Autoimmune encephalopathies

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Autoimmune encephalopathies

http://www.ncbi.nlm.nih.gov/pubmed/17495758

Abstract

BACKGROUND: Evaluation of patients with recent onset of progressive cognitive

and behavioral problems can be challenging. Psychiatric disorders, metabolic

derangements, toxins and infections are generally considered in the differential

diagnosis along with prion disorders (Creutzfeldt-Jakob disease) and rapidly

progressive degenerative dementias. Some subacute encephalopathies are caused by

autoimmune or inflammatory mechanisms, recognized by the association with

autoantibody markers and/or clear response to immunomodulatory treatment. This

review describes the clinical features of these potentially reversible

autoimmune encephalopathies. REVIEW SUMMARY: Morvan syndrome, paraneoplastic

limbic encephalitis (PLE), and nonparaneoplastic autoimmune limbic encephalitis

have characteristic clinical and serological features. Limbic encephalitis is

characterized by short-term memory impairment, complex partial temporal lobe

seizures and psychiatric symptoms. Signal abnormalities in the mesial temporal

lobes without contrast enhancement are the typical MRI findings. Morvan syndrome

presents with behavioral changes, hallucinations, severe insomnia, autonomic

hyperactivity and neuromyotonia (spontaneous muscle activity).

Corticosteroid-responsive encephalopathy associated with evidence of thyroid

autoimmunity (sometimes called Hashimoto encephalopathy) has a broad range of

clinical presentation. Cognitive impairment with tremor, seizures, stroke-like

events (including transient aphasia) and normal thyroid hormone levels is a

common scenario. In the absence of diagnostic serological findings, clinical

improvement with corticosteroids may be the only evidence of autoimmune

encephalopathy. CONCLUSIONS: Autoimmune encephalopathies are an important cause

of rapidly progressive cognitive and behavioral decline that probably remain

under recognized. Electroencephalography, brain MRI, cerebrospinal fluid

examination and serological tests are useful diagnostic tools. With increased

clinical suspicion, these diseases may be diagnosed and treated successfully.