What causes intermittent weakness and hypoesthesia in cervical myelomalacia after surgical decompression?

From the Guidelines

For intermittent weakness and hypoesthesia related to cervical myelomalacia after surgical decompression, the primary cause is often residual or recurrent extrinsic compression of the spinal cord, which can be due to various factors such as seromas, pseudomeningoceles, hematomas, and/or epidural abscesses, as well as degenerative changes, disc herniations, and malalignment 1.

Causes of Intermittent Weakness and Hypoesthesia

The causes of intermittent weakness and hypoesthesia in patients with cervical myelomalacia after surgical decompression can be multifactorial, including:

• Residual or recurrent extrinsic compression of the spinal cord
• Degenerative changes, such as spinal degenerative changes, disc herniations, and malalignment
• Inflammatory conditions, such as demyelinating diseases, systemic inflammatory diseases, and infection
• Vascular abnormalities, such as spinal dural arteriovenous fistulas

Recommended Approach

The recommended approach for managing intermittent weakness and hypoesthesia related to cervical myelomalacia after surgical decompression includes:

1. Physical therapy: Focus on strengthening exercises for affected muscle groups and range of motion exercises for the cervical spine. Frequency: 2-3 times per week for at least 6-8 weeks.
2. Medications:
   • Gabapentin: Start at 300mg three times daily, gradually increasing to 600mg three times daily as tolerated for neuropathic pain.
   • Baclofen: 5-10mg three times daily for muscle spasticity if present.
3. Regular follow-up with a neurologist or neurosurgeon: Every 3-6 months to monitor symptoms and assess for any progression.
4. MRI surveillance: Annual cervical spine MRI to evaluate for any recurrence or progression of myelomalacia.
5. Lifestyle modifications: Avoid activities that involve repetitive neck movements or prolonged neck extension.
6. Cervical collar: Use as needed for temporary relief during symptom flare-ups, but avoid prolonged use to prevent muscle weakness. This approach addresses both symptom management and prevention of further neurological deterioration, as supported by the most recent and highest quality study 1.

From the Research

Causes of Intermittent Weakness and Hypoesthesia in Cervical Myelomalacia after Surgical Decompression

• Ischemic reperfusion injury, which can occur after surgical decompression of a previously compressed segment of the spinal cord, leading to oxidative damage and inflammatory responses 2
• Postoperative spondylolisthesis, a serious complication that can occur after anterior cervical corpectomy and fusion with instrumentation, potentially causing new or persistent symptoms 3
• Parsonage-Turner syndrome (PTS) or neuralgic amyotrophy, which can be precipitated by surgery and is unrelated to technical or structural issues 4
• White cord syndrome (WCS), a rare case of severe neurological deterioration after surgical decompression for cervical myelopathy, proposed to be secondary to an ischemia/reperfusion injury 5, 2
• Delayed C5 weakness, a known entity in cervical spine surgery, although with varied clinical presentation and poorly understood mechanism of action, which can lead to bilateral phrenic nerve dysfunction and respiratory distress 6

Possible Mechanisms

• Rapid return of blood flow to the spinal cord after decompression, leading to oxidative damage and inflammatory responses 2
• Inflammatory response known as ischemic reperfusion injury, triggered by the immediate relief from chronic compression on the spinal cord 2
• Technical or structural issues during surgery, although Parsonage-Turner syndrome is unrelated to these factors 4

Clinical Presentations

• Intermittent weakness and hypoesthesia in the affected limbs 4, 6, 2
• Delayed onset of symptoms, such as monoplegia or bilateral phrenic nerve dysfunction, after surgical decompression 6, 2
• Sudden neurological deterioration after surgical decompression, characterized by white cord syndrome 5, 2