Efficacy and Safety of Radiosurgical Callosotomy: A Retrospective Analysis

Abstract

Summary:Purpose: Anterior callosotomy is a surgical option for the treatment of generalized tonic or atonic seizures associated with drop attacks. Besides open surgery, a radiosurgical callosal disconnection using the gamma knife (GK) also can be performed, but reliable data about tolerability and efficacy are sparse.Methods: Eight patients (three female, five male age range, 5 to 69 years) with severe generalized epilepsy associated with disabling drop attacks underwent GK callosotomy between 1993 and 2004. In six patients, the anterior third of the corpus callosum was radiosurgically disconnected. In one patient a second procedure with GK treatment of the middle third of the corpus callosum was added 17 months later. In two patients posterior GK callosotomy had followed partial hemispherotomy.Results: Drop attacks (DAs) were completely abolished in three patients, and two patients had a marked DA seizure reduction of 60%. Two of four patients with additional generalized tonic-clonic seizures showed a reduction of 100%, and the remaining, a 50% and 60% decrease, respectively. Other seizure types responded less well to the radiosurgical treatment. In both patients with posterior GK callosotomy after hemispherotomy, partial seizures decreased. Beside transient headache in two patients, no immediate or long-term postradiosurgical side effects were observed.Conclusions: Palliative radiosurgical callosotomy is an efficient and safe noninvasive alternative to the open procedure with comparable results. No signs of postradiosurgical side effects were noted within an up to 12-year posttreatment period.

Potential intracranial applications of magnetic resonance–guided focused ultrasound surgery

“…53 Noninvasive techniques involving stereotactic radiosurgery have shown promise for mesial temporal epilepsies, hypothalamic hamartomas, and corpus callosotomy. 1,4,11,13,41 Concerns regarding the use of stereotactic radiosurgery in epilepsy involve the latency of the treatment effect and the potential risk of secondary malignancy due to ionizing radiation, which is very pertinent in a pediatric or young adult population. Transcranial MRgFUS could similarly treat many forms of epilepsy without craniotomy by lesioning of epileptogenic foci or by interrupting the fiber pathways involved in the propagation of epileptiform activity.…”

Radiosurgical posterior corpus callosotomy in a child with Lennox–Gastaut syndrome

“…20 Recently they reviewed their entire experience with radiosurgical callosal disconnection in eight patients (two children and six adults) over the past 12 years. 4,5 Other approaches to minimally invasive transection of the corpus callosum have included proposals for primary endoscopic callosotomy 32,33 and endoscope-assisted microsurgery. 8 In this paper we report the successful use of radiosurgery to complete the posterior third corpus callosotomy in a child in whom initial standard anterior microsurgical callosotomy failed to treat his intractable seizures.…”

Corpus callosotomy in children with intractable epilepsy using frameless stereotactic neuronavigation: 12-year experience at The Hospital for Sick Children in Toronto

“…13,17 Radiosurgical corpus callosotomy may be a promising safe and noninvasive alternative to open callosotomy. 1,4,6,19,26 This modality of treatment can be used in situations where patients have more than 2 seizure types and after a failed partial callosotomy. Small case series and individual case reports have claimed that the noninvasive nature of radiosurgery may serve to avoid transient and permanent surgical morbidity, including the disconnection syndromes, related to surgical manipulation, frontal lobe retraction, and venous injury.…”