Hereditary neuropathy with liability to pressure palsies and amyotrophic lateral sclerosis

A 56-year-old male with recurrent painless focal neuropathies and a family history of peripheral neuropathy of unknown etiology presented with progressively worsening of impaired sensations and weakness in his lower extremities. His initial electrodiagnostic evaluation was suggestive of severe sensory and motor peripheral polyneuropathy. The genetic testing was performed for familial causes of peripheral neuropathy as there was a family history of peripheral neuropathy of unknown etiology. The patient was found to have 1.5-Mb deletion in the PMP22 gene which was confirmatory of hereditary neuropathy with liability to pressure palsies (HNPP). He developed progressive upper and lower extremity weakness, bulbar dysfunction and widespread fasciculations during the course of his illness. He was subsequently diagnosed with amyotrophic lateral sclerosis (ALS). This is the second reported case of HNPP associated with ALS. We discuss significant clinical and electrodiagnostic findings of this interesting case.