Motoneuron pool excitability of hemiplegic patients: Assessing recovery stages by using H-reflex and M response

Objectives: To compare the excitability of the motoneuron pools of both the spastic and the unimpaired sides of patients with hemiplegia with a new me thod by using H-reflexes and M responses. The method determines the ratio o f the developmental slope of the H-reflex (Hslp) to the slope of the M resp onse (Mslp). We also examined the relation between the Brunnstrom stages an d the Hslp/Mslp. Design: Experiment. Setting: Electrophysiologic experimental laboratory in a Japanese medical s chool. Patients: Fifteen hemiplegic patients (9 men. 6 women age range, 48-71 yr; mean, 60yr) with spasticity caused by a stroke. Interventions: The subject was instructed to relax while seated in a reclining chair with his foot fix ed on an immobile pedal. After the soleus H-reflex and M responses on one s ide were recorded. the same experimental procedures were carried out on the other side. Main Outcome Measures: Hslp/Mslp Brunnstrom stages. Results: Hslp/Mslp had better predictive value than conventional indicators of motoneuron pool excitability. Hslp/Mslp appeared to be a better match f or the bell-shaped pattern of the Brunnstrom stages. Conclusion: Hs1p/Mslp is the preferred index for evaluating the motoneuron pool excitability of the spastic side of hemiplegic patients. (C) 2001 by t he American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.