X-linked bulbo-spinal neuronopathy of late onset.

Two cases of X-linked bulbo-spinal neuronopathy (BSN) of late onset are presented. An extensive review of the literature shows that, in addition to the signs of a chronic degeneration of brainstem and spinal neurons, other clinical features may also be present at the onset of the disease, or develop during its course. Some clinical, electrophysiological and anatomical data support the hypothesis that BSN is not purely a motoneuronopathy but also concerns sensory nerve.