Conus medullaris

The conus medullaris is the tapered end of the spinal cord. In adults it usually lies near the L1–L2 vertebral levels, with anatomical variation; below it, the canal contains descending nerve roots forming the cauda equina.

Lire cette fiche en français

Structure and function

The adult spinal cord does not extend all the way to the sacrum. It ends at the conus, while roots serving lumbosacral regions continue downward toward their exit openings. A vertebral level seen on MRI and a neurological cord segment are therefore not interchangeable descriptions of location.

Possible manifestations

A conus lesion may affect perineal sensation, urinary, bowel or sexual function and sometimes the legs. Compression, trauma and other neurological conditions are possible causes. Symptoms can overlap with cauda equina involvement, so distinguishing them should not delay assessment. Pain severity alone cannot establish whether important neurological structures are threatened.

Assessment and management

Medical assessment considers symptom progression and neurological function. MRI is particularly useful for locating a lesion. A conus described at an unusual level requires contextual interpretation rather than an automatic disease label. Treatment depends on the cause; acute compression may require urgent intervention, while other findings need a different specialist pathway.

Role of TAGMED care

At TAGMED, symptoms suggesting conus involvement require immediate referral to appropriate medical care. Traction, laser and manual therapy should not precede that assessment or be described as decompressing the spinal cord. A routine conservative treatment trial is not an appropriate response to new sphincter dysfunction.

Warning signs

New urinary retention, loss of bladder or bowel control, saddle numbness or rapidly progressive weakness requires emergency evaluation. Do not wait for every feature to appear, and do not postpone assessment until the next scheduled appointment.

Frequently asked questions

Is it the cauda equina?

No. The conus is spinal cord; the cauda equina consists of roots.

Is it always exactly at L1?

No. Its vertebral level varies between individuals.

Are symptoms always symmetrical?

No. Their distribution alone cannot exclude involvement.

Must pain be severe to cause concern?

No. New neurological or sphincter symptoms also matter.

Is exercise the first response to suspicion?

No. Urgent assessment of the cause takes priority.

Educational information from The Spine Page. This entry does not replace an individual assessment. Documentary version: October 12, 2026. Sylvain Desforges, B.Sc., D.O., N.D., osteopath and naturopath.