Neurosarcoidosis is the involvement of the central or peripheral nervous system by granulomatous inflammation in people with sarcoidosis. It may affect the brain, cranial nerves, spinal cord, meninges, or peripheral nerves and can present acutely or with a chronic, relapsing course. Nervous system involvement is uncommon compared with pulmonary disease but can produce significant disability when present.
Typical features and presentations
Symptoms vary depending on the site and degree of inflammation. Common presentations include cranial neuropathies (especially facial nerve palsy), headache, meningitis-like syndromes, seizures, cognitive or behavioral changes, hypothalamic-pituitary dysfunction and myelopathy. Peripheral neuropathy and small-fiber complaints occur less often. Clinical severity ranges from mild sensory changes to progressive weakness, visual loss or hormonal disturbances.
Signs, testing and diagnosis
Diagnosis integrates clinical findings, imaging, laboratory studies and often tissue sampling. Helpful investigations include magnetic resonance imaging (MRI) with contrast to show enhancing lesions or leptomeningeal involvement, cerebrospinal fluid analysis for inflammation, and systemic evaluation for non-neurologic sarcoidosis. Laboratory tests such as serum angiotensin-converting enzyme or inflammatory markers may support but do not confirm the diagnosis. When possible, histologic demonstration of noncaseating granulomas from an accessible site is preferred for definitive diagnosis.
Treatment
First-line therapy is immunosuppression, most commonly high-dose corticosteroids such as Prednisone, tapered according to response. Because long-term steroid side effects are a concern, steroid-sparing agents (for example methotrexate, azathioprine, mycophenolate) or biologic therapies (such as anti-TNF agents) are used for refractory or severe disease. Symptomatic therapies—anticonvulsants for seizures, hormone replacement for pituitary involvement, and rehabilitation—are important adjuncts.
Prognosis and important distinctions
Outcome is variable: some patients improve with treatment, while others develop chronic deficits or relapsing illness. Early recognition and treatment improve the chance of recovery. Neurosarcoidosis must be distinguished from infections, neoplasms, vasculitis and other inflammatory disorders. Multidisciplinary care with neurology, pulmonology and rheumatology is often required.
Further resources
For general information about the underlying systemic condition and nervous system anatomy, see background material on sarcoidosis and the brain. Clinical guidance and trial data may be available through specialty centers and published reviews that discuss long-term management and newer immunomodulatory options.