The lower earlier houses the terminal end of the spinal cord and also mostly encloses the cauda equina—nerve roots that descend native the spinal cord. The spinal cord and also the cauda equina are delicate and important structures. The spinal canal created by the lumbar vertebrae protects these structures by offering a strong, bony casing.

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Video: Lumbar Spine Anatomy

Learn how the lumbar spinal discs role and exactly how lower earlier conditions deserve to cause ago pain and/or radiating pain. Watch now

Lumbar Spinal Cord

The spinal cord terminates in the lumbar spine. The exact allude of termination varies among individuals; many commonly, the terminates at the level the the L1 or L2 vertebrae. A couple of anatomical structures related to the lumbar spinal cord are highlighted below.

Conus medullaris

The terminal section of the spinal cord in the lumbar region is cone-shaped and is dubbed the conus medullaris.

The conus medullaris is consisted of of number of neurons (nerve cells) and also has 3 protective layers. Starting from the outermost layer, these space the dura mater, arachnoid mater, and also pia mater. The pia mater tapers and also continues down as the filum terminale in ~ the end of the conus medullaris.1


Filum terminale

The pia mater develops a delicate, fibrous strand the tissue referred to as the filum terminale that extends down from the conus medullaris. This strand stabilizes the spinal cord by connecting the conus medullaris come the coccyx (end the the spine).1

Thecal sac

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

Lumbar cistern

The room inside the arachnoid mater is filled with cerebrospinal fluid (CSF). Listed 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 group of nerve root that travel down native the spinal cord and also the conus medullaris is referred to as the cauda equina. The cauda equina has nerve root from L2 in the lumbar spine come Co1 in the coccygeal (tail bone end) spine.1 every nerve root from the cauda equina exits the spinal canal in ~ its respective vertebral level, because that example, the L4 nerve root exits between the L4 and L5 vertebrae.

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Spinal Cord and Cauda Equina the the Lumbar Spine

Problems pertained to the Lumbar Spinal Cord and Cauda Equina

The terminal tissues of the spinal cord in the lower ago can get compressed, irritated, or abnormally stretched and also typically reason serious clinical problems. Feasible conditions influence this an ar along v the details symptoms, signs, and causes are described below.

Cauda Equina Syndrome

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

Conus medullaris syndrome

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

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

Conus medullaris syndrome is a clinical 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 called tethered cord syndrome and also causes the spinal cord to gain abnormally stretched, especially during actions such together spinal flexion (bending forward).1 common signs and also symptoms include3:

Urinary dysfunction: increased urination or retention the urineUrinary tract infectionsBack pain, i m sorry is raised while bending the spine forward and also relieved when bending the neck backwardConstipation

While this problem is frequently identified during periods the rapid development in adolescence, the symptoms might not take place until adulthood. Common causes of tethered cord syndrome are break-up spinal cord (diastematomyelia), spinal cord lining problems (dermal sinuses), and also lumps the fatty tissue in the spinal cord an ar (lipomas).1

Cauda Equina Syndrome Video

Cauda equina syndrome

Compression of the cauda equina in ~ the lumbar cistern can reason serious symptom in the lower body. The condition is dubbed cauda equina syndrome and presents with the complying with signs and symptoms4:

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

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

Read much more about Cauda Equina Syndrome symptoms


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Cauda equina syndrome is most frequently caused by compression from a lumbar herniated disc. Compression may additionally occur because of tumors, cysts, stenosis (abnormal narrowing the the spinal canal), or trauma. Cauda equina syndrome is a clinical emergency. Prompt treatment is an important for the prevention of paralysis and preservation of foot function.4

Read much more about reasons of Cauda Equina Syndrome

If any of this spinal cord related problems are suspected, it is recipient to above a physician immediately. Spinal cord disorders may be treated nonsurgically or surgically depending on the cause and also the overall health that the patient. The prognosis increases significantly when cure early.

See When ago Pain might Be a medical Emergency