Synopsis
Recognise a central spinal-cord cavity from dissociated sensory and segmental motor signs, identify the cause of disturbed CSF flow and refer progressive disease for specialist neurosurgical management.
- Syringomyelia is a fluid-filled cavity within spinal-cord tissue or the central canal, most often cervical and commonly associated with Chiari I malformation or another obstruction to CSF flow.
- Other causes include intramedullary tumour, previous trauma, arachnoiditis, meningitis, tethering and postoperative scarring; the cause must be sought rather than treating the word syrinx as complete.
- Expansion across the anterior white commissure disrupts crossing spinothalamic fibres, causing bilateral segmental loss of pain and temperature with preserved vibration and position.
- A cervical cavity can create a cape-like sensory loss across shoulders and arms, painless burns or injuries and neuropathic pain, although real patterns are often patchy or asymmetric.
- Anterior-horn involvement produces hand weakness, wasting, fasciculation and reduced arm reflexes at the level, while corticospinal expansion causes spastic, brisk legs below.
- Horner syndrome, scoliosis and autonomic or trophic hand changes are additional clues; extension into the medulla can impair swallowing, voice, tongue and breathing.
- MRI brain and the craniocervical junction plus the whole relevant spinal cord defines the cavity, Chiari anatomy, tumour and CSF obstruction; contrast helps identify an underlying mass.
- Cavity size alone does not predict symptoms or mandate surgery. Incidental stable syrinxes may be observed with clinical and MRI surveillance through a specialist plan.
- Progressive symptomatic Chiari-associated disease is usually treated by restoring CSF flow with posterior fossa decompression rather than directly shunting the cavity first.
- Established cord loss may not reverse after successful surgery, so prevention of progression, injury education, pain care and rehabilitation are realistic goals.
Key red flags
Intrinsic hand muscles weaken and waste, reflexes at affected cervical segments fall and fasciculation may appear, despite brisk legs from long-tract involvement below.
Years after spinal injury, a patient develops new ascending sensory loss, pain, weakness, spasticity or autonomic change above or below the original neurological level.
Nystagmus, facial sensory change, palatal or tongue weakness, dysphonia, dysphagia and respiratory symptoms suggest extension into the brainstem and require expedited review.
Rapid progression, marked focal pain, cord expansion or an enhancing nodule raises ependymoma, haemangioblastoma or another intramedullary tumour rather than isolated flow disturbance.
Investigation priorities
Identify Chiari I, foramen-magnum crowding, hydrocephalus and brainstem extension that determine cause and operation.
Management branches
Dissociated sensation, segmental hand wasting or mixed arm and leg signs suggest central cord disease.
- Document pain-temperature versus dorsal-column sensation, segmental power and reflexes, long-tract signs, bulbar function, trauma, meningitis, surgery and Valsalva headache history.
- Arrange MRI of brain, craniocervical junction and whole spine with contrast as appropriate, seeking Chiari, tumour, tethering, scar and cavity extent.
- Refer to a specialist neurosurgical service and provide protection advice for burns, pressure and insensate joints while progression and cause are assessed.
A tumour, post-traumatic scar, tethering or an incidental stable cavity is identified.
- For tumour or tethering, coordinate resection, biopsy, oncology or untethering according to pathology and neurological risk; for trauma, assess CSF obstruction and spinal stability.
- Use direct syrinx shunting only after specialist assessment of recurrence, blockage and alternative correction, not because a cavity is visually large.
- For incidental stable disease, agree symptom triggers, examination and interval MRI rather than offering no follow-up or unnecessary emergency surgery.