Neurosarcoidosis

Abstract

Neurosarcoidosis is an uncommon but potentially serious manifestation of sarcoidosis. While the cranial nerves are most frequently affected, neurosarcoidosis can involve other nervous system tissues including the meninges, brain parenchyma (especially the hypothalamic region), spinal cord, peripheral nerve, and muscle. Diagnosis may be particularly challenging when neurosarcoidosis occurs in isolation. Diagnostic criteria usually include histologic identification of a noncaseating granuloma, supportive laboratory or imaging tests or both, and a compatible clinical course. Treatment has not been subjected to rigorous study, but corticosteroids are typically the first line of therapy and approximately half of patients have substantial benefit. For patients who are refractory to or intolerant of corticosteroid therapy, second-line agents include azathioprine, methotrexate, cyclosporine, cyclophosphamide, mycophenolate, and even cranial irradiation. The combination of infliximab and mycophenolate mofetil is under study as well. Treatment options will likely evolve as well-designed studies are undertaken.

Keywords: Neurosarcoidosis; cranial neuropathy; meningitis; myopathy.; neuroendocrine dysfunction; peripheral neuropathy; sarcoidosis; seizures.

Fig. (1)

A hematoxylin- and eosin-stained paraffin section of a superficial peroneal sensory nerve biopsy specimen reveals a granuloma consisting of epithelioid histiocytes surrounded by a rim of lymphocytes. Giant cells are not seen and may not be readily apparent in most nerve granulomas. The granuloma is in the epineurium adjacent to the endoneurium (E).

Fig. (2)

A photomicrograph of a hematoxylin- and eosin-stained paraffin section from a skeletal muscle biopsy specimen reveals a granuloma containing giant cells. It is located in the perimysium. Some lymphocytes course outside the granuloma, but the adjacent muscle fibers are mostly unaffected.