- Clinical science
Syringomyelia is a condition in which an abnormal fluid-filled cavity, or syrinx, develops within the central canal of the spinal cord. The syrinx is a result of disrupted CSF drainage from the central canal, commonly caused by a Chiari malformation or previous trauma to the cervical or thoracic spine. In select cases, the syrinx may occur in the brainstem, and is then referred to as syringobulbia. The syrinx initially compresses and permanently damages crossing fibers of the spinothalamic tract. Further expansion may affect other tracts of the spinal cord. Symptoms include dissociated sensory loss, presenting as a cape-like distribution of decreased sensitivity to pain and temperature, and flaccid atrophic paralysis in the upper extremities. MRI is the diagnostic modality of choice. Treatment depends on clinical features and associated findings. Symptomatic treatment commonly suffices in stable courses of disease, while patients with progressive neurological deterioration require surgical decompression.
- 3–4% of patients with traumatic spinal cord injury (SCI) develop symptomatic syringomyelia.
- Sex: ♂ > ♀, especially in SCI-related syringomyelia
- Age range: 30–40 years; however SCI-related syringomyelia may occur in all age groups
Epidemiological data refers to the US, unless otherwise specified.
- Obstructed central canal of spinal cord (usually cervical spine, may affect the thoracic spine) → impaired CSF drainage → formation of a dilated fluid-filled cavity in central spinal cord (syrinx) → compression and damage (with reactive gliosis) to crossing neural fibers of the lateral spinothalamic tract first (which affect pain and temperature) → bilateral dissociated sensory loss and dysesthetic pain
- Expansion of the syrinx may damage:
- Lower motor neurons in the medial part of the corticospinal tract → initially bilateral weakness → eventual bilateral flaccid paralysis and muscle atrophy
- Descending hypothalamic fibers in T1 to T4 cord segments → Horner syndrome
- Posterior column (advanced disease) → loss of position sense and vibration sense in the feet
- Medulla →
- A hydromyelia is an abnormal widening of the central canal of the spinal cord in which CSF collects, despite there being a connection to the 4th ventricle of the brain.
- Often asymptomatic
- Cape-like distribution (neck, shoulders, arms) of:
- Spastic paraparesis of the lower limbs may occur.
- Autonomic disturbances: anhidrosis, disturbances in bladder and colon function, erectile dysfunction ,
- Respiratory insufficiency
- Other: painless ulcers of the hands, s, thoracic scoliosis
- Hemiparaplegic syndrome ()
The differential diagnoses listed here are not exhaustive.
Conservative therapy is usually sufficient, but definitive surgical treatment is recommended for; patients with progressive neurological symptoms.
- Removal of the tumor (if present)
Decompression by drainage of CSF fluid from the cavity
- Laminectomy and syringotomy
- Physiotherapy and psychotherapy
- Spasticity: , methocarbamol
- Analgesia: amitriptyline, s, gabapentin (not FDA-approved for use in syringomyelia, but may be considered due to its effectiveness in treating neuropathic pain)