HEAD AND SPINAL INJURY Flashcards

1
Q

Epidemiology of head injuries?

A

Commonest cause of death and disability in people aged 1-40
1.4 million ED attendances a year. >70% male. And 33-50% are children
Incidence of death from head injury is 0.2% and the majority of fatal outcomes are in the moderate or severe GCS head injry group - only accounts for only 5% (95% of people with head injury present with a normal or minimally impaired GCS)

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2
Q

What is primary brain injry?

A

The insult or damage done to the brain at the time of the injury
E.g. cerebral lacerations, cerebral contusions, skulls fractures, diffuse axonal injury

These are things that can only be cured by accident prevention strategies

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3
Q

What is secondary brain injury?

A

The damage to the brain that results from complications after the initial primary brain injury
E.g. hypoxia, reduced cerebral blood flow, raised ICP, metabolic abnormalities, infection etc

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4
Q

Classification of head injury based on GCS?

A

Mild GCS13-15
Moderate GCS 9-12
Severe GCS 8 or less

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5
Q

The is the Monro-Kellie doctrine?

A

the sum of volumes of brain, CSF, and intracranial blood is constant

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6
Q

What is the normal ICP?

A

10mmHg

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7
Q

How dou you calculate the cerebral perfusion pressure?

A

Mean arterial pressure - ICP

(This is used as an indicator of the cerebral blood flow)

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8
Q

Outline the head injury physiology?

A

When there is a mass in the brain the body responds by removing some venous blood and some CSF from the brain. The body can compensate with a normal ICP for a while.
Eventually you get to a poin where it is not possible to remove any more venous blood or CSF form the brain and this is known as the point of decompensation. This is when herniation of the brain

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9
Q

How is a head injury different to a traumatic brain injury?

A

Head Injury = a patient who has sustained any form of trauma to the head, regardless of whether they have any symptoms of neurological damage
Traumatic Brain Injury = evidence of damage to the brain as a result from trauma to the head, represented with a reduced Glasgow Coma Scale or presence of a focal neurological deficit

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10
Q

Features of transtentorial herniation?

A

Compression of 3rd nerve -> ipsilateral pupillary dilatation -> loss of eye movement
Compression of ipsilateral corticospinal tracts in brainstem -> contralateral hemiparesis

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11
Q

Features of foramen magnum/tonsillar herniation?

A

Decreased level of consciousness
Decorticate posturing
Irregular respirations
Loss of brainstem reflexes
Bilateral fixed and dilated pupils
Cushing triad: hypertension, bradycardia and abnormal breathing

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12
Q

Signs of basal skull fractures?

A

Panda eyes
Battles sign
Haemotympanum
CSF rhinorrhoea or otorrhoea
LMN facial nerve palsy

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13
Q

Features of depressed or open skull vault fractures?

A

Visible fracture to skull vault
Palpable depression or an irregularity in the skulls

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14
Q

What artery is typically involved in extradural haematoma?

A

Middle meningeal artery

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15
Q

What is the classic presentation of extradural haematomas?

A

Pt with head trauma who initially loss consciousness followed by an lucid interval before they lose consciousness again

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16
Q

What causes subdural haematomas?

A

Tearing of bridging veins between brain and dura
More common in elderly and alcoholics as bridging veins are stretched

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17
Q

Why is the prognosis of subdural haematomas worse than extradural haematomas?

A

More damage to underlying brain tissue
Often affect elderly and alcoholics - often have other health problems

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18
Q

How are intracerebral haematomas described?

A

Coup
Contra-coup

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19
Q

What is a coup injury?

A

Injury to the brain region directly related to the site of external injury

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20
Q

What is a contre-coup injury?

A

When the region affected is on the opposite side to the site of external injury due to the movement of the brain within the skull vault

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21
Q

What mechanism causes diffuse axonal injury?

A

Rapid acceleration and deceleration forces which cause shearing of the neurones

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22
Q

How do diffuse axonal injuries ted to present?

A

LOC at time of injury with prolonged coma
Decorticate and decerebrate posturing
Autonomic dysfunction
Hypertension
Hyperpyrexia

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23
Q

Why might a CT scan appear normal in a diffuse axonal injry?

A

As the damage is microscopic

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24
Q

How should pts with head injuries be managed?

A

A-E approach
If GCS 8 or less -> involve anaesthetist early for appropriate airway management - intubate, avoid hypoxia and aim for normal PaCO2
Avoid hypotension and hypoglycaemia
Treat seizures
Treat raised ICP
Wound management
Manage pain
Give pt written head injury advice

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25
Q

Which pts require an immediate CT head?

A

GCS <13 on initial assessment or <15 2 hours after injry
Suspected open or depressed skull fracture
Any sign of basal skull fracture
Post-traumatic seizure
For all neurological deficit
>1 episode of vomiting since the head injury

26
Q

Who need a CT head within 8 hours of injury?

A

If there’s LOC or amnesia and one of the following:
Aged 65 or over
Any bleeding or clotting disorders
Dangerous mechanism of injury
>30 mins retrograde amnesia of events immediately before the head injury

Or if no LOC or amnesia but are taking anticoagulants or antiplatelets

27
Q

Risk factors for cervical spine injury?

A

Age >65
Known chronic spinal conditions e.g. ankylosing spondylitis, RA
Dangerous mechanism of injury e,g. Falling from a height >1m, axial load to head, high speed motor vehicle collisions, bicycle collision, horse riding accidents

28
Q

What features might indicate a C-spine injury?

A

GCS <15 on initial assessment
Neck pain or tenderness
Focal neurological deficit
Paraesthesia in extremities
Any other clinical suspicion of c-spine injury

29
Q

What are the Canadian C-spine rules?

A

1: any one high risk factor - age >=65, dangerous mechanism or numbness/tingling in extremities -> if yes immobilise!
2: any one low risk factors which allows safe assessment of range of motion - simple reared MVC, ambulatory at any time at scene, no neck pain at scene, no pain in midline c-spine palpation -> if no immobilise?
3: pt voluntarily able to actively rotate neck 45 degrees left and right when requested regardless of pain -.> if unable immobilise

30
Q

What are the 2 ways to immobilise the c-spine?

A

Manual in-line immobilisation
Hard collar, blocks and tape

31
Q

What is the NICE criteria for doing a CT cervical spine scan within 1 hour?

A

Pts with a head injury and any of these:
GCS 12 or less
Person has been intubated
Definitive diagnosis of a c-spine injury is urgently needed e.g. surgery
There has been blunt poly trauma involving the head, chest, abdomen or pelvis in someone who is alert and stable
There is clinical suspicion and any of these factors: aged 65 or older, dangerous mechanism of injury, focal peripheral neurological deficit, paraesthesia in limbs
Its not safe to assess range of movement in neck or you can assess it and the pt cannot rotate their neck 45 degrees to the L and R
The person had a condition predisposing them to higher risk of injury e.g. axial spondyloarthritis

32
Q

When a pt presents to A&E with evidence of head injury, how soon should they be examined?

A

Within 15 minutes

33
Q

Red flag sympotms for possible serious spinal pathology?

A

Onset <20 or >55
Non-mechanical pain or constant and worsening or pain at night
Thoracic pain
Previous Hx of carcinoma, steroids or HIV infection
Fever, night sweats, weight loss
Widespread neurological symptoms especially sphincter disturbance
Structural spinal deformity

34
Q

Myotome for hip flexion?

A

L2

35
Q

Myotome for knee extension?

A

L3

36
Q

Myotome for ankle dorsiflexion and big toe dorsiflexion?

A

L4

37
Q

Myotome for foot inversion?

A

L5

38
Q

Myotome for ankle plantar flexion?

A

S1

39
Q

Nerve roots involves in the knee jerk?

A

L3 and L4

40
Q

Nerve roots involved in the ankle jerk?

A

S1 and S2

41
Q

Red flags for cauda equina syndrome

A

Acute low back pain (which may be superimposed on a history of chronic back problems)
Radiation of pain to the legs (usually, but not always, bilateral)
Lower limb weakness (frequently bilateral)
Alteration of sacral and perineal sensation (usually, but not always, bilateral)
Alteration of bladder and/or bowel habit leading to urinary retention and constipation

42
Q

What is the lifetime risk of a vertebral fracture in patients over 50?

A

1 in 3

43
Q

What is spondylolisthesis?

A

The forward slippage of 1 vertebrates on another
Most commonly L5 on S1 and L4 on L5

44
Q

What usually causes L5/S1 spondylolisthesis?

A

Defect of pars inter-articularis of L5 which allows slippage of the body of L5
Can be congenital, traumatic and tends to occur in young people

45
Q

What usually causes L5/L4 spindylolisthesis?

A

Degeneration

46
Q

Red flags for malignancy with back pain?

A

pain in the middle (thoracic) or upper (cervical) spine
progressive lower (lumbar) spinal pain
severe unremitting lower spinal pain
spinal pain aggravated by straining (for example, at stool, or when coughing or sneezing)
localised spinal tenderness
nocturnal spinal pain preventing sleep

47
Q

Symptoms of a osteoporotic vertebral fractures?

A

Asymptomatic: an osteoporotic vertebral fracture may be diagnosed through an incidental finding on X-ray
Acute back pain
Breathing difficulties: changes in the shape and length of vertebrae lead to the compression of organs such as the lungs, heart and intestine
Gastrointestinal problems: due to compression of abdominal organs
Only a minority of patients will have a history of fall/trauma
Loss of height
Kyphosis
Localised tenderness on palpation of spinous processes

48
Q

What are the types of spinal infection?

A

Vertebral osteomyelitis
Discitis
Spinal epidural abscess
Spinal subdural empyema
Meningitis
Spinal cord abscess

49
Q

What are examples of secondary brain injuries?

A

Cerebral oedema
Ischaemia
Infection
Tonsillar herniation
Tentorial herniation

50
Q

What mechanism most commonly causes an extradural haematoma?

A

Acceleration-deceleration trauma or a blow to the side of the head

51
Q

How often should a GCS be calculated?

A

Every 30 minutes until its 15

52
Q

Why is it important to monitor CBG levels in a pt with a head injury?

A

Hyperglycaemia after severe TBI is associated with poor clinical outcomes and increased mortality

53
Q

Why is it important to monitor CBG levels in a pt with a head injury?

A
54
Q

What might a unilaterally dilated pupil with a fixed/sluggish light response with a head injury indicate?

A

3rd nerve compression secondary to tentorial herniation

55
Q

Which region of the brain do extradural haematomas typically affect?

A

The temporal region where the middle meningeal artery is

56
Q

Which areas of the brain do subdural haematomas typically affect?

A

Frontal and parietal lobes

57
Q

What might a B/L dilated pupil with a fixed/sluggish light response with a head injury indicate?

A

Poor CNS perfusion
B/L 3rd nerve palsy

58
Q

What might a unilaterally dilated or equal pupil with a cross reactive light response (Marcus Gunn/RAPD) with a head injury indicate?

A

Optic nerve injury

59
Q

What might a B/L constricted pupil with a head injury indicate?

A

Opiates
Pontine lesions
Metabolic encephalopathy

60
Q

What might a U/L constricted pupil with a good light response with a head injury indicate?

A

Sympathetic pathway disruption i.e. horners