consciousness and head trauma by alex hammant and phil copeman

Consciousness and Head TraumaBy Alex Hammant and Phil Copeman

What 3 things is a normal state of Consciousness dependent on?

Alertness – upper brainstem reticular formation intact

Attention – limbic system and frontoparietal association areas

Awareness – cerebral cortex

What are the 4 levels of consciousness?

Normal – fully oriented in place, time and person.

Lethargy (Somnolence; Sleepiness) – awareness impaired but may become normal on arousal

Stupor – no real awareness; speech only in response to pain; voluntary movements minimal.

Coma (Unconsciousness) – no awareness; speech absent; movements absent or only reflex in response to pain.

Causes of Coma

Supratentorial lesion – usually tumour or haemorrhage having mass lesion effect.

Infratentorial lesion – tumour, haemorrhage or infarction, often with mass lesion effect.

Toxic/Metabolic disorders – infection, drugs, hypoglycaemia, hyperglycaemia, uraemia, anoxia, etc.

Herniation syndrome (Coning)(a) anatomical progression

Subfalcine (1)

Central (2)

Transtentorial (3)

Tonsillar (4)

Extra dural hematoma- Mass lesion

4

3

2

1

What symptoms would you expect to see as herniation progresses?

Headache/nausea/vomiting.

Hypertension, bradycardia and widened pulse pressure.

Pupillary changes.

Hemiparesis and/or hemisensory loss.

Somnolence (sleepiness/drowsiness).

Stupor.

Coma.

Cheyne-Stokes (periodic abnormal breathing) or other abnormal breathing pattern.

Death.

What 3 methods would you use to assess cerebral herniation?

Size and reactions of pupils.

Vestibulo-ocular reflex.

Response to painful stimulus.

Glasgow Coma Scale - What are the 3 components?

Eye opening.

Verbal response.

Motor response.

What are the maximum and minimum scores? Maximum: 15 Minimum: 3

Glasgow Coma ScaleEye opening

Open spontaneously. 4

Open to verbal command. 3

Open in response to pain. 2

No eye opening. 1

Score

Glasgow Coma ScaleVerbal response

Oriented in place/time/person. 5

Confused in place/time/person but uses sentences. 4

Inappropriate use of words. 3

Uses only non-speech sounds. 2

No vocalisation. 1

Score

Glasgow Coma ScaleMotor response

Obeys commands. 6

Localises response to pain. 5

Withdrawal response to pain. 4

Decorticate response (abnormal flexion) to pain. 3

Decerebrate response (abnormal extension) to pain 2

No response to pain. 1

Score

What is this person’s GCS?

Eyes: open to voice 3

Verbal: moaning incomprehensibly 2

Motor: Withdraws from painful stimulus 4

Score: 9

What is this person’s GCS?

No eye opening

Random, inappropriate exclamatory words

Decorticate response to pain

Score 7

AVPU Scale

A – Alert and oriented in place/time/person.

V – Responsive to verbal stimulation.

P – Responsive to pain.

U – Unresponsive.

NB. Level A may be subdivided according to degree of deficit.

A quick gander through Mr Dardis’ lecture

Where are Le Fort’s fractures

What is CSF rhinorrhoea?

Drainage of cerebrospinal fluid through the nose

No, because it may result in pneumocephalus and/(or) meningitis

Should you blow your nose?

Which bones converge at the pterion?  

Frontal, parietal, greater wing of sphenoid, squamous temporal

Middle meningeal

Which artery lies within the bony groove ininside the pterion?

What is this?

A ‘blow-out’ fracture.(Most commonly effect the orbital floor and the medial wall).

What is this?

A midline shift

What is this?

An extradural haematoma

What is this bro?

A contusion

What is this mate?

A normal CT head

What is this buddy?

Subdural haematoma

What is this babe?

An subarachnoid haemorrhage*The worst headache you’ll ever have

Here are a few slides from Colin Melville’s Anaesthesia lecture related to consciousness

Definitions and behaviours Sleep

a period of rest for the body and mind, during which volition and consciousness are in abeyance and bodily functions are partially suspended;

also described as a behavioural state, with characteristic immobile posture and diminished but readily reversible sensitivity to external stimuli

Sedation allows patients to tolerate unpleasant diagnostic or surgical procedures and to

relieve anxiety and discomfort verbal contact can be maintained

Coma from Greek koma – ‘sleep’

a state of extreme unresponsiveness, in which an individual exhibits no voluntary movement or behaviour

Anaesthesia from Greek an – ‘without’ and aesthesia – ‘feeling’

If GA then drug induced and predictably reversible coma

Sedation scoring uno

American Society of Anesthesiologists

1. Minimal Sedation Normal response to verbal stimuli.

2. Moderate Sedation Purposeful response to verbal/tactile stimulation. (This

is usually referred to as "conscious sedation")

3. Deep Sedation* Purposeful response to repeated or painful stimulation.

4. General Anesthesia Unrousable even with painful stimulus.

*In UK, deep sedation regarded as anaesthesia

Sedation scoring dos

Ramsay Sedation scale (Melville bloody loves this)

1. anxious and agitated or restless, or both

2. co-operative, oriented, and calm

3. responsive to commands only

4. exhibiting brisk response to light glabellar tap or loud auditory stimulus

5. exhibiting a sluggish response to light glabellar tap or loud auditory stimulus

6. unresponsive

A few slides from Prof Stansbie’s lecture

Persistent Vegetative State (PVS)

Reticular formation is intact but cerebral cortex is non-functional – so no connection between the two.

Person is awake, ie. eyes are open and move around and sleep-awake cycles are present.

Awareness is absent.

Meaningful response to verbal command or pain is absent.

EEG contains rhythmic activity resembling sleep cycles.

Minimally Conscious State (MCS)

A sub-group of patients with severe alteration of consciousness who do not meet diagnostic criteria for coma or PVS.

Inconsistent but discernable behavioural evidence of consciousness, eg. response to command, verbalisation, visual pursuit.

May be temporary or permanent but overall prognosis more favourable than that of Persistent Vegetative State. So has indications for treatment.

Locked-in Syndrome (LIS)

Sensation, reticular formation and cortical function are intact.

Person is fully awake and aware.

Motor function is absent but vertical eye movements and eyelid elevation may be spared.

Usually due to infarct in ventral pons involving corticobulbar and corticospinal tracts.