Cauda equina syndrome is severe compression of the nerve roots at the bottom of the spinal canal, usually from a large disc herniation, tumour, infection, or trauma.
Warning signs include severe low back pain, weakness in both legs, numbness in the saddle area (inner thighs, perineum, around the anus), loss of bladder or bowel control, and sexual dysfunction.
Urgent MRI is the test that confirms or excludes the diagnosis and shows what is compressing the nerve roots.
MRI of the lumbar spine is the priority; CT is used if MRI is not available or not safe.
Most cases need urgent surgical decompression to give the best chance of recovery; the longer compression continues, the more lasting the damage may be.
This entry explains the condition. The next step is having a radiologist interpret your specific scan, not a general definition.