L23 - Introduction to spinal cord/nerve compression disorders Flashcards
Define claudication?
Discomfort, numbness and pain in feet, calves, thighs, hips or buttocks
Define Radiculopathy?
range of symptoms produced by the pinching of a nerve root in the spinal column, causing pain in dermatome and impaired motor function
Define Myelopathy?
disorder that results from severe compression of the spinal cord
How to examine a patient with spine disorder by history taking?
Approaches:
Pain: character, aggrevating, location, severity
Numbness: sensory fibers affected
Weakness: motor fibers affected
Balance: Priprioception and severe weakness
Sphincter control in Bowel, bladder: severe compression
Pathogenesis of IVD herniation?
General degeneration > nucleus pulposus becomes dehydrated and lose shock absorption ability > Forces transmit to inextendible annulus fibrosis and cause crack > Nucleus pulposus herniates out
What are the 4 types of IVD herniation?
Types / severity of herniation:
- Protrusion
- Prolapse
- Extrusion
- Sequestration
What structures are affected by IVD herniation in different directions?
- Lateral = compress spinal nerve exiting at that level
- Posterolateral - Compress on spinal nerve about to emerge at the next intervertebral foramen
- Central = compress on spinal cord or cauda equina
List 5 pathologies that can cause lumbar spinal stenosis? Result of lumbar spinal stenosis?
- IVD herniation
- Ligamentum flavum hypertrophy
- Facet joint hypertrophy
- Osteophyte formation
- Tumour
> > Dural sac and nerve root compression
What causes ligamentum flavum hypertrophy?
fibrosis caused by the accumulation of mechanical stress with the aging process
What causes facet joint hypertrophy?
cartilage degeneration causes conjoined vertebrae to rub
> > cause inflammation, swelling and other painful symptoms
> > creation of new bone to stabilize joint
List the boundaries of intervertebral foramina?
– Superior: pedicle of vertebra above
– Inferior: pedicle of vertebra below
– Posterolaterally: facet joint
– Anteromedially: uncovertebral joint, intervertebral disk
Describe the articulation between cervical vertebrae?
5 articulations between each adjacent cervical vertebrae
– Intervertebral disk
– 2 uncovertebral joints
– 2 facet joints
Arrangement of the cervical spinal nerve roots?
■ 7 cervical vertebrae
■ 8 cervical nerve roots exit ABOVE it’s pedicle unlike lumbar or thoracic region
– C1 root exits above C1
– C8 root exits between C7/T1
Define cervical radiculopathy?
NERVE ROOT (not the cord itself) compression from herniated disk material or arthritic bone spurs (i.e. from spondylosis) at the same spinal level
Causes dermatomal effects: Sharp pain and tingling or burning sensations
Causes motor deficit: motor dysfunction in the neck and upper extremities
Define cervical myelopathy?
compression on the cervical spinal cord
Caused by:
- IVD herniation,
- deformed uncovertebral processes,
- Ligamentum flavum hypertrophy,
- spondylitic spurs,
- an ossified posterior longitudinal ligament
- spinal stenosis
Difference between myelopathy and radiculopathy?
Radiculopathy = pinching of the nerve roots as they exit the spinal cord or cross the intervertebral disc
myelopath = compression of the cord itself
Clinical presentation of Lumbar spinal stenosis?
Numbness in legs
Lean forward to relieve pressure on lower back
Claudication (leg pain with walking)
What causes facet joint dislocation?
Facet dislocation refers to anterior displacement of one vertebral body on another caused by forced flexion of cervical spine
Treatment for cervical myelopathy?
- Widening of the spinal canal (laminoplasty)
- Spine decompression surgery by discectomy with spinal fusion
- Removal of herniated discs, bone spurs or ossified ligaments by i.e. Anterior discectomy and interbody fusion surgery
- physical therapy and a cervical collar brace
- fusion = replace removed tissue with graft*
What are the major descending motor tracts?
Lateral corticospinal tract = Main voluntary motor
Ventral corticospinal tract = voluntary motor
What are the ascending sensory tracts?
Dorsal column = deep touch, proprioception (maintain normal standing posture), vibration
Lateral spinothalamic tract = pain, temperature
Ventral spinothalamic tract= light touch
Define central cord syndrome?
Central cord syndrome (CCS) is an incomplete traumatic injury to the cervical spinal cord, causing incomplete paralysis
What is the most common cause of central cord syndrome?
- Narrowing of cervial vertebral canal due to cervical arthritis + trauma (i.e. forceful extension of head in car crash) = crushing central cord
What are rarer causes of central cord syndrome?
- Spondylotic myelopathy
- Syringomyelia
- Neoplasm: Metastatic, glial, lymphoma
Outcomes of central cord syndrome?
- Sensory loss below the site of the injury: Pain and temperature sensation loss (more spinothalamic than DCML damage)
- loss of bladder control
- paralysis or loss of fine control of movements in the arms and hands, much less in legs
Define Brown-Séquard: Hemicord injury?
result of damage to the left or right side of the spinal cord, causing motor and sensory deficit characteristic of decussation of nerve pathways.
List the consequences of Brown-Séquard: Hemicord injury?
Ipsilateral loss of proprioception, touch, and vibration sense below the lesion due to damage to the ascending dorsal columns
ipsilateral upper motor neuron spastic paralysis below the lesion due to damage to the descending lateral corticospinal tracts
Contralateral loss of pain and temperature sensation 2 to 3 levels below the level of the lesion due to damage to the ascending lateral spinothalamic tract
Ipsilateral loss of motor and sensory function
Prognosis of Brown-Séquard: Hemicord injury?
- 75-90% ambulate/ walking on discharge
- 70% independent ADL
- 89% bladder, 82% bowel continent
Causes of Brown-Séquard: Hemicord injury?
- Penetrating trauma/ compression
- Spinal cord tumours
- Vertebral aortic dissection
- Radiotherapy
- Decompression sickness
- Multiple sclerosis
Describe the blood supply in the vertebral bodies?
■ Segmental nutrient vessels from the vertebral, intercostal and lumbar arteries
■ Rich supply of vessels in vertebral end plates
■ Intervertebral disc: Avascular structure, Obtain nutrients by diffusion from tissue fluid
Describe the blood supply to the spinal column?
- Single anterior spinal artery
- Two posterior spinal arteries
- Radicular arteries - form anastomoses
Structure of 2 posterior spinal arteries?
Arise from posterior inferior cerebellar artery or vertebral artery above the foramen magnum
Forming longitudinal trunks that run through and behind the posterior rootlets for the whole length of the cord
Supplies the grey and white posterior columns of its own side
Root, course and supply of the anterior spinal artery?
Root = union of two spinal arteries from vertebral artery at foramen magnum
Course = anterior median fissure, along the whole length of cord
Supply = whole cord anterior to the posterior grey column
Define anterior cord syndrome?
Ischemia at anterior spinal artery territory caused by fracture fragments or retro-pulsed disc
Outcome of anterior cord syndrome?
Outcome:
Loss of function of the anterior two-thirds of the spinal cord = Loss of motor function, pain and temperature sensation
Posterior columns are spared, light touch, vibration, and proprioceptive input are preserved
Prognosis of anterior cord syndrome?
Poor prognosis
•10-20% muscle recovery, poor muscle power and coordination
Root, course and supply of posterior spinal artery?
Root = posterior inferior cerebellar artery or vertebral artery above foramen magnum
Course = longitudinal trunks that run through and behind posterior rootlets for whole length, some anastomoses
Supply = grey and white posterior columns of its own side
Define posterior cord syndrome?
Injury of the posterior spinal cord affecting the posterior column’
caused by posterior spinal artery damage, Diffuse atherosclerosis causing deficient collateral perfusion and Vit. B12 deficiency
Outcome of posterior cord syndrome?
ipsilateral loss of vibration and proprioceptive sensation below the lesion
Preservation of motor, pain and temperature sensations
Prognosis of posterior cord syndrome?
- Better than anterior syndrome
* Poor ambulation prospect: proprioceptive deficit
Which area of the spine is a watershed area susceptible to damage by ischemia?
Lower thoracic spine
Supplied only by weak radicular arteries anastomoses
Function of radicular arteries of the spine?
■ Highly important contribution to reinforce the longitudinal trunks
■ Most of the radicular arteries disappeared as fetal growth proceed
■ Remained: form anastomoses with anterior/posterior spinal arteries
Which radicular artery is the most important and largest?
artery of Adamkiewicz: usually arise from left T10 (80%) (varies from T5-L5)
Venous drainage of vertebral column?
Spinal venous plexus»_space; Batson plexus
= Link between intra-abdominal venous return and spinal column venous return
What vessel can act as route of tumour and infection spread from pelvis to spine?
Batson plexus
List the steps in pyogenic spondylitis pathogenesis?
■ blood borne infection starts in the region of the vertebral end plate (rich capillary)
■ suppurative inflammation, bone necrosis and collapse
■ spread to adjacent intervertebral disc & vertebra
■ paravertebral abscess
■ Epidural abscess
■ Infection of the meninges and spinal cord
Progression of pyogenic spondylitis on IVD damage?
Focus of osteomyelitis in vertebral body
> > spread into IVD by perforation of vertebral end plate
> > Destruction and narrowing of intervertebral space
TB spine unique characteristics compared to pyogenic infection?
- Slow progression with insidious onset
- More bony involvment at multiple levels with chronic bone destruction (pyogenic = bone preserved normally)
- Subligamentous spread (doesnt break ligament but pyogenic does)
- Skip lesions
List some routes of transmission of infection or tumour from other parts of body to spine?
From breast via azygous vein
From lung via pulmonary vein
From prostate via pelvic plexus to Batson’s plexus
What is Batson’s plexus and it’s function?
network of longitudinal valveless veins that anastomose with the vertebral marrow and epidural venous channels
Connects between peri-prostatic plexus and vertebral venous plexus
Winking Owl Sign is a classic finding of what pathology?
- Spinal metastasis
- Seen after 30 to 50% cancellous bone destruction on X-ray
How does ascites lead to metastatic embolization of vertebral bodies?
Ascites > increase intra-abdominal pressure > divert blood into epidural venous plexus of vertebra
Which part of the spine is most susceptible to cancer metastasis?
Venous sinusoids of vertebral body
List the barrier to local spread of tumour in the spine?
Anterior longitudinal ligament (ALL) Posterior longitudinal ligament (PLL) Ligamentum flavum Periosteum Endplates Annulus fibrosis of IVD
invaded by tumour cells in order to spread