Cauda Equina Syndrome: Difference between revisions
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Cauda equina syndrome is | Cauda equina syndrome is a rare acute polyradiculoneuropathy of the conus medullaris and lumbosacral nerve roots. It can be caused by a lesion in the spinal canal at any level below T10.<ref name="patten">Patten, John. Neurological differential diagnosis. London New York: Springer, 1996.</ref> Cauda equina syndrome with bilateral lumbosacral radiculopathies, rapidly progressive weakness, saddle anaesthesia and urinary retention is a neurologic emergency that requires emergent MRI and surgical review. | ||
==Anatomy== | ==Anatomy and Embryology== | ||
The cauda equina | The spinal cord runs from the medulla oblongata to the level of T12-L1. The next caudal part of the spinal cord is the medullary cone. The cauda equina starts from the medullary cone and consists of the spinal nerves L2-L5, S1-S5, and the coccygeal nerve. These nerves are comprised of dorsal (sensory) and ventral (motor) nerve roots. The nerve root functions include sensory supply to the saddle region, voluntary control of the outer surface of the rectum, voluntary control of the urinary sphincters, and the sensory and motor innervation of the lower limbs. Dysfunction of the cauda equina can cause problems in the above functions. The cauda equina is situated in the thecal sac and is surrounded by cerebrospinal fluid in the subarachnoid space.{{#pmid:29341941|Kapetanakis}} | ||
==Clinical | The cauda equina starts forming in the third month of gestation, and the spinal cord extends the entire length of the body at this time. After this time, the verebtral column bones and cartilage grows faster than the spinal cord. This causes the nerves below the cervical spine to follow a slanted path. The lumbar and sacral nerves therefore move caudally and vertically inside the spinal canal, before exiting through the intervertebral foramina. The nerve roots below L1 form the cauda equina.<ref name="Kapetanakis"/> | ||
==Epidemiology== | |||
Lumbar disc herniation is the primary cause (45%) of cauda equina syndrome, and this occurs in 1-3% of all disc herniations. <ref name="Kapetanakis"/> | |||
==Clinical Features== | |||
{{Red flags| | |||
*Bilateral radiculopathy | |||
*Progressive neurological deficits in the legs | |||
*Impaired perineal sensation | |||
*Impaired anal tone | |||
White flags (missed the boat): Urinary retention or incontinence, faecal incontinence, perineal anaesthesia<ref>{{#pmid:28637110}}</ref> | |||
}} | |||
There are three main clinical pictures of Cauda Equina lesions in adults. In children, disc lesions are exceptionally rare below 15 years of age.<ref name="patten"/> Cauda equina syndrome generally presents as lower limb radicular pain, sensory deficit, bowel and bladder dysfunction, and asymmetric bilateral lower limb weakness. | There are three main clinical pictures of Cauda Equina lesions in adults. In children, disc lesions are exceptionally rare below 15 years of age.<ref name="patten"/> Cauda equina syndrome generally presents as lower limb radicular pain, sensory deficit, bowel and bladder dysfunction, and asymmetric bilateral lower limb weakness. | ||
Revision as of 22:32, 15 May 2021
Cauda equina syndrome is a rare acute polyradiculoneuropathy of the conus medullaris and lumbosacral nerve roots. It can be caused by a lesion in the spinal canal at any level below T10.[1] Cauda equina syndrome with bilateral lumbosacral radiculopathies, rapidly progressive weakness, saddle anaesthesia and urinary retention is a neurologic emergency that requires emergent MRI and surgical review.
Anatomy and Embryology
The spinal cord runs from the medulla oblongata to the level of T12-L1. The next caudal part of the spinal cord is the medullary cone. The cauda equina starts from the medullary cone and consists of the spinal nerves L2-L5, S1-S5, and the coccygeal nerve. These nerves are comprised of dorsal (sensory) and ventral (motor) nerve roots. The nerve root functions include sensory supply to the saddle region, voluntary control of the outer surface of the rectum, voluntary control of the urinary sphincters, and the sensory and motor innervation of the lower limbs. Dysfunction of the cauda equina can cause problems in the above functions. The cauda equina is situated in the thecal sac and is surrounded by cerebrospinal fluid in the subarachnoid space.[2]
The cauda equina starts forming in the third month of gestation, and the spinal cord extends the entire length of the body at this time. After this time, the verebtral column bones and cartilage grows faster than the spinal cord. This causes the nerves below the cervical spine to follow a slanted path. The lumbar and sacral nerves therefore move caudally and vertically inside the spinal canal, before exiting through the intervertebral foramina. The nerve roots below L1 form the cauda equina.[2]
Epidemiology
Lumbar disc herniation is the primary cause (45%) of cauda equina syndrome, and this occurs in 1-3% of all disc herniations. [2]
Clinical Features
- Bilateral radiculopathy
- Progressive neurological deficits in the legs
- Impaired perineal sensation
- Impaired anal tone
White flags (missed the boat): Urinary retention or incontinence, faecal incontinence, perineal anaesthesia[3]
There are three main clinical pictures of Cauda Equina lesions in adults. In children, disc lesions are exceptionally rare below 15 years of age.[1] Cauda equina syndrome generally presents as lower limb radicular pain, sensory deficit, bowel and bladder dysfunction, and asymmetric bilateral lower limb weakness.
Lateral Cauda Equina Syndrome
Neurofibroma is the most frequent cause, and high disc lesions are a rarer cause. The clinical features include anterior thigh pain, quadriceps wasting, weakness of foot inversion (L4 root lesion), and an absent knee jerk. With very high lesions that lie lateral to the terminal spinal cord, there may be pyramidal signs below the lesion. In this case there may be very brisk ankle jerks, ankle clonus, and an extensor plantar response. In this context, any sphincter compromise is likely a result of the cord compression.[1]
Midline Cauda Equina Lesions from Within
This is also called a conus lesion. The most common causes are ependymomas, dermoid tumours, and lipomas of the terminal cord. The roots are damaged from the inside, that is from S5 to S4 to S3 etc. In the early stages clinical features include rectal and genital pain, urination problems, and erectile dysfunction, but with no clear physical signs except if the perianal sensation (saddle anaesthesia) and anal reflex are tested carefully. Later clinical features include reduced ankle jerks and weakness of L5 and S1 myotomes. For ependymomas, the patient may have a 5 year history of a dull backache.[1]
Midline Cauda Equina Lesions From Outside
This is characterised by bilateral lumbar and sacral root lesions. If the patient has pain in unusual dermatomes such as L2, L3, S2, or S3, then the clinician should be suspicious. Pain in an L4, L5, or S1 region on the other hand is usually due to disc disease, but further imaging may still be required to exclude other pathology. Sinister causes include primary sacral bone tumours (chordomas), metastatic disease (especially prostate), reticulosis, leukaemia, direct seeding from malignant tumours in the CNS (medulloblastomas, ependymomas, pinealomas).[1]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Patten, John. Neurological differential diagnosis. London New York: Springer, 1996.
- ↑ 2.0 2.1 2.2 Kapetanakis et al.. Cauda Equina Syndrome Due to Lumbar Disc Herniation: a Review of Literature. Folia medica 2017. 59:377-386. PMID: 29341941. DOI.
- ↑ Todd. Guidelines for cauda equina syndrome. Red flags and white flags. Systematic review and implications for triage. British journal of neurosurgery 2017. 31:336-339. PMID: 28637110. DOI.
Literature Review
Literature Review
- Reviews from the last 7 years: review articles, free review articles, systematic reviews, meta-analyses, NCBI Bookshelf
- Articles from all years: PubMed search, Google Scholar search.
- TRIP Database: clinical publications about evidence-based medicine.
- Other Wikis: Radiopaedia, Wikipedia Search, Wikipedia I Feel Lucky, Orthobullets,
