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Biomedical subjects

B Pillon

Publications and source records attributed to B Pillon.

116 records · Page 7Linked to original sources
PubMed1975

[Prosopagnosia. Role of the right hemisphere in visual perception. (Apropos of a case after right occipital lobectomy)].

The authors describe a case of prosopagnosia which appeared a month after right occipital lobectomy. Results obtained by means of various tests devised to analyse this perception disorder have produced the following conclusions: 1) results of pairing tests which require a high level of perceptive differentiation are successful but after abnormally long delays; 2) in spite of this success, faces--even the patient's own--are not recognized; 3) this disorder extends to affect every task requiring recognition of the individual nature of a stimulus; 4) this individuality has the peculiarity of being based on visual patterns which it is impossible, or almost impossible, to express verbally; 5) the part played by defective visual representation in the brain is discussed; 6) a posterior lesion of the minor hemisphere is a prerequisite of prosopagnosia; 7) these facts, in conjunction with the findings in cases of inter-hemispheric disconnection lead one to think that the minor hemisphere, in right-handed subjects, plays a major part in the development and treatment of highly differentiated visual patterns which it is impossible, or almost impossible, to express verbally.

Adult↗
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

[A test of progressive enrichment of visual information (results in 102 patients with cerebral lesions) (author's transl)].

A new test is reported in which probabilistic activity is imposed on the subject in order to identify the visual stimuli presented to him. The test was validated in 109 normal subjects. When applied to 102 patients with focal cerebral lesions it demonstrated that all lesions of the right hemisphere provoked erroneous or delayed responses and that only lesions in the left occipital region produced the same effects.

Adult↗
PubMedDate not supplied

Attentional deficits in Parkinson's disease: partial reversibility with naphtoxazine (SDZ NVI-085), a selective noradrenergic alpha 1 agonist.

Several authors have suggested that catecholamine depletion may affect attentional processes in human subjects and could be implicated in the frontal lobe syndrome that has been described in Parkinson's disease (PD). The present study reports the effects of a placebo and naphtoxazine (SDZ-NVI-085), a selective noradrenergic alpha 1 agonist. These substances were administered to nine parkinsonian patients who were assessed on measures of attention, including neuropsychological tests and evoked potentials. The results indicate that naphtoxazine may improve performance on some tests of "frontal functions," including the Stroop and the Odd-Man-Out tests, which have been previously found to be affected in PD. However, the results of some other neuropsychological tests of frontal function were not affected by naphtoxazine. Specific evoked potentials such as the Nd1 and Nd2 curves--which are thought to reflect attentional processes and which have been found to be affected in PD--were improved by naphtoxazine. Finally, naphtoxazine reduced the percentage of errors and restored the lateralization of N100 during the Shifting Reaction Time Task, suggesting that this substance may act on the processes underlying the shifting deficit in these patients. The results are discussed in terms of the specific cognitive processes that may be affected by naphtoxazine and in terms of the role of the noradrenaline in attentional deficits found in PD.

Adrenergic alpha-Agonists↗