Terminal syringohydromyelia and occult spinal dysraphism

Area of Science:

• Neurology
• Neurosurgery
• Radiology

Background:

• Terminal syringohydromyelia involves cystic dilation in the lower spinal cord.
• It is often associated with occult spinal dysraphism, a congenital condition affecting spinal cord development.
• Understanding its characteristics and treatment is crucial for patient outcomes.

Purpose of the Study:

• To determine the incidence and characteristics of terminal syringohydromyelia in patients with occult spinal dysraphism.
• To evaluate the clinical significance and effectiveness of surgical treatment, particularly shunting.
• To identify common associated spinal anomalies.

Main Methods:

• Retrospective review of 143 occult spinal dysraphism cases treated between 1972 and 1992.
• Analysis of imaging studies, primarily magnetic resonance (MR) imaging, to detect syringohydromyelia.
• Correlation of syrinx characteristics with clinical presentation and surgical outcomes.

Main Results:

• Terminal syringohydromyelia was identified in 27% of cases evaluated by MR imaging, compared to 6.2% by myelography/CT.
• Large syringes were frequently symptomatic, causing pain, lower extremity deficits, scoliosis, and bowel/bladder dysfunction.
• Common associations included tethered spinal cord, meningocele manqué, and diastematomyelia.
• Surgical shunting led to syrinx resolution in 91% of cases, complete pain relief in all symptomatic patients, and neurological improvement in one-third.

Conclusions:

• Terminal syringohydromyelia is a significant finding in occult spinal dysraphism.
• Early surgical intervention, especially shunting for large or symptomatic cysts, is necessary and effective.
• MR imaging is superior to myelography/CT for diagnosing terminal syringohydromyelia in this population.