Lésion cérébrale

Résumé

Une lésion cérébrale est une lésion qui touche le cerveau. En général, il s'agit d'une destruction plus ou moins étendue du tissu nerveux entraînant un déficit dans la perception, la cognition, la sensibilité ou la motricité en fonction du rôle que jouait la région atteinte dans l'architecture neurocognitive. Cette lésion peut être de nature diverse : ischémique, hémorragique, compressive par un processus extensif de type tumoral ou un hématome. Un exemple célèbre, rapporté par le neurologue Oliver Sacks, est celui d'un peintre subitement atteint d'achromatopsie (absence totale de vision des couleurs) à la suite d'un accident de voiture. La neuropsychologie est la discipline scientifique et clinique cherchant à mettre en relation les lésions cérébrales avec les troubles qu'elles entraînent et à améliorer ainsi notre compréhension du fonctionnement du cerveau. Prise en charge Diverses professions peuvent être impliquées dans les soins médicaux et de réadaptation d'une perso

Source officielle

https://fr.wikipedia.org/wiki/L%C3%A9sion_c%C3%A9r%C3%A9brale

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Publications associées (87)

Publications associées

Chargement

Personnes associées (16)

Personnes associées

Chargement

Unités associées (13)

Afficher plus

Unités associées

Chargement

Concepts associés (62)

Concepts associés

Chargement

Cours associés (5)

Cours associés

Chargement

Séances de cours associées (8)

Séances de cours associées

Chargement

Hyperschematia after right brain damage: a meaningful entity?

Roberta Ronchi, Giuseppe Vallar

In recent years we reported three right-brain-damaged patients, who exhibited a left-sided disprortionate expansion of drawings, both by copying and from memory, contralateral to the side of the hemispheric lesion (Neurology, 67: 1801, 2006, Neurocase 14: 369, 2008). We proposed the term "hyperschematia" for such an expansion, with reference to an interpretation in terms of a lateral leftward distortion of the representation of extra-personal space, with a leftward anisometric expansion (relaxation) of the spatial medium. The symptom-complex shown by right-brain-damaged patients with "hyperschematia" includes: (1) a disproportionate leftward expansion of drawings (with possible addition of details), by copy and from memory (also in clay modeling, in one patient); (2) an overestimation of left lateral extent, when a leftward movement is required, associated in some patients with a perceptual underestimation; (3) unawareness of the disorder; (4) no unilateral spatial neglect. In most right-brain-damaged patients, left "hyperschematia" involves extra-personal space. In one patient the deficit was confined to a body part (left half-face: personal "hyperschematia"). The neural underpinnings of the disorder include damage to the fronto-temporo-parietal cortices, and subcortical structures in the right cerebral hemisphere, in the vascular territory of the middle cerebral artery. Here, four novel additional patients are reported. Finally, "hypeschematia" is reconsidered, in its clinical components, the underlying pathological mechanisms, as well as its neural underpinnings.

Frontiers Research Foundation2014

Chargement

Right-brain-damaged patients with unilateral spatial neglect are usually unaware (anosognosic) about their spatial deficits. However, in the scientific literature there is a lack of systematic and quantitative evaluation of this kind of unawareness, despite the negative impact of anosognosia on rehabilitation programs. This study investigated anosognosia for neglect-related impairments at different clinical tasks, by means of a quantitative assessment. Patients were tested in two different conditions (before and after execution of each task), in order to evaluate changes in the level of awareness of neglect-related behaviours triggered by task execution. Twenty-nine right-brain-damaged patients (17 with left spatial neglect) and 27 neurologically unimpaired controls entered the study. Anosognosia for spatial deficits is not pervasive, with different tasks evoking different degrees of awareness about neglect symptoms. Indeed, patients showed a largely preserved awareness about their performance in complex visuo-motor spatial and reading tasks; conversely, they were impaired in evaluating their spatial difficulties in line bisection and drawing from memory, showing over-estimation of their performance. The selectivity of the patients' unawareness of specific manifestations of spatial neglect is further supported by their preserved awareness of performance at a linguistic task, and by the absence of anosognosia for hemiplegia. This evidence indicates that discrete processes are involved in the aware monitoring of cognitive and motor performance, which can be selectively compromised by brain damage. Awareness of spatial difficulties is supported by a number of distinct components, and influenced by the specific skills required to perform a given task. (C) 2014 Elsevier Ltd. All rights reserved.

Elsevier Masson2014

Chargement

Somatoparaphrenia: a body delusion. A review of the neuropsychological literature

Roberta Ronchi, Giuseppe Vallar

A review of published brain-damaged patients showing delusional beliefs concerning the contralesional side of the body (somatoparaphrenia) is presented. Somatoparaphrenia has been reported, with a few exceptions, in right-brain-damaged patients, with motor and somatosensory deficits, and the syndrome of unilateral spatial neglect. Somatoparaphrenia, most often characterized by a delusion of disownership of left-sided body parts, may however occur without associated anosognosia for motor deficits, and personal neglect. Also somatosensory deficits may not be a core pathological mechanism of somatoparaphrenia, and visual field disorders may be absent. Deficits of proprioception, however, may play a relevant role. Somatoparaphrenia is often brought about by extensive right-sided lesions, but patients with posterior (parietal-temporal), and insular damage are on record, as well as a few patients with subcortical lesions. Possible pathological factors include a deranged representation of the body concerned with ownership, mainly right-hemisphere-based, and deficits of multisensory integration. Finally, the rubber hand illusion, that brings about a bodily misattribution in neurologically unimpaired participants, as somatoparaphrenia does in brain-damaged patients, is briefly discussed.

2008

Chargement