Lack of epidural pressure change with neck flexion in a patient with Hirayama disease: case report.

OBJECTIVE: Hirayama disease is a nonprogressive cervical myelopathy associated with epidural venous engorgement and spinal canal narrowing. It has been unclear whether dural venous pressure influences spinal cord injury in this illness. CLINICAL
PRESENTATION: An 18-year-old man presented with profound hand weakness and atrophy that had developed over a period of 1 year. Electromyographic, magnetic resonance imaging, and angiographic findings are presented. INTERVENTION: The epidural space was accessed using a microcatheter technique. Pressure measurements were recorded with and without Valsalva maneuver in the inferior vena cava, vertebral veins, and epidural space at C4 and C6 in both the flexion and neutral positions. Cervical epidural venous pressure measurements in flexion and neutral positions are presented. The patient underwent duraplasty with C4 to T1 laminectomies and fusion using lateral mass screws and facet arthrodeses.
CONCLUSION: Lack of significant pressure change with neck flexion suggested that dural venous engorgement is passive and not the direct cause for spinal cord injury. Data presented herein and review of the literature suggest that surgical treatment targeting the underlying pathophysiological mechanism in Hirayama disease can benefit patients, especially early in the course of the disease.