Syringomyelia presenting as shoulder dysfunction.

An elderly woman developed humeral subluxation secondary to syringomyelic neuroarthopathy. Atypical features included her advanced age, the unilaterality of sensory symptoms and signs, the nearly normal motor function, and the absence of long tract signs. Magnetic resonance imaging confirmed the presence of a cervical syrinx, and electrodiagnostic studies suggested superimposed compressive brachial plexopathy. This case suggests that syringomyelia may be underdiagnosed in patients with atypical presentations.