TY - JOUR
T1 - Post-exercise facilitation and depression of motor evoked potentials to transcranial magnetic stimulation
T2 - A study in multiple sclerosis
AU - Perretti, A.
AU - Balbi, P.
AU - Orefice, G.
AU - Trojano, L.
AU - Marcantonio, L.
AU - Brescia-Morra, V.
AU - Ascione, S.
AU - Manganelli, F.
AU - Conte, G.
AU - Santoro, L.
PY - 2004/9
Y1 - 2004/9
N2 - Objective: To evaluate motor cortex excitability changes by transcranial magnetic stimulation (TMS) following repetitive muscle contractions in patients with multiple sclerosis (MS); to state whether a typical pattern of post-exercise motor evoked potentials (MEPs) is related to clinical fatigue in MS. Methods: In 41 patients with definite MS (32 with fatigue and 9 without fatigue according to Fatigue Severity Scale) and 13 controls, MEPs were recorded at rest: at baseline condition, following repetitive contractions until fatigue, and after fatigue, to evaluate post-exercise MEP facilitation (PEF) and depression (PED). Results: After exercise, MEP amplitude significantly increased both in patients and controls (PEF). When fatigue set in, MEP amplitude was significantly reduced in normal subjects (PED), but not in patients. Post-exercise MEP findings were similar both in patients with and without fatigue. Conclusions: Our findings suggest an intracortical motor dysfunction following a voluntary contraction in MS patients, possibly due to failure of depression of facilitatory cortical circuits, or alternatively of inhibitory mechanisms.
AB - Objective: To evaluate motor cortex excitability changes by transcranial magnetic stimulation (TMS) following repetitive muscle contractions in patients with multiple sclerosis (MS); to state whether a typical pattern of post-exercise motor evoked potentials (MEPs) is related to clinical fatigue in MS. Methods: In 41 patients with definite MS (32 with fatigue and 9 without fatigue according to Fatigue Severity Scale) and 13 controls, MEPs were recorded at rest: at baseline condition, following repetitive contractions until fatigue, and after fatigue, to evaluate post-exercise MEP facilitation (PEF) and depression (PED). Results: After exercise, MEP amplitude significantly increased both in patients and controls (PEF). When fatigue set in, MEP amplitude was significantly reduced in normal subjects (PED), but not in patients. Post-exercise MEP findings were similar both in patients with and without fatigue. Conclusions: Our findings suggest an intracortical motor dysfunction following a voluntary contraction in MS patients, possibly due to failure of depression of facilitatory cortical circuits, or alternatively of inhibitory mechanisms.
KW - Depression
KW - Facilitation
KW - Fatigue
KW - Magnetic stimulation
KW - Multiple sclerosis
KW - Post-exercise facilitation
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U2 - 10.1016/j.clinph.2004.03.028
DO - 10.1016/j.clinph.2004.03.028
M3 - Article
C2 - 15294215
AN - SCOPUS:3843103674
VL - 115
SP - 2128
EP - 2133
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
SN - 1388-2457
IS - 9
ER -