1-Pediatric Infectious Diseases Unit, Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central, EPE; Lisbon
2-Pediatric Neurology Department, Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central, EPE; Lisbon
3-Neurorradiology Department, Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central, EPE; Lisbon - Reunião de Casos Clínicos Difíceis de Infecciologia, Almada. 20 de Junho de 2014
Background: Postinfectious encephalitis (PIE) is an immune process caused by deregulation of the immune system following infection or immunization. Acute secondary neurological deterioration after herpes simplex encephalitis has been reported. We discuss a case of PIE after herpetic encephalitis treated with interferon after respiratory infection and vaccination.
Case report: 12 month-old otherwise healthy child presented with vomiting, fever, tonic seizures, altered state of consciousness (Glasgow 8) and left hemiparesis. MRI showed multiple cortical lesions in temporal, parietal and occipital lobes. PCR HSV-1 in CSF was positive. Acyclovir was started on D2 (21 days) and per protocol interferon alfa-2b on D3 (10 days) without complications. She was discharged clinically asymptomatic with prophylactic acyclovir and antiepileptic drugs.
Two weeks later she had an upper respiratory infection. Also, live attenuated MMR vaccination was undertaken. Five weeks following herpetic encephalitis, she revealed irritability alternated with sleepiness, no interest on interacting, superior left limb and cervical choreiform movements, axial ataxia and stereotypies. Electroencephalography showed paroxysmal right predominant bifrontal activity. MRI showed deterioration of previous abnormalities with extensive white matter lesions, suggesting possible immune-mediated demyelization. PCR HSV-1 and measles in CSF was negative but oligoclonal bands in serum and CSF were found. She was treated with corticosteroids and human immunoglobulin with both clinical and imagiological improvement.
Discussion: An immune mediated process better explains the pathogenesis of this relapse. It may be due to the herpetic encephalitis itself or induced by interferon treatment, but viral infection or live vaccination cannot be overruled as triggering factors.
Palavras Chave: Postinfectious encephalitis, HSV-1, interferon, MMR vaccination