Disability Assessment & Neuro Observations

The two systems

• CNS: brain + spinal cord – the control centre and main pathway
• PNS: 12 cranial nerves, 31 spinal nerves, autonomic nerves
• PNS connects the CNS to sensory organs, muscles, vessels, organs

The autonomic nervous system

• Runs the "life support systems" without conscious control
• Heart rate, BP, respiratory drive, pupils, sweating, digestion
• A neurological problem can show up across ABCDE, not just in the D box

Why cranial nerves matter

• Pupils depend on cranial nerve + brainstem pathways
• Pupil checks are neurological checks, not just "eye checks"
• Facial movement, swallowing, gag reflex all tie back to specific nerves

Why the brain deteriorates

• Needs constant oxygen, glucose, blood flow, safe pressure, normal signalling
• Head injury, raised ICP, hypoxia, hypoglycaemia, infection, shock, seizures all threaten this
• Assess the whole child – not every neuro sign means a primary brain problem

What AVPU stands for

• Alert – spontaneously awake and responsive
• Voice – responds to verbal stimulation
• Pain – only responds to a painful stimulus
• Unresponsive – no response at all

Why it comes first

• Quick, needs no equipment, usable by anyone
• A fast first read before a detailed GCS
• A change from Alert to Voice or below is a red flag on its own

What it does not tell you

• Not detailed enough to show which part of function has changed
• Does not separate eye, verbal, and motor components
• GCS is needed for that level of detail

How to use it clinically

• Use AVPU as the rapid screen in any A–E assessment
• Move to full GCS if AVPU is anything other than Alert
• Always compare with the child’s own baseline

Eye opening (E4–E1)

• E4 spontaneous → E3 to voice → E2 to pain → E1 none
• "C" if eyes are closed by swelling/bandage – do not score as poor response
• Shows whether enough arousal exists to open the eyes at all

Verbal response (V5–V1)

• Older child: orientated → confused → inappropriate words → sounds → none
• Younger child: usual babble/words → irritable cry → cries to pain → moans → none
• Always compare with what carers say is usual for that child

Motor response (M6–M1)

• M6 obeys commands/normal movement – most reassuring
• M5–M4: localises or withdraws to pain
• M3–M2: abnormal flexion or extension – serious
• M1: no response – emergency if new

Why the total score is not enough

• A GCS of 14 could mean a fallen eye score OR a fallen motor score
• The pattern of change matters, not just the number
• Always report and document E, V, and M separately

The core problem

• You cannot ask an 18-month-old orientation questions
• Paediatric GCS compares the child against their own developmental stage
• Eye opening scoring stays the same across all ages

Verbal response differs most

• Under 5: alert/babbles/coos/words → irritable cry → cries to pain → moans → none
• Over 5: orientated → confused → inappropriate words → sounds → none
• Carers are often the only ones who know the child’s "usual" cry/interaction

Motor response also adapts

• Under 5: normal spontaneous movement → withdraws to touch → withdraws to pain → flexion → extension → none
• Over 5: obeys commands → localises/withdraws → withdraws to pain → flexion → extension → none

Why this matters clinically

• Missing the age adjustment can make a normal toddler look falsely concerning
• Or mask real deterioration by expecting adult-level responses
• Always ask: is this normal for this child, at this age?

Assessing pupils

• Check equal, then measure size before testing reactivity
• Measuring first avoids missing a baseline abnormality the light would mask
• Document size (mm), equality, and reaction (brisk/sluggish/non-reactive)

Why pupils matter

• Pupil light reflex depends on cranial nerve + brainstem pathways
• New unequal or non-reactive pupils can mean pressure, swelling, or bleeding
• New unequal pupils after head injury are always urgent

Decorticate posturing

• Abnormal flexion pattern
• Suggests serious neurological dysfunction
• Not a normal withdrawal-from-pain movement

Decerebrate posturing

• Extension pattern: shoulders adducted, elbows extended, wrists hyperpronated
• Hips/knees extended, ankles plantar-flexed
• Often reflects more severe brain/brainstem involvement than decorticate

Why glucose is part of disability

• Normal range from the lecture: 4–8 mmol/L
• The brain depends heavily on glucose for energy
• Hypoglycaemia can look exactly like neurological deterioration

Hypoglycaemia signs

• Shakiness, sweating, hunger, anxiety – stress hormone response
• Confusion or abnormal behaviour – can mimic distress
• Severe: seizures, loss of consciousness

Why it is reversible

• Unlike many causes of neuro deterioration, hypoglycaemia is quickly treatable
• Missing it means missing an easy fix for a dangerous picture
• Always check glucose in any unexplained altered consciousness

Why the trend matters most

• A GCS of 14 after a previous 15 is deterioration, even though 14 "sounds fine"
• Stable, improving, or deteriorating – that classification drives the action
• New posturing, new pupil change, or falling scores should never be ignored