What is the treatment for Hirayama disease?

Treatment of Hirayama Disease

Primary Treatment Strategy

Conservative management with neck immobilization using a rigid cervical orthosis is the first-line treatment for Hirayama disease, aimed at preventing flexion-induced spinal cord compression and halting disease progression. 1, 2

Conservative Management

Neck flexion avoidance and rigid cervical collar immobilization form the cornerstone of initial treatment, as the disease results from forward displacement of the posterior cervical dural sac during neck flexion, causing anterior horn compression and ischemic changes. 1, 2

• Duration of immobilization: Cervical collar application for 3-4 years is generally advocated, as progression typically ceases spontaneously within several years of onset. 3

• Mechanism of benefit: External orthoses prevent repetitive flexion injury across involved cervical segments, which is the primary driver of disease progression up to 5 years from initial diagnosis. 2

• Success rate: Among conservatively managed patients, only 1 in 9 experienced further deterioration in one institutional series, though long-term collar compliance can be challenging. 2, 3

Surgical Intervention

Surgical treatment should be considered for patients who fail conservative management, experience rapid clinical deterioration, or cannot tolerate prolonged external immobilization. 2, 4, 3

Indications for Surgery

• Failed conservative treatment after appropriate trial of cervical orthosis 2, 3
• Rapid or progressive neurological deterioration despite conservative measures 2
• Inability to tolerate prolonged cervical collar use (which may extend 3-4 years) 3
• Continued disease progression beyond the expected self-limiting course 4

Surgical Approach and Outcomes

Anterior cervical stabilization alone (without decompression) provides superior outcomes compared to decompression-based procedures, with 84.3% of surgical patients experiencing neurological improvement. 4

• Optimal surgical strategy: Stabilization-alone was the only significant predictor of neurological improvement in univariable analysis, outperforming decompression with or without stabilization. 4

• Age considerations: Patients under 20 years of age demonstrate higher likelihood of neurological improvement following surgery compared to older patients. 4

• Surgical approach preference: Anterior-only approach shows superior outcomes compared to posterior-only or staged anterior-posterior approaches in decision-tree analysis. 4

• Specific technique: Anterior cervical discectomy with fusion (ACDF) or vertebrectomy with fixation using iliac bone graft and plate system provides permanent stable fixation with shorter immobilization period than prolonged collar therapy. 2, 3

• Surgical success: No patient who underwent ACDF experienced disease progression in one institutional series, compared to 1 of 9 conservatively managed patients. 2

Surgical Benefits Beyond Disease Arrest

Surgery offers the advantage of permanent cervical stabilization with much shorter external immobilization compared to 3-4 years of collar therapy, significantly improving quality of life. 3

Functional Restoration for Established Deficits

For patients with stable disease and persistent hand dysfunction, reconstructive hand surgery including tendon transfers and selective joint arthrodeses can restore functional grip and pinch strength. 5

• Timing: Reconstruction should only be performed after disease stabilization, as risk of progression must be carefully managed. 5

• Surgical options: Tendon transfers for thumb opposition, grasp, and anticlaw deformity, combined with thumb interphalangeal joint arthrodesis, are tailored to specific deficits. 5

• Outcomes: All patients in one surgical series demonstrated postoperative grip strength improvement with average 3.2-year follow-up. 5

• Common deficits addressed: HD mimics high ulnar neuropathy, lower trunk brachial plexopathy, or C8-T1 radiculopathy, requiring specific reconstructive strategies. 5

Multidisciplinary Approach

Diagnosis and treatment require collaboration between spine surgeons, neurologists, and hand surgeons, as many specialists may be unaware of functional restoration options. 5, 2

• Diagnostic workup: Electromyography demonstrating denervation in C7-T1 myotomes and flexion/extension MRI showing focal cord atrophy with anterior displacement of posterior dura and epidural enhancement in flexion are essential. 2

• Clinical presentation: Painless progressive distal upper extremity weakness and atrophy without sensory loss, predominantly affecting male adolescents in the second decade. 2

Key Clinical Pitfalls

• Delayed recognition: Early diagnosis and management can effectively halt progressive deterioration, making prompt identification critical. 1

• Premature surgical intervention: Surgery should not be offered before adequate trial of conservative management unless rapid deterioration occurs. 2

• Inappropriate decompression: Decompression-based procedures show inferior outcomes compared to stabilization-alone strategies. 4

• Overlooking functional restoration: Hand surgeons should be consulted for patients with stable disease and persistent functional deficits, as reconstructive options are often underutilized. 5