The classification of spinal meningeal cysts (MC's) in the literature is indistinct, confusing, and in certain categories histologically misleading. Based on a series of 22 cases, the authors propose a classification comprising three categories: spinal extradural MC's without spinal nerve root fibers (Type I); spinal extradural MC's with spinal nerve root fibers (Type II); and spinal intradural MC's (Type III). Although water-soluble myelography may disclose a filling defect for all three categories, computerized tomographic myelography (CTM) is essential to reveal communication between the cyst and the subarachnoid space. Communication demonstrated by CTM allows accurate diagnosis of a spinal MC and rules out other mass lesions. Magnetic resonance imaging appears useful as an initial study to identify an intraspinal cystic mass. Final characterization is based on operative inspection and histological examination for all three categories.

We report a patient who had a spinal abscess due to a retained surgical sponge. Through the use of magnetic resonance imaging, the sponge was identified. Postoperative foreign body complications are discussed.

The authors are presenting seven patients who had operations between July 1984 and July 1985 and who developed herpes infections postoperatively. Four of the patients developed their infections in a dermatomal distribution that correlated with the nerve roots manipulated at operation. A spectrum of localized herpes reactivation is demonstrated in this series. The use of corticosteroids and other associated variables are discussed. Like reactivation of herpes simplex after trigeminal nerve operation, we believe reactivation of herpes simplex and herpes zoster can occur in operation of the cervical, thoracic, or lumbosacral spine.