Neurosarcoidosis: a personal perspective based on the study of 37 patients

Clinically apparent involvement of the nervous system occurs in a relatively small number of patients with sarcoidosis. The diagnosis of neurosarcoidosis is often difficult and particularly so in patients who lack either pulmonary or systemic manifestations of sarcoidosis. Furthermore, clinical features of neurosarcoidosis are extremely variable. In this series of 37 patients, seen during the last 30 years, cranial nerve palsies occurred in 52%, polyneuritis or polyneuropathy in 24%, meningeal involvement in 24%, muscle disease in 8%, and Guillain-Barré syndrome in 5% of the patients. Other presentations included seizures, brain mass, pituitary/hypothalamic syndrome, and memory loss associated with confusion. The chest radiograph was abnormal in 8 of every 10 patients with neurosarcoidosis. In 18 (85%) of 21 patients, gallium uptake was consistent with the diagnosis of active sarcoidosis. Serum angiotensin-converting enzyme levels were raised in about half of the patients. Cerebrospinal fluid features, including lymphocyte pleocytosis, raised protein levels, and decreased glucose concentration, were of little help. MRI with gadolinium enhancement was the most sensitive diagnostic tool, particularly in patients with meningeal involvement. The ultimate arbiter of the diagnosis of neurosarcoidosis, the presence of noncaseating granulomas in the involved tissue, was not always available. Although corticosteroids are the mainstay of therapy, in this series, 12 patients received chloroquine or hydroxychloroquine. Prognosis of chronic neurosarcoidosis is poor. Six (18%) of 37 patients died of complications related to sarcoidosis.