Clinical features:
Progressive encephalopathy, cognitive impairment. Ataxia, seizures, tremors and visual hallucinations can occur.
Findings on investigations:
ESR may be raised
SS-A or SS-B: may be positive
CSF analysis:
- Often raised WCC and protein
- Immunoglobulin (Ig)G index and synthesis rate
EEG: mild-moderate diffuse slowing
MRI: normal
Cerebral angiography: normal
Pathology, brain biopsy:
Leptomeningeal perivascular lymphocytic inflammation, mild without evidence of vasculitis.
- Vessel walls are intact
- Immunohistochemistry: CD3+ T-cell and B-cell infiltration
Salivary gland biopsy:
Lymphocytic infiltration, Immunohistochemistry: CD3+ T-cell and B-cell infiltration
Treatment:
Steroid therapy with methylprednisone or prednisone
Associated conditions:
- Sjogren’s syndrome
- Hypereosinophilic syndrome
- Hashimoto’s disease
- Systemic lupus erythematosus
Related articles:
- Approach to cognitive impairment, approach to acute confusion,
- Primary CNS angiitis, Hashimoto’s encephalopathy, non-paraneoplastic autoimmune imbic encephalitis, paraneoplastic limbic encephalitis,
References:
- Caselli RJ, Boeve BF, Scheithauer BW, O’Duffy JD, Hunder GG. Nonvasculitic autoimmune inflammatory meningoencephalitis (NAIM): a reversible form of encephalopathy. Neurology. 1999 Oct 22;53(7):1579-81.
- Josephs KA, Rubino FA, Dickson DW. Nonvasculitic autoimmune inflammatory meningoencephalitis. Neuropathology. 2004 Jun;24(2):149-52.