The lower back houses the terminal finish of the spinal cord and also mostly encloses the cauda equina—nerve roots the descend from the spinal cord. The spinal cord and the cauda equina room delicate and important structures. The spinal canal created by the lumbar vertebrae protects these structures by giving a strong, bony casing.

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Video: Lumbar Spine Anatomy

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Lumbar Spinal Cord

The spinal cord terminates in the lumbar spine. The exact allude of discontinuation varies amongst individuals; most commonly, it terminates at the level of the L1 or L2 vertebrae. A couple of anatomical structures concerned the lumbar spinal cord space highlighted below.

Conus medullaris

The terminal portion of the spinal cord in the lumbar region is cone-shaped and also is called the conus medullaris.

The conus medullaris is comprised of numerous neurons (nerve cells) and also has 3 safety layers. Beginning from the outermost layer, these are the dura mater, arachnoid mater, and also pia mater. The pia mater tapers and also continues under as the filum terminale at the end of the conus medullaris.1


Filum terminale

The pia mater forms a delicate, fibrous strand the tissue called the filum terminale the extends down from the conus medullaris. This strand stabilizes the spinal cord through connecting the conus medullaris to the coccyx (end of the spine).1

Thecal sac

The dura mater and arachnoid mater are collectively called the dural sac or the thecal sac. This sac covers the conus medullaris, cauda equina, and each individual spinal nerve root as it courses out that the cauda equina and also travels right into the intervertebral foramen (bony opening through which the nerve exit the spinal canal).2

Lumbar cistern

The an are inside the arachnoid mater is filled v cerebrospinal fluid (CSF). Below the conus medullaris, this an are is enlarged. This enlargement is called the lumbar cistern and contains CSF, the filum terminale, and the cauda equina.2

The Cauda Equina

A team of nerve roots that travel down from the spinal cord and also the conus medullaris is called the cauda equina. The cauda equina includes nerve root from L2 in the lumbar spine to Co1 in the coccygeal (tail bone end) spine.1 each nerve source from the cauda equina exits the spinal canal at its corresponding vertebral level, for example, the L4 nerve root exits between the L4 and L5 vertebrae.

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Spinal Cord and also Cauda Equina that the Lumbar Spine

Problems pertained to the Lumbar Spinal Cord and also Cauda Equina

The terminal organization of the spinal cord in the lower ago can acquire compressed, irritated, or abnormally stretched and also typically reason serious medical problems. Feasible conditions affect this region along with the particular symptoms, signs, and also causes are explained below.

Cauda Equina Syndrome

The cauda equina is formed by the continuation of nerve fibers beyond the spinal cord. Compression of the cauda equina, such together by a herniated disc, may cause severe pain and also numbness in both legs. Read an ext about Cauda Equina Syndrome

Conus medullaris syndrome

Compression the the conus medullaris in the lumbar an ar at L1-L2 (typically in between T12 to L2) reasons conus medullaris syndrome. This syndrome is identified by the complying with signs and also symptoms1:

Sudden start of severe ago painNumbness roughly the anal regionWeakness the occurs symmetrically in both legsSudden beginning of bowel and bladder dysfunctionThe many common causes of conus medullaris syndrome incorporate spinal fracture, bowl herniation, tumors, trauma, and also collection the pus in the epidural space due to infection (epidural abscess).1

Conus medullaris syndrome is a medical emergency and requires prompt treatment to keep leg function.

Tethered cord syndrome

An abnormal filum terminale can transform the security of the conus medullaris and also prevent the normal motion in the spinal canal. This condition is referred to as tethered cord syndrome and also causes the spinal cord to acquire abnormally stretched, especially throughout actions such together spinal flexion (bending forward).1 typical signs and symptoms include3:

Urinary dysfunction: raised urination or retention of urineUrinary tract infectionsBack pain, which is raised while bending the spine forward and relieved when bending the neck backwardConstipation

While this problem is commonly identified during periods that rapid expansion in adolescence, the symptoms may not take place until adulthood. Common reasons of tethered cord syndrome are separation spinal cord (diastematomyelia), spinal cord lining difficulties (dermal sinuses), and lumps the fatty tissue in the spinal cord region (lipomas).1

Cauda Equina Syndrome Video

Cauda equina syndrome

Compression the the cauda equina in ~ the lumbar cistern can reason serious symptoms in the reduced body. The condition is called cauda equina syndrome and presents with the complying with signs and also symptoms4:

Numbness the the within thighs (saddle anesthesia)Urinary retentionLoss of bowel and/or bladder controlSevere lower ago painSciatica-like shooting and burning pain in the leg(s)A emotion of pins-and-needles in the leg(s)

Cauda equina syndrome can present in 2 ways: acute onset, where the symptoms and also signs occur rapidly, and insidious onset, whereby the condition starts as lower back pain and also slowly progresses to bowel and also urinary incontinence.4

Read more about Cauda Equina Syndrome symptoms


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Cauda equina syndrome is most typically caused by compression native a lumbar herniated disc. Compression may additionally occur due to tumors, cysts, stenosis (abnormal narrowing of the spinal canal), or trauma. Cauda equina syndrome is a medical emergency. Immediate treatment is critical for the avoidance of paralysis and also preservation of leg function.4

Read much more about causes of Cauda Equina Syndrome

If any of these spinal cord related difficulties are suspected, that is advisable to top a doctor immediately. Spinal cord disorders may be cure nonsurgically or surgically relying on the cause and the as whole health the the patient. The prognosis increases substantially when treated early.

See When back Pain might Be a medical Emergency