Conditions Of The Cervical & Thoracic Spine Flashcards
What is cervical spondylosis? 1️⃣
-a chronic degenerative osteoarthritis affecting the intervertebral joints in the cervical spine
Describe the pathology of cervical spondylosis 1️⃣
-age-related disc degeneration (leads to reduced joint space)
Followed by
-marginal osteophytosis (osteophyte formation adjacent to the end plates of the vertebra, bodies)
-facet joint osteoarthritis
How does radiculopathy occur in cervical spondylosis? 1️⃣
-narrowing of the intervertebral foramina can put pressure in the spinal nerves
What are the symptoms of radiculopathy? 1️⃣
- dermatomal sensory symptoms e.g paraesthesia, pain
- myotomal motor weakness
How can myelopathy occur instead of radiculopathy in cervical spondylosis? 1️⃣
- if the degenerative process leads to narrowing of the spinal canal, may instead put pressure in the spinal cord
- less common outcome
How many myelopathy manifest? 1️⃣
- global muscle weakness
- gait dysfunction
- loss of balance &/or loss of bowel and bladder control
What are the symptoms of myelopathy due to? 1️⃣
Due to compression and dysfunction of the ascending and descending tracts within the spinal cord
What is a Jefferson’s fracture? 2️⃣
-fracture of the anterior and posterior arches of the atlas
What is the mechanism of injury in a Jefferson’s fracture? 2️⃣
Axial loading E.g: -diving into shallow water -impacting head against roof of a vehicle -falling from playground equipment
Patients may present to ED supporting their head with their hands
Describe how the Jefferson’s fracture reduces likelihood of spinal cord impingement 2️⃣
- atlas burst open like a broken polo mint
- anterior and posterior arches separated from the lateral masses
What can Jefferson’s fracture cause? 2️⃣
-pain but no neurological signs
Occasionally:
-damage to arteries at base of the skull leading to secondary neurological sequelae e.g. ataxia, stroke or Horner’s syndrome (damage to sympathetic trunk)
What is a Hangman’s fracture? 3️⃣
-fracture of the axis through the pars interarticularis (region between superior and inferior articular processes)
What is the mechanism of injury for a Hangman’s fracture? 3️⃣
-usually forcible hyperextension of the head on the neck
Historically by hanging and more recently in road traffic collisions
Describe how the Hangman’s fracture reduces likelihood of spinal cord impingement 3️⃣
-fracture configuration tends to expand the spinal canal, thereby reducing risk of associated spinal cord injury
What is the mechanism of injury for fractures of the odontoid process (peg fractures)? 3️⃣
- either flexion or extension injuries
- most common mechanism is an elderly patient with osteoporosis falling forwards and impacting their forehead on the pavement. This hyperextension injury of the cervical spine can result in a peg fracture
-alternatively, fracture can be caused by a blow to the back f the head, resulting in a hyperflexion injury
E.g falling against a wall when balance compromised
How can peg fractures be detected? 3️⃣
This fracture can be detected on an ‘open mouth’ AP X-ray or during a CT scan of the cervical spine
What is a whiplash injury? 4️⃣
-forceful hyperextension-hyperflexion injury of the cervical spine
Why is the cervical spine very prone to whiplash? 4️⃣
-head accounts for 7-10% of body weight and is balanced on the cervical spine which has high mobility, therefore has low stability
Describe the classical mechanism of whiplash injury (when patient’s car is being struck from the rear leading to an acceleration-deceleration injury) 4️⃣
- at time of impact, vehicle suddenly accelerates forward, then patient’s trunk and shoulders follow, induced by similar acceleration of the car seat
- patient’s head, with no force acting on it, remains in static space. The result is forced extension of the neck as the shoulders travel anteriorly under the head. With this extension, the inertia of the head is overcome and the head then accelerates forwards
- neck then acts as lever to increase forward acceleration of the head, forcing the neck into flexion
What does the forced hyperextension followed by hyperflexion cause? 4️⃣
- tearing of the cervical muscles and ligaments
- secondary oedema, haemorrhage and inflammation may occur
- muscles response to the injury by contraction (spasm), with surrounding muscles being recruited in an attempt to splint the injured muscle
- the spasms cause pain and stiffness
What else may a patient experience following a whiplash injury? 4️⃣
- arm pain and paraesthesia as a result of injury to spinal nerves
- shoulder injuries due to holding steering wheel at time of collision
- acute lower back pain
-chronic myofascial pain syndrome can sometimes develop as a secondary tissue response to disc or facet joint injury
How can whiplash sometimes result in injury to the cervical cord despite there being no accompanying bone fractures? 4️⃣
- cervical spine is highly mobile and ligaments and capsule of the joints are weak and loose
- hence there can be significant movement of the vertebrae (subluxation or dislocation) at the time of impact, with return to normal anatomical position afterwards
-soft tissue swelling may be the only visible feature on imaging
What is a protective factor against spinal cord injury? 4️⃣
-large vertebral foramen relative to the diameter of the cord
In what age group does cervical intervertebral disc prolapse commonly develop? 5️⃣
-prolapse w/ associated compression of nerve roots or spinal cord in 30 to 50 year olds
Describe the mechanism of disc herniation in the cervical spine 5️⃣
(Similar to that of the lumbar spine)
- tear in AF, NP protrudes from disc with impingement onto an adjacent nerve root or spinal cord.
- sometimes sequestration occurs in which an extruded segment of NP separates from main body of disc and enters spinal canal where it is ultimately resorbed over a period of weeks, with resolution of symptoms
Why can even a small cervical disc herniation impinge on the nerve and cause significant pain? 5️⃣
-discs in cervical region are not very large, however there is also little space available for the exiting nerve
What can cause cervical intervertebral disc prolapse? 5️⃣
- may be spontaneous in origin
- may be related to trauma and neck injury
Describe the symptoms of a cervical intervertebral disc prolapse 5️⃣
Symptoms are dependent on the site of prolapse
- paracentral prolapse may impinge on a spinal nerve, leading to radiculopathy
- a canal-filling prolapse may lead to acute spinal cord compression
What will a patient complain of in a left-sided C5/6 prolapse? 5️⃣
- cervical nerves exit above their respective vertebrae so the exiting nerve root at C5/6 is C6.
- cervical spinal nerves travel more horizontally from the spinal cord to the intervertebral foramen so there is no traversing root, just an exiting root
- nerve being compressed is C6
- patient may complain of paraesthesia of the left C6 dermatome (radial border of left forearm, thumb and index finger) and weakness in the left C6 myotome (left elbow flexion, supination and wrist extension)
- experience pain in neck that will radiate down left arm (often felt over biceps) into the skin supplied by the C6 dermatome
What is cervical myelopathy? 6️⃣
Spinal cord dysfunction due to compression of the cord, caused by narrowing of the spinal canal
What is a common cause of cervical myelopathy? 6️⃣
-degenerative stenosis of the spinal canal caused by cervical spondylosis
Most commonly affects 50-80 year olds
What is ‘cervical spondylotic myelopathy’? 6️⃣
Myelopathy secondary to cervical spondylosis
- is the result of degenerative changes which develop with age, including ligamentum flavum hypertrophy or buckling, facet joint hypertrophy, disc protrusion and osteophyte formation
- one or all of these changes contribute to an overall reduction in canal diameter which may result in cord compression
What are some other causes of cervical myelopathy? 6️⃣
- congenital stenosis of the spinal canal
- cervical disc herniation
- spondylolisthesis
- trauma
- tumour
- rheumatoid arthritis
Describe the symptoms of cervical myelopathy 6️⃣
- symptoms due to compression of the long tracts in the spinal cord
- patients may present with a range of symptoms and many of these are non specific
*although cervical myelopathy is a disease of the cervical spine, it may manifest with lower as well as upper limb symptoms due to damage to the long tracts of the spinal cord
Describe the classical presentation of cervical myelopathy 6️⃣
- loss of balance with poor coordination
- decreased dexterity
- weakness
- numbness
- paralysis in severe cases
- pain
older patients may also have rapid deterioration of gait and hand function
Contrast between the effects of upper and lower cervical lesions 6️⃣
Upper cervical lesions:
- tend to cause a loss of manual dexterity with difficulty in writing
- nonspecific alteration in arm weakness and sensation
- may demonstrate dysdiadochokinesia: impaired ability to perform rapid alternating movements
Lower cervical lesions:
- tend to lead to spasticity (increased muscle tone)
- loss of proprioception in legs
- patients commonly say their legs feel heavy and experience reduced exercise tolerance. Have gait disturbance and may suffer multiple falls
What does damage to the long tracts lead to? 6️⃣
*normally, signals in the long tracts dampen the spinal reflexes so a person does not overreact to stimuli
When long tracts damaged, these protective capabilities are less effective and the patient may demonstrate an exaggerated response to stimulation, as seen in positive Hoffman’s or Babinski sign
Describe Hoffman’s test 6️⃣
-doctor holds patient’s middle finger at the middle phalanx and flicks the finger nail
-ve sign (normal): no movement in index finger or thumb after the motion
+ve sign (abnormal): index finger and thumb move
Describe the Babinki sign 6️⃣
-lateral side of sole of foot stroked with blunt instrument from heel toward the toes
-ve sign (normal) : toes plantarflex
+ve sign (abnormal) : hallux dorsiflexes and toes fan out
What is L’Hermitte’s phenomenon? 6️⃣
-sensation of intermittent electric shocks in the limbs, exacerbated by neck flexion
Classically associated with cervical myelopathy
If surgical decompression is not performed late in the course of cervical myelopathy when compression is severe, what can occur? 6️⃣
-symptoms may progress to sphincter dysfunction and quadriplegia
If a patient develops myelopathy of the cervical spine at the level of C5, with a C4 neural level, what will be the likely symptoms? 6️⃣
-neck pain
Motor weakness: weakness of shoulder abduction and external rotation (C5 myotome weakness) and weakness of all myotomes distally, including the trunk and lower limbs
Sensory: paraesthesia from the shoulder distally, trunk and lower limbs
What are the commonest causes of thoracic cord compression? 7️⃣
- vertebral fractures w/ bony fragments in the spinal canal
- tumours in the spinal canal (spine is the second most common site for skeletal metastases)
State the most common cancers that arise from solid organs and spread to bone 7️⃣
- breast
- lungs
- thyroid
- kidney
- prostate
In thoracic cord compression, why does a metastasis in a vertebra, impinging on the spinal canal, not compress the same numbered spinal cord segment? 7️⃣
In thoracic spine (and lumbar):
-neural segments do not line up with their respective vertebral segments because the spinal cord is much shorter than the vertebral column
What would be the symptoms if the patient has a metastasis in the T10 vertebral body compressing the thoracic cord? 7️⃣
-T10 vertebra is aligned with the T11-12 segments of the spinal cord
symptoms would therefore include:
- pain at the site of the lesion (thoracic spine)
- spastic paralysis of all muscles in the legs
- paraesthesia in the dermatome distal to the site of cord compression
- loss of sphincter control
If the tumour was at T5, how would the presentation change? 7️⃣
-in addition to the symptoms from tumour in T10,
- weakness of the intercostal muscles from 5th intercostal space distally, leading to reduced chest expansion on inspiration and patients predominantly relying on diaphragmatic breathing
- paraesthesia from nipples distally
State 3 routes by which pathogens can reach the bones and tissues of the spine 8️⃣
- haematogenous
- direct inoculation during invasive spinal procedure (e.g lumbar puncture, epidural or spinal anaesthesia)
- spread from adjacent soft tissue infection
Describe the most common route by which pathogens reach the bones and tissues of the spine 8️⃣
-haematogenous spread from a septic focus elsewhere in the body
Typically occurs via arterial supply to the vertebral bodies but can also occur though retrograde venous flow
What is spondylodiscitis (aka discitis)? 8️⃣
-infection of the intervertebral disc
Who does discitis most commonly occur in? 8️⃣
Immunocompromised patients
Diabetes, HIV and patients on steroids
In adults, intervertebral discs are avascular so how are they infected? 8️⃣
Thought that organisms are therefore initially deposited in the vertebral body, via its segmental artery, leading to bony ischaemia and infarction .
Necrosis of the bone then allows direct spread or organism into the adjacent disc space, epidural space and adjacent vertebral bodies
By what mechanisms can the spread of infection into the spinal canal lead to neurological damage? 8️⃣
- septic thrombosis leading to ischaemia
- compression of neural elements by abscess/inflammatory tissue
- direct invasion of neural elements by inflammatory tissue
- mechanical collapse of bone leading to instability
What organisms infect the intervertebral discs? 8️⃣
-most commonly Staph. Aureus, Gram -ve bacilli such as E. coli
Following invasive spinal procedures: coagulase negative staphylococci e.g staph. Epidermis
Infections with pseudomonas and candida may be seen in IV drug users
