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, 48-71yr; 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

Hslp/Mslp is the preferred index for evaluating the motoneuron pool excitability of the spastic side of hemiplegic patients.