Post-activation depression of the soleus H-reflex in stroke patients.
OBJECTIVE
We examined post-activation depression in 35 stroke patients and 10 healthy subjects, and investigated whether their clinical symptoms were correlated to post-activation depression.


METHODS
Post-activation depression of the soleus H-reflex evoked by electrical stimulation of the common peroneal nerve with supramaximal intensity of motor response on the tibialis anterior muscle.


RESULTS
Post-activation depression was decreased on the affected side of the stroke patients. There was a significant difference between the affected and unaffected sides of the patients with post-activation depression, but no difference between the unaffected sides of the patients and healthy subjects. The presence of ankle clonus and the decrease in post-activation depression were correlated.


CONCLUSIONS
Decreased post-activation depression in stroke patients suggests that a mechanism other than postsynaptic inhibition, such as reciprocal Ia inhibition and Ib inhibition, and presynaptic inhibition, may contribute to the exaggerated stretch reflexes, in particular, the manifestation of clonus.
Masakado
Y
Y
Department of Rehabilitation Medicine, School of Medicine, Keio University, Tokyo, Japan. masakado@sc.itc.keio.ac.jp
Kagamihara
Y
Y
Takahashi
O
O
Akaboshi
K
K
Muraoka
Y
Y
Ushiba
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D004558:Electric Stimulation; D005260:Female; D006181:H-Reflex; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation*; D010543:Peroneal Nerve / Q000502:physiology; D020521:Stroke / Q000150:complications*