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 method by using H-reflexes and M responses. The method determines the ratio of the developmental slope of the H-reflex (Hslp) to the slope of the M response (Mslp). We also examined the relation between the Brunnstrom stages and the Hslp/Mslp. Design: Experiment. Setting: Electrophysiologic experimental laboratory in a Japanese medical school. 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 fixed on an immobile pedal. After the soleus H-reflex and M responses on one side 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 for 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 the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.