Supratentorial Cavernous Angiomas and Epileptic Seizures: Preoperative Course and Postoperative Outcome

To the Editor: We read with interest the article by Casazza et al.(1) on supratentorial cavernous angiomas and epileptic seizures. The authors clearly show that in cases with good concordance between electroclinical data and site of the lesion, complete lesionectomy generally leads to the disappearance of the seizures. This is true for cases with sporadic seizures. We agree with the authors to separate from this cohort patients with chronic seizures. In these patients, a simple lesionectomy often fails to control the seizures (2). As two of the reviewers pointed out, in severe cavernoma-related epilepsy, it is better to perform surgery for seizures instead of lesionectomy alone. In cavernomas presenting with intractable seizures and a seizure history of more than 1 year, we implant subdural electrodes for several days to make sure that the cavernoma is really epileptogenic. This is especially helpful in temporal and multiple cavernomas. In a second procedure, the cavernoma is completely removed after performing electrocorticography of the surrounding brain tissue. If electrocorticography after cavernoma extirpation does not reveal any epileptogenic activity, the operation is finished. However, in some of our cases, the lesionectomy alone did not result in disappearance of spikes after brevimytal application. Therefore the perifocal parenchyma electrocortico-graphically identified as epileptogenic is resected. All of our patients treated in this manner have been free of seizures. We strongly recommend the use of intraoperative electrocorticography in cavernomas with chronic epilepsy to increase the accuracy in localizing the epileptogenic focus and to reach a seizure-free outcome for the patient. Henry W.S. Schroeder, M.D. Michael R. Gaab, M.D., Ph.D. U. Runge, M.D. Greifswald, Germany