Coma, Persistent Vegetative State and Brain Death

Question 1

How is a coma neurologically assessed?

Answer 1

Glasgow coma scale
Brainstem function
Motor function and reflexes

Question 2

What does GCS stand for?

Answer 2

Glasgow coma scale

Question 3

What does the GCS look at?

Answer 3

Eye opening
Verbal response
Motor response

Question 4

Eye opening scores of the GCS

Answer 4

Spontaneous - 4
To speech - 3
To pain - 2
None - 1

Question 5

Verbal response score of the GCS

Answer 5

Orientated - 5
Confused - 4
Inappropriate words - 3
Incomprehensible sounds - 2
None - 1

Question 6

Motor response scores of the GCS

Answer 6

Obeying commands - 6 
Localizing to pain - 5
Withdrawing from pain - 4
Flexing to pain - 3
Extending to pain - 2
None - 1

Question 7

Scores if a GCS score = 8 or under

Answer 7

Eye - 2 or less
Verbal - 2 or less
Motor - 4 or less

Question 8

What is a full score of the GCS?

Answer 8

15

Question 9

How do you test the brainstem function?

Answer 9

Pupillary reactions
Corneal responses
Spontaneous eye movements
Oculocephalic responses (dolls eye)
Oculovestibular responses
Resp pattern

Question 10

What CNs control pupillary reactions?

Answer 10

II and III

Question 11

What CNs control corneal responses?

Answer 11

V and VII

Question 12

What CNs control spontaneous eye movements?

Answer 12

III, IV and VI

Question 13

What CNs control oculocephalic responses?

Answer 13

III, IV, VI, VIII

Question 14

What CNs control oculovestibular responses?

Answer 14

III, IV, VI and VIII

Question 15

What controls the respiratory pattern?

Answer 15

Medullary centre

Question 16

How to test the motor function?

Answer 16

Motor response
Muscle tone
Tendon reflexes
Seizures

Question 17

What GCS score is needed to indicate a coma?

Answer 17

< 8

Question 18

Causes of a coma with no meningism and no focal brainstem or lateralising cerebral signs

Answer 18

Intoxications
Anoxic/ischaemic conditions
Metabolic disturbances
Systemic infections
Hyperthermia/hypothermia
Epilepsy

Question 19

Causes of a coma with meningism and no focal brainstem or lateralising cerebral signs

Answer 19

SAH
Meningitis
Encephalitis

Question 20

Causes of a coma with possible meningism with focal brainstem and lateralising cerebral signs

Answer 20

Focal cerebral e.g. tumour infarct

Question 21

Causes of coma with focal brainstem or lateralising cerebral signs

Answer 21

Cerebral tumour
Cerebral haemorrhage
Cerebral infarction
Cerebral abscess

Question 22

Medical causes of coma lasting more than 5 hours

Answer 22

40% due to drug ingestion +/- alcohol
25% due to hypoxia e.g. secondary to MI
20% due to cerebrovascular event, either haemorrhage or infarction
15% metabolic e.g. DM, Hepatic failure, renal failure, sepsis, hypercapnia/hypoxia

Question 23

Investigations of coma without focalising or lateralising signs and without meningism

Answer 23

Toxicology screen including alcohol level 
Blood sugar
Electrolytes
Hepatic and renal function 
Acid-base measurement and blood gases
Measure BP
Consider CO poisoning

Question 24

Investigations of a coma without focal or lateralising signs but with meningism

Answer 24

CT head scan

LP

Question 25

Investigations of coma with focal brainstem or lateralising cerebral signs

Answer 25

``` CT or MRI obligatory If CT/MRI not diagnostic, then investigate as far as can for other causes of coma e.g. - metabolic screens - LP - EEG ```

Question 26

Causes of a patient in a coma with decreased respiration

Answer 26

Drug overdose | Metabolic disturbance

Question 27

Causes of a patient in a coma with increased respiration

Answer 27

Hypoxia Hypercapnia Acidosis

Question 28

Causes of a patient in a coma with fluctuating respiration

Answer 28

Brainstem lesion

Question 29

Factors affecting the outcome of a coma

Answer 29

``` Age Cause of coma Depth of coma Duration of coma Certain clinical signs, most important of which are brainstem reflexes ```

Question 30

What % of patients in a non traumatic coma for more than 6 hours will make a good or moderate recovery?

Answer 30

15%

Question 31

Continuing care of patients in a coma

Answer 31

``` Maintenance of vital functions Care of skin, avoidance of pressure sores Attention to bladder and bowel function Control of seizures Prophylaxis of CVT, peptic ulceration Prevention of contractures Consider the "locked in" syndrome ```

Question 32

Definition of coma

Answer 32

A state of unarousable psychological unresponsiveness in which the subjects lie with their eyes closed and show no psychologically understandable response to external stimulus or inner need

Question 33

What does consciousness depend on?

Answer 33

AROUSAL - An intact ascending reticular activating system to act as the alerting or awakening element of consciousness AWARENESS OF THE ENVIRONMENT - A functioning cerebral cortex or both hemispheres which determines the content of that consciousness

Question 34

Definition of persistent vegetative state

Answer 34

A state in which the brainstem recovers to a considerable extent but there is no evidence of recovery of cortical function

Question 35

Causes of decreased GCS

Answer 35

``` Toxic/metabolic states - hypoxia - hypercapnia - sepsis - hypotension - drug intoxication - renal or liver failure - hypoglycaemia - ketoacidosis Seizures Damage to the reticular activating system Causes of raised ICP - Tumour - Stroke - EDH - SDH - SAH - hydrocephalus ```

Question 36

Why do elderly patients have loads of space around their brain?

Answer 36

Their brain shrinks

Question 37

Does focal damage to part of the cortex affect the conscious level?

Answer 37

No

Question 38

Causes of diffuse hemisphere damage

Answer 38

Trauma Ischaemia Hypoglycaemia Hepatic or renal failure

Question 39

Give an example of a condition that can cause bilateral thalamic involvement

Answer 39

Astrocytoma

Question 40

Causes of brain stem involvement

Answer 40

Ischaemia Haemorrhage Tumour Drugs (sedatives, hypnotics)

Question 41

What is the "locked in" syndrome?

Answer 41

The patient has total paralysis below the level of the third nerve nuclei, and although able to open, elevate and depress the eyes, has no horizontal eye movements and no other voluntary eye movement. They can still breath. Usually fully aware

Question 42

What types of head injury can lead to focal neurological signs/epilepsy?

Answer 42

``` Diffuse axonal injury Contusion (bruise) Intracerebral haematoma Extracerebral haematoma - extra dural haematoma - sub dural haematoma ```

Question 43

What does a subdural haematoma look like on CT?

Answer 43

Convex/convex

Question 44

What does a extradural haematoma look like on CT?

Answer 44

Concave/convex (lens)

Question 45

Treatment of head injury

Answer 45

``` Stabilize cervical spine ABC If GCS < 8 = intubation and ventilation Treat raised ICP Cranial imaging - may need decompressive surgery or removal of haematoma Neuro-observation ```

Question 46

Treatment of raised ICP

Answer 46

``` Surgery to relieve pressure - haematoma, ventricular shunt Osmotic agents e.g. mannitol Head at 30-45% venous return Reduce pain Maintain good PO2, reduce PCO2 Reduce metabolism (reduce temp, barbituates) ```