Total Agenesis of Superior Sagittal Sinus and Falx Cerebri in a Patient Who Has a Subacute Subdural Hematoma Crossing Midline

Abstract

Anatomic variations of the superior sagittal sinus (SSS) and falx cerebri (FC) are uncommon in that agenesis of these structures is extremely rare. We report an extremely rare anatomic variation, total agenesis of the SSS and FC, and briefly discuss it from the anatomical, embryological, radiological, and clinical perspectives. A 49-year-old woman presented with long-standing headache, gait disturbance, and nausea. Imaging studies showed a bilateral subdural hematoma crossing the midline, dilated venous structures, and perineural cysts, but SSS and FC. Following right-sided hemiparesis and consciousness disturbances, the subdural hematoma was evacuated from a left-sided parietal burr hole because of thick hematoma in this side. After the surgical evacuation, the hemiparesis and consciousness disturbances were regressed; however, she still had severe headache. On account of ongoing headaches and related imaging findings, it was thought that she had possible spontaneous intracranial hypotension. She was treated with autologous epidural blood patch and recovered well. Agenesis of the SSS and FC are extremely rare variations. Agenesis of the SSS results in development of alternative venous pathways and may lead to misdiagnosis as dural arteriovenous fistulas. Agenesis of FC may cause diagnostic confusion, because subdural pathologies such as hematomas can cross the midline in rare occasions.