Evident difference in the excitability of the motoneuron pool between normal subjects and patients with spasticity assessed by a new method using H-reflex and M-response

The excitability of the motoneuron (MN) pool in the resting state was compared between normal control subjects and patients with spasticity resulting from HTLV-I-associated myelopathy, using a new parameter, Hslp/Mslp, and the conventional parameters Hmax/Mmax and Hth/Mth. Differences in the excitability of the MN pool between these two groups reached a high degree of statistical significance only when assessed with the new parameter. This suggests the methodological advantage of the Hslp/Mslp over both Hmax/Mmax and Hth/Mth for evaluation of the excitability of the MN pool in the resting state.