Cervical Spine and Brachial Plexus (Session 6) Flashcards
What is cervical spondylosis?
- Chronic degenerative osteoarthritis
- affecting intervertebral joints- cervical spine
What is the primary pathology of cervical spondylosis?
- Age related disc degeneration
- Osteophytosis
- Facet joint osteoarthritis
What are the symptoms of radiculopathy?
- Dermal sensory symptoms (paresthesia, pain)
- Myotomal motor weakness
How can cervical spondylosis cause radiculopathy?
- Narrowing of intervertebral foramina
- Pressure on spinal nerves
How might myelopathy manifest?
- Global muscle weakness
- Gait dysfunction
- Loss of balance
- Loss of bowel/bladder control
What is myelopathy?
Narrowing of spinap canal puts pressure on spinal chord itself
What’s more common; radiculopathy or myelopathy?
Radiculopathy
What is a Jefferson’s fracture?
Fracture of anterior and posterior arches of atlas vertebra (C1)
Give 3 mechanisms of injury for a Jefferson’s fracture.
Axial loading:
- Diving into shallow water
- Impacting head against roof of vehicle
- Falling from playground equipment
How might a patient present to the emergency department (if they have a Jefferson’s fracture)?
Supporting their head with their hands
Why does a Jefferson’s fracture typically cause pain but no neurological signs?
- Bone fragments ‘burst open’ (like polo mint)
- Reduces likelihood of impingement of spinal chord
What complications (damage) can a Jefferson’s fracture cause?
- Damage to arteries at base of skull
- Can cause:
- Ataxia
- Stroke
- Horner’s syndrome
What is a Hangman’s fracture?
Axis vertebrae C2
=fractured trough pars interarticularis
What is the usual mechanism of injury for a Hangman’s fracture?
Forcible hyperextension of head on neck:
- Eg. road traffic collisions
Why is there a reduced risk of spinal chord injury with a Hangman’s fracture?
Like Jefferson’s fracture–>
Fracture configuration expands spinal canal
What is a Peg fracture?
Fracture of odontoid process
What is the most commonly seen mechanism for a peg fracture?
Flexion/extension
- Elderly patient w./ osteoporosis
- Falls forwards
- Impacting forehead on pavement (hyperextension)
Apart from an elderly patient hyperextending their neck, what is another mechanism of injury for a Peg fracture?
- Blow to back of head
- Hyperflexion
How can a peg fracture be detected?
‘Open mouth’ x-ray or CT scan of cervical spine
What % of the total body weight does the head account for?
7-10%
What is a whiplash injury?
Forceful hyperextension-hyperflexion injury of cervical spine
What is the classic mechanim of injury for a whiplash injury?
- Car hit from behind
- Cervical muscles and ligaments tear
-
May be followed by:
- Secondary oedema
- Haemorrhage
- Inflammation
- Muscles contract (spasm)- surrounding muscles recruited to attempt to splint injured muscle
- –> pain and stiffness caused
What pain/other injuries may patients complain of following a whip lash injury? (3)
- Arm pain/paraesthesia
- Shoulder injuries
- Lower back pain (with acute injury in 50% patients)
What is chronic myofascial pain syndrome?
- =Secondary tissue response to disc/facet joint injury
How can a whiplash injury cause injury to the cervical spine?
(despite no accompanying bone fracture)
- Cervical spine=highly mobile
- (ligaments and capsule joints=weak and loose)
- therefore, significant movement of vertebrae- subluxation/dislocation
What is the protective factor against spinal chord injury in whiplash injury?
Vertebral foramen= relatively large compared to diameter of spinal chord
In what age group does a cervical disc prolapse with assosciated compression of nerve roots or spinal cord most commonly develop?
30-50 yrs
In 3 steps, outline the mechanism for disc herniation.
- Tear develops in annulus fibrosus
- Nucleus pulposus protrudes from disc
- –> impinges on adjacent nerve root or spinal cord
What happens if sequestration occurs?
- (Extruded segment of nucleus pulposus separates from main body of disc and enters spinal canal)
Rebsorbed over weeks- resolution of symptoms
Why is it that even a small cervical disc herniation can impinge on a nerve and cause significant pain?
Little space available for exiting nerves (unlike lumbar spine)
In a cervical intervertebral disc prolapse, which nerve root will be compressed?
Exiting
What type of cervical intervertebral disc prolapse would could cause compression of the spinal nerve?
Paracentral
What type of cervical intervertebral disc prolapse would could cause compression of the spinal cord?
Canal-filling prolapse
What will a patient complain of in a left-sided C5/6 prolapse?
- C6 affects
- Parasthesia in left C6 dermatome
- Weakness in left C6 myotome
- Left elbow flexion
- Supination
- Wrist extension
- Pain in neck- radiates down left arm into skin supplied by C6 dermatome
What is cervical myelopathy?
Spinal cord dysfunction
- due to compression of spinal cord
- due to narrowing of spinal (vertebral canal)
What is the most common cause of cervical myelopathy?
Degenerative stenosis
- caused by cervical spondylosis
- due to degenerative changes w./ age
- eg ligamentum flavum hypertrophy
- facet joint hypertrophy
- disc protrusion
- osteophyte formation
(most commonly affects 50-80 year olds)
Other than cervical spondylosis, name some other causes of cervical myelopathy. (6)
- Congenital stenosis (often asymptomatic until adulthood–> when age-related secondary degeneration begins)
- Cervical disc herniation
- Spondylolisthesis (anterior slippage of vertebral body on vertebra below)
- Trauma
- Tumour
- Rheumatoid arthirits
What is the normal diameter of the spinal canal? At what diameter may myelopagthic symptoms begin?
Normal= 17-18mm
Spinal chord in cervical region= 10mm
Myelopathic= 12-14mm
What is the classic patient presentation of cervical myelopathy?
- Poor coordination
- Decreased dexterity
- Weakness
- Numbness
- Paralysis (severe cases)
- Pain
- Deterioration of gait/hand function (older patients)
Specifically, upper cervical lesions tend to cause what symptoms?
Loss of manual dexterity
- Eg. Difficulties writing
Dysdiodochokinesia
- Impaired ability to perform rapid alternating movements
Specifically, lower cervical lesions tend to cause what symptoms?
Spasticity
- Increased muscle tone
Loss of proprioception in legs
Legs feel heavy, reduced exercise tolerance
Gait disturbance
Falls
How is Hoffman’s test carried out and what does it show?
- Doctor holds patient’s middle finger at middle phalanx
- Doctor flicks finger nail
- If no movement in index finger/thumb
- =Negative (normal)
- If movement in index finger/thumb
- =Positive (abnormal)
tests reflexes of upper extremities
How is Babinski’s sign tested for and what does it show?
Lateral side- of sole of foot= stroked
Normal: Toes plantarflex
Babinski sign (positive): Toes fan out- hallux dorsiflexes
(suggests damage to long tracts of spinal chord)
What is L’Hermitte’s phenomenon?
Sensation- intermittent electric shocks in limbs
-exacerbated by neck flexion
(Associated with cervical myelopathy)
What complications may occur if surgical decompression is not peformed in the later stages of cervical myelopathy?
- Sphincter dysfunctionn
- Quadriplegia
What is shown in this image?
Cervical spondylolisthesis at C3/4
If a patient develops myelopathy at the C5 level, what will the likely symptoms and signs will include?
Pain: Neck pain
Motor weakness:
- weakness of shoulder abduction
- external, lateral rotation
- weakness of all myotomes distally
Sensory: -paraesthesia from shoulder distally
What are the 2 most common causes of thoracic chord compressions?
- Vertebral fractures
- Tumours in spinal canal
What % of patients with cancer will have skeletal metastases at death?
50-60%
What are the 2 most common sites for skeletal metastases?
- Pelvis
- Spine
What are the most common cancers that spread to bone? (5)
- Breast
- Lung
- Thyroid
- Kidney
- Prostate
If there was a metastasis on the T12 vertebra, which segments of the spinal chord would it compress?
L4-5
(Lower thoracic spine and lumbar spine= more compressed)
What are the 3 routes by which pathogens can reach the bones and tissues of the spine?
- Haematogenous (most common)
- Direct inoculation- invasive spinal procedures (eg epidural)
- Spread from adjacent soft tissue infection
What is an infection of the intervertebral disc known as?
Spondylodiscitis
Discitis
In what group of patients does spondylodiscitis usually occur?
Immunocompromised:
Diabetes
HIV
Patients on steroids
What is the pathophysiology of discitis?
- Organisms initally deposited in vertebral body
- (since disc=avascular)
- Bony ischaemia
- Infarction
- Necrosis of bone- allows direct spread of organisms into:
- adjacent disk space
- epidural space
- adjacent vertebral bodies
What are the 4 mechanims by which the spread of infection in the spinal canal can lead to neurological damage?
- Septic thrombosis-leading to ischaemia
- Compression of neural elements by absess/inflammatory tissue
- Direct invasion- of neural elements- by inflammatory tissue
- Mechanical collapse of bone- instability
What are the most common organims which cause infections in the spinal canal?
- Staphylococcus aureus (50%)
- Gram negative bacilli (30%) eg E.coli
- coagulase negative Staphylocci (eg Staph epidermis) (following invasive spinal procedures)
What are the mechanisms of injury for injuries to the upper brachial plexus?
Excessive increased in angle between neck and shoulder
- Trauma
- Birth of baby (shoulders impacted in pelvis)
- Excessive traction applied to baby’s neck
In an upper brachial plexus injury, which movements will be lost?
C5:
Shoulder abduction
External rotation
C6:
Elbow flexion
Wrist extension
Supination
Which muscles will be paralysed in an upper brachial plexus injury?
Axillary nerve:
- Deltoid
- Teres minor
Musculocutaneous nerve:
- Biceps brachii
- Brachialis
- Coracobrachilais
Radial nerve:
- Brachioradialis
What is an injury to the upper roots of the brachial plexus known as?
Erb’s palsy
in what position is the arm held if someone has Erb’s palsy?
- Limb hangs by side
- Medial rotation
- Adducted arm
- Extended elbow
(Waiter’s tip position)
What is the name of an injury to the lower roots of the brachial plexus?
Klumpke’s palsy
What are the 2 mechanisms of injury for Klumpke’s palsy (lower brachial plexus)?
- Fall from tree- grabs branch on way down
- (Klumpke the monkey)
- Baby’s arm delivered first- traction applied to pull baby out
What motions will be lost in Klumpke’s palsy?
C8:
Finger flexion and extension
T1:
Finger adduction and abduction
What is the usually deformity which is seen with Klumpke’s palsy?
Claw hand
- Hyperextension of metacarpophalangeal joints
- Flexion of interphalangeal joints
- Abduction of thumb
- Wasting of interossei
(NOT to be confused with high ulnar nerve injury)
What causes ‘winging of the scapula to occur’?
- Long thoracic nerve damaged
- Serratus anterior paralysed
- Serratus anterior holds scapula in place (usually)
What may cause ‘winging of the scapula’?
- Long thoracic nerve acute trauma
- Blunt trauma to neck or shoulder eg wearing heavy backpack
What clinical procedure has a risk of causing long thoracic nerve trauma?
Surgical trauma- mastectomy with axillary clearance
Long thoracic nerve passes superficial to serratus anterior muscle
What is axillary lymphadenopathy?
Enlargement of axillary lymph nodes
What might cause axillary lymphodenopathy? (5)
- Infection of upper limb (lymphangitis)
- Infection of pectoral region/breast
- Metastases from breast cancer
- Leukaemia/lymphoma
- Metastases from malignant melanoma of upper limb
Why would an axillary lymph node dissection be performed?
Part of staging of breast cancer
Apart from the long thoracic nerve, what other nerve might be damaged by axillary lymph node dissection?
Thoracodorsal nerve (latissimus dorsi)
What complication can occur as a result of axillary lymph node dissection (interupting lymphatic drainage of upper limb)?
Lymphodema
If fractures of the scapula occur, what are they an indication of?
Severe chest trauma
Why does a fractured scapula not usually require fixation?
Surrounding muscles hold fragments in place
What are the usual mechanisms of injury of the surgical neck of the humerus?
- Blunt trauma to shoulder
- FOOSH
What are the 2 neurovascular structures at risk of damage in a fracture of the surgical neck of the humerus?
- Axillary nerve
- Posterior circumflex artery
Which muscles will be paralysed if the axillary nerve is damaged due to a fracture of the surgical neck of the humerus?
- Deltoid
- Teres minor\
Abduction lost/weakened
What will be the sensory impairment if there is damage to the axillary nerve due to a surgical neck of humerus fracture?
Regimental badge area (insertion of deltoid)
