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Titolo:
ABNORMAL ACCESS OF AXIAL VIBROTACTILE INPUT TO DEAFFERENTED SOMATOSENSORY CORTEX IN HUMAN UPPER-LIMB AMPUTEES
Autore:
KEW JJM; HALLIGAN PW; MARSHALL JC; PASSINGHAM RE; ROTHWELL JC; RIDDING MC; MARSDEN CD; BROOKS DJ;
Indirizzi:
RIVERMEAD REHABIL CTR,ABINGDON RD OXFORD OX1 4XD ENGLAND RIVERMEAD REHABIL CTR OXFORD OX1 4XD ENGLAND HAMMERSMITH HOSP,MRC,CYCLOTRON UNIT LONDON W12 0HS ENGLAND INST NEUROL,MRC,HUMAN MOVEMENT & BALANCE UNIT LONDON WC1N 3BG ENGLAND RADCLIFFE INFIRM,NEUROPSYCHOL UNIT OXFORD OX1 4XD ENGLAND UNIV OXFORD,DEPT EXPT PSYCHOL OXFORD OX1 3UD ENGLAND
Titolo Testata:
Journal of neurophysiology
fascicolo: 5, volume: 77, anno: 1997,
pagine: 2753 - 2764
SICI:
0022-3077(1997)77:5<2753:AAOAVI>2.0.ZU;2-L
Fonte:
ISI
Lingua:
ENG
Soggetto:
MASSIVE CORTICAL REORGANIZATION; POSITRON EMISSION TOMOGRAPHY; VISUAL-CORTEX; PET IMAGES; PERCEPTUAL PLASTICITY; MAGNETIC STIMULATION; GABAERGIC NEURONS; CEREBRAL-CORTEX; MOTOR CORTEX; HUMAN BRAIN;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
49
Recensione:
Indirizzi per estratti:
Citazione:
J.J.M. Kew et al., "ABNORMAL ACCESS OF AXIAL VIBROTACTILE INPUT TO DEAFFERENTED SOMATOSENSORY CORTEX IN HUMAN UPPER-LIMB AMPUTEES", Journal of neurophysiology, 77(5), 1997, pp. 2753-2764

Abstract

We studied two human subjects with total deafferentation of one upperlimb secondary to traumatic multiple cervical root avulsions. Both subjects developed a phantom limb and underwent elective amputation of the paralyzed, deafferentated limb. Psychophysical study revealed in each subject an area of skin in the pectoral region ipsilateral to the amputation where vibrotactile stimulation (VS) elicited referred sensations (RS) in the phantom limb. Positron emission tomography was then used to measure regional cerebral blood flow changes during VS of the pectoral region ipsilateral to the amputation with RS and during VS of a homologous part of the pectoral region adjacent to the intact arm without RS. A voxel-based correlation analysis was subsequently used to study functional connectivity. VS of the pectoral region adjacent to the intact arm was associated with activation of the dorsal part of thecontralateral primary somatosensory cortex (S1) in a position consistent with the S1 trunk area. In contrast, VS of the pectoral region ipsilateral to the amputation with RS was associated with activation of the contralateral S1 that extended from the level of the trunk representation ventrally over distances of 20 and 12 mm, respectively, in the two subjects. The area of S1 activated during VS of the digits in a normal control subject was coextensive with the ventral S1 region abnormally activated during VS of the ectopic phantom representation in the two amputees, suggesting that the deafferented digit or hand/arm area had been activated by sensory input from the pectoral region. Correlation analysis showed an abnormal pattern of intrinsic connectivity within the deafferented S1 hand/arm area of both amputees. In one subject,the deafferented S1 was functionally connected with 3 times as many S1 voxels as the normally afferented S1. This abnormal functional connectivity extended in both the rostrocaudal and ventrodorsal dimensions. The results demonstrate that sensory input delivered to the axial body surface may gain access to the S1 hand/arm area in some humans who have suffered extensive deafferentation of this area. The findings are consistent with the hypothesis that deafferentation of an area of S1 may result in activation of previously dormant inputs from body surfaces represented in immediately adjacent parts of S1. The results also provide evidence that changes in functional connectivity between these adjacent areas of the cortex play a role in the somatotopic reorganization.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 20/01/20 alle ore 04:49:52