Is cervical spinal myelomalacia correlated with increased intraspinal pressures?

Cervical Spinal Myelomalacia and Its Correlation with Increased Intraspinal Pressure

Yes, cervical spinal myelomalacia does correlate with increased intraspinal pressures, particularly in the context of cervical spondylotic myelopathy (CSM) where chronic compression leads to irreversible spinal cord damage.

Pathophysiological Relationship

Myelomalacia represents softening of the spinal cord that occurs as a consequence of several interrelated factors:

1. Mechanical Compression Effects:

   • Direct compression of the spinal cord from degenerative changes, disc herniations, or osteophytes increases intraspinal pressure 1
   • Long periods of severe stenosis are associated with demyelination and may result in necrosis of both gray and white matter 1

2. Location Patterns:

   • Myelomalacia typically appears at or distal to the area of spinal cord compression 2
   • In more than 50% of cases, the increased T2 signal intensity (representing myelomalacia) is located distal to the pressure point or starts at the level of pressure and extends distally 2
   • It rarely appears solely proximal to the compression site 2

3. Vascular Compromise:

   • Increased intraspinal pressure leads to compromised blood flow and ischemia
   • Chronic compression causes microvascular damage and reduced perfusion of the spinal cord 3

Diagnostic Correlation

MRI findings strongly support this relationship:

• T2 hyperintensity within the spinal cord (myelomalacia) is a key indicator of cervical myelopathy and correlates with areas of increased pressure 3
• Intramedullary cord signal changes on MRI in patients with spondylotic myelopathy represent prognostic factors for neurosurgical outcomes 1
• Characteristic patterns of enhancement can be seen immediately at and below the level of stenosis where pressure is highest 1

Clinical Implications

The correlation between myelomalacia and increased intraspinal pressure has important clinical implications:

1. Surgical Decision-Making:

   • Presence of myelomalacia on MRI is an indication for surgical decompression to relieve pressure 3
   • Surgical decompression is strongly recommended for patients with progressive symptoms and evidence of myelomalacia 3

2. Prognosis:

   • All 15 patients with preoperative myelomalacia in one study had residual spinal cord abnormalities after decompression, indicating irreversible changes 1
   • However, there was no difference in clinical improvement between patients with or without myelomalacia, suggesting that decompression can still provide clinical benefit despite persistent MRI changes 1

3. Monitoring:

   • In patients with cervical stenosis without myelopathy, the presence of abnormal EMG findings or clinical radiculopathy is associated with the development of symptomatic CSM 1
   • This supports the need for monitoring intraspinal pressure effects before myelomalacia develops

Management Considerations

For patients with evidence of myelomalacia due to increased intraspinal pressure:

• Surgical decompression is the first-line treatment for moderate to severe myelopathy (mJOA ≤12) 3
• Anterior approach is preferred for 1-3 level disease, while posterior approach may be better for ≥4 level disease 3
• Nonoperative therapy may be considered for patients with mild myelopathy (mJOA >12) but requires close monitoring for neurological deterioration 3

Atypical Presentations

It's important to recognize that myelomalacia from increased intraspinal pressure can present atypically:

• Some patients may present with only lower extremity symptoms despite cervical pathology 4
• In rare cases, cervical myelomalacia can mimic intramedullary tumors on MRI, with contrast enhancement in the high-intensity areas 5

Understanding the correlation between myelomalacia and increased intraspinal pressure is crucial for early diagnosis and appropriate management of cervical spondylotic myelopathy to prevent permanent neurological deficits.