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Biomedical subjects

J P Neau

Publications and source records attributed to J P Neau.

At least 19 recordsLinked to original sources
PubMed2006

[Neurological complications of Herpes zoster].

INTRODUCTION: Herpes zoster is a disease which occurs secondary to the reactivation of varicella-zoster virus (VZV). Its frequency is high in the general population. STATE OF ART: Herpes zoster leads to numerous complications, among which there were neurological peripheral or central lesions. Antiviral treatment must be instituted, particularly if neurological complications develop, as soon as possible. Corticosteroid therapy can be used, especially in Ramsay-Hunt syndrome or central nervous system involvement. CONCLUSION: Herpes-zoster is a frequent disease which can lead to serious neurological complications. Early treatment is necessary in order to improve functional outcome.

Acute Disease↗
PubMed2004

Mutations within the programmed cell death 10 gene cause cerebral cavernous malformations.

Cerebral cavernous malformations (CCMs) are hamartomatous vascular malformations characterized by abnormally enlarged capillary cavities without intervening brain parenchyma. They cause seizures and cerebral hemorrhages, which can result in focal neurological deficits. Three CCM loci have been mapped, and loss-of-function mutations were identified in the KRIT1 (CCM1) and MGC4607 (CCM2) genes. We report herein the identification of PDCD10 (programmed cell death 10) as the CCM3 gene. The CCM3 locus has been previously mapped to 3q26-27 within a 22-cM interval that is bracketed by D3S1763 and D3S1262. We hypothesized that genomic deletions might occur at the CCM3 locus, as reported previously to occur at the CCM2 locus. Through high-density microsatellite genotyping of 20 families, we identified, in one family, null alleles that resulted from a deletion within a 4-Mb interval flanked by markers D3S3668 and D3S1614. This de novo deletion encompassed D3S1763, which strongly suggests that the CCM3 gene lies within a 970-kb region bracketed by D3S1763 and D3S1614. Six additional distinct deleterious mutations within PDCD10, one of the five known genes mapped within this interval, were identified in seven families. Three of these mutations were nonsense mutations, and two led to an aberrant splicing of exon 9, with a frameshift and a longer open reading frame within exon 10. The last of the six mutations led to an aberrant splicing of exon 5, without frameshift. Three of these mutations occurred de novo. All of them cosegregated with the disease in the families and were not observed in 200 control chromosomes. PDCD10, also called "TFAR15," had been initially identified through a screening for genes differentially expressed during the induction of apoptosis in the TF-1 premyeloid cell line. It is highly conserved in both vertebrates and invertebrates. Its implication in cerebral cavernous malformations strongly suggests that it is a new player in vascular morphogenesis and/or remodeling.

Apoptosis Regulatory Proteins↗
PubMed2004

Do robots need to sleep?

The present paper exposes algorithmic results providing a vision about sleep functions which complements biological theory and experiments. Derived from the algorithmic theory of information, the theory of adaptation aims at quantifying how an inherited or acquired piece of knowledge helps individuals to survive. It gives a scale of complexity for survival problems and proves that some of them can only be solved by a dynamical management of memory associating continuous learning and forgetting methods. In this paper we explain how a virtual robot "Picota" has been designed to simulate the behavior of a living hen. In order to survive in its synthetical environment, our robot must recognize good seeds from bad ones, and should take rest during night periods. Within this frame, and facing the rapid evolution of to-be-recognized forms, the best way to equilibrate the energetic needs of the robot and ensure survival is to use the nightly rest to reorganize the pieces of data acquired during the daily learning, and to trash the less useful ones. Thanks to this time sharing, the same circuits can be used for both daily learning and nightly forgetting and thus costs are lower; however, this also forces the system to "paralyse" the virtual robot, and therefore the night algorithm is reminiscent of paradoxical (REM) sleep. The algorithm of the robot takes advantage of the alternation between wakefulness or activity and the rest period. This diagram quite accurately recalls the REM period. In the future, the convergence between the neurophysiology of sleep and the theory of complexity may give us a new line of research in order to elucidate sleep functions.

Algorithms↗
PubMed2004

[Sleep apnea syndrome in the elderly].

INTRODUCTION: Sleep apnoea/hypopnoea syndrome (SAHS) is distinct in the elderly as age-related co-morbidity may be aggravated by sleep-related breathing disorders or may mask typical clinical symptoms. STATE OF ART: The SAHS prevalence in the elderly varies from one study to another, with an average rate of 25% that might increase according to the importance of associated pathologies. Clinical symptoms tend to be the neurological manifestations of excessive daytime sleepiness and cognitive deterioration. PERSPECTIVES: Treatment of SAHS should include weight reduction strategies if obesity is present. There is no role for surgery in this age group. On the other hand, adjustable oral appliances can be used depending on the severity of the SAHS, but nasal continuous positive airway pressure (CPAP) remains the most effective therapy available. Acceptance of and compliance with CPAP treatment is as good in this age group as in younger patients, with remarkable effectiveness in terms of improvement in daytime sleepiness and cognitive function. However, the effectiveness of treatment for SAHS is related to the level of symptoms present and this should be taken into account when making a therapeutic decision. CONCLUSIONS: These results fully justify treatment of SAHS in the elderly, but the decision to treat should be governed by the level of clinical symptoms from SAHS.

Aged↗
PubMed2002

[Depression and Parkinson's Disease: study of a series of 135 Parkinson's patients].

OBJECTIVE: The prevalence of depression in Parkinson's disease (PD) raises the issues of the difficulties of diagnosing the condition and of the relationships between depression and the natural history of the disease. METHODS: A cohort of 135 consecutive patients with idiopathic PD underwent psychiatric (DSM-III-R, Goldberg depression scale), neurological (distinguishing "axial" signs from other signs of parkinsonism), and neuropsychological (particularly frontal tests) evaluations. RESULTS: Depression is present in more than half of the patients and it seems to be more frequent in patients with the akinetic and fluctuating forms of the disease. The subjects who are depressed do not have a greater degree of cognitive impairment, but their scores on frontal tests are higher. Moreover, the axial signs of the disease (postural instability, axial rigidity) are more severe in depressed parkinsonians suggesting a link between depression and the non-dopaminergic lesions of the disease. Even though slowness, appetite and sleep disturbances, and fatigue may be encountered in non-depressed parkinsonian patients, separation of the parkinsonian population into subgroups shows that certain symptoms are never seen in parkinsonians who are not depressed: it is thus evident that "the impression that life is not worth living", "the hopelessness", "the impression of being worthless and incompetent", "the low level of energy", "the morning sadness" are characteristic of parkinsonian depression. Parkinsonian depression has two major clinical forms. The first one is associated with a greater number of somatic manifestations: sleep disturbances, morning fatigue. corresponding to more severe depression with hopelessness and loss of self confidence. The second exhibits few somatic manifestations with apathy and slowness as frequent complaints. CONCLUSIONS: This study defines the symptoms of parkinsonian depression which should be better recognised in order to be treated. The link between depression and axial signs of the disease may explain why L-dopa and dopaminergic agonists improve the motor signs of depression without influencing depressive manifestations in most cases.

Aged↗
PubMed2001

[Dissection of cervical arteries].

INDICENCE: Cervical artery dissection (CAD) is one of the major cause of cerebral infarction before 45 years of age. The average annual incidencerate is between 2.5 and 3 per 100,000, but the reported incidence of CAD is probably underestimated because of frequent asymptomatic forms, or producing only minor and local symptoms. Dissection of the internal carotid artery (ICA) is more frequent than dissection of the vertebral artery (VA) and intracranial dissection is less frequent than extracranial dissection. PATHOGENESIS: Traumas and primary diseases of the arterial wall are the main predisposing factors, but the pathogenesis of spontaneous DAC remains unknown in most cases, although the possibility of an underlying arteriopathy is suspected. CLINICAL AND RADIOLOGICAL MANIFESTATIONS: The clinical presentation of ICA dissections includes isolated local signs (Homer's sign, headaches) followed by a few hours or days later by signs of cerebral or retinal ischemia. Brainstem infarcts and occipital or cervical pain are the most strinking clinical feature of VA dissection. Recent progress in neuroradiology (i.e. CT-scan, MRI, magnetic resonance ongiography) and neurosonology (i.e. transcranial Doppler) allows a non invasive approach in the diagnosis and follow-up of CAD. MANAGEMENT: The prognosis is highly variable, but remains usually good. Heparin in the acute stage, followed by an oral anticoagulant or aspirin treatment for 3 to 6 months is most commonly used, although it has never been proved by a randomized trial.

Adolescent↗
PubMed2001

[The recording of cognitive evoked potentials during and after transient global amnesia: report of three cases].

It is of interest to record event-related potentials in the course of transient global amnesia (TGA) because the hippocampus and diencephalon, generally considered to be the sites of the dysfunction responsible for the amnesic episodes are also considered as two possible generators of the P300 wave. However, the only four cases reported so far in the literature showed an intact auditive P300 in three cases and an intact auditive P300 with reduction of visual P300 in one case. Here are reported four new cases. The P300 wave was readily identifiable in all four cases, without any amplitude reduction, thus suggesting that the condition did not entail inactivation or functional depression of P300 generators. Concerning P300 latency, in one case it was delayed but became normal after the ictus. In the second case, the latency, although within normal limits, shortened after the ictus. In the third and the fourth cases, the latency, initially within normal limits, remained unchanged. These apparently disparate results should be analysed in the light of the results of isotope measurement of cerebral blood flow during the amnesia, which are also inconsistent but most frequently indicate bilateral temporal or thalamic flow reduction. It remains to be determined in the future whether the stability or change in the P300 will make it possible to predict the brain region involved in transient global amnesia, which could perhaps vary from one patient to another.

Acoustic Stimulation↗
PubMed2001

Self-consciousness and Alzheimer's disease.

OBJECTIVES: To propose a neuropsychological study of the various aspects of self-consciousness (SC) in Alzheimer's disease. METHODS: Forty-five patients with probable mild or moderate AD were included in the study. Severity of their dementia was assessed by the Mini Mental State (MMS). Fourteen questions were prepared to evaluate SC. RESULTS: No significant correlations were found between SC score and educational level, age, and duration of disease. A significant correlation was found between SC score and the severity of dementia, whereas frontal disturbances were just short of the significance threshold. The various aspects of SC were not impaired to the same degree. The most disturbed ones were awareness of cognitive deficiencies, moral judgements and prospective memory. The least disturbed aspects were awareness of identity and of mental representation of the body. Items relating to anosognosia and moral judgements were significantly correlated with the MMS score, whereas affective state, body representation disorders, prospective memory, and capacities for introspection were not related to the severity of the dementia. Consciousness of identity was sound, regardless of MMS score. CONCLUSIONS: AD clearly induces an heterogeneous impairment of SC. SC requires a convergence of many neural networks. In AD, neuronal alterations involve many cortical areas and information sent to the associative frontal cortex from memory, language and visuospatial areas is lacking or disturbed. Thus, the sequential order of successive stimuli cannot be maintained by the heteromodal associative cortex (dorsal convexity of the prefrontal cortex), and the supramodal associative cortex (located rostrally in the frontal lobes) is unable to provide reliable monitoring and assessment of simultaneous neural cognitive networks carrying insufficient and inadequate input. The core deficiency in AD patients might be impaired SC equated with the disability to maintain sequential and simultaneous "attention to life". The Self-Consciousness Questionnaire, a clinical scale providing multidimensional measurement, indicates that different aspects of consciousness are not correlated with overall cognitive deficiency as determined by the MMSE.

Aged↗
PubMed2001

Intracranial hemorrhage and oral anticoagulant treatment.

OBJECTIVE: To detect risk factors for intracranial hemorrhage (ICH) in patients with long-term oral anticoagulant and to identify clinical or radiological data specific of anticoagulant-related ICH. METHODS AND PATIENTS: Three groups of patients were included. Group 1 represents patients who were admitted because of anticoagulant-related ICH between January 1984 and February 1996. All patients underwent CT scan. Clinical data, anticoagulation parameters, location and volume of the ICH, treatment and the 30-days in-hospital mortality were analyzed. Group 2 consisted of patients selected at random among all patients with spontaneous ICH admitted to our department during the same period of time. Patients without ICH, but regularly taking oral anticoagulants constituted group 3. RESULTS: Seventy-nine patients with anticoagulant-related ICH were compared to 127 patients with spontaneous ICH. The volume of supratentorial ICH was greater in group 1 of patients and was correlated with a worse prognosis. Comparison of group 1 with group 3 (212 controls) demonstrated that length of anticoagulation, prothrombin time or excessive anticoagulation, prior cerebral infarct and use of acénocoumarol, but not age or indication of anticoagulant, were significant risk factors for ICH in multivariate analysis. CONCLUSIONS: The results emphasize that anticoagulant-related ICH are not clinically different from spontaneous ICH except for volume of bleeding, and that frequent and careful coagulation monitoring is needed, especially during the first year in order to decrease the risk of ICH.

Administration, Oral↗
PubMed2001

[Vascular disorders and obstructive sleep apnea syndrome].

The relationships between obstructive sleep apnoea syndrome (OSAS) and vascular diseases are still under discussion, but increasing evidence demonstrates that the OSAS is an independent risk factor for stroke, coronary artery diseases and hypertension. Many recent studies have found a 70 to 95 percent frequency of OSAS in patients with acute stroke. Furthermore the presence of OSAS in stroke patients could lead to a poor outcome. The potential mechanisms linking OSAS and stroke and probably multiple (arterial hypertension, cardiac arrhythmia, increased atherogenesis, coagulation disorders, and modifications of cerebral metabolism and hemodynamic). Despite numerous incertainties, OSAS should be systematically screened when it is clinically suspected in patients with acute vascular event (stroke, coronary artery diseases). However, the best time for treatment with continuous positive airway pressure remains to be determined.

Coronary Disease↗
PubMed2000

Early carotid endarterectomy after a nondisabling stroke: a prospective study.

On the recommendation of several studies, carotid endarterectomy (CEA) should be delayed for at least 6 weeks in patients suffering an acute nondisabling stroke. Our objective was to determine if these patients could be safely operated on earlier, thus decreasing the risk of a recurrent stroke prior to surgery. This prospective study, carried out from January 1990 to December 1997, included 72 consecutive patients having a nondisabling hemispheric stroke with severe ipsilateral carotid stenosis (NASCET 70-99%). All patients underwent CEA within 15 days of stroke onset. Patients were considered to have a nondisabling hemispheric stroke if (1) symptoms of hemispheric ischemia persisted longer than 24 hr and (2) the resulting deficit caused no major impairment in their everyday activities. All patients were examined by a neurologist prior to carotid angiography and contrast CT scan. Hemorrhage seen on the initial CT scan eliminated the patient from the study. If the CT scan with contrast injection was negative, patients underwent magnetic resonance imaging. CEA was performed under general anesthesia with intraluminal shunting. All patients had a postoperative duplex scan and yearly follow-up by a neurologist and a surgeon, with a duplex scan of the carotid arteries. Mean follow-up was 53 months. Our study shows that CEA can be performed relatively safely within 15 days following an acute nondisabling stroke. The arbitrary 6-week delay for CEA may unnecessarily expose patients with high-grade stenosis to a recurrent stroke, which could be prevented by earlier surgery.

Aged↗
PubMed2000

Neuropsychological disturbances in cerebellar infarcts.

BACKGROUND: Recent clinical and research reports suggest that the cerebellum may contribute to the modulation of higher cognitive functions. MATERIAL AND METHODS: We included 15 consecutive patients with isolated cerebellar infarcts (4 superior cerebellar artery territory infarcts, 1 anterior inferior cerebellar artery territory infarct and 10 posterior inferior cerebellar artery territory infarcts), all confirmed by magnetic resonance imaging. These subjects plus 15 controls matched for age, sex, and educational level underwent a neuropsychological test battery including vocabulary, similarities and block design subtests of the Wechsler Adult Intelligence Scale Revised (WAIS-R); verbal fluency tests (categorial, phonemic, and alternate categorial fluency tests); Rey's 15 auditory word learning list; the paced auditory serial addition task; the Stroop test and the Zerssen Rating Scale. One year after the cerebellar infarct, each subject with cerebellar infarct was asked to undergo a second neuropsychological examination with the same test battery. RESULTS: Patients with cerebellar infarcts exhibited significantly lower neuropsychological performances compared to those of the control group without any obvious difference between the different vascular cerebellar territories. After 1 year of follow-up, this neuropsychological impairment tended to improve. CONCLUSIONS: The pattern of deficits observed in isolated cerebellar infarcts highlights the nonmotor functions of the cerebellum and functional relationship between the cerebral cortex and the cerebellum.

Adult↗
PubMed2000

[Pathological laughter after the brainstem infarction].

We report a case of 'fou rire prodromique' heralding a brainstem infarct with favorable prognosis after thrombolysis. Different clinical forms of pathological laughter, the pathophysiological mechanisms and clinico-anatomical correlations of this rare phenomenon are discussed.

Anticoagulants↗
PubMed2000

[Bilateral medial medullary infarction].

We report a case of a 42-year old man with a bilateral medial medullary stroke (MMS) with favorable outcome. First described by Spiller in 1908, the MMS accounts for less than 0,5% of all cerebral infarcts. It may be unilateral or more rarely bilateral, and may often be the consequence of the atherosclerosis. The clinical features of MMS classically associate contralateral hemiparesis and lemniscal hypoesthesia accompanied by ipsilateral lingual palsy and sometimes oculomotor disturbances (upbeat nystagmus). With the advent of magnetic resonance imaging, some restricted or unusual clinical manifestations can be attributed to this localization. The benign form of MMS seems much more common than MMS with poor prognosis.

Adult↗
PubMed1998

[Cerebral ischemic disorders in the young subject. Epidemiologic and prognostic data].

A COMMON EVENT: Cerebral vascular events in young subjects account for 5 to 15% of all such cases admitted to specialized services. The incidence of cerebral vascular events in young subjects varies from 3 to 40 per 100,000 depending on the study period (incomplete explorations in early studies), the study site (industrialized or developing country) and the ethnic background of the population. A HETEROGENEOUS GROUP: Although cerebral vascular events are defined as those occurring in subjects aged 18 to 45 years, the population is nevertheless quite heterogeneous due to rising incidence after 35 years and variable frequency of age-dependent and site-dependent underlying causes. RELATIVELY GOOD PROGNOSIS: Early mortality is relatively low (approximately 5%) and two-thirds of the subjects suffer minor or mild sequellae. However, depression, which is frequent, and the impossibility to return to normal work activities have an important impact on quality of life.

Adult↗