Spinal cord compression and cauda equina syndrome Flashcards
Vertebrae in which the spinal cord is found
C1 (junction with medulla) to L1 (conus medullaris)
At what level would you take a lumber puncture
L4
Below L1 are the lumber and sacral nerve roots - grouped together, what is this called
Cauda equina
Deine paraplegia
Paralysis of BOTH legs always caused by spinal cord lesion
Define hemiplegia
Paralysis of ONE side of body caused by lesion of he brain
Signs of UMN lesion
Signs contralateral to lesion
Increased muscle tone (Spasticity)
Weakness (flexors generally weaker than extensors in legs and reverse in arms)
Increased reflexes, they are brisk - Hyperreflexia
Signs of LMN lesion
Signs ipsilateral to lesion Decreased muscle tone Wasting/Atrophy Fasciculations possible Reflexes reduced or absent Weakness (relating to areas supplied by peripheral nerves)
What are fasciculations and what could they be a sign of
Spontaneous involuntary twitching
LMN lesion
Give examples of how the level of the LMN problem can be inferred from accompanying symptoms
Back pain/sciatica suggest a root problem
Weakness of the biceps with absence of the biceps reflex with UMN signs in the legs suggests cord disease e.g. a disc prolapse at C5/C6 (LMN at this level and UMN below)
What is spondylolisthesis
Slippage of one vertebra over the one below
Nerve root comes out ABOVE the disc therefore root affected will be the one BELOW the disc herniation e.g. L4/5 herniation leads to L5 nerve root compression
What is spondylosis
Degenerative disc disease
What is myelopathy
Spinal cord disease caused by spinal cord compression
Upper motor neurone signs e.g. spasticity, weakness, hyperreflexia
What is radiculopathy
Caused by spinal root compression Lower motor neurone signs e.g. decreased muscle tone, wasting, weakness and fasciculations Pain down dermatome supplied by root Weakness in myotome supplied by root No UMN signs
Signs of acute radiculopathy (spinal root compression with no UMN signs)
No LMN signs as fasciculations and wasting take time to develop
Spinal root of Clavicle dermatome
C4
Spinal root of Nipples dermatome
T4
Spinal root of Medial side of arm dermatome
T1
Spinal root of Umbilicus dermatome
T10
Spinal root of Anterior and inner leg dermatome
L2-3
Spinal root of Knee dermatome
L4
Spinal root of Posterior and outer leg dermatome
L5, S1-2
Spinal root of Perianal area dermatome
S4
What is myelopathy
Compression of the spinal cord resulting in upper neurone signs and specific symptoms dependent on where compression is
Aetiology of spinal cord compression
Vertebral body neoplasms (secondary malignancy) Disc herniation Degenerative disc Disc prolapse Rarer: Infection e.g. epidural abscess Haematoma e.g. warfarin Primary spinal cord tumour e.g. glioma, neurobiroma
What are the 2 parts of discs of the spinal column called
Nucleus pulposus Annulus fibrosus (surrounding)
What is disc prolapse
When nucleus pulposus moves and presses against the annulus resulting in pressure on nerve root and pain.
Can produce a bulge in the disc which can cause pressure on the nerve root and thus pain
Clinical presentation
Progressive weakness of the legs with upper motor neurone pattern and eventual paralysis.
Hours to days onset.
Arms affected if lesion is above thoracic spine.
Sensory loss below lesion.
Most common cause of spinal cord compression
Vertebral body neoplasms (secondary to malignancy elsewhere e.g. lung, breast, prostate, myeloma, lymphoma)
Gold standard for diagnosis of spinal cord compression
MRI
identifies the cause and site of cord compression
Why should imaging for spinal cord compression not be delayed at all
Since irreversible paraplegia may follow if the cord is NOT decompressed
Other investigations (other than MRI) for spinal cord compression
Biopsy/surgical exploration - may be required to identify the nature of any mass
Screening blood tests - FBC, ESR, B12, U and Es, Syphilis serology, LFT, PSA
CXR - if TB or malignancy (see primary tumour)
Treatment of spinal cord compression
Surgical decompression of the cord.
Correction of pathology.
DEXAMETHASONE reduces oedema around the lesion.
Refer to neurosurgeons.
Treatment of spinal cord compression - epidural abscess
Surgical decompression
Antibiotics
Examples of surgical decompression of spinal cord
Laminectomy - removal of lamina/spongy tissue between discs to relieve pressure and thus symptoms
Microdiscectomy - removal of herniated tissue from disc
What is the cauda equina
Bundle of nerve roots from the lumbar and sacral levels that branch off the bottom of the spinal cord (conus medullaris).
Nerve roots caudal (distal) to the level of the termination of the spinal cord at L1/L2.
When does the cauda equina start
L1/2 (more L1)
Cauda equina syndrome epidemiology
Rare, occurring mainly in adults but can
occur at any age
Occurs in around 2% of herniated discs
Most common cause of cauda equina syndrome
Lumbar disc herniation at L4/5 and L5/S1
Aetiology/Risk factors of Cauda equina
Herniation of lumber disc (most commonly at L4/5 and L5/S1) Tumours/metastases Trauma Infection Spondylolisthesis Post-op haematoma
Pathophysiology of Cauda equina
Nerve root compression CAUDAL to the termination of the spinal cord at L1/2
Usually large central disc herniations at L4/5 or L5/S1 levels
Bladder function can be affected due to S1-5 nerve root compression
Clinical presentation of cauda equina syndrome
BB SAFE Bilateral sciatica Saddle anaesthesia Bladder/bowel dysfunction Erectile dysfunction Variable leg weakness that is FLACCID & AREFLEXIC (LMN signs)
*What is major difference in clinical presentation between cauda euqina and lesions higher up in the cord
Leg weakness is flaccid and Areflexic (LMN)
NOT spastic and hyperreflexic
What is sciatica
Pain, numbness and a tingling sensation that radiates from lower back and travels down one of the legs to the foot and toes
Cauda equina syndrome investigations
History and clinical examination with appropriate radiological investigation.
MRI is preferred method for diagnosis and determine level of compression and any underlying cause.
MRI scan is only way to exclude CES
Further investigations for underlying cause and focusing on localised site of compression
Urodynamic studies - may be required to monitor recovery of bladder function following decompression surgery
Cauda equina syndrome differential diagnosis
Conus medullaris syndrome
Mechanical back pain or prolapsed lumber disc
Fracture of lumber vertebrae due to trauma
Spinal tumour
Spinal cord compression
Peripheral neuropathy
What is conus medullaris syndrome
Conus medullaris is located above the cauda equina at T12-L2; nerve root pain is less prominent and the main features are urinary retention and constipation
Complications of cauda equina syndrome
Paralysis.
Sensory abnormalities.
Bladder, bowel and sexual dysfunction.
Management of cauda equina syndrome
Immediate referral to neurosurgery to relieve pressure
Tests of specific nerve roots: L5-S1
Knee flexion
Or Straight leg raising
Tests of specific nerve roots: S1-S2
Ankle plantar flexion (downwards)
Tests of specific nerve roots: L4
Femoral stretch test
Example surgical decompression to remove causative agent in cauda equina synrome
Microdiscectomy
Epidural steroid injection (more effective for leg pain)
Surgical spine fixation (if vertebrae slipped)
Spinal fusion (reduces pain from motion and nerve root inflammation)
What is microdiscectomy
Removal of part of disc (may tear dura)
50yr old nurse comes in with longstanding back pain and pain radiating down right leg to sole of right foot.
On examination there is weak plantar flexion, absent right ankle jerk, decreased sensation over lateral edge and sole of right foot
WHERE IS LESION?
Sciatica
Right S1 lesion due to disc prolapse placing pressure on root
