HEAD INJURY

E Woo

Non-penetrating

head injury

Most controversial issues

• Are the deficits consistent with the injury? Malingering?

• Is there any pre-existing disease that may cause or contribute to his deficits?

• Should he be cared for at home?

• What is the remaining life expectancy?

• Mild injury→ mild deficits

• Severe injury → not necessarily severe residuals

Glasgow coma scale• Eye opening (E)• 4 Spontaneous • 3 To questions/command• 2 To pain• 1 Nil• Verbal response (V)• 5 Normal and oriented• 4 Confused speech• 3 Inappropriate speech• 2 Incomprehensible words• 1 Nil• Motor response (M)• 6 Normal and following commands• 5 Localize pain• 4 Withdrawal to pain• 3 Flexor posturing• 2 Extensor posturing• 1 No response

Severity of head injury

Mild GCS 14 to 15

Moderate GCS 10 to 13

Severe GCS ≤ 9

Post traumatic amnesia (PTA)

Mild less than 1 hour

Moderate 1 to 24 hours

Severe more than 24 hours

Retrograde amnesia

• how much the plaintiff can recall of what happened immediately before the accident

• variable, hence not a good guide for the severity of the head injury

• in general terms, for a mild injury, retrograde amnesia should be minimal

Fractures

• Vault - Linear

- Depressed

• Base

Sites of hemorrhage

Scalp hematomaIntracranial bleeding

- intracerebral- intraventricular- subarachnoid- extradural- subdural- combination

ICH

EDH

SDH

SDH

SAH

PARENCHYMAL DAMAGE

ContusionDiffuse axonal injury- shearing injury in acceleration/deceleration- no fracture or external wound- deep coma but normal intracranial

pressure- punctate lesions throughout the white

matter especially corpus callosum

Contusion

Contusion

Diffuse axonal Injury

Vascular damage

• Dissection of internal carotid artery

• Carotid-cavernous fistula

• Pseudo-aneurysm

Dissection

Carotid-cavernous Fistula

Pseudo-aneurysm

Treatment

Conservative

Surgical - evacuation of hematoma/contusion

- intracranial pressure monitoring

Late complications

• chronic subdural hematoma

• hydrocephalus

• CSF rhinorrhoea after skull-base fracture

Chronic subdural hematoma

• 4 to 6 weeks after accident, often mild injury

• Increasing headache

• Focal neurological deficits

• Burr-hole drainage

• Good prognosis (as distinct from acute subdural hematoma)

Hydrocephalus

- a few months after accident

- complicating subarachnoid/intraventricular

hemorrhage

- shunt operation (ventriculo-peritoneal)

- prognosis depends on shunt

Radiological investigations

• CT scan in acute phase

• MR scan in chronic phase

Outcome (Glasgow outcome scale)

• Normal ]

• Good recovery ] Independent

• Moderate disability ]

• Severe disability }

• Vegetative state } Dependent

• Death }

Residual disabilities• Headache• Dizziness• Vestibular dysfunction - vertigo

positional effect nystagmus• Memory loss - absent-mindedness loss of recent memory• Emotional disturbance - irritable anxious depressed• Frontal lobe dysfunction - apathy aggressiveness disinhibition, impulsivity suggestibility executive dysfunction frontal release signs

Sequelae

• Physical - cranial nerve deficits - hemiparesis

• Cognitive - dementia

• Emotional/Psychiatric

Post-concussional syndrome

• following upon mild/moderate head injury

• headache, nonspecific dizziness, tinnitus, insomnia, irritability, anxiety

• no structural pathology on imaging studies

• good prognosis

Persistent vegetative state

• Total lack of awareness of self or environment• No language function

(expression/comprehension)• Own sleep-wake cycles• No purposeful or behavioural response to visual,

auditory, tactile or noxious stimulus• Incontinence• Preserved brainstem reflexes

• May moan or groan• May even cry or shed tears• May blink• Jerky myoclonic movements (spinal origin)

Minimally conscious state

• Some sign of awareness

• Follow simple commands

• Gestural or verbal yes/no response

• Intelligible verbalization

• Purposeful behaviours contingent to relevant environmental stimuli (not reflexive)

Assessment

• starts before plaintiff walks in and continues through history taking

• Cognitive - mini-mental state examination (MMSE) • Physical:→eye movements→motor and sensory→reflex→co-ordination→gait

Malingering

• Cognitive - approximate answers - worsening MMSE over time• Physical - nonphysiological distribution of weakness

- Hoover’s sign - give-way weakness

- bizarre gait• Inconsistency of deficits• Incompatibility with site/extent of lesion• Discrepancy between history and examination• Handwriting

Impairment of the whole person

• Guides to the Evaluation of Permanent Impairment (American Medical Association)

• Based on ability to perform activities of daily living

• A numerical range for deficits in cognition and physical abilities

• No provision for headache

Loss of earning capacity

• Depends on occupation

Duration of sick leave

• Mild to moderate cases – recover over 6 to 12 months

• Severe cases – recover over 1 to 2 years

Life expectancy

• Adverse factors →severe cognitive dysfunction→swallowing difficulties (tube feeding)→physical deficits (immobility)→incontinence→Seizure

• Does good supportive care prolong survival?

Persistent vegetative state

• Markedly reduced survival

• 2 to 5 years

• Survival beyond 10 years unusual

Future medical treatment

• usually none after 1 to 2 years

• for those with severe deficits, e.g. bedbound or PVS, follow-up every 3 months

• tests

• medications

Post-traumatic epilepsy

• Risk factors

→severe injury (PTA > 24 hours)

→depressed skull fracture

→cerebral contusion

→acute subdural or intracerebral hematoma

→early epilepsy (occurring within first 7 days)

• Most (80%) do so within first 2 years

Seat belts

• reduce fatal injuries and severe injuries in survivors, each by a factor of about 4 times

• most marked reduction in head-on crashes

• head injuries caused by frontal impacts against windshield or dashboard greatly reduced

• belts protect against ejection from the car

Home care vs Institutional care

• In PVS/MCS cases

Pre-existing lesion – hypertension with intracerebral

hemorrhage• unknown but severe hypertension

• a minor injury or some form of physical stress/exertion

• common sites of hypertensive hemorrhage

ICH

Pre-existing lesion – aneurysm with subarachnoid hemorrhage

• Asymptomatic aneurysm

• Minor head injury

• Exertion

Pre-existing lesion – anticoagulant use for artificial

heart valves

• anticoagulant at therapeutic level (not overdosed)

• minor head injury

• diffuse/multifocal hemorrhages