Sri Moturu, DO
Resident Physician
Memorial Healthcare System
Austin, Texas, United States
Joanne Delgado, MD
Attending Physician
Memorial Healthcare System
Hollywood, Florida, United States
A 24-year-old African American male with Klinefelter syndrome, severe autism, and nonverbal at baseline was admitted with several months of worsening bilateral upper extremity weakness, inability to grasp objects, and difficulty with transfers. On physical examination, he presented with varying degrees of bilateral intrinsic hand muscle atrophy and severe weakness. MRI cervical spine in flexed position was significant for a congenital mild stenotic cervical canal and forward displacement of the posterior thecal sac. The contrast between the patient’s mild spinal stenosis and his severe physical presentation was concerning for myelopathy secondary to Hirayama Disease. The patient underwent C3-C6 posterior cervical laminectomy and fusion to limit neck flexion and delay the advancement of Hirayama disease per neurosurgical recommendations.
Discussions:
Hirayama disease, also known as monomelic amyotrophy (MMA) is a rare form of juvenile cervical myelopathy with less than 1500 reported cases, occurring predominantly in Asia. Patients present with progressive upper extremity weakness due to anterior shift of the posterior thecal sac, specifically during neck flexion, resulting in cervical cord compression. MRI cervical spine in flexion will reveal movement of the posterior thecal sac and expansion of epidural space due to increased venous return in the epidural venous plexus. Treatment involves minimizing progression via cervical laminectomy and fusion along with using a hard cervical collar post-operatively. Patients who also undergo intensive rehabilitation post-operatively have been shown to improve functional capabilities.
Conclusions:
This is a rare case of an adolescent male patient with cervical cord myelopathy in the setting of Hirayama disease. This case report highlights the importance of a thorough neurological examination and early neurosurgical intervention as these can delay progression and improve rehabilitation goals of care.
