ROOT STIMULATION STUDIES IN THE EVALUATION OF PATIENTS WITH MOTOR-NEURON DISEASE

Nerve root stimulation may be employed in patients with motor neuron d isease (MND) to rule out motor neuropathy with conduction block. The d iagnostic utility of these studies is unknown, in part because the ran ge of amplitude changes across nerve root segments in patients with ac tive neuronal degeneration has not been well studied. We reviewed root stimulation studies in 32 patients (59 nerves) with MND and found seg mental amplitude reduction from 0 to 45%, a range similar to values re ported for normal subjects; there was no suggestion of conduction bloc k based on our usual criteria.