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Titolo:
Cortical activation by tactile and painful stimuli in hemispherectomized patients
Autore:
Olausson, H; Ha, B; Duncan, GH; Morin, C; Ptito, A; Ptito, M; Marchand, S; Bushnell, C;
Indirizzi:
McGill Univ, Dept Anaesthesia, Montreal, PQ H3A 2T5, Canada McGill Univ Montreal PQ Canada H3A 2T5 esia, Montreal, PQ H3A 2T5, Canada McGill Univ, Montreal Neurol Hosp & Inst, Montreal, PQ, Canada McGill Univ Montreal PQ Canada Neurol Hosp & Inst, Montreal, PQ, Canada Univ Montreal, Fac Med Dent, Montreal, PQ H3C 3J7, Canada Univ Montreal Montreal PQ Canada H3C 3J7 nt, Montreal, PQ H3C 3J7, Canada Univ Quebec Abitibi Temiscamingue, Dept Clin Sci, Rouyn Noranda, PQ, Canada Univ Quebec Abitibi Temiscamingue Rouyn Noranda PQ Canada da, PQ, Canada
Titolo Testata:
BRAIN
, volume: 124, anno: 2001,
parte:, 5
pagine: 916 - 927
SICI:
0006-8950(200105)124:<916:CABTAP>2.0.ZU;2-D
Fonte:
ISI
Lingua:
ENG
Soggetto:
FUNCTIONAL MAGNETIC-RESONANCE; PRIMARY SOMATOSENSORY CORTEX; POSITRON-EMISSION-TOMOGRAPHY; CORPUS-CALLOSUM; CEREBRAL-CORTEX; NOXIOUS STIMULI; HUMAN BRAIN; RESPONSES; PERCEPTION; PARIETAL;
Keywords:
hemispherectomy; touch; pain; functional MRI; cortex;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
51
Recensione:
Indirizzi per estratti:
Indirizzo: Olausson, H Sahlgrens Univ Hosp, Dept Clin Neurophysiol, S-41345 Gothenburg, Sweden Sahlgrens Univ Hosp Gothenburg Sweden S-41345 enburg, Sweden
Citazione:
H. Olausson et al., "Cortical activation by tactile and painful stimuli in hemispherectomized patients", BRAIN, 124, 2001, pp. 916-927

Abstract

Hemispherectomized patients are able to perceive tactile and painful stimuli on their nonparetic as well as paretic body halves. We have used functional MRI to study the cortical mechanisms underlying this preserved somatosensory capacity. Nonpainful brushing and painful heat were applied to the skin of the legs in four hemispherectomized patients and, for comparison, in four normal subjects. Cortical activation was studied with a 1.5 T scanner using a BOLD (blood oxygen level dependent) protocol. All patients rated both the brushing and the heat pain as almost equally intense on each leg andthe ratings were similar to those in normals. Brushing on the nonparetic leg activated primary and secondary somatosensory cortices (S1 and S2) in all patients, similar to findings in normals. Brushing on the paretic leg activated S1 in two patients and S2 in one of these patients. Heat pain activated S2, insular cortex and anterior cingulate cortex to a similar degree for both legs, but the activation was weaker in the patients than in the normals. For the individual patient, there was generally no obvious correlationbetween cortical activation as studied with the BOLD technique and psychophysical performance, The findings from tactile stimulation of the nonparetic leg, that the activation was similar to the contralateral activation in normals, suggest that tactile information processing in the hemisphere contralateral to the stimulation is independent of the corpus callosum, In contrast, the pain activation for the nonparetic leg was weaker than in normals,suggesting that pain activation in the hemisphere contralateral to the stimulation is dependent on transcallosal information processing, The latter finding was corroborated by a subnormal capacity for pain localization on the nonparetic foot in two of the patients. The findings from stimulation of the paretic leg show that areas typically involved in the processing of tactile and painful stimuli can be activated by ipsilateral pathways directly from the periphery. The tactile-evoked ipsilateral S1 activation may be dueto subcortical reorganization, since it was not observed in the normal subjects.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 31/03/20 alle ore 22:45:45