Albert Tu

Occult tethered cord syndrome: a review

BackgroundTethered cord syndrome is a well-defined condition, the management of which is fairly uniform. In contrast, occult tethered cord syndrome is a recently defined entity, where the management is still controversial. The pathophysiology is unclear and may be conceptually incongruent with current understanding of typical tethered cord syndrome. Presentation, investigation, and management of this condition are reviewed, and current understanding is presented.PurposeThe aim of this study is to review the presentation, pathophysiology, investigation, and management of occult tethered cord syndrome.MethodsLiterature review.ResultsPatients with occult tethered cord syndrome presents predominantly with urologic symptoms. Adult and pediatric patients vary slightly in their presentation with a higher incidence of pain in the former and incontinence in the latter. Operative management for these patients is associated with consistent improvement in urologic function in particular, although surgery is also associated with risk of worsening symptoms. The natural history of untreated patients is unknown.ConclusionsAs occult tethered cord syndrome becomes increasingly recognized, it is important to be aware of the potential benefits of operative intervention for appropriately selected patients. Given that the natural history of this entity remains unknown, a clinical trial is currently underway that may assist in defining the role for operative management in treating this condition.

Stereotactic Radiosurgery versus Natural History in Patients with Growing Vestibular Schwannomas

Objective To describe our experience with stereotactic radiosurgery and its efficacy on growing tumors, and then to compare this result with the natural history of a similar cohort of non-radiation-treated lesions. Study Design A retrospective chart review and cohort comparison. Methods The long-term control rates of patients having undergone radiosurgery were collected and calculated, and this population was then compared with a group of untreated patients from the same period of time with growing lesions. Results A total of 61 patients with growing vestibular schwannomas treated with radiosurgery were included. After a mean of 160 months, we observed a control rate of 85.2%. When compared with a group of 36 patients with growing tumors who were yet to receive treatment (previously published), we found a corrected control rate or relative risk reduction of only 76.8%. Conclusion Radiosurgery for growing vestibular schwannomas is less effective than previously reported in unselected series. Although radiosurgery still has a role in managing this disease, consideration should be given to the actual efficacy that may be calculated when the natural history is known. We hope other centers will similarly report their experience on this cohort of patients.