Cauda equina syndrome and conus medullaris syndrome
Cauda equina syndrome is a consequence of compression of the cauda equina, the nerve fibres of L3 – S5. Conus medullaris syndrome is a consequence of compression of the conus medullaris, the spinal cord segments T12 – L2. Both are neurological emergencies as they may cause permanent neurological injury if untreated. They are usually caused by spinal disc herniation.
These syndromes are medical emergencies and so any patient with these signs must undergo imaging and decompressive surgery immediately. Urgent neurosurgery to decompress the spine is necessary.
Warning signs
- Saddle anaesthesia
- Paraplaegia
- Urinary retention or incontinence
- Loss of lower extremity reflexes
These signs are suspicious for spinal cord compression, conus medullaris syndrome or cauda equina syndrome.
Clinical features
| Conus medullaris syndrome | Cauda equina syndrome |
|---|---|
| An upper motor neuron lesion | A lower motor neuron lesion |
| Symmetric symptoms | Asymmetric symptoms |
| Motor symptoms rare | Paraparesis and loss of patellar and Achilles reflex |
| Sensory loss of pelvic and perianal region (saddle anaesthesia) | |
| No pain | Radicular pain |
| Vegetative symptoms like urinary retention, faecal incontinence, erectile dysfunction, loss of anal and bulbocavernosus reflexes | |