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Biomedical subjects

D Laplane

Publications and source records attributed to D Laplane.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Motor consequences of motor area ablations in man.

Motor disorders reported in the present paper do not result from cortical ablations stricto sensu since some white matter was excised in every patient. However they appear to suggest that, as suggested by Walshe (1935), the central region and premotor area are a functional entity, i.e. they work as a whole. The extensive lesions of the premotor area, leaving untouched the motor region, have the same motor and tonic consequences as lesions limited to the central region. This point which appears specific for man does not imply that the premotor region subserves activities similar to those subserved by the central region. Rather it may suggest a deafferentiation of the central region, the consequences of which would be more important than is generally assumed. Extensive central or premotor lesions determine various tonic disorders: a well known spasticity, with exaggeration of the stretch reflex, associated with an increase in passive swinging of segments of limbs and in extensibility of joints. These two latter phenomena are usually defined as hypotonia. With premotor and precentral lesions the hypotonia disappears and a hemiplegic posture is observed. This hemiplegic posture is a dystonia which apparently does not result directly from the exaggeration of the stretch reflex. Anatomically it appears to result from lesions of both central and premotor regions. This is in agreement with Denny-Brown's (1966) contention that an extrapyramidal region lies rostral to the prerolandic sulcus. As suggested by Evarts (1973) motor regions appear to control automatic as well as voluntary movements. They probably play a role in the trophic function of muscle, since, despite rehabilitation, amyotrophy was present in every case reported in the present paper.

Adolescent↗
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

Extracranial vertebral artery dissections: a review of 13 cases.

Clinical and radiologic findings in 13 patients (11 women, 2 men) with extracranial vertebral artery dissection are reported. Dissection was spontaneous in 8 patients, occurred after neck manipulation in 2 and after a potential minor injury to the neck in 3. Six had a history of common migraine, 4 were using oral contraceptives at the time of dissection, and 3 had fibromuscular dysplasia. Dissection was bilateral in 8 patients and associated with carotid dissection in 3. It usually presented with neck or occipital pain preceding basilar ischemic symptoms by a few minutes to 1 month. In 3 patients, transient ischemic attacks were the only manifestation of basilar ischemia, and in 1 patient there was no symptom of basilar ischemia despite bilateral vertebral dissection. In 19 of the 21 dissected vertebral arteries, the angiographic appearance was that of an irregular stenosis, which was associated in 6 arteries with pseudoaneurysmal formation. In 2 patients, 1 vertebral artery was occluded but the contralateral artery showed the typical irregular stenosis. The dissection involved only the third segment in 33%, only the second segment in 24%, and 2 or more segments in 38%. Eleven patients were treated with anticoagulants and 2 with aspirin; 11 recovered without sequelae and 2 had residual deficit. No recurrence was observed (mean follow-up 34 months). At control angiography (n = 12) or ultrasonic study (n = 1), 63% of dissected vertebral arteries had returned to normal, 26% showed marked improvement, and 11% were occluded. Our patient characteristics are compared with those of previously published cases. The validity of the distinction between spontaneous dissection and dissection associated with minor trauma is discussed.

Adult↗
PubMedDate not supplied

[Bilateral isolated trigeminal neuropathy (author's transl)].

Spillane and Wells (1959) were the first to describe the syndrome known as isolated trigeminal neuropathy in which deficit in the trigeminal nerve occurs either unilaterally or bilaterally without evidence of any local lesion. It may be a truly isolated disorder but can also be the predominant element of a more diffuse neuropathy provoking, more particularly, ageusia and anosmia. The bilateral forms are fairly frequently related to connective tissue diseases but many are of unknown aetiology. A case is reported of the bilateral form with ageusia and anosmia, cubital deficit, and slowing of the conduction rate in the limbs. No aetiology was found.

Aged↗
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

[The thought-brain relationship. New facts. New hypotheses].

The close links between Thought and the brain having been amply demonstrated by the neurosciences, it is now time to draw conclusions. After having shown that the specific characteristic of thought is the self, the author underlines the impossibility of explaining the self by objective study and the consequent need to preserve for the thought its specificity in relation to Matter-Energy. After having excluded, by this statement, attitudes tending to deny explicitly or implicitly the specificity of Thought and having rejected spiritualist hypotheses as not conforming to scientific data, only two possible interpretations remain: that of the identity of Thought and Matter-Energy treats Thought as the other face of Energy, that of creation makes it necessary to admit a transformation from Energy to Thought (E = KP). The problems of thermodynamics and of the quantification of Thought thus raised are considered. Whatever the solution, it is necessary to admit that a "Universal Thought" exists. The universe is conscious of itself. The effort of cerebralisation in the evolution of species seems a mean of giving autonomy to individual thought which is necessarily included in Universal Thought.

Brain↗