Bilateral brachial plexopathy as an initial presentation in a newly-diagnosed, uncontrolled case of diabetes mellitus.

A 55-year-old Indian woman with newly-diagnosed diabetes mellitus presented with acute onset right upper limb proximal weakness. This was followed three weeks later by pain, weakness and sensory loss in the left upper limb. Electrodiagnosis showed patchy multiple proximal and distal axonal neuropathies in both upper limbs, consistent with bilateral brachial neuritis. Laboratory investigations, cerebrospinal fluid analysis, and imaging studies were normal except for an antinuclear antibody titre of 1:640. Sural nerve and quadriceps biopsy did not show vasculitis. Brachial plexopathy has seldom been associated with diabetes mellitus and could represent a rare subtype of the diabetic neuropathies.