gms | German Medical Science

Objective: The ventriculus terminalis is a small cavity inside the conus medullaris, which is formed during the embryonic development. Previous reports regarding cyst lesion of the ventriculus terminalis (CLVT) in adults demonstrated broad and diversified clinical symptoms, different clinical evolution and neurological findings. Thereby, non-standardized management has lead to unsatisfactory outcomes. Based on a literature review and three treated cases we propose a classification system considering the clinical presentation in order to standardize the cases and facilitate the proper management.

Methods: Literature was reviewed dividing the patients into three groups by clinical presentation, as follows: CLVT Type I – patients with non-specific neurological symptoms or non-specific complaints (2 patients); CLVT Type II – presence of focal neurological deficit (3 patients) and CLVT Type III – presence of bowel or bladder dysfunction (12 patients). In our own patients a laminotomy electrophysiological mapping of the conus medullare including sphincter monitoring was performed for identification of the optimal entry point for cyst decompression.

Results: In Type I, no improvement was observed in clinical evaluation after surgery and stable symptoms were achieved with clinical management. In Type II, two patients had total improvement and one had a subtotal improvement after surgery. Finally, in Type III, 92% of the patients improved postoperatively, among these 36% presented complete resolution of symptoms.

Conclusions: This new classification is useful to group the patients into three clinical types guiding to the best management options. The Type I might benefit from conservative treatment, while Types II and III seem to gain from microsurgical decompression of the cyst. Intraoperative mapping of the conus medullare is essential for identifying the ideal entry point.