Neurosarcoidosis: a clinical approach to diagnosis and management.

Sarcoidosis is a rare but important cause of neurological morbidity, and neurological symptoms often herald the diagnosis. Our understanding of neurosarcoidosis has evolved from early descriptions of a uveoparotid fever to include presentations involving every part of the neural axis. The diagnosis should be suspected in patients with sarcoidosis who develop new neurological symptoms, those presenting with syndromes highly suggestive of neurosarcoidosis, or neuro-inflammatory disease where more common causes have been excluded. Investigation should look for evidence of neuro-inflammation, best achieved by contrast-enhanced brain magnetic resonance imaging and cerebrospinal fluid analysis. Evidence of sarcoidosis outside the nervous system should be sought in search of tissue for biopsy. Skin lesions should be identified and biopsies taken. Chest radiography including high-resolution computed tomography is often informative. In difficult cases, fluorodeoxyglucose positron emission tomography and gallium-67 imaging may identify subclinical disease and a target for biopsy. Symptomatic patients should be treated with corticosteroids, and if clinically indicated other immunosuppressants such as hydroxychloroquine, azathioprine, cyclophosphamide or methotrexate should be added. Anti-tumour necrosis factor alpha therapies may be considered in refractory disease but caution should be exercised as there is evidence to suggest they may unmask disease.