TY - JOUR
T1 - Patterns of impairment in digit independence after subcortical stroke
AU - Raghavan, Preeti
AU - Petra, Electra
AU - Krakauer, John W.
AU - Gordon, Andrew M.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2006/1
Y1 - 2006/1
N2 - The nature of impairment in hand motor control after stroke and its relationship to hand function are still not well understood. In this study, we investigated digit independence in patients with subcortical stroke (n = 8) and moderate hand impairment, defined by wrist and hand Fugl-Meyer scale scores ≤25/33, and age-matched controls (n = 8). Subjects made cyclical flexion-extension movements of an instructed digit while keeping the other digits as still as possible. Movements of the metacarpo-phalangeal (MCP) joints of the five digits were measured using an instrumented glove. The ability to move an instructed digit individually (individuation index), and the ability to keep a noninstructed digit as still as possible (stationarity index) were determined for each digit. Contrary to the finding of normal thumb individuation in a recent study of patients with variable hand motor impairment after stroke, we found that independent movement for all digits was significantly impaired, although individuation and stationarity were differentially affected for each digit. All the digits, including the thumb, showed a similar impairment in individuation. In contrast, stationarity was affected in a digit-dependent pattern: the thumb was affected least, and the middle finger was most impaired. Stroke subjects did not extend their digits fully to the baseline position, and the angular displacement at maximum digit extension correlated significantly with digit individuation. Contrary to expectation, digit independence correlated weakly with clinical tests of hand function, which emphasize grasp. This suggests that corticospinal projections might be separated with respect to function rather than finger topography.
AB - The nature of impairment in hand motor control after stroke and its relationship to hand function are still not well understood. In this study, we investigated digit independence in patients with subcortical stroke (n = 8) and moderate hand impairment, defined by wrist and hand Fugl-Meyer scale scores ≤25/33, and age-matched controls (n = 8). Subjects made cyclical flexion-extension movements of an instructed digit while keeping the other digits as still as possible. Movements of the metacarpo-phalangeal (MCP) joints of the five digits were measured using an instrumented glove. The ability to move an instructed digit individually (individuation index), and the ability to keep a noninstructed digit as still as possible (stationarity index) were determined for each digit. Contrary to the finding of normal thumb individuation in a recent study of patients with variable hand motor impairment after stroke, we found that independent movement for all digits was significantly impaired, although individuation and stationarity were differentially affected for each digit. All the digits, including the thumb, showed a similar impairment in individuation. In contrast, stationarity was affected in a digit-dependent pattern: the thumb was affected least, and the middle finger was most impaired. Stroke subjects did not extend their digits fully to the baseline position, and the angular displacement at maximum digit extension correlated significantly with digit individuation. Contrary to expectation, digit independence correlated weakly with clinical tests of hand function, which emphasize grasp. This suggests that corticospinal projections might be separated with respect to function rather than finger topography.
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U2 - 10.1152/jn.00873.2005
DO - 10.1152/jn.00873.2005
M3 - Article
C2 - 16207778
AN - SCOPUS:33644790987
SN - 0022-3077
VL - 95
SP - 369
EP - 378
JO - Journal of neurophysiology
JF - Journal of neurophysiology
IS - 1
ER -