Consciousness and Head Trauma By 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

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 Scale Eye opening  Open spontaneously.4  Open to verbal command.3  Open in response to pain.2  No eye opening.1 Score

Glasgow Coma Scale Verbal 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 Scale Motor 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 pain2  No response to pain.1 Score

What is this person’s GCS?  Eyes: open to voice 33  Verbal: moaning incomprehensibly 22  Motor: Withdraws from painful stimulus 4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 in inside 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.