Almost 40 cases of spontaneous transdural spinal cord herniation have been reported in the literature. These patients often present with gait disturbance and sensory changes, and their condition is diagnosed as Brown-Séquard syndrome. The pathogenesis of this condition has remained poorly understood. In particular, there is no agreement whether the dural defect is acquired or congenital. In the reported case, a 21-year-old man presented with a 3-year history of intermittent low-pressure headaches consistent with intracranial hypotension. Eventually, the headaches resolved but he developed myelopathy due to a spinal cord herniation. In this case, the authors hypothesize that the progressive spinal cord herniation through a spontaneous dural tear sealed the site of the cerebrospinal fluid leak, causing the resolution of headaches.