Neurosarcoidosis

Neurosarcoidosis can involve either the central nervous system (CNS), the peripheral nervous system (PNS), or both. The clinical manifestations are varied and include cranial neuropathy, aseptic meningitis, hydrocephalus, headache, seizure, neuropsychiatric symptoms, neuroendocrine dysfunction, myelopathy, and peripheral neuropathy. Neurologic problems that develop in sarcoidosis patients should not be assumed to represent neurosarcoidosis, as they are often attributable to another cause. The diagnostic work up of neurosarcoidosis should include an evaluation for potential extra-neural involvement and histologic confirmation of sarcoidosis. If there is no appropriate extra-neurologic organ for biopsy, a biopsy from involved neural tissue needs to be considered. Biopsy of the dura and leptomeninges is less invasive than biopsy of the brain or spinal cord parenchyma. Gadolinium-enhanced magnetic resonance imaging (MRI) of the brain and spinal cord is the most sensitive test for neurosarcoidosis, while the diagnostic specificity of cerebrospinal fluid (CSF) analysis is limited. Corticosteroids are the mainstay of treatment for neurosarcoidosis. In general, oral corticosteroids are used for mild to moderate cases, while high-dose intravenous methylprednisolone is used in severe cases or refractory cases that fail to respond to oral corticosteroids. Immunomodulating and cytotoxic agents are often required for steroid-refractory neurosarcoidosis or for patients who develop significant corticosteroid adverse effects. Methotrexate is used as a first-line corticosteroid sparing agent. Tumor necrosis factor-alpha inhibitors, including infliximab, are effective for refractory neurosarcoidosis. Cyclophosphamide is also used for refractory neurosarcoidosis patients, but, because of the drug's significant toxicity, it is usually reserved for severe cases that have failed oral therapies when tumor necrosis factor alpha antagonists cannot be obtained. In addition to anti-granulomatous therapy, treatment is frequently required for neurosarcoidosis-associated conditions, such as epilepsy and neuroendocrine dysfunction. Surgical intervention is indicated for life threatening complications such as hydrocephalus, steroid-refractory spinal cord compression, or mass lesions causing increased intracranial pressure.