivation is an exceptional situation, encountered in special environments such as sports, civilian and military, and which induces deficits in vigilance and performance. Among the array of measures which may be used to counteract these effects, the authors described a protocol using the combination of small naps, and administration of a pharmacological aid. A detailed description of advantages and drawbacks of each one of these measures is given, illustrated by several examples extracted from different studies. Four aspects of pharmacological aid are reviewed: the effects of amphetamines and amphetamine-like substances, caffeine, eugregoric substances, and the effect of the association small nap + eugregoric substances. The use of these various aids is discussed, and findings show that each one of them finds an application in a specific context.
15 citations
TL;DR: In this article, the influence of suicidal risk and hopelessness on P300 amplitude among 40 depressive inpatients was assessed and the results showed that significant relationships between P3 amplitude and suicidal risk (r = -0.68, p < 0.001) and with hopelessness.
Abstract: P300 amplitude represents a useful tool to assess information processing in normal and psychopathological subjects. In depressive disorders, many studies have shown a decrease of P300 amplitude and an increase of its latency. However, functional significance of the P300 modifications remain unclear. The aim of the study was to assess the influence of suicidal risk and hopelessness on P300 amplitude among 40 depressive inpatients. The results showed significant relationships between P300 amplitude and suicidal risk (r = -0.68, p < 0.001) and with hopelessness (r = -0.76, p < 0.001). From a clinical point of view, P300 amplitude should be considered as a psychophysiological index of suicidal risk in major depressive disorder.
13 citations
TL;DR: In this article, the successive components of the ERP's evoked by target and standard stimuli (N1, P2, N2, P3a and P3b) were analyzed using an auditory oddball paradigm with motor response.
Abstract: The use of P300 in psychopathology raises the important problem of the constitution of reference normative data and of the high variability of auditive ERP's in controls. To handle better this problem, we recorded 86 control subjects, using an auditory oddball paradigm with motor response. We analyzed the successive components of the ERP's evoked by target and standard stimuli (N1, P2, N2, P3a, P3b and slow wave negativity). Our results underlined the role of age, sex and psychological factors on the ERP's interindividual variability: P3 amplitude decreased and its latency increased with age, while its topography was more frontal in the older than in the younger subjects. The P300 occurrence after standard stimuli and P3 amplitude after target stimuli were different according to sex. Moreover, P300 amplitude, latency and topography were related to the subject's anxiety level. Finally, our results also propose new description modes of ERP's relying on P3a and P3b relative peak amplitude (P300 with prominent P3a or P3b), topographical predominance (frontal or parietal P300) and duration of the late positive complex (brief or long-lasting P300). These data will improve the clinical use of P300.
TL;DR: The fact that both disorders of arousal and epilepsy are strictly related to sleep and often share common features such as age range of onset and precipitating factors, suggests the existence of common functional substrates identifiable in constitutional maturative and biologic factors.
Abstract: Summary Six patients (3M, 3F, mean age 17.3 yrs) presenting different types of evolution from disorders of arousal to epilepsy are described. All subjects during their childhood had been diagnosed in a sleep center as affected by sleep-walking (three cases) and night terrors (the other three). Successively they developed nocturnal events different from those previously exhibited and consisting of clear epileptic seizures, generalized tonic-clonic in one case and complex partial in five cases. Nocturnal monitoring allowed recognition of clear interictal paroxysmal activity in three patients, while ictal events were recorded in the remaining three. Anticonvulsant treatment (carbamazepine in five patients, phenytoin in one patient) led to the resolution of the ictal events in all cases. The fact that both disorders of arousal and epilepsy are strictly related to sleep and often share common features such as age range of onset and precipitating factors, suggests the existence of common functional substrates identifiable in constitutional maturative and biologic factors. The possible occurrence of seizures in subjects exibiting parasomnia during their childhood has to be considered in patients with familial history of epilepsy and in all doubtful cases.
TL;DR: In this paper, a revue sur les potentiels evoques cognitifs chez l'enfant comporte deux volets correspond a deux exemples de pathologie developpementale (trouble de l'attention and autisme) or les PE cognitifiers permettent de mieux comprendre les dysfonctionnements qui sous-tendent les desordres cognitifier observes.
Abstract: Resume Cette revue sur les potentiels evoques (PE) cognitifs chez l'enfant comporte deux volets. Le premier concerne l'apport des PE cognitifs dans les etudes du developpement normal. Les PE cognitifs varient en effet d'une part en fonction de l'âge de l'enfant et d'autre part en fonction des processus cognitifs mis en jeu lors des tâches realisees. Les etudes topographiques permettent egalement de preciser les regions du cerveau impliquees dans ces processus cognitifs specifiques. Le deuxieme volet correspond a deux exemples de pathologie developpementale (trouble de l'attention et autisme) ou les PE cognitifs permettent de mieux comprendre les dysfonctionnements qui sous-tendent les desordres cognitifs observes.
TL;DR: In this article, the authors analyse les effets hypnogenes de l'automassage du point 7 cœur d'acupuncture, le sommeil nocturne de six volontaires sains (27,8 1,6 ans) a ete etudie par polygraphie de 23 h a 7 h, apres une nuit d'adaptation au laboratoire.
Abstract: Resume Afin d'analyser les effets hypnogenes de l'automassage du point 7 cœur d'acupuncture, le sommeil nocturne de six volontaires sains (27,8 1,6 ans) a ete etudie par polygraphie de 23 h a 7 h, apres une nuit d'adaptation au laboratoire. Une premiere session de 2 nuits consecutives a ete analysee avec le systeme des cones PEBA (polyether block amides; Isocones ® ) soit en application active (AA, point 7 cœur), soit en application placebo (AP, dos de la main). L'application inverse a ete analysee 2 semaines plus tard, l'etude etant randomisee, en double-aveugle et selon un ordre de passage equilibre. L'organisation des activites cycliques biphasiques electroencephalographiques (CAP: cyclic alternating patterns ) a ete analysee au cours du sommeil orthodoxe (stades 1 a 4). L'efficacite du sommeil a augmente en AA, l'eveil diminuant au profit d'un accroissement du temps de sommeil total lie a celui du sommeil orthodoxe. Le nombre de CAP a decru en AA, ainsi que le nombre de sequences de CAP et le taux de CAP rapporte au temps de sommeil total et a la duree du sommeil lent profond. L'application des cones au point 7 cœur chez des sujets sains a donc induit une diminution de l'eveil persomnique et une augmentation du sommeil orthodoxe.
TL;DR: This review considers the experimental insomnia created by raphe nuclei, anterior hypothalamic, or thalamic lesions and concludes that agrypnia in humans corresponds to either lesionnal or infra microscopic synaptic prion linked disorders.
Abstract: 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.
TL;DR: In this article, a classification of crises epileptiques is proposed, based on the serneiologie critique clinique, which is used in l'universale de Bancaud et al. (1976).
Abstract: Resume Malgre son utilisation quasi-universelle, la classification internationale des crises epileptiques souffre de certains inconvenients. Les distinctions fondamentales, d'une part entre crises partielles et generalisees, d'autre part entre crises partielles simples et complexes, ne sont pas toujours pratiques ni meme souhaitables. La terminologie est souvent lourde, et ne contient pas la semeiologie localisatrice essentielle. Enfin, la classification precise des crises est parfois dependante de l'EEG. Nous proposons une classification differente, qui repond a ces inconvenients, et est utilisee depuis plusieurs annees dans l'un des grands centres d'epilepsie. Cette classification est basee exclusivement sur la serneiologie critique clinique et ne prend en compte aucun autre test, en accord avec les conceptions de Bancaud (1976) . Ce systeme parait etre plus pratique, et plus adapte aux centres qui mettent l'accent sur un traitement chirurgical des epilepsies.
TL;DR: In this article, the authors propose the use of the EEG ambulatoire (EEG-A) for pratiquer des enregistrements polygraphiques diurnes et nocturnes de longue duree, particulierement utiles dans le diagnostic de la narcolepsie-cataplexie (N/C).
Abstract: Resume L'EEG ambulatoire (EEG-A) permet de pratiquer des enregistrements polygraphiques diurnes et nocturnes de longue duree, particulierement utiles dans le diagnostic de la narcolepsie-cataplexie (N/C). Au moyen du systeme Medilog 9000 a huit canaux, cet examen a ete pratique pendant un total de 36 periodes de 24 heures chez 20 patients narcoleptiques consecutifs, et a permis d'enregistrer en moyenne 3,5 assoupissements diurnes, dont 2,2 en sommeil paradoxal (SP), avec 21 endormissements nocturnes en SP sur 36 (58%). Un test iteratif a ete pratique dans 16 cas avec la meme methode. L'EEG-A continu se revele plus informatif que la derniere methode, et represente une alternative interessante aux enregistrements continus en laboratoire de sommeil, plus contraignants. Bien qu'une polysomnographie classique reste indiquee si l'on suspecte une pathologie du sommeil associee a la N/C, l'EEG-A peut etre envisage comme methode de premiere intention pour la confirmation du diagnostic de N/C, qui reste avant tout clinique.
TL;DR: Interictal epileptic spikes (IES) were recorded and averaged in 4-15 channels, in seven adult epileptics with intracerebral electrodes, revealing the main basic relationships in the large numbers of IES.
Abstract: Interictal epileptic spikes (IES) were recorded and averaged in 4-15 channels, in seven adult epileptics with intracerebral electrodes. IES relations were revealed by comparing the onset of the averaged IES in each channel, with one being used alternatively as the triggering channel. The records were analysed and sorted by comparing the morphology of individual IES and the final average morphology. There was a dominant group of IES on each recording site channel representing about 65-80% and decidedly influencing the average morphology of all IES. The major limitation of IES averaging is the loss of information due to the IES relative heterogeneity. Nevertheless, it reveals the main basic relationships in the large numbers of IES. On the other hand, IES averaging helps to minimize fortuitous spatiotemporal relations between recording sites. The relationship between IES in two channels was considered as significant only when these channels were observed both before and after the mutual switching of the role of triggered and triggering channel. The relations were then considered significant in only about 18% of all possible relations.
TL;DR: In this paper, the relative organization of three of the stages of Sanders' 1990 information processing model: "features extraction", "response choice", and "motor adjustment" was tested. And the results suggest that the response choice processing would be contemporary to the N200 component.
Abstract: The main aim of this study was to test the relative organization of three of the stages of Sanders' 1990 information processing model: "features extraction", "response choice", and "motor adjustment". The variables influencing these stages: stimulus degradation, stimulus-response (SR) compatibility and preparatory period have been manipulated. Event related potentials (N100, N200, P300) and reaction time were recorded from ten healthy subjects, in a dichotic listening task. Reaction times are lengthened for degraded stimuli, in the absence of a preparatory period and for SR non compatible conditions. However, the interaction between preparatory period and stimulus degradation variables, suggests an overlapping of the corresponding stages contrary to Sanders' postulate. The non compatible condition increases the latency of N200 and P300 components. The results suggest that the response choice processing would be contemporary to the N200 component. They are discussed within the framework of models of early communication between sensory and motor systems.
TL;DR: Observe chez des malades qui ont des troubles de la vigilance, du comportement et de the motricite, et des traces EEG tres alteres, est indicatif d'un stade d'encephalite beaucoup plus severe.
Abstract: Resume Les donnees constituees a partir des signes cliniques et electroencephalographiques d'eveil de 104 trypanosomes en phase meningoencephalitique de la maladie ont ete soumises a une analyse factorielle des correspondances. Trois profils ont pu etre ainsi determines. Le premier est rencontre chez des patients qui presentent des troubles cliniques et electroencephalographiques relativement discrets et suggestifs d'un debut de phase de polarisation cerebrale. Le second, observe chez des malades qui ont des troubles de la vigilance, du comportement et de la motricite, et des traces EEG tres alteres, est indicatif d'un stade d'encephalite beaucoup plus severe. Le troisieme, rencontre chez des patients qui presentent des pointes ondes et polypointes plus ou moins organisees de facon periodique, et des crises d'epilepsies, est suggestif d'une souffrance cerebrale aigue.
TL;DR: The Modafinil as mentioned in this paper is an electrophysiologic clinic for narcoleptique patients, where the maintien de la vigilance and le niveau de certain performances psychometriques are evaluated.
Abstract: Resume L'efficacite clinique du Modafinil a ete clairement demontree chez les patients narcoleptiques, mais peu d'etudes electrophysiologiques confirment ces observations. Le Modafinil ne modifiant pas la capacite a s'endormir, le but de ce travail est d'etudier son efficacite sur le maintien de la vigilance et sur le niveau de certaines performances psychometriques chez les patients narcoleptiques. Sur les 16 patients traites, 12 sont repondeurs au Modafinil; l'etude porte sur ces 12 patients. Apres une nuit d'enregistrement, les tests electrophysiologiques comprennent: des analyses spectrales de references, des tests de maintien de l'eveil, effectues les yeux ouverts en lumiere diffuse puis les yeux fermes dans l'obscurite, au cours desquels sont calculees: la latence d'endormissement, l'evolution du rapport theta/alpha et la duree du test. Les performances psychometriques sont evaluees au moyen des tests suivants: temps de reaction auditif et visuel, Trail Making Test, Stroop, Fluence verbale et WAIS-R (code et memoire des chiffres). Chez les narcoleptiques le Modafinil ameliore la vigilance uniquement si les conditions d'environnement sont favorables. Les performances a certaines epreuves psychometriques ont tendance a etre ameliorees.
TL;DR: In this paper, the authors proposed a different seizure classification, which answers the above shortcomings of the international classification, and which has been used for years in major epilepsy centers, in this system, the seizure classification is based exclusively on seizure symptomatology.
Abstract: In spite of its universal acceptance, the international classification of epileptic seizures suffers from certain limitations. The fundamental divisions between partial and generalized seizures on the one hand, and between partial simple and complex seizures on the other, are not always practical, nor useful. The terminology is often cumbersome, and does not contain essential localizing information. Finally, the seizure classification is sometimes dependent on ancillary testing, particularly the EEG. We propose a different seizure classification, which answers the above shortcomings of the international classification, and which has been used for years in major epilepsy centers. In this system, the seizure classification is based exclusively on seizure symptomatology. The terms are generally more concise than those of the international classification, and yet convey more precise information. For example, the term left visual aura-->automotor seizure-->generalized tonic clonic seizure would be equivalent to simple partial seizure with visual symptom evolving into complex partial seizure evolving into generalized tonic clonic seizure. The international classification is longer and omits essential later-alizing information. This classification is easy to apply, and can be an extremely useful complement to the international seizure classification, especially for centers whose emphasis is on surgical treatment of epilepsy.
TL;DR: The spectroscopie du proton visualise des metabolites tels que la choline, le N-acetylaspartate, le lactate ou la taurine as mentioned in this paper.
Abstract: Resume Le metabolisme cerebral a ete abondamment etudie ces dernieres annees par spectroscopie par resonance magnetique (SRM). L'application en neonatalogie permet de suivre la maturation cerebrale ainsi que l'installation et l'evolution de la souffrance cerebrale. L'utilisation de la spectroscopie phosphore permet de quantifier les metabolites phosphoryles ; ainsi, la mesure des concentrations relatives en phosphocreatine et en phosphate inorganique constitue un element pronostique fiable quant au devenir d'un nouveau-ne ayant subi un accident hypoxoischemique. L'etude des concentrations absolues a fait l'objet de travaux recents et semble encore plus performante. La spectroscopie du proton visualise des metabolites tels que la choline, le N-acetylaspartate, le lactate ou la taurine. Son utilisation est plus recente que celle du phosphore mais les resultats montrent deja son interet en neonatalogie.
TL;DR: In this article, l'exploration des variations regionales de debit sanguin cerebral a commence, which tendent a montrer une diminution relative to the debit cerebral dans les regions frontales durant le sommeil lent.
Abstract: Resume La tomographie a emission de positons permet, a un niveau macroscopique, l'etude de phenomenes physiologiques ou biochimiques chez l'homme vivant. Son application a l'etude de la veille et du sommeil a d'abord montre que la consommation cerebrale de glucose diminuait en sommeil lent profond, alors qu'en sommeil paradoxal, le metabolisme glucidique etait a un niveau comparable a celui de l'etat de veille. Plus recemment, l'exploration des variations regionales de debit sanguin cerebral a commence. Seuls des resultats partiels et preliminaires sont actuellement disponibles. Ils tendent a montrer une diminution relative du debit sanguin cerebral dans les regions frontales durant le sommeil lent. Cette courte revue des apports de la tomographie a emission de positons dans l'etude du sommeil envisage egalement l'etude de la privation de sommeil et des pathologies liees au sommeil.
TL;DR: L'aspect electrophysiologique est similaire a celui de the myasthenie grave montrant un decrement pathologique aux stimulations repetitives a 3 par seconde.
Abstract: Resume Deux patients ont ete victimes d'une morsure par un cobra tunisien (Naja haje haje). Quelques heures apres la morsure ils presentent une paralysie flasque globale s'etendant aux muscles respiratoires. L'aspect electrophysiologique est similaire a celui de la myasthenie grave montrant un decrement pathologique aux stimulations repetitives a 3 par seconde. Les neurotoxines agiraient sur le versant postsynaptique de la jonction neuromusculaire. Le bloc de transmission produit par le venin de Naja haje haje peut etre reversible par la neostigmine intraveineuse.
Journal Article•
TL;DR: The effects of pure benzodiazepine antagonist (Flumazenil) on the responses R1 and R2 of the blink reflex, psychomotor tests, and Event Related Potentials (ERP), in six healthy volunteers sedated with Midazolam have been compared as mentioned in this paper.
Abstract: The effects of a pure benzodiazepine antagonist (Flumazenil) on the responses R1 and R2 of the blink reflex, psychomotor tests, and Event Related Potentials (ERP), in six healthy volunteers sedated with Midazolam have been compared. Measurements were made during each of four successive phases. Phase 0 corresponded to control recordings. Midazolam was administered rapidly during phase 1 and slowly during phase 2. Phase 3 corresponded to spontaneous waking once the administration of Midazolam had been stopped. Flumazenil was administered during phase 2. As the subjects fell asleep, R1 and R2 were the last parameters to disappear. Under the influence of Flumazenil, R1 was the first to reappear, while R2 did not recur until complete waking, and the other tests were unpracticable. During phase 3, R1 reappeared before R2 once more, the psychomotor test responses and ERP returning only later. The modifications of both R1 and R2 of the blink reflex are a good criterion of the presence of BZD in a toxic coma and a good test to indicate the depth of a coma or a sedation with BZD, whilst ERP, since they require the cooperation of the patient, are a test of vigilance and not of awakening.