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

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Video: Lumbar Spine Anatomy

Learn just how the lumbar spinal discs role and how lower back conditions have the right 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 discontinuation varies among individuals; most commonly, the terminates in ~ the level that the L1 or L2 vertebrae. A couple of anatomical structures related to the lumbar spinal cord space highlighted below.

Conus medullaris

The terminal part of the spinal cord in the lumbar an ar is cone-shaped and also is dubbed the conus medullaris.

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


Filum terminale

The pia mater creates a delicate, fibrous strand the tissue called the filum terminale the extends under from the conus medullaris. This strand stabilizes the spinal cord by connecting the conus medullaris come the coccyx (end of the spine).1

Thecal sac

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

Lumbar cistern

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

The Cauda Equina

A group of nerve root that take trip down indigenous the spinal cord and the conus medullaris is referred to as the cauda equina. The cauda equina has nerve root from L2 in the lumbar spine to Co1 in the coccygeal (tail bone end) spine.1 every nerve source from the cauda equina exits the spinal canal in ~ its respective vertebral level, for example, the L4 nerve root exits in between the L4 and also L5 vertebrae.

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Spinal Cord and also Cauda Equina of the Lumbar Spine

Problems pertained to the Lumbar Spinal Cord and Cauda Equina

The terminal tissues of the spinal cord in the lower earlier can gain compressed, irritated, or abnormally stretched and also typically cause serious clinical problems. Feasible conditions affecting this an ar along with the certain symptoms, signs, and also causes are described below.

Cauda Equina Syndrome

The cauda equina is developed by the continuation of nerve fibers past 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 more about Cauda Equina Syndrome

Conus medullaris syndrome

Compression the the conus medullaris in the lumbar region at L1-L2 (typically in between T12 come L2) causes conus medullaris syndrome. This syndrome is defined by the following signs and symptoms1:

Sudden start of severe back painNumbness approximately the anal regionWeakness the occurs symmetrically in both legsSudden onset of bowel and bladder dysfunctionThe most common causes of conus medullaris syndrome incorporate spinal fracture, disc herniation, tumors, trauma, and collection of pus in the epidural room due to epidemic (epidural abscess).1

Conus medullaris syndrome is a medical emergency and requires immediate treatment to preserve leg function.

Tethered cord syndrome

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

Urinary dysfunction: enhanced urination or retention that urineUrinary tract infectionsBack pain, which is increased while bending the spine forward and also relieved while bending the neck backwardConstipation

While this condition is commonly identified throughout periods that rapid expansion in adolescence, the symptoms may not take place until adulthood. Common causes of tethered cord syndrome are split spinal cord (diastematomyelia), spinal cord lining difficulties (dermal sinuses), and also lumps of fatty organization in the spinal cord an ar (lipomas).1

Cauda Equina Syndrome Video

Cauda equina syndrome

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

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

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

Read much more about Cauda Equina Syndrome symptom


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Cauda equina syndrome is most frequently caused through compression indigenous a lumbar herniated disc. Compression may likewise occur due to tumors, cysts, stenosis (abnormal narrowing that the spinal canal), or trauma. Cauda equina syndrome is a clinical emergency. Immediate treatment is an important for the prevention of paralysis and also preservation of leg function.4

Read much more about reasons of Cauda Equina Syndrome

If any of these spinal cord related difficulties are suspected, that is recipient to above a physician immediately. Spinal cord disorders may be cure nonsurgically or surgically depending on the cause and the in its entirety health that the patient. The prognosis increases considerably when cure early.

See When ago Pain might Be a clinical Emergency