Control of epilepsy associated with cerebral arteriovenous malformations after radiosurgery

Abstract

Objective-To investigate the eVect of radiosurgery for symptomatic epilepsy associated with cerebral arteriovenous malformations (AVMs). Methods-Thirty five patients with unruptured epileptogenic AVMs were studied with a mean follow up of 43.0 months. The duration of epilepsy before radiosurgery ranged from 2 months to 21 years (mean 2.8 years). Fifteen patients showed partial seizures; eight of these had associated secondary generalisation. The remaining 20 patients showed only generalised seizures without preceding focal seizures. Results-At the final follow up examination, 28 patients remained seizure free, whereas seizures continued in seven. Variables significantly associated with continuity of seizures after radiosurgery were the number of seizures before therapy (p<0.01) and duration of epilepsy (p<0.05). According to Engel's classification, the 10 patients with intractable seizures before treatment included five with grade I, four with grade III, and one with grade IV. The frequency of seizures began to decrease several months after radiosurgery; much shorter than the time required for morphological change in the AVMs.Conclusions-Radiosurgery seems to be beneficial for seizure control in patients with unruptured epileptogenic AVM. (J Neurol Neurosurg Psychiatry 1998;65:648-655) Keywords: arteriovenous malformation; symptomatic epilepsy; gamma knife; radiosurgery Various therapeutic alternatives are currently available for eliminating the risk of bleeding from cerebral arteriovenous malformations (AVMs), and the reported treatment results have been favourable in terms of overall morbidity and mortality. However, the prognosis of epilepsy associated with cerebral AVMs has received little attention. Controversy exists on the surgical treatment of AVMs associated with epilepsy, and seizure outcome after AVM radiosurgery has not been documented in detail.In this study, we analysed the characteristics and frequency of seizures in 35 patients with epileptogenic unruptured AVMs after gamma knife radiosurgery. A retrospective survey of 22 additional patients with unruptured nonepileptogenic AVMs was also done to assess the development of seizures after the procedure. Here we report the early eVect of focused irradiation on seizures associated with AVMs and discuss the various factors that influence the prognosis. Patients and methods PATIENT POPULATIONBetween June 1990 and December 1995, 315 patients with angiographically demonstrable cerebral arteriovenous malformations (AVMs) underwent radiosurgical treatment at our institution. The initial manifestation at diagnosis was haemorrhage in 228 (72.4%), seizure in 42 (13.3%), headache in 15 (4.8%), progressive or stable neurological deficits in 10 (3.2%), and other clinical symptoms in three (1.0%). In the remaining 17 patients (5.4%), AVM was an incidental finding (table 1).From 42 patients who had epilepsy as a diagnostic symptom, we excluded five who underwent surgical resection or had a bleeding episode before radiosurgery, one whose AVM bled during t...

Seizure outcomes following radiosurgery for cerebral arteriovenous malformations

“…16,33,39,57,71 In contrast, other studies have also found no significant relationship between seizure outcome and seizure type, duration, frequency, and pattern or age at seizure onset. 16,37,39,57,71 The influence of hemorrhage on seizure outcome was also controversial. Two of the 3 studies that evaluated radiosurgery margin and/or maximum dose showed no significant association between these radiosurgical parameters and seizure outcome.…”

“…For the final quantitative analysis, we identified 19 series comprising 1104 patients with AVMs and seizures who underwent SRS. 2,13,16,20,22,33,34,37,39,41,43,48,57,58,63,64,69,71,73 Figure 1 shows a flow chart of the review process.…”

“…22,37,39,57 Relationships between seizure characteristics and seizure outcomes following SRS were also inconsistent; complex partial seizures with or without secondary generalization, generalized tonic-clonic seizures, infrequent and shortduration seizures, and seizure frequency have been associated with improved seizure control. 16,33,39,57,71 In contrast, other studies have also found no significant relationship between seizure outcome and seizure type, duration, frequency, and pattern or age at seizure onset. 16,37,39,57,71 The influence of hemorrhage on seizure outcome was also controversial.…”

Stereotactic radiosurgery for sylvian fissure arteriovenous malformations with emphasis on hemorrhage risks and seizure outcomes

“…1,14 Rates of seizure elimination after SRS for cortical AVMs, regardless of location, range from 50% to 85%. 1,11,23,24 Seizure-free outcomes according to treatment modalities are 78% after microsurgery, 63% after radiosurgery, and 50% after embolization.…”

Radiosurgery for temporal lobe arteriovenous malformations: effect of temporal location on seizure outcomes

“…52 In contrast, our findings are in agreement with those of Kurita et al, who studied 35 patients with unruptured, epileptogenic AVMs and did not find superior seizure control in patients with obliterated AVMs. 29 Another AVM radiosurgery study of 15 pediatric patients with seizures at presentation did not find obliteration to be associated with seizure outcomes. 22 Additionally, Schauble et al reported on a series of 65 patients with AVM-associated seizures who underwent radiosurgery without a significant association between obliteration and seizure control.…”