Histopathologic Analysis of 5 Patients with CSF-Venous Fistulas after Surgical Nerve Root Ligation and Resection

SUMMARY: CSF-venous fistulas (CVFs) are recognized as the most common cause of spontaneous intracranial hypotension, however, exactly how and why CVFs form remains unclear. To better elucidate CVF pathophysiology, histopathologic analysis was performed in 5 patients with CVFs who underwent operative ligation and removal of the implicated nerve root. There were no archetypal findings seen uniformly in all 5 cases, and no definitive CSF-venous connections were visualized. However, all cases manifested variable vascular abnormalities. These included dystrophic mineralization in venous walls, focal venous wall thinning, thrombosis, and hemosiderin deposition. Collectively, these findings suggest venous alterations are associated with CVFs, though causality cannot be determined.