SRS35 - Syrinx in spontaneous intracranial hypotension treated by surgical disconnection of CSF venous fistula: a case series

Abstract Introduction CSF venous fistula (CVF) is an increasingly recognised cause of spontaneous intracranial hypotension. However, syringomyelia is a rare and less recognised complication of CVF. Methods We describe two cases of syringomyelia secondary to CVF, and our MDT approach for diagnosis and subsequent treatment. Clinical and radiographic information were collected. Results Two patients were identified with syringomyelia secondary to CVF. Both patients suffered from orthostatic headaches during their disease course and had a prolonged diagnostic delay (>3 years). One patient had previously had a foramen magnum decompression without improvement in their symptoms, while the other patient had no improvement with multiple blood patches. Both patients underwent myelography to identify a thoracic CVF with subsequent surgical disconnection of the CVF by a minimally invasive, paramedian, extra-facetal approach. Both patients had near resolution of their headache after surgery with significant improvement in the size of the syrinx. There were no surgical complications. One patient had rebound hypertension which resolved with a short course of acetazolamide. Conclusions CVF should be considered as a cause of syringomyelia in patients with clinical and radiological features of SIH. Treatment should be targeted at treating the underlying CVF rather than surgery for the syrinx alone.