Epilepsy following brain abscess. The evaluation of possible risk factors with emphasis on new concept of epileptic focus formation

Abstract

The study is based on follow-up data of 108 patients treated for brain abscess (mean follow-up period 11 years). The overall incidence of epilepsy was 34% (37% in supratentorial lesions). The author compared the incidence of several parameters between two groups of patients: those presenting, and those not presenting with epilepsy after brain abscess treatment. Parameters characterized by significantly different incidence in each group were taken into account as possible risk factors influencing the development of epilepsy. Sex, age of the patient, localisation and size of the abscess are discussed as presumptive risk factors modifying prediction to epilepsy. The author presents a new concept of epileptic focus formation to explain satisfactorily the results of the study on the basis of pathological mechanisms. A protocol, which may be useful to evaluate the prediction to epilepsy after brain abscess treatment is proposed.

Predictors and long-term outcome of seizures after bacterial brain abscess

“…Among the 37 surviving seizure patients, 7 progressed to epilepsy. The incidence of epileptic seizures here is lower than in other reported series,4 16 18 which may be attributed to the exclusion criteria that excluded the high-risk group of seizure patients (eg, pre-existing neurological deficits and chronic epilepsy), the advent of modern neurosurgical techniques and treatment.…”

“…In these studies, most of the patients included were treated in the pre-CT era, and the seizures were reported to have manifested within 1 y after discharge in 86%,18 within 2 y in 78%16 or in 41% within 1 y and in 76% within 4 y4; however, intervals of more than 10 y have also been observed. By comparison, several recent studies, though with fewer patients and a much shorter follow-up period, have reported seizures in 10–16% of the survivors 13–15.…”

Surgery for medically intractable epilepsy due to postinfectious etiologies

“…However, surgery has been uncommonly reported (as low as 1.6%) (Carpio & Hauser, 2002; Velasco et al, 2006; Singla et al, 2007). Likewise, postpyogenic pathologies may cause epilepsies in up to 35% of cases (Rosman et al, 1985; Koszewski, 1991), yet surgical intervention is rarely reported (Lee et al, 1997; Donaire et al, 2007). Our center’s prevalence was 5.9%, despite being a referral center located in a highly endemic area.…”

Clinical characteristics, risk factors and pre‐surgical evaluation of post‐infectious epilepsy

“…Epilepsy resulting from brain abscess Incapacitating epilepsy and mental retardation are frequent sequelae of brain abscesses [96,97]. Amongst [100]: class I (seizure free, auras only, or single seizure associated with discontinuation of medication); class II (less than three seizures per year and >95% reduction in seizure activity); class III (80-95% reduction in seizure activity) and class IV (<80% reduction in seizure activity).…”

“…Incapacitating epilepsy and mental retardation are frequent sequelae of brain abscesses . Amongst the 20 patients with brain abscesses of the Innsbruck cohort, which were evaluated after a mean of 10.4 years, 12 (60%) had symptomatic seizures and five (25%) had later residual epilepsy .…”