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The frequency of neurologic involvement is generally 5% of all cases of sarcoidosis
About two thirds of patients with neurosarcoidosis have a self-limited monophasic illness, the rest have a chronic remitting relapsing course
Occurs in adults aged 25-50 years
Neurosarcoidosis generally occurs within 2 years of onset of sarcoidosis
If diagnosis of sarcoidosis is known then symptoms may not pose diagnostic challenge (however other differential should be kept in mind esp. Infections)
Clinical Features
Any cranial nerve may be involved
Facial nerve most commonly involved – (Heerfordt syndrome – fever, uveitis, facial nerve palsy)
Peripheral nerve involvement – Mononeuropathy, mononeuritis multiplex, polyneuropathy
Central nervous system involvement may affect the hypothalamus/pituitary gland, cerebral cortex, cerebellum, and rarely spinal cord
Space-occupying lesion of brain (necrotizing sarcoidosis may manifest as agranulomatous mass lesion)
Hypopituitarism (and other endocrine manifestations)
Optic neuritis leading to optic atrophy (and other forms of eye involvement)
Meningitis, especially basal brain involvement
Cerebral infarct or transient ischemic attack due to vasculitis
Spinal cord lesions are rare (Intramedullary lesions resemble demyelinating disease)
Brain stem (sarcoid brainstem encephalitis) and cerebellar involvement (rare)
Seizures may be the first manifestation of neurosarcoidosis
Look for other signs of “regular” sarcoidosis
Workup
CSF may be normal 30%. When abnormal CSF may have nonspecific pattern with high protein level (>0.5 g/L), high leukocyte count (>5 cells/µL), usually lymphocytosis
ACE, lysozyme, and beta2-microglobulin can be elevated in the CSF
Imaging (esp MRI & CT brain) may localize lesions and give other clues
Biopsy of involved tissue to look for non-caseating granulomas
Treatment
Immunosuppressive therapy steroids, azathioprine, cyclosporine, cyclophosphamide, infliximab and methotrexate
Low dose cranial irradiation
