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.
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.
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.
A tumour, post-traumatic scar, tethering or an incidental stable cavity is identified.
Key medicines
No cavity-shrinking medicineThere is no oral or intravenous regimen that reliably removes a syrinx or restores CSF flow.
Neuropathic-pain treatmentChoose and titrate one formulary agent according to renal function, comorbidity and functional response.