Neurosarcoidosis

Background

• Neurosarcoidosis is a noncaseating granulomatous disease of unknown etiology that can involve the central, peripheral, and autonomic nervous system.
• Neurosarcoidosis tends to occur in older patients compared to other systems affected by sarcoidosis.
• It is a fairly uncommon manifestation of sarcoidosis with < 10% of patients developing neurologic involvement.

Evaluation

• Neurosarcoidosis is most often found in conjunction with sarcoidosis in other organs.
• Neurologic features of sarcoidosis tend to occur within the first 2 years of sarcoidosis diagnosis and presenting symptoms can include:
  • unilateral facial nerve palsy and symptoms of optic neuritis (loss of vision, pain with eye movement)
  • mono- or polyneuropathies
  • headache, seizure, visual impairment, ataxia, or altered mental status
  • weakness, paraparesis, quadriparesis, radicular pain, sphincter disturbances, and cauda equine syndrome
• Diagnose neurosarcoidosis in patients with suggestive clinical presentation, exclusion of other causes, and evidence of nervous system involvement, such as:
  • nervous system histology demonstrating noncaseating granulomas (definite diagnosis)
  • laboratory or radiologic support for central nervous system inflammation (probable diagnosis)
    • cerebrospinal fluid (CSF) showing CD4:CD8 ratio > 5, increased protein with or without cells (usually lymphocytosis with 10-200 lymphocytes/mm³), oligoclonal bands
    • magnetic resonance imaging (MRI) findings compatible with neurosarcoidosis

Management

• Neurological involvement almost always requires treatment, but currently there are no randomized trials to guide treatment.
• Corticosteroids are considered first-line therapy, with dose and duration dependent on disease severity and response to treatment.
• Consider a loading dose of methylprednisolone 1 g/day IV for 3 days, followed by 40-80 mg/day (0.5-1 mg/kg/day) orally, then tapered slowly based on response.
• Immunosuppressive agents such as methotrexate, cyclophosphamide, cyclosporine, chloroquine, hydroxychloroquine, and infliximab may be used alone or in combination with corticosteroids if the disease fails to respond to corticosteroid monotherapy, or if corticosteroids are contraindicated or cause unacceptable side effects.