Neurosarcoidosis

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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

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