Stereotactic Radiosurgery Can Control Cerebral Arteriovenous Malformation-Associated Seizures: Presented at AANS

By Frances Morin

SAN DIEGO -- April 18, 2019 -- Stereotactic radiosurgery (SRS) is effective in controlling seizures in most patients with cerebral arteriovenous malformations (AVM), according to results from a systemic review and meta-analysis presented here at the 2019 Annual Meeting of the American Association of Neurological Surgeons (AANS).

“SRS affords seizure control to the majority of patients with cerebral AVM-associated seizures, and approximately two-thirds of those with seizure freedom after SRS are completely off of anticonvulsants,” said Natasha Ironside, MbChB, Penn State College of Medicine Department of Neurosurgery, Hershey, Pennsylvania, on April 15.

In the systemic review, Dr. Ironside and colleagues identified 27 studies that met criteria among 311 that reported data on post-SRS outcomes for ≥5 patients with AVM-related seizures.

Of the 4,826 patients with SRS-treated AVM included in the 27 studies, 1,456 (34.7%) had ≥1 seizure, and the mean follow-up duration was 48 months.

Seizure control, defined as seizure freedom or seizure improvement, occurred in 910 (73%) of 1,312 patients at a mean time to control of 26 months. Seizure freedom was observed in 55.7% of the SRS-treated patients, among whom cessation of antiepileptic drugs was achieved in 65%. Seizures were unchanged in 19% and worsened in 6% of patients with AVM-associated seizures.
De novo seizures were observed in 5% of SRS-treated patients without previous seizure presentation.

Factors that were significantly associated with seizure freedom included achievement of complete AVM obliteration (odds ratio [OR], 4.41; P< .001), a history of ≤5 seizures (OR, 6.80; P< .001), generalised seizure type (OR, 2.30; P = .01), and a history of ≤5 prior AVM haemorrhages (OR, 4.83; P< .001).

Seizure freedom was observed in 75% of patients who achieved AVM obliteration and in 43% of patients without obliteration; however, the studies had significant heterogeneity, Dr. Ironside noted.

“In this study, the primary endpoint of seizure control was observed in the majority of SRS treated patients with AVM-associated seizures; however, the 55% rate of seizure freedom suggests that a proportion of patients failed to achieve seizure freedom and should continue to be monitored,” said Dr. Ironside.

Dr. Ironside noted that, considering the modest rate of de novo seizures after SRS, “prescribing prophylactic antiepileptic drugs to patients without seizure presentation does not appear to be warranted.”

“Achievement of AVM obliteration after SRS affords the dual benefits of eradicating haemorrhage risk and improving seizure outcomes,” she added.

With seizures representing the second-most common presentation in patients with cerebral AVMs and being associated with significant comorbidity and impaired quality of life, the potential benefits of SRS are important.

Ultimately, “patients with seizures secondary to AVM haemorrhage may have better outcomes after SRS,” concluded Dr. Ironside.

[Presentation title: Seizure Outcomes Following Radiosurgery for Cerebral Arteriovenous Malformations: An Updated Systematic Review and Meta-Analysis. Abstract 275]

To read more Conference Dispatch articles, click here.