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

Abstract

Object Sylvian fissure arteriovenous malformations (AVMs) present substantial management challenges because of the critical adjacent blood vessels and functional brain. The authors investigated the outcomes, especially hemorrhage and seizure activity, after stereotactic radiosurgery (SRS) of AVMs within or adjacent to the sylvian fissure. Methods This retrospective single-institution analysis examined the authors' experiences with Gamma Knife surgery for AVMs of the sylvian fissure in cases treated from 1987 through 2009. During this time, 87 patients underwent SRS for AVMs in the region of the sylvian fissure. Before undergoing SRS, 40 (46%) of these patients had experienced hemorrhage and 36 (41%) had had seizures. The median target volume of the AVM was 3.85 cm3 (range 0.1–17.7 cm3), and the median marginal dose of radiation was 20 Gy (range 13–25 Gy). Results Over a median follow-up period of 64 months (range 3–275 months), AVM obliteration was confirmed by MRI or angiography for 43 patients. The actuarial rates of confirmation of total obliteration were 35% at 3 years, 60% at 4 and 5 years, and 76% at 10 years. Of the 36 patients who had experienced seizures before SRS, 19 (53%) achieved outcomes of Engel class I after treatment. The rate of seizure improvement was 29% at 3 years, 36% at 5 years, 50% at 10 years, and 60% at 15 years. No seizures developed after SRS in patients who had been seizure free before treatment. The actuarial rate of AVM hemorrhage after SRS was 5% at 1, 5, and 10 years. This rate equated to an annual hemorrhage rate during the latency interval of 1%; no hemorrhages occurred after confirmed obliteration. No permanent neurological deficits developed as an adverse effect of radiation; however, delayed cyst formation occurred in 3 patients. Conclusions Stereotactic radiosurgery was an effective treatment for AVMs within the region of the sylvian fissure, particularly for smaller-volume AVMs. After SRS, a low rate of hemorrhage and improved seizure control were also evident.

Seizure control after radiosurgery for cerebral arteriovenous malformations: a 25-year experience

“…The rates of seizure improvement were 29% at 3 years, 36% at 5 years, 50% at 10 years, and 60% at 15 years. In that study, the rate of improved seizure control was higher for patients with 3 10. incomplete obliteration (p = 0.042), lower among patients with a history of prior hemorrhage, and higher for patients with small nidus diameter (< 2 cm). In comparison to the current study, seizures may be more difficult to control and may have different prognosticating factors (obliteration, hemorrhage, and nidus size) in patients with sylvian fissure seizures.…”

“…Bowden et al studied 87 patients who underwent SRS for AVMs of the sylvian fissure. 3 Of these, 36 patients experienced seizures before SRS. The risk for pre-SRS seizures was lower for younger patients and for patients with a history of previous intracranial hemorrhage.…”

Radiosurgery for Arteriovenous Malformations and the Impact on Headaches

“…We also found that a prior hemorrhage tended to lead to less successful headache management of AVM patients. This type of negative impact on symptom resolution in patients with a hemorrhagic AVM has been illustrated also in patients with seizures …”

“…This type of negative impact on symptom resolution in patients with a hemorrhagic AVM has been illustrated also in patients with seizures. 23,24 Study Limitations.-There are inevitable limitations of this study, the most pronounced being the impact of recall bias, which can significantly impact headache reporting and subsequently can result in an increased margin of error. The natural waxing and waning of migraine symptoms may have significant impact on our findings.…”

Stereotactic Radiotherapy in the Management of Epilepsy

“…Improvement or cure from the epilepsy is a desirable additional therapeutic effect. The results in terms of Engel class I outcomes depend on a number of factors such as anatomical location, size, and age of patient but is in the order of 53% -66% [16,17]. However the median time to seizure free status is in the order of 20 months, again reflecting the late radiation effects on tissue [16].…”