Characterization of postoperative fevers after hemispherotomy

Patients who have undergone hemispherotomy for intractable epilepsy tend to develop postoperative fevers, which can be severe and/or prolonged, for unclear reasons. The purpose of this paper is to characterize postoperative fever curves after hemispherotomy based on factors including seizure etiology, perioperative blood loss, and the presence or absence of ventricular drainage. We present 72 patients who underwent hemispherotomy at our institution between 1995 and 2013 by four surgeons. Data including daily maximum body temperature, seizure etiology, ventricular drain use, steroid and antipyretic use, and seizure control were gathered retrospectively based on electronic records including operative summaries, nursing notes, discharge summaries, and follow-up clinic notes. Seventy-two patients from 11 weeks to 21 years old (mean 7.4 years old) underwent hemispherotomy between 1995 and 2013. Sixty (83 %) had fevers postoperatively, while the remainder were afebrile. Patients without external ventricular drains had higher and more prolonged fevers compared to those with drains (p = 0.003). Patients with Rasmussen's encephalitis tended to have higher postoperative fevers than patients with other seizure etiologies (p = 0.005), while patients with cortical dysplasia and polymicrogyria tended to have less severe fevers (p = 0.027 and 0.017, respectively). Fifty-five patients (76 %) had freedom from disabling seizures (Engel class I), and 96 % showed worthwhile improvement or better (Engel classes I-III). Postoperative fever can be anticipated in hemispherotomy patients, may vary based on certain seizure etiologies, and may be mitigated by routinely utilizing external ventricular drainage. Hemispherotomy is an effective surgical procedure for intractable epilepsy in selected patients.