March 25, 2016: Autoimmune encephalitis can mimic HSV relapse
March 25, 2016
Autoimmune encephalitis can mimic HSV relapse
Patients treated for herpes simplex virus encephalitis (HSVE) may subsequently develop a neurologic syndrome that can mimic viral relapse. However, persistent or recurrent viral infection occurs in only a small minority.1 The syndrome may include fevers, encephalopathy/encephalitis, seizures, or other manifestations. Children more often present with abnormal movements like choreoathetosis, while adults usually present with neuropsychiatric manifestations.2 Autoantibodies targeting neuronal cell surface or synaptic antigens can develop subsequent to HSVE, most commonly anti-N-methyl-D-aspartate receptor antibodies.3 This syndrome may develop prior to full recovery from HSVE or a few weeks thereafter with a median of 39 days (range 12-51 days)2, may be associated with contrast-enhancement on MRI and generally responds well to immunotherapy (steroids, IVIg or plasma exchange). Any new neurologic syndrome that develops after HSVE should trigger consideration of an immune-mediated process. If infectious evaluation is negative, immunotherapy should be considered while autoantibody testing from the cerebrospinal fluid is pending.2
- Skoldenberg B, Aurelius E, Hjalmarsson A, et al. Incidence and pathogenesis of clinical relapse after herpes simplex encephalitis in adults. Journal of Neurology 2006; 253: 163-170.
- Armangue T, Moris G, Cantarin-Extremera V, et al. Autoimmune post-herpes simplex encephalitis of adults and teenagers. Neurology 2015; 85: 1736-1743.
- Armangue T, Leypoldt F, Malaga I, et al. Herpes simplex virus encephalitis is a trigger of brain autoimmunity. Annals of Neurology 2014; 75: 317-323.
Submitted by Michael J. Bradshaw, MD, Department of Neurology, Vanderbilt University Medical Center.
Dr. Bradshaw reports no disclosures.