On the cause of tendon areflexia in the Holmes-Adie syndrome.

A case of Holmes-Adie syndrome was studied clinically and electrophysiologically. A total loss of tendon reflexes was observed in upper and lower limbs. The main electrophysiological finding was a marked increase of the central conduction time after stimulation of peroneal and tibial nerves. Motor evoked potentials in soleus muscle after transcranial magnetic stimulation showed normal threshold and latencies. We suggest that tendon areflexia could be a consequence of a dysfunction of somatosensory large diameter afferent fibres at the spinal level.