TY - JOUR
T1 - Interhemispheric differences of hand muscle representation in human motor cortex
AU - Cicinelli, Paola
AU - Traversa, Raimondo
AU - Bassi, Andrea
AU - Scivoletto, Giorgio
AU - Rossini, Paolo Maria
PY - 1997
Y1 - 1997
N2 - Focal magnetic transcranial stimulation (TCS) is employed for mapping of the motor cortical output to abductor digiti minimi (ADM) muscle. The aim of this study was to evaluate the interhemispheric asymmetries in normals. Motor maps were obtained through motor evoked potentials (MEPs) recordings from ADM muscle in 20 healthy subjects in right and left hemispheres TCS. Measurement of several indexes such as excitability threshold, MEPs amplitude, MEPs latency, and silent period duration did not show differences between the hemispheres. Moreover, no interhemispheric asymmetries were found when the amplitude ratio values were analyzed. The hand motor cortical area, as represented by the number of responsive sites (3.6 vs. 3.5) and the 'hot spot' site localization presented a fairly symmetrical organization. Absolute values displayed a relatively wide intersubject variability, while their interhemispheric differences were extremely restricted. This observation can offer a new tool in diagnosing and following up neurological disorders affecting the central motor system, mainly for those concerning monohemispheric lesions.
AB - Focal magnetic transcranial stimulation (TCS) is employed for mapping of the motor cortical output to abductor digiti minimi (ADM) muscle. The aim of this study was to evaluate the interhemispheric asymmetries in normals. Motor maps were obtained through motor evoked potentials (MEPs) recordings from ADM muscle in 20 healthy subjects in right and left hemispheres TCS. Measurement of several indexes such as excitability threshold, MEPs amplitude, MEPs latency, and silent period duration did not show differences between the hemispheres. Moreover, no interhemispheric asymmetries were found when the amplitude ratio values were analyzed. The hand motor cortical area, as represented by the number of responsive sites (3.6 vs. 3.5) and the 'hot spot' site localization presented a fairly symmetrical organization. Absolute values displayed a relatively wide intersubject variability, while their interhemispheric differences were extremely restricted. This observation can offer a new tool in diagnosing and following up neurological disorders affecting the central motor system, mainly for those concerning monohemispheric lesions.
KW - focal transcranial magnetic stimulation
KW - human motor cortex
KW - interhemispheric asymmetries
KW - motor mapping
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U2 - 10.1002/(SICI)1097-4598(199705)20:5<535::AID-MUS1>3.0.CO;2-A
DO - 10.1002/(SICI)1097-4598(199705)20:5<535::AID-MUS1>3.0.CO;2-A
M3 - Article
C2 - 9140359
AN - SCOPUS:0030939837
VL - 20
SP - 535
EP - 542
JO - Muscle and Nerve
JF - Muscle and Nerve
SN - 0148-639X
IS - 5
ER -