Dale J. Lange

Sensory Nerve Abnormalities in Brachial Plexopathy

Sensory nerve action potential (SNAP) amplitude should be abnormal in brachial plexopathies (BP) which cause axonal degeneration in distal segments. Fifty-six patients with BP were identified. In diffuse BP, 22/25 (88%) showed low amplitude or absent median or ulnar SNAP. Three of 5 patients with upper trunk BP had low amplitude or absent SNAP (1 median, 1 radial, 1 lateral antebrachial cutaneous). Seventy-five percent of patients with lower trunk/medial cord BP had low amplitude or absent SNAP (8/24 median, 18/24 ulnar). Overall, 82.5% of patients had low amplitude or absent SNAP when a sensory nerve in the distribution of signs was studied. Testing multiple sensory nerves to include symptomatic regions enhances the diagnostic yield of SNAP in BP.

Amyotrophic lateral sclerosis in an adult following acute paralytic poliomyelitis in early childhood

Abstract About 30% of polio survivors develop a post-polio syndrome. Some of these patients develop slowly progressive muscle weakness known as post-poliomyelitis muscular atrophy (PPMA). We describe an unusual form of amyotrophic lateral sclerosis (ALS) in a patient with acute poliomyelitis in childhood. An 80-year-old woman had acute poliomyelitis at 2 years of age and developed weakness limited to the lower extremities. Residual weakness was stable until the age of 75 when she developed rapidly progressive weakness that first affected her left arm and subsequently the right arm. Neurological examination revealed both upper and lower motor neuron signs. These clinical features were more consistent with ALS than PPMA. At autopsy, there was marked atrophy of the precentral gyrus. Microscopic examination revealed a severe loss of all nerve cells and pronounced fibrillary astrocytosis of the lumbar ventral horns in the spinal cord, presumably a result of poliomyelitis. Superimposed on these spinal cord alterations were the pathological features of ALS, consisting of loss of Betz cells, corticospinal tract degeneration and loss of motor neurons of other levels of the spinal cord. The findings included some atypical features for ALS, namely, sparing of the hypoglossal nucleus, absence of Bunina bodies and absence of ubiquitin-immunoreactive inclusions. Although poliomyelitis and ALS may be coincidental, the unusual pathological expression of ALS raise the possibility that it is related to the antecedent poliomyelitis.