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Biomedical subjects

M Baulac

Publications and source records attributed to M Baulac.

122 records · Page 7Linked to original sources
PubMed1981

[Obsessional-type compulsive behavior caused by bilateral circumscribed pallidostriatal necrosis. Encephalopathy caused by a wasp sting].

A previously healthy young man developed encephalopathy after a wasp sting in 1968. Neurological complications included chorea, currently of a minor degree, replaced by buccofacial dyskinesias and compulsive movements. The most disabling consequences were of psychic nature, the patient presenting an unusually marked compulsive activity of an obsessional type. The whole psychic picture however was quite different from that of the usual neurosis, since there was neither anxiety nor doubt, but a mental vacuum contrasting with almost normal intellectual and affective capacities. It was as though there was a loss of the auto-activation system of psychic life, postulated by dynamic psychologists. C.A.T. demonstrated bilateral pallidostriatal necrosis. This suggests that the striatum plays a motor and psychic role. In the field of motor control, its hypoactivity appears to determine not only chorea but dyskinesias similar to tics and compulsive movements. In the psychic field, the striatum appears to play the very general role of an auto-activation system of intellectual and affective life, its deficiency leading to mental activity of a compulsive nature. Improvement in knowledge of striatal biology should clarify not only the basic mechanisms of chorea, but those of tics and obsessions.

Brain Diseases↗
PubMed1979

[Motoneural organisation of the anterior horn with respect to the peripheral nerves in the rat (as studied by the method of retrograde transport of horseradish peroxidase)(author's transl)].

The motoneuronal organisation of the anterior horn with respect to the peripheral nerves, is still imprecise due to methodological problems. The chromatolytic and Golgi methods have furnished some fruitful but incomplete data. The retrograde transport of horseradish peroxidase permits to obtain both the topography of cells and their dendritic tree. With such a method we studied the cervical enlargment of the rat's spinal cord. Each nerve is in relation with a column of motoneurons whose both the metameric extension and the exact topography in the anterior horn have been defined. An histogram of the cell volumes has been performed for some nerves. These data permit to discuss the possible significance of the topographical separation of the cells related to the girdle with those in relation with the distal part of the upper limb. The histogram shows that the small cells, claimed to be gamma motoneurons, are much more numerous than generally supposed. The significance of the dendritic tree, which seemed oriented selectively in the cranio-caudal axis, is discussed.

Animals↗
PubMed1979

[Dendroarchitectonic study of the neurons of the corpus quadrigeminum superius in man].

Two different functional zones may be described in the superior colliculus. The superficial layers receive retinal and cortical fibers, the deep layers are a multimodal center and are implied in the oculo-motor control mechanisms. The aim of the present study has been to use network analysis in order to quantify the cell types of the deep layers of the superior colliculus in Man. 50 Golgi impregnated cell have been drawn in the three plans of space. Topological analysis permits to emphasize the existence of two different cell types: collaterally-branched cells or CB cells, and dichotomously-branched cells or DR cells. Quantitative analysis of the dendritic arcs has shown the spatial orientation of the dendritic tree. The proximal dendrites of DR cells are in the horizontal plane, the terminal dendrites are in the vertico-frontal plane. This difference seems to be due to different functional afferences.

Aged↗
PubMed1979

[Intramedullary topography of the motor neurons of the brachial plexus of the rat. Preliminary study].

The exact localisation of the motor pools of anterior horn providing the different nerves of the brachial plexus remains unclear. The data obtained have been furnished by different methods: Nissl methods furnish cytoarchitectonic data -- Golgi methods furnish dendro-architectonic data. The topographical data were obtained by the chromatolytic modifications of the moto-neurons after a peripheral nerve injury. The recently used method of the retrograde transport of HRP permits to get information about the exact localisation and the dendritic extent of the neurons of a motor pool related to a particular nerve. We have studied the localisation of the nerves of the brachial plexus in the cervical enlargement of the spinal cord. We have determined the exact extent of the different motor pools in relation to each nerve. It seems that two different regions may be recognized in the anterior horn: a ventro lateral one in relation with the girdle muscles and a dorso lateral region related with the more distal muscles of the anterior limb.

Animals↗
PubMedDate not supplied

Correlations between magnetic resonance imaging-based hippocampal sclerosis and depth electrode investigation in epilepsy of the mesiotemporal lobe.

Quantitative analysis of hippocampal formations (HF) by magnetic resonance imaging (MRI) was correlated with depth electrode recordings in 18 patients with partial epilepsy. All had seizures of mesiotemporal origin. Electrodes explored three HF segments: amygdala and HF head and anterior and posterior HF body. Corresponding HF measurements were made on coronal MRI sequences, and atrophy was quantified by one global and three segmental indexes of asymmetry per patient. HF from which seizure originated showed global atrophy in 15 patients. Segmental analysis demonstrated discrete tissue damage in 1 patient; thus, 16 patients (88%) had significant hippocampal atrophy ipsilateral to the mesial focus. The existence of more pronounced atrophy in segments giving rise to ictal onset than in segments without ictal onset was not statistically significant. Nevertheless, in posterior HF, all segments (four) with seizure onset were atrophied and none of the nonatrophied posterior segments (four) were at seizure origin. These findings confirm that MRI-detected hippocampal atrophy is a powerful indicator of a mesiotemporal focus and strongly contributes to consideration of resective surgery without intracerebral EEG monitoring. Study of the distribution of maximal tissue damage may add some information, and help surgeons decide on the posterior extent of hippocampus removal. As illustrated by 3 patients who had multiple sites of seizure onset, however, the presence of this marker should not be interpreted systematically as evidence of pure mesiotemporal epilepsy.

Adolescent↗
PubMedDate not supplied

Transplantation of CNS fragments into the brain of shiverer mutant mice: extensive myelination by implanted oligodendrocytes. I. Immunohistochemical studies.

Solid fragments of olfactory bulb from new-born normal (B6CBA and C57BL6) mice were implanted into new-born shiverer (shi/shi) brains. The shiverer mouse being characterized by the absence of myelin basic protein (MBP), myelination due to implanted oligodendrocytes can be detected in the shiverer brain using an antiserum anti-MBP. Observation of sagittal sections of the host brains revealed very extensive areas of normal myelination from the level of the graft (rostral thalamus) up to the caudal brain (diencephalon, cerebellum, pons). Thus, oligodendrocytes contained in the implant migrate out of the graft over long distances in the host brain, before they differentiate and synthesize myelin. These results raise the question of the behaviour of oligodendrocytes in normal development.

Animals↗
PubMedDate not supplied

[Obsessive-compulsive behavior caused by bilateral lesions of the lenticular nuclei. A new case].

Another case of obsessive behaviour as the consequence of lentiform nuclei lesions is reported. All the aspects of an obsessive neurosis were present: irresistible compulsiveness, acute anxiety in case of non accomplishment, magic-like clues. The symptoms appeared after a carbon monoxide poisoning, in a 31-years-old woman who had previously a pathological personality, of the psychopathic type, but without obsessive features. The onset of compulsions was paralleled by frontal-like psychological changes, but there was no reduction of intellectual or mnesic functions. A previous depressive state continued after the poisoning, so that the patient did not show an empty mind as did the other patients; the loss of "self-psychic activation" was only partial. All these case-reports emphasize the fact that the neuropsychological testing must not be limited to the behaviour and must investigate the "mental content" as well. They also lead us to emphasize similitudes between psychic disorders related to lenticular lesions and those related to frontal lobe lesions, including obsessive-like activities. Such case-reports provide a model in which some components of the obsessive neurosis, hebephrenia and depression are the consequence of an identified brain damage. It can be suggested that the neural circuits involving frontal lobes and parts of the neostriatum and of the pallidum are implicated in the mechanisms of these three types of psychoses.

Adult↗
PubMedDate not supplied

[Morphometric and radioautographic study of neuronal loss and gliosis in sclerosis of the hippocampus associated with temporal lobe epilepsy].

Hippocampal sclerosis is a complex combination of neuronal and glial changes. It is frequently associated with temporal lobe epilepsy. Six hippocampal specimen were obtained from patients operated on for intractable mesial temporal lobe epilepsy. Comparisons were made with six autopsy controls. The neuronal and glial cells populations were studied by morphometric quantitative analysis. The glial cell types were identified by immunohistochemistry procedures. Distribution of the central (neuronal location) and the peripheral (glial location) benzodiazepine (BZ) binding sites was studied by quantitative autoradiography using [3H]-flumazénil and [3H]-PK11195 as respective ligands. Neuronal death and glial proliferation with the usual HS pattern were confirmed in all cases. Microglial cells, labelled with KP1 antibody (resident component) and with HLA-DR alpha (reactive component) were qualitatively similar in patients and controls. Particular radial organization of numerous, long and thin astrocytic processes, as labelled with GFAP antibody, was observed in the molecular layer of the dentate gyrus in 5 cases. These fibrillary processes were intermingled with the granule cells, which were markedly dispersed in 4 of the cases. In comparison with control group, all the epileptic cases had significant selective decreased central-type and increased peripheral-type BZ receptor. These results were respectively correlated with neuronal loss and glial proliferation. Morphologic results suggest that a specific configuration of astrocytic cell processes may be associated with some of the neuronal changes of human HS. Such aspect has not been reported in the astroglial growth observed in animal models of limbic epilepsy. The lack of reactive microglia suggested the absence of recent cell death.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

MR determination of hippocampal volume: comparison of three methods.

PURPOSE: To determine whether measurements of the volume of the hippocampal formation obtained from a three-dimensional acquisition not perpendicular to the hippocampus are statistically different from those obtained from a perpendicular acquisition. METHODS: Both hippocampi were studied in 10 healthy volunteers with two three-dimensional acquisitions, allowing three different volume-calculation protocols: (a) on sections from a coronal 3-D acquisition not perpendicular to the axis of the hippocampal formation (NOPERP protocol), (b) on sections obtained with the same acquisition but reformatted perpendicular to the axis of the hippocampal formation (REFOR protocol), and (c) on sections from a coronal 3-D acquisition perpendicular to the axis of the hippocampal formation (PERP protocol) obtained with the patient's head tilted backward. To obtain measurements of the volume of the hippocampal formations, an accurate 3-D processing technique was used to segment the hippocampus. In all subjects, two hippocampal formation right-left asymmetry indexes were calculated by using each of the three protocols. RESULTS: For the right hippocampus, the mean volume was 3.42 cm3 (NOPERP protocol), 4.18 cm3 (REFOR protocol), and 3.91 cm3 (PERP protocol). For the left hippocampus, the mean volume was 3.29 cm3 (NOPERP protocol), 4.02 cm3 (REFOR protocol), and 3.74 cm3 (PERP protocol). For both hippocampi, the differences of the mean volumes were significant between each protocol. However, for both hippocampi, a high correlation was observed between volumes obtained with the different protocols. For the two asymmetry indexes, there were no significant differences for the means obtained with the three protocols. CONCLUSION: With the use of 3-D acquisitions in the study of hippocampal formation biometry, different procedures lead to significant variations in the absolute values of the volume of the hippocampal formation. However, there is a strong correlation between the results obtained by each method.

Adult↗