Sarcoidosis and the Nervous System

This article provides an overview and update on the neurologic manifestations of sarcoidosis.

The 2018 Neurosarcoidosis Consortium diagnostic criteria emphasize that biopsy is key for diagnosis and determines the level of diagnostic certainty. Thus, definite neurosarcoidosis requires nervous system biopsy and probable neurosarcoidosis requires biopsy from extraneural tissue. Without biopsy, possible neurosarcoidosis can be diagnosed if the clinical, imaging, and laboratory picture is compatible and other causes are ruled out. Recent large retrospective studies from the United States and France established that infliximab appears to be efficacious when other treatments are inadequate.

Sarcoidosis is a multisystem noninfectious granulomatous disorder that is immune mediated, reflecting the response to an as-yet unidentified antigen or antigens. Neurosarcoidosis refers to neurologic involvement due to sarcoidosis that clinically manifests in 5% of cases of sarcoidosis, with asymptomatic involvement in as many as another one in five patients with sarcoidosis. Sarcoid granulomas can occur in any anatomic substrate in the nervous system, causing protean manifestations that have earned neurosarcoidosis the sobriquet the great mimic. Nevertheless, central nervous system sarcoidosis occurs in well-defined presentations that can be classified as cranial neuropathies, meningeal disease, brain parenchymal (including pituitary-hypothalamic) disease, and spinal cord disease. In addition, the peripheral nervous system is affected in the form of peripheral neuropathy and myopathy. Glucocorticoids are the cornerstone of treatment, especially in the acute stage, whereas steroid-sparing agents such as methotrexate, mycophenolate mofetil, and azathioprine are used for prolonged therapy to minimize steroid toxicity. Anti-tumor necrosis factor agents may help in refractory cases.