An unusual clinical course of peripheral neuropathy in neurofibromatosis type 2

We report an unusual clinical course of peripheral neuropathy in a patient with neurofibromatosis type 2 (NF2). Clinically, a progressive course of focal amyotrophy had been noted since childhood, followed by bilateral vestibular and intraspinal schwannomas at the fourth decade, and then chronic asymmetric polyneuropathy after menopause. Electrophysiological studies revealed a predominantly axonal type of peripheral neuropathy. A sural nerve biopsy showed an abundant proliferation of Schwann cells and a reduction of the large myelinated fibers. A review of the literature showed that peripheral neuropathy might present with focal amyotrophy, mononeuropathy, mononeuropathy multiplex, or symmetric or asymmetric polyneuropathy in patients with NF2. The etiologies of peripheral neuropathy in patients with NF2 include an abnormal proliferation of Schwann cells and tumorlet compression of the peripheral nerves. From our study, we conclude that an abundant proliferation of Schwann cells plays an important role in the pathogenesis of peripheral neuropathy in patients with NF2.