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Biomedical subjects

M Baulac

Publications and source records attributed to M Baulac.

At least 91 records · Page 5Linked to original sources
PubMed1994

[Surgery for temporal lobe epilepsy].

Interest in surgery for intractable temporal lobe epilepsy has increased during the last ten years, mainly due to a better identification of the epileptogenic focus by modern imaging techniques (MRI) or functional tools (TEP and SPECT scanning). Depth electrodes recording is not mandatory and can be restricted to patients who do not meet congruent non invasive criteria. Simultaneously, modification of surgical techniques has been proposed: in addition to classical temporal lobectomy, other methods are used in order to minimize the resection of temporal lateral neocortex, and increase that of mesial temporal structures; the latter can be selectively performed through amygdalo-hippocampectomy. Outcome of surgery is generally excellent or good. More than three-fourths of patients are seizure free or show major reduction in seizure frequency. Outcome at the end of the second year is a good indication of long-term prognosis.

Cerebral Cortex↗
PubMed1994

Carbamazepine and its epoxide: an open study of efficacy and side effects after carbamazepine dose increment in refractory partial epilepsy.

We evaluated the efficacy, development of adverse effects, and possible correlation between the plasma concentration of carbamazepine (CBZ) and its major metabolite, carbamazepine-10,11-epoxide (CBZ-E), in a group of epileptic patients in whom selective increases in CBZ doses were made. Eighteen patients with refractory partial epilepsy participated in an open trial. Five were on monotherapy and 13 on polytherapy. All the patients were on CBZ before the trial and had plasma levels within the therapeutic range (17-42 mumol/L). After a baseline period, CBZ doses were progressively increased either to reach a 50% reduction in seizure frequency for 2 months or until side effects appeared. Thirty-nine percent of the patients had a 50% decline in seizure frequency, but only 17% improved for > 6 months. Mild or moderate side effects were observed in 78% of the patients. Side effects were correlated with CBZ plasma levels but not with CBZ-E plasma levels. Correlation between CBZ and CBZ-E plasma levels were found in the monotherapy group, but not in the polytherapy group. Our results confirm that higher doses of CBZ can successfully be used in some patients with refractory partial epilepsy. Furthermore, the plasma level of CBZ-E does not seem to be a useful indicator of toxicity in CBZ-treated ambulatory epileptic patients.

Adolescent↗
PubMed1994

Amygdalohippocampal MR volume measurements in the early stages of Alzheimer disease.

PURPOSE: To evaluate the accuracy of hippocampal and amygdala volume measurements in diagnosing patients in the early stages of Alzheimer disease. METHODS: Measurements of the hippocampal formation, amygdala, amygdalohippocampal complex (the two measurements summed), caudate nucleus, and ventricles, normalized for total intracranial volume, were obtained on coronal sections (1.5 T, 400/13 [repetition time/echo time], 5 mm) of 13 patients in the mild (minimental status > or = 21) and five patients in the moderate stages of Alzheimer disease (10 < minimental status < 21), and eight age-matched control subjects. RESULTS: For patients with a minimental status score of 21 or greater, atrophy was significant for the amygdala and hippocampal formation (-36% and -25% for amygdala/total intracranial volume and hippocampal formation/total intracranial volume, respectively), but not for the caudate nucleus. No significant ventricular enlargement was found. For patients with a minimental status score less than 21, atrophy was more severe in all structures studied (amygdala/total intracranial volume, -40%; hippocampal formation/total intracranial volume, -45%; caudate nucleus/total intracranial volume, -21%), and ventricles were enlarged (63%). No overlap was found between Alzheimer disease and control values for the amygdalohippocampal volume, even in the mild stages of the disease. In Alzheimer disease patients, hippocampal formation volumes correlated with the minimental status. CONCLUSION: Hippocampal and amygdala atrophy is marked and significant in the mild stages of Alzheimer disease. Volumetric measurements of the amygdala and the amygdalohippocampal complex appear more accurate than those of the hippocampal formation alone in distinguishing patients with Alzheimer disease.

Aged↗
PubMed1993

Impairment of consciousness induced by valproate treatment following neurosurgical operation.

Eight patients, who underwent neurosurgery for various supratentorial lesions presented unexplained impairment of consciousness during the first post-operative days. These states ranged from stupor to deep coma, and two patients had an emergency re-exploration. All these patients were receiving the usual dosage (1000 to 1500 mg per day) of Valproic acid (VPA). The treatment had been initiated either several weeks or months previously in 4 cases, and was thus well tolerated, or the day before surgery in the 4 other cases. EEG recordings displayed diffuse abnormalities, delta waves and/or high voltage triphasic complexes, that led to the diagnosis of VPA intolerance and drug withdrawal. Then full clinical recovery and EEG clearing occurred within 1 to 5 days. VPA intolerances are wellknown but remain exceptional, about 1 case per 100.000. In our neurosurgical population, however, the rate was higher, approximately 2%. Wide areas of blood brain barrier destruction may contribute to the higher frequency of this easily reversible cause of post-operative stupor or coma.

Adolescent↗
PubMed1992

[Research and surgical treatment of epilepsy].

The currently available surgical procedures for the treatment of epilepsy, from fundamental data to therapeutic results, including various means of investigation are reported. The work is based on a review of the literature and on the cases studied by the two teams from the Universities of Montreal and Bordeaux who share the same concept of epilepsy surgery. The patient groups of the two teams include 316 S.E.E.G., 214 cortectomies, 39 callosotomies and 2 multiple sub-pial transsections. In the first part, the authors attempt to demonstrate that the epileptic focus corresponds to the region where the seizures arise, that this focus is not directly comparable to the region where inter-ictal spikes are recorded and sometimes becomes autonomous from the causal lesion. The epileptic phenomenon has a definite harmful effect on cerebral functions and a probable self-aggravating potential. The second chapter summarizes the clinical data on which the indications and contraindications are based. These obviously depend on whether the intervention is intended to be curative or palliative. Various non-invasive and invasive investigations are then reviewed, according to their relative importance and the experience of each team. The main points developed are: the electroclinical correlations during seizures, the symptomatological data for differentiating between temporal and frontal lobe seizures, the contribution of M.R.I. in demonstrating the epileptogenic and epileptic lesions, the electrophysiological information suggesting that S.E.E.G. remains the most informative mean of investigation. The various methods of investigation of assessing electrical, functional (cerebral blood flow, metabolism) and morphological aspects of epilepsy, supply non-redondant findings about the localisation of the epileptic focus. The chapter on surgical techniques mainly discusses the various modes of implantation of subdural and intracerebral electrodes and reports the same rate of morbidity in both cases. Orthogonal teleradiography is still perfectly suited to the implantation of intracerebral electrodes. S.E.E.G. is still the most anatomically precise technique. However, in certain conditions, extraoperative E.Co.G. is more adequate. New surgical modalities have recently appeared such as the multiple subpial transsections which allow treatment of epileptic foci unapproachable by cortectomy and such as modified techniques of hemispherectomy, which by decreasing morbidity, renew interest in them. In the chapter on surgical results, the authors emphasize the methodological problems of evaluation that partly account for their wide variability. The results obtained with the various surgical modalities are reviewed. The outcome in cortectomies is discussed at length in terms of the data from the literature as well as the results reported by both teams.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1991

The commissuro-mamillary plane in MRI of the brain (preliminary communication).

MRI sections of the brain in the coronal plane through the line joining the anterior commissure and the mamillary bodies display the constituent parts of the basal forebrain. The visualisation of the septal nuclei and the anterior columns of the fornix show the importance of this plane in the study of behaviour disorders and amnesic syndromes.

Corpus Striatum↗
PubMed1990

[Alcohol and epilepsy].

Two kinds of epileptic events are frequently related to alcohol consumption: 1) seizures triggered by alcohol withdrawal. Often multiple, they occur within between 10 and 48 hours after discontinuing or reducing alcohol intakes and can be followed by a delirium tremens. 2) recurring unprovoked seizures. They are usually rare, 1 or 2 yearly. The risk is increased for heavy drinkers but returns to normal for ex-drinkers. Seizures related to alcoholism are usually generalized tonico clonic seizures with normal EEG and CT-scan. When partial seizures are identified they are attributed to preceding brain damage, head trauma or stroke.

Alcohol Drinking↗
PubMed1990

The commissuro-mamillary plane in MRI of the brain (preliminary communication)

MRI sections of the brain in the coronal plane through the line joining the anterior commissure and the mamillary bodies display the constituent parts of the basal forebrain. The visualisation of the septal nuclei and the anterior columns of the fornix show the importance of this plane in the study of behaviour disorders and amnesic syndromes.

Brain↗
PubMed1989

Radiological studies in trigeminal nerve pathology.

The authors have used CT scans and MRI to study pathology in anatomical and radiological correlations of brain slices. The CT scan was particularly useful for studying structures at the skull base, although at the level of the posterior fossa such scans could visualize only those tumors that were larger than 8 mm. even after injection. The CT scan was found to be the most useful examination before surgery for facial neuralgia. In contrast MRI gave a precise cisternal course of the trigeminal nerve and its relations with vascular structures.

Cranial Nerve Neoplasms↗
PubMed1989

Obsessive-compulsive and other behavioural changes with bilateral basal ganglia lesions. A neuropsychological, magnetic resonance imaging and positron tomography study.

Eight patients are reported who shared the combination of bilateral basal ganglia lesions and a frontal lobe-like syndrome. The main features were inertia and loss of drive, with preservation of intellectual function. Some patients showed stereotyped activities with compulsive and obsessive behaviour which were sometimes highly elaborate in pattern. Extrapyramidal clinical signs were absent or mild. Brain damage, related to anoxic or toxic encephalopathy, was demonstrated by CT scans and MRI. The lesions appeared to be confined to the lentiform nuclei, particularly affecting the pallidum, although there was generalized brain atrophy in 2 cases. Positron emission tomography (PET) in 7 patients revealed hypometabolism of the prefrontal cortex relative to other parts of the brain. The PET studies suggest dysfunction of the prefrontal cortex as a result of damage to the lentiform nuclei. These clinical, anatomical and functional observations emphasize the role of the circuits linking the prefrontal associative cortex and some specific areas of the neostriatum, including the pallidum. The existence of distinct nonoverlapping circuits in the motor field or in the associative field can explain the fact that basal ganglia lesions may give rise to a clinical picture that is either purely motor, purely behavioural (as in some of our patients), or both. Similarities existed between some symptoms found in our patients and certain features of major psychiatric illnesses such as severe depression, catatonic schizophrenia, and obsessive-compulsive disorder. This raises the hypothesis that some aspects of these psychiatric disorders could be related to structural and physiological disturbances in the systems linking the frontal associative cortex and the basal ganglia.

Adult↗
PubMed1989

[Cyclosporin and convulsions after cardiac transplantation].

6 p. 100 of a population of 129 heart transplant recipients presented isolated convulsions under cyclosporin (Ci) immunosuppressive treatment. These seizures were unexplained by acute causes, infectious or cerebro-vascular. Seizures started generally a few days after Ci therapy onset, and led often to severe convulsive states, with sometimes a status epilepticus. For most of them, Ci serum levels were within, or just above, the recommended therapeutic range. Ischemic brain damage that occurred prior to surgery and Ci therapy, could be a contributing factor to Ci-induced seizures in this population of heart transplant recipients.

Adolescent↗
PubMed1988

[Loss of psychic self-activation and stereotyped mental activity caused by a frontal lesion. Relation of the obsessive-compulsive disorder].

A case of frontal lobe lesions is reported, its interest being that it is similar to a syndrome that we have previously described as the consequence of lenticular nucleus lesions. This syndrome includes primarily a loss of psychic self-activation (psychic akinesia) and compulsive or pseudo-compulsive activities. In the present case the lesions involved the deep white matter of the prefrontal cortex on both sides, and were most extensive in the depth of the middle frontal gyrus. This similitude brings further support to the notion that subcortical damage of the lenticular nuclei can induce a frontal-like syndrome. The similitude with some of the behavioural aspects or depressive of hebephrenic states is emphasized. The occurrence of stereotyped mental activities is the basis for a discussion of the relationships with some features of obsessive-compulsive neurosis.

Activities of Daily Living↗
PubMed1987

Transplantation of oligodendrocytes in the newborn mouse brain: extension of myelination by transplanted cells. Anatomical study.

The shiverer model allows for the immunocytochemical staining of the patches of myelin formed by transplanted oligodendrocytes from a normal newborn mouse. Fragments of the olfactory bulb were transplanted into various parts of the brain to place the myelinating cells in different anatomical conditions. Whole brains were horizontally sectioned in order to study the full pattern of migration and myelination of the grafted oligodendrocytes. Transplanted oligodendrocytes were capable of short and long distance migration before their differentiation. Long distance migration occurred in the caudal as well as in the rostral direction and into the contralateral part of the brain through the commissures. The patches of immunoreactive myelin were mainly found in the large myelinated bundles: corpus callosum, internal capsule, fimbria-fornix, medial lemniscus, cerebellar peduncles and spinal cord funiculi. Some sites of migration indicate that oligodendrocytes followed at least two different axonal pathways successively. The thalamic area which contained numerous patches could be a place where oligodendrocytes switch from one fasciculus to another.

Animals↗