At a glance
What it is
A syrinx is an abnormal fluid-filled cavity within the central canal or parenchyma of the spinal cord — essentially a pocket of CSF-like fluid that forms under abnormal pressure dynamics. Also called hydromyelia when it involves the central canal. Causes include Chiari I malformation (the most common), tethered spinal cord, spinal cord trauma, hydrocephalus, spinal arachnoiditis, and spinal cord tumours. A large proportion of syringes are idiopathic. The cavity expands over time, compressing cord grey and white matter and producing a progressive neurological deficit. MRI has revolutionised diagnosis and monitoring.
Symptoms
Symptoms develop gradually over months to years and reflect the level and extent of the syrinx. Characteristic early features of a central cord lesion: cape-like distribution of dissociated sensory loss (loss of pain and temperature but preserved light touch and proprioception) in the upper body. Progressive weakness and wasting of the hands and arms; spasticity and hyperreflexia below the lesion; scoliosis (especially in children). Pain — often a deep, aching discomfort in the neck, shoulders, or arms. Bladder and bowel dysfunction. Symptoms may also arise from the underlying cause (e.g. headache and neck pain from Chiari malformation).
Approach
MRI of the full neuraxis to identify the syrinx extent and underlying cause. If a cause is found, treat the cause first: Chiari decompression (posterior fossa craniectomy) reliably resolves the syrinx in 50–70% of cases; tethered cord release and tumour resection also allow spontaneous syrinx resolution. If the syrinx persists or the cause cannot be corrected, direct surgical drainage via stenting or syringopleural/syringoperitoneal shunting is considered. Asymptomatic or non-progressive syringes may be observed with periodic MRI. Pain, spasticity, and neuropathy are managed symptomatically with physiotherapy, neuromodulation, and medications.
What syringomyelia is
The spinal cord contains a central canal that is normally microscopic. Under abnormal CSF flow dynamics — usually caused by a structural obstruction at the craniocervical junction, tethering at the cord's lower end, or post-traumatic scarring — fluid is driven under pressure into the cord substance, creating an expanding cavity (syrinx). The enlarging syrinx destroys cord tissue from the inside outward.
**How it causes symptoms**
The syrinx first damages crossing sensory fibres in the cord's central grey matter, producing the characteristic dissociated sensory loss: pain and temperature sensation (carried by spinothalamic fibres that cross at that cord level) is lost, while vibration and proprioception (carried in the posterior columns) are initially preserved. This creates the "cape" pattern over the shoulders and arms in cervical syringes.
As the cavity expands: - Anterior horn cells are destroyed → weakness and wasting of the hands and arms - Corticospinal tracts are compressed → spasticity in the legs below the lesion - Posterior columns are eventually affected → loss of proprioception and vibration - Autonomic fibres may be involved → Horner's syndrome, bladder/bowel/sexual dysfunction
**Causes and their treatment**
*Chiari I malformation* — herniation of cerebellar tonsils > 5 mm below the foramen magnum obstructs CSF pulsations at the craniocervical junction. Posterior fossa decompression (removing a small amount of occipital bone and C1 arch) restores normal CSF flow and allows the syrinx to collapse in the majority of cases.
*Tethered cord* — restriction of the cord at its lower end creates traction that alters CSF dynamics. Surgical release of the tether allows the syrinx to resolve.
*Post-traumatic syrinx* — scar tissue and arachnoiditis following spinal cord injury or surgery alter CSF flow. These syringes may progress slowly or be asymptomatic and are managed expectantly unless symptoms progress.
*Idiopathic syrinx* — no identifiable cause despite full neuraxis imaging. Careful observation with serial MRI is appropriate if the patient is stable; surgical exploration may be considered if the syrinx is progressing and causing neurological deterioration.
**Direct syrinx surgery**
When the underlying cause cannot be treated or when the syrinx persists after cause correction, direct drainage is performed. Options include: - *Syrinx stenting* — a short hollow tube is placed to drain the cavity into the subarachnoid space - *Syringoperitoneal or syringopleural shunting* — fluid is diverted to the peritoneal or pleural cavity
Results vary and re-accumulation can occur; follow-up imaging is essential.
Treatment options at Alimran Medical Center
Neuromodulation
Injection therapies
- Botox® injections
- Ozone injection
- Trigger point injections
- Epidural steroid injections
Advanced therapies
Physiotherapy & rehabilitation
- Electrical stimulation
- Short and long wave therapy
- Laser therapy
- Ultrasound therapy
- Spasticity management and scoliosis rehabilitation
- SpineMED® system
- Sigma
Book a consultation
The secretary schedules first appointments during clinic hours; please have prior imaging, operative notes and a current medication list available at the time of the call.
This page provides general information about syringomyelia (syrinx) and is not a substitute for individual medical assessment. If your symptoms are severe or worsening, contact a clinician promptly.