INTRACTABLE PARTIAL EPILEPSY RELATED TO AN ARTERIO-VENOUS MALFORMATION - DOES GAMMA KNIFE SURGERY HELP?
Abstract number :
E.02
Submission category :
Year :
2003
Submission ID :
3626
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
Barbara Schauble, Gregory D. Cascino, Deborah A. Gorman, Bruce E. Pollock, Robyn McClelland Division of Epilepsy, Department of Neurology, Mayo Clinic Foundation, Rochester, MN; Department of Neurosurgery, Mayo Clinic Foundation, Rochester, MN; Department
Epilepsy is the second most common symptom of a cerebral arteriovenous malformation (AVM). Approximately 17%-40% of patients will present with seizures without evidence of an intracerebral hemorrhage. The beneficial effect of surgical treatment on seizure tendency has been demonstrated. The efficacy of gamma knife radiosurgery remains to be determined in the management of intractable partial epilepsy related to an AVM.
227 consecutive patients underwent gamma knife radiosurgery for an AVM at Mayo Clinic, Rochester, MN between 1990 and 1998. Seventy patients presented with seizures and 65 patients (93%) had at least one year follow-up. The 65 patients were then subdivided into those with and without [ge] 12 months of seizures prior to therapy. The group consisted of 27 females and 38 males with a mean follow-up of 48 months (range, 12-144 months). Forty-one of the 65 patients had recurrent seizures for more than one year.
Twenty-three patients had intractable partial epilepsy prior to radiosurgery. Twelve of 23 patients (52%) and 11 of 18 patients (61%) had an excellent outcome at one year and three years, respectively.
Following factors were associated with seizure-free or excellent outcome: generalized tonic-clonic seizures as predominant seizure-type, older age at first seizure, shorter interval between 1st seizure to radiosurgery, a low seizure frequency score ([le] 4) before treatment, and male gender. Patients whose AVM had a lesser volume and diameter ([lt] 3cm) were more likely to have an excellent outcome. There was no statistical significance between seizure outcome and total occlusion of AVM. An excellent preoperative seizure frequency score ([le] 4) was consistently associated with an overall excellent outcome during a 36 months follow-up period. Only one patient had a non-excellent outcome at year one (94.4% versus 5.6%) and year three (92.9% versus 7.1%). Adverse effects included significant edema in one patient and hemorrhage in a second patient who declined follow up. No significant changes in AED medication occurred after radiosurgery.
Radiosurgery is an effective and well-tolerated alternative therapy in selected patients with a seizure disorder related to an AVM. Preoperative non-disabling seizures are consistently associated with an excellent outcome. Approximately, 50%-60% of patients with intractable partial epilepsy experience an excellent outcome at one year and three years, respectively.
[Supported by: Mayo Clinic Foundation]