Abstract
Introduction: The purpose of this report is to present a rare case of Hirayama disease (HD) in a patient with a history of late-onset symptomatic vein of Galen aneurysmal malformation (VGAM). This report may provide new insights into the pathophysiology of HD, a rare disorder consisting of insidious onset of unilateral weakness and atrophy of the forearm and intrinsic hand muscles. These symptoms are believed to result from cervical myelopathy affecting the anterior horn cells due to abnormal compressive forces on the spinal cord from adjacent anatomical structures (i.e., dura and/or epidural veins), but this has not been proven. VGAM is a rare congenital cerebral vascular malformation, consisting of high-flow arteriovenous shunting between a persistent median prosencephalic vein and arterial feeders, which most frequently presents in the early neonatal period with congestive heart failure.
Case Presentation: We report the case of an otherwise healthy boy who presented with heart failure due to VGAM at 7 years and subsequently presented at 14 years with left-sided HD. His cervical MRI with neck flexion revealed enlarged epidural veins at the C5-C6 spinal level with anterior, leftward displacement of the posterior dura and spinal cord as well as left hemicord flattening and/or atrophy at this level. He underwent successful surgical treatment by C5-C6-C7 osteoplastic laminotomies and tenting and expansile autologous duraplasty, during which enlarged, engorged epidural veins were confirmed and coagulated. This halted the progression of his left hand weakness and atrophy and allowed significant functional improvement. Postoperative catheter angiogram showed no anatomical connection between the persistent VGAM and the engorged epidural veins, and genetic testing revealed no genetic predisposition of vascular malformations.
Discussion/Conclusion: In this patient, a combined surgical technique was performed that included epidural venous plexus coagulation with posterior autologous duraplasty and dural fixation using tenting sutures. This combined approach led to a favorable clinical and radiographic outcome with no complications or limitations and has not been previously proposed in the literature, to our knowledge. Although not completely ruled out, we found no angiographic connection or genetic predisposition to suggest there is a pathophysiological link between HD and VGAM.