Autoimmune post-herpes simplex encephalitis of adults and teenagers

Armangue T, Moris G, Cantarín-Extremera V, Conde CE, Rostasy K, Erro ME,
Portilla-Cuenca JC, Turón-Viñas E, Málaga I, Muñoz-Cabello B, Torres-Torres C,
Llufriu S, González-Gutiérrez-Solana L, González G, Casado-Naranjo I, Rosenfeld
M, Graus F, Dalmau J; Spanish Prospective Multicentric Study of Autoimmunity in
Herpes Simplex Encephalitis. Autoimmune post-herpes simplex encephalitis of
adults and teenagers. Neurology. 2015 Oct 21. pii: 10.1212/WNL.0000000000002125.
[Epub ahead of print]

Abstract

OBJECTIVE:

To report 14 patients with immune-mediated relapsing symptoms post-herpes simplex encephalitis (HSE) and to compare the clinical and immunologic features of the teenage and adult group with those of young children.

METHODS:

Prospective observational study of patients diagnosed between June 2013 and February 2015. Immunologic techniques have been reported previously.

RESULTS:

Among the teenage and adult group (8 patients, median age 40 years, range 13-69; 5 male), 3 had an acute symptom presentation suggesting a viral relapse, and 5 a presentation contiguous with HSE suggesting a recrudescence of previous deficits. Seven patients developed severe psychiatric/behavioral symptoms disrupting all social interactions, and one refractory status epilepticus. Blepharospasm occurred in one patient. Five patients had CSF antibodies against NMDA receptor (NMDAR) and 3 against unknown neuronal cell surface proteins. In 5/6 patients, the brain MRI showed new areas of contrast enhancement that decreased after immunotherapy and clinical improvement. Immunotherapy was useful in 7/7 patients, sometimes with impressive recoveries, returning to their baseline HSE residual deficits. Compared with the 6 younger children (median age 13 months, range 6-20, all with NMDAR antibodies), the teenagers and adults were less likely to develop choreoathetosis (0/8 vs 6/6, p < 0.01) and decreased level of consciousness (2/8 vs 6/6, p < 0.01) and had longer delays in diagnosis and treatment (interval relapse/antibody testing 85 days, range 17-296, vs 4 days, range 0-33, p = 0.037).

CONCLUSION:

In teenagers and adults, the immune-mediated relapsing syndrome post-HSE is different from that known in young children as choreoathetosis post-HSE and is underrecognized. Prompt diagnosis is important because immunotherapy can be highly effective.