Mycoplasma pneumoniae–related postencephalitic epilepsy in children

Purpose: Mycoplasma pneumoniae, a common respiratory pathogen, has been implicated as an etiology of encephalitis, but there are few reports about it and postencephalitic epilepsy. This study aimed to investigate clinical factors, electroencephalography, and neuroradiologic features of M. pneumoniae–related encephalitis in a series of children with postencephalitic epilepsy and to examine possible prognostic factors.

Methods: Cases of M. pneumoniae–related encephalitis between January 2001 and June 2010 were retrospectively reviewed. Systematic clinical data were evaluated.

Key Findings: The 99 enrolled patients with M. pneumoniae–related encephalitis were all positive by serology and 47 (47.5%) of them developed postencephalitic epilepsy. During the acute phase, 53 patients (53.5%) had seizures, the most common type of which was primary focal with secondary generalized tonic–clonic seizure (39.6%). The most common initial electroencephalography was focal/diffuse cortical dysfunction (37.4%) and focal epileptiform discharge (26.4%). The time of follow-up ranged from 6–131 months. At the end of the study, 19 (40.4%) of the 47 children with postencephalitic epilepsy had intractable seizures.

Significance: Postencephalitic epilepsy is not a rare complication of M. pneumoniae–related encephalitis. Seizures in the acute phase and focal epileptiform discharges in initial electroencephalography are significant prognostic factors.