Chronic inflammatory demyelinating polyneuropathy involving the oculomotor and abducens nerves in a patient with chronic Miller–Fisher syndrome.

Abstract

Abstract: : Purpose: To describe a rare case of location of chronic inflammatory demyelinating polyneuropathy (CIDP) involving the oculomotor and abducens nerves. Methods: We report on a 40–year–old man with a 6–year history of CIDP and with fluctuating symptoms of partial ophthalmoplegia, ataxia and areflexia (Miller–Fisher subtype). He had high titers of antibodies against ganglioside GQ1b. MRI was performed because of slowly progressive right exophthalmia and revealed two spindle–shaped tumors in the right orbit, one medially and one laterally, extending into the cavernous sinus. The maximal diameter of the lesions was respectively 0.6 and 2.6 cm. No enhancement with gadolinium was seen. A biopsy of the lateral mass was performed. Results: Light and electron microscopy confirmed the presence of a hypertrophic nerve bundle. Most axons were surrounded by many onion bulb formations, consisting of concentrically organized layers of very thin and often degenerated Schwann cells and collagen fibers. Myelinated as well as demyelinated axons were found. After the biopsy the patient showed a complete paralysis of the right abducens nerve, which recovered to the preoperative situation after 5 months. Conclusions: Chronic demyelination followed by remyelination can result in hypertrophic neuropathy and in a unique neuroradiological and clinical image of the orbit.

Keywords: imaging/image analysis: clinical • orbit • tumors