Biomedical subjects
Publications and source records attributed to C Hommet.
Neurological syndromes secondary to acute aortic dissection (AAD) are uncommon and usually consist of focal deficits after an embolic cerebral infarction. This article reports the observation of an AAD with the chief complaint of transient acute memory impairment-that is, a non-usual stroke-like symptom.
Malformations of cortical development are increasingly recognized as important causes of epilepsy, developmental delay and other neurological disorders. Our purpose is to present the relevance of the MRI in these pathologies with the clinical, genetic and therapeutic aspects. This classification is based on the three fundamental events of cortical formation: proliferation of neurons and glie in the periventricular zone, migration of postmitotic neurons to the periphery, subsequent cortical organization. MR analysis evaluates particularly the cortical thickness, sulcal and cortical morphology, gray-white matter junction, and looks for gray matter in abnormal location. These data coupled with the familial history, the seizure characteristics and genetic findings should allow an appropriate classification of the lesions. MR imaging allows the detection and classification of cortical malformations. MR imaging findings are primordial to consider surgery when the epilepsy becomes refractory to the anti-epileptic drugs. An adequate classification of these malformations should help to provide to the family an appropriate counseling both in terms of genetics and outcome.
We report the case of a patient with streptococcal mitral endocarditis discovered following an ischaemic cerebrovascular accident. The clinical evolution was marked by the progressive development of a mycotic aneurysm. Surveillance was performed with repeated angio-MRI which provided an indication for embolisation. We demonstrate the value and the current quality of angio-MRI for the diagnosis of mycotic aneurysms, and the value of active management of these lesions which present a high risk of rupture and which are associated with a significant excess mortality. Embolisation can allow earlier cardiac surgery for haemodynamically unstable patients and for those whose neurological state until now contra-indicated intervention.
Pachymeningitis is an inflammatory process that thickens the dura mater. This disease has various etiologies including infectious, neoplastic, or autoimmune diseases. We present the case of a patient who developed cranial pachymeningitis with a clinical and biological picture suggestive of a neurological form of vasculitis. A 51-year-old woman developed rhinitis, otitis media, headaches, and deterioration of her condition after a course of recombinant hepatitis B vaccine. After a booster dose of the vaccine, she developed unilateral visual loss and impairment of multiple cranial nerves. Blood analysis showed inflammation and presence of antimyeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA). Cranial magnetic resonance imaging (MRI) showed pachymeningitis. A complete remission was obtained with immunosuppressive therapy. The initial clinical presentation and subsequent remission under immunosuppressive therapy were suggestive of a vasculitis with nervous system involvement. Though vasculitis was not proven histologically in this patient, we believe that MPO-ANCA-related autoimmunity provoked the patient's disease as already reported in similar cases. As pachymeningitis is a fibrosing process, early recognition and treatment of an autoimmune etiology, even in the absence of previous pulmonary or renal involvement, is required to prevent definitive neurological impairment.
PURPOSE: The indications of emergency electroencephalogram (eEEG) were defined by a French consensus conference in May 1996. We retrospectively confronted the recommendations with the actual requests for emergency EEG in our University hospital, in order to determine the contribution of the eEEG in the most frequent clinical situations encountered. MATERIAL AND METHOD: Three hundred and twenty nine consecutive eEEGs over a 6-months period were retrospectively analyzed. RESULTS AND CONCLUSION: The most frequent indications were presumption of brain death (13%), convulsive status epilepticus after treatment (12.1%), and suspicion of nonconvulsive epilepticus status (10.6%). More than one third of the requests (38.6%) were not in conformity with the recommendations of the consensus conference. The contribution of the EEG is much improved by the application of the consensual criteria. Thus, the EEG remains essential for the management of convulsive status epilepticus after treatment, to seek a subtle epilepticus status or a nonconvulsive epilepticus status. Conversely, the EEG did not prove useful in emergency after a transient loss or alteration of consciousness or a focal, non-febrile, neurological transient or permanent deficit.
Research in brain-damaged patients has suggested that the right hemisphere plays a role in unilateral spatial neglect (USN), but provides only limited information for pinpointing the intraparietal localization of the lesions associated with this syndrome. We report a case of unilateral neglect in a patient who underwent a right inferior parietal cortectomy for refractory epilepsy without any macroscopic lesion. We describe the evolution of the neuropsychological disturbances observed at 3 and 24 months after cortectomy. This case illustrates the role played by the inferior parietal lobe and, particularly, the parietal opercule in USN syndrome, and provides strong "experimental" evidence of the special role played by the inferior parietal lobule in the perception processes related to spatial attention.
Ornithine transcarbamylase deficiency (OTCD) is the most common urea cycle disorder. This condition usually presents in neonates or children. This report describes the clinical case of a 21 year old woman who was diagnosed in adulthood during the course of an unexplained coma. After recovery from the coma, she presented very unusual neuropsychological disorders involving memory and the meaning of certain words, suggesting a semantic deficit. The discovery of OTCD in adulthood is rare and the neuropsychological consequences may be unique.
The functional specialization of each hemisphere in adults is now well accepted. Neuropsychology of hemispheric functioning in young children is a more debatable issue and must take into account additional factors such as development and maturation, characterized by complex changes in anatomy and organization. The first part of this review describes the theory behind the development of the functional organization of the brain. Second, we discuss data regarding brain lesions in children with brain damage and with normal development. We comment on the concept of plasticity and the critical period. We also discuss the neurobiological processes underlying the functional organization of the brain in the model of developmental disorders in children. We chose three disorders involving the left hemisphere (developmental dysphasia), both hemispheres (benign rolandic epilepsy) or the right hemisphere (congenital hydrocephalus) in order to examine their relationship to a specific hemispheric functional organization. We used classic neuropsychological tests such as the dichotic listening task, the dichaptic palpation and the time-sharing paradigm. The patterns observed in each pathology are discussed in light of data obtained in children with brain lesions.
We studied the morphometric MRI findings and their correlation with cognitive functions in a population of 10 young adults shunted for congenital hydrocephalus related to spina bifida. Morphometric MRI analysis included measurement of the ventricular dilatation index, frontal and occipital parenchymal thickness and the size of the corpus callosum. The neuropsychological status was evaluated, notably to look for a discrepancy between verbal and performance skills, a finding which has previously been described in hydrocephalic children. We also investigated whether there was a correlation between cognitive function and cerebral morphometric indexes. In each case, MRI demonstrated the structural changes associated with the Chiari II malformation. The size of the lateral ventricles varied, ranging from important dilatation to small ventricles. Six patients had only partial development of the corpus callosum. All patients had a normal global IQ. In our population of young adults, we did not observe any discrepancy between verbal and visuospatial performances as has been described in children with hydrocephalus. We found no relationship between cognitive function and ventricle dilatation or parenchymal thickness or between the size of the corpus callosum and callosal transfer.
Hemimegalencephaly is a rare cerebral malformation that usually presents with mental retardation, controlateral hemiparesis and intractable seizures. We report a case of hemimegalencephaly diagnosed in adulthood based on MRI findings. The electroencephalogram initially suggested partial status epilepticus. The diagnosis of this cerebral malformation has been made easier thanks to recent progress in cerebral imagery with MRI. We describe and discuss the relevant encephalographic aspects.
We present a comprehensive review of sleep studies performed in patients with brain lesions complemented by 16 additional personal selected cases and by discussion of the corresponding animal data. The reader is cautioned about the risk of establishing an erroneous correlation between abnormal sleep and a given disorder due to the important inter and intra variability of sleep parameters among individuals. Salient points are stressed: the high frequency of post-stroke sleep breathing disorders is becoming increasingly recognised and may, in the near future, change the way this condition is managed. Meso-diencephalic bilateral infarcts induce a variable degree of damage to both waking and non-REM sleep networks producing and abnormal waking and sometimes a stage 1 hypersomnia reduced by modafinil or bromocriptine, which can be considered as a syndrome of cathecholaminergic deficiency. Central pontine lesions induce REM and non-REM sleep insomnia with bilateral lateral gaze paralysis. Bulbar stroke leads to frequent sleep breathing disorders. Polysomnography can help define the extent of involvement of various degenerative diseases. Fragmented sleep in Parkinson's disease may be preceded by REM sleep behavioural disorders. Multiple system atrophies are characterised by important sleep disorganization. Sleep waking disorganization and a specific ocular REM pattern are often seen in supra-nuclear ophtalmoplegia. In Alzheimer patients, sleep perturbations parallel the mental deterioration and are possibly related to cholinergic deficiency. Fronto-temporal dementia may be associated with an important decrease in REM sleep. Few narcoleptic syndromes are reported to be associated with a tumour of the third ventricle or a multiple sclerosis or to follow a brain trauma; all these cases raise the question whether this is a simple coincidence, a revelation of a latent narcolepsy or, as in non-DR16/DQ5 patients, a genuine symptomatic narcolepsy. Trypanosomiasis and the abnormal prion protein precociously after sleep patterns. Polysomnography is a precious tool for evaluating brain function provided it is realised under optimal conditions in stable patients and interpreted with caution. Several unpublished cases are presented: one case of pseudohypersomnia due to a bilateral thalamic infarct and corrected by modafinil, four probable late-onset autosomal recessive cerebellar ataxias without sleep pattern anomalies, six cases of fronto-temporal dementia with strong reduction in total sleep time and REMS percentage on the first polysomnographic night, one case of periodic hypersomnia associated with a Rathke's cleft cyst and four cases of suspected symptomatic narcolepsy with a DR16-DQ5 haplotype, three of which were post-traumatic without MRI anomalies, and one associated with multiple sclerosis exhibiting pontine hyper signals on MRI.
Benign childhood epilepsy with centrotemporal spikes (BECTS) is a frequent, benign childhood epilepsy with a good prognosis. However, neuropsychological deficits have been reported during its active phase. In this study, we evaluate the long-term neuropsychological consequences of this reputedly benign epilepsy, particularly the relation between paroxysmal abnormalities and cerebral language lateralization. The neuropsychological outcomes concerning both overall cognitive and lateral hemispheric functions were studied in twenty-three adolescents and young adults in total recovery from BECTS, in thirty-three controls without any significant past neurological history and in ten adolescents and young adults with complete resolution of generalized idiopathic epilepsy (childhood absence epilepsy or CAE). Language lateralization was evaluated using classical neuropsychological procedures (dichotic listening tasks, dual-task procedure). No difference was seen in the three populations with respect to overall cognitive function: memory, language and the executive functions. Although the Performance IQ was lower in patients in remission from CAE, the results were within normal limits. However, qualitative analysis of the dual-task procedure suggested a different organizational pattern for cerebral language in adolescents and young adults in remission from BECTS as compared to controls and patients in remission from CAE. The different organization in cerebral pattern in BECTS patients appeared to be related to the initial epileptic focus as determined by the EEG and/or the sleep-recording. We discuss the relationship between the presence of paroxysmal anomalies in childhood and subtle functional lateralized hemispheric abnormalities in adulthood.
We report the case of a 60-year-old man who developed visual and cognitive disorders. Investigations confirmed the diagnosis of idiopathic hypereosinophilic syndrome even though the patient had a history of rectal cancer. The olinical course was favorable after treatment. We discuss the different clinical forms, imaging data and treatments of eosinphilic syndrome.
BACKGROUND: Cognitive disorders have been described in amyotrophic lateral sclerosis, but usually after the diagnosis has ben established. CASE REPORT: A 57-year-old man was intubated for acute respiratory distress subsequent to pneumonia and diaphragm palsy. He had a 2-year history of drug-resistant depression and deterioration of cognitive functions. A pyramidal syndrome associated with biopsy-proven chronic neurogenic atrophy led to the diagnosis of amyotrophic lateral sclerosis. The electromyogram did not contribute to diagnosis. Brain MRI only evidenced moderate bilateral frontal-temporal atrophy. Brain SPECT demonstrated major perfusion defects in the frontal lobes. DISCUSSION: This patient had amyotrophic lateral sclerosis and frontal-temporal dementia with an unusually late onset clinical presentation: cognitive disorder was the inaugural sign. Brain SPECT and muscle biopsy enabled us to identify the cortical and peripheral motor neurone involvement in this uncooperative intensive care patient totally dependent on mechanical ventilation.
An association between central nervous system neoplasm and pregnancy is uncommon although its frequency is underestimated. The most commonly observed tumors are acoustic neuromas, meningiomas and gliomas. The interactions between these tumors and pregnancy is not well known : Pregnancy could affect tumor growth by : - activating tumor growth by stimulating receptors; - increasing the peritumoral edema; - favoring immunotolerance due to pregnancy. Steroid hormone receptors and their therapeutic significance are described here, focusing particularly in meningiomas. Central nervous system tumors do not effect the progress of pregnancy per se but do the therapeutic implications. The clinical aspects are the same as in non-pregnant women. MRI appears to be the most adapted imaging technique. Neurosurgical guidelines are also described, with emphasis on symptomatic therapeutics, especially for seizure. Attitudes concerning the nature of the tumor and time of pregnancy are then discussed. The obstetrical attitude should be therapeutic abortion or delivery, with cesarean if necessary. Prognosis is getting better for the child and mother alike, but still remains poor.
We report a longitudinal, electroencephalographic and neuropsychological analysis of epilepsy with continuous spikes and waves during slow sleep (CSWS) in a 19 year-old boy. The clinical course fluctuated, with temporary worsening or improvement of the paroxysmal abnormalities, epilepsy and cognitive functions. At the end of the follow-up period, seizures persisted. Evaluation of the boy's behaviour, language and cognitive function suggested a dysexecutive syndrome. We discuss the relationship between paroxysmal abnormalities and neuropsychological disorders.
Spectral analysis of the EEG alpha rhythm was studied in nine temporal epileptic right-handed patients in order to predict localization of the speech area. We studied the variation of the spectral power of the alpha rhythm during an activation paradigm previously validated in normal right-handed subjects. Significant alpha power decreases in the left hemisphere during writing with the right hand (as compared to resting) and/or significant alpha power decreases in the right hemisphere during left-hand recognition and classification of cardboard objects (as compared to resting) were considered as consistent with left-hemisphere dominance for language. The results of EEG spectral analysis were compared with those of the Wada test. The left hemisphere was dominant for language according to the Wada test in eight subjects and the right hemisphere in one subject. Six patients had a significant alpha power reduction in the hemisphere concerned during lateralized cognitive tasks, consistent with language localization in the left hemisphere according to the Wada test. The three remaining patients had no significant EEG spectral power variations. A significant decrease of alpha power in the active hemisphere during cerebral activation seems statistically related to left-hemispheric dominance for language in right-handed subjects (hemispheric specialization). However, the localization of the speech area using this electrophysiological method does not appear clinically relevant for a case-by-case decision in individual patients.
This review considers the effect of sleep on seizures and interictal electroencephalogram (EEG) paroxysmal activities (PAs), as classified by the International League Against Epilepsy criteria. No type of seizure is, per se, specifically linked with non-rapid eye movement (NREM) or rapid eye movement (REM) sleep. However, in some syndromes, seizures are more frequent in slow wave sleep (SWS) [partial motor or generalized seizure in benign epilepsy with centro-temporal spikes (BECTS), frontal seizures in idiopathic familial or not familial frontal lobe epilepsy and generalized tonic seizure in secondary generalized epilepsy are increased by SWS]. Conversely myoclonia and grand mal seizures are associated with awakening in some forms of generalized idiopathic epilepsy. There is a mean increase in PAs during SWS in generalized and in partial epilepsies on the whole. However, precise analysis shows that in partial cryptogenic or symptomatic epilepsy and, most likely, in the majority of generalized idiopathic epileptic syndromes about 20% of patients have an increase in PA density during SWS, 20% experience an increase in waking, 50% have very few PAs and in 10% there is no significant difference between sleep and waking. BECTS, however, exhibits a definite increase in sleep PA increase and in juvenile myoclonic epilepsy an increase in PAs during the intra-night awakening is reported. There are at least three syndromes, which cause a huge increase in PAs during sleep: the Landau-Kleffner syndrome and the syndromes of continuous focal or generalized spike-waves during SWS. Their physiopathology and neuropsychological consequences are discussed. Neurophysiological animal data are also reported highlighting the relationships between slow sleep oscillations and the generation of spike waves. A biochemical review is also presented.