Extradural arachnoid cysts: a study of seven cases.

Analysis of the management of 7 cases of extradural arachnoid cyst is presented. A brief review of the literature on the subject is presented. Seven cases of extradural arachnoid cysts were treated surgically between the years 1996 to 2002. These patients were analysed retrospectively. The average follow-up period was 32 months. Three patients were males and four were females and their ages ranged from 12 to 35 years. The patients presented with predominant complaint of progressive motor deficits. There were two cysts in the dorsal region, four in the dorsolumbar region and one in the cervicodorsal region. The extradural arachnoid cyst was located posterior to the dural tube and in the midline in six cases and all these cysts had bilateral multiple intervertebral foraminal extensions. In the case with a cervicodorsal cyst, the cyst was anterolateral to the dural tube and there was no foraminal extension. The surgery comprised of wide exposure of the cyst and radical marsupialization or resection of the cyst wall. There was no recurrence of the cyst during the period of follow-up. Radical resection of the walls leads to a lasting cure from extradural arachnoid cyst. The site of communication of the cyst contents with subarachnoid CSF could not be identified during the surgery in the series.