Approach to Syncope

Question 1

What is consciousness?

Answer 1

Awake person who is fully responsible to a thought/perception and indications by his speech/behavior the awareness of self/surroundings

Question 2

How do you test for/confirm consciousness?

Answer 2

1) Response to external stimuli
- visual response
- verbal/non-verbal response correct for context/situation
- social response appropriate to context/situation

2) Memory/recall, high cognitive function

Question 3

What are 3 physiological systems that are important in maintaining consciousness?

Answer 3

1) CVS
2) Respi
3) CNS
4) Electrolytes and energy

Question 4

What is the role of the heart and blood vessels in maintaining consciousness?

Answer 4

Heart:
- HR and rhythm + SV

Vessels:
- Sufficient blood volume/BP

Together → adequate perfusion via cerebral circulation (carotid/vertebral/cerebral/venous system)

Question 5

What is the role of the lungs and respiratory muscles in maintaining consciousness?

Answer 5

Lungs:
- air exchange → maintain pO2/pCO2 → adequate perfusion + prevent acidosis

Respiratory muscles:
- effective air exchange for lung function

Question 6

What are 2 areas of the brain that help maintain consciousness?

Answer 6

1) Reticular activating system of brainstem
2) Cerebral hemispheric function (left more important for adequate function)

Question 7

What are 4 energy substrates/electrolytes that are essential to maintaining consciousness?

Answer 7

1) Glucose
2) Ketones
3) K+
4) Ca2+
5) Na+

Question 8

What is the difference between sleep and impaired consciousness?

Answer 8

A patient who is asleep can be awoken and regain full consciousness

Question 9

What are the 4 levels of impaired consciousness?

Answer 9

Increasing severity:
1) Lethargy
- difficulty maintaining awake state

2) Obtunded/obtundation
- responsive to non-pain stimuli

3) Stupor
- only responsive to pain

4) Coma
- no clinical response to external stimuli

Question 10

What is the GCS?

Answer 10

Measurement of consciousness level (3-15, <12 → BAD)

1) Eye-opening (E)
- spontaneous → voice → pain

2) Best verbal (V)
- orientated → confused → inappropriate → incomprehensible

3) Best motor (M)
- obey → localise → withdraw → pain flexion → pain extension

Question 11

What are 4 limitations of GCS?

Answer 11

1) Cannot evaluate eye with severe orbito-facial injury

2) Cannot evaluate verbal if intubated

3) Cannot score differences between L/R function

4) Lack of neuro-ophthalmic evaluation (pupillary size/reactivity)

5) Lack of brainstem assessment

Question 12

A lens-shaped bleed on a cranial CT is indicative of _______________________.

Answer 12

Epidural hematoma (arterial bleed from middle meningeal)

Question 13

A crescent-shaped bleed on a cranial CT is indicative of __________________.

Answer 13

Subdural hematoma (venous bleed from bridging veins)

Question 14

What are 12 causes of impaired consciousness?

Answer 14

1) Brain trauma
2) Cerebrovascular event
- hemorrhage, thromboemboli, vasculitis
3) Seizures/status epilepticus
4) Syncope
- transient cerebral hypoperfusion
5) CNS infection
- meningitis, encephalitis, brain abscess
6) Post-infectious/inflammatory rxn/disorder
- ADEM, MS
7) Medications
- OD of meds/multiple sedative meds
8) Drugs of abuse/alcohol
9) Toxins
10) Severe sepsis
11) Major organ failure
12) Electrolyte abnormalities, ABDs
13) Metabolic crisis

Question 15

What are 4 causes of a comatose state?

Answer 15

Large and persistent area of brain affected:
1) Trauma
2) Cerebrovascular events
3) Encephalitis
4) Refractory status epilepticus

Question 16

What is the most common cause of transient LOC?

Answer 16

Syncope

Question 17

What is syncope?

Answer 17

Paroxysmal event with LOS and postural tone due to cerebral hypoperfusion (perfusion/oxygenation) with spontaneous recovery

Question 18

How does falling over correct syncope?

Answer 18

Fall down → brain same height as heart → restored perfusion

Question 19

What are 5 typical presentations of syncope?

Answer 19

1) LOC and postural tone
2) Pallor + sweating
3) Brief (~secs) extensor stiffening/spasm
4) Few irregular myoclonic jerks (convulsive syncope)
5) <30s per episode

Question 20

What are 2 triggers for syncope?

Answer 20

Peripheral vasodilation
1) prolonged standing
2) Hot, closed, crowded areas with poor ventilation

↑Vagal tone
3) Painful stimuli
4) Fear/shock

Question 21

How can syncope be averted when prodromal symptoms are experienced?

Answer 21

Lie down horizontally with head down and legs up

Question 22

What are 4 prodromal symptoms of syncope?

Answer 22

1) Lightheadedness/ dizziness/ nausea
2) Warmth
3) Sweating
4) Vision greying/blackening
5) Hearing muffled/distant

Question 23

What are 7 types of syncope?

Answer 23

Neurally-mediated:
1) Vasovagal
2) Reflex anoxic (pallid spells)
3) Orthostatic (no pallor and sweating)
4) Reflex-mediated situational syncope (Valsalva maneuver, micturition)

Cardiogenic:
5) Arrhythmias
6) Cardiac defects
7) Cardiomyopathies

Question 24

What are seizures?

Answer 24

Sudden unusual/erratic electrical changes in cortical neurons → brief alteration in a person’s consciousness, sensation, movements, actions

Question 25

True or false.
All epilepsies are seizures but not all seizures are epileptic.

Answer 25

True.
Acute (eg. hypoglycemia) not termed as epilepsy

Question 26

What are 5 causes of acute seizures?

Answer 26

1) Hypoglycemia/electrolyte disturbances
2) Trauma
3) Stroke
4) Alcohol/alcohol withdrawal
5) Drugs/drug withdrawal

Question 27

True or false:
All forms of seizures can be life-threatening and thus should be treated with anti-epileptics.

Answer 27

False.
Never give for hypoglycemia/electrolyte imbalances.

Question 28

What is epilepsy?

Answer 28

Predisposition to recurrent, usually spontaneous seizures.
- 2 initial <24 hours → not epilepsy
- reflex specific stimuli seizures → not epilepsy

Question 29

What is the pathophysiology of seizures and their spread?

Answer 29

Repetitive cortical activation → potential excitatory transmission + depress inhibitory transmission
→ self-perpetuating excitatory circuit/bursts and facilitating excitation/recruitment of neighbouring neurons
→ bursts to corpus callosum
→ opposite hemisphere

Question 30

How does a generalised seizure differ from a partial seizures?

Answer 30

Generalised → both hemispheres

Partial → start in 1 hemisphere → spread

Question 31

What are 2 types/signs of frontal lobe seizures?

Answer 31

1) Jacksonian seizures
- tingling in hand/arm

2) Adversive seizures
- eyes/head turn to one side

Question 32

What is a sign of parietal lobe seizures?

Answer 32

Tingling and jerking of leg, arm or face

Question 33

What is a sign/symptom of occipital lobe seizures?

Answer 33

Flashing lights/spots

Question 34

What are 3 signs/symptoms of occipital lobe seizures?

Answer 34

1) Strange smells/tastes
2) Altered behaviour
3) Deja vu
4) Lip smacking/chewing movements

Question 35

What are 5 clinical presentations of epileptic seizures?

Answer 35

1) Sudden stiffening → jerks/shakes
2) Sudden falls/drop of head
3) Blank spell/repetitive eyeblinks
4) Loss of awareness w semi-purposeful movements
5) Spasms

Question 36

How is epilepsy diagnosed?

Answer 36

1) Clinical
- detailed description of events by px/witness before, during, and after an event

2) Video recording

Question 37

What are 2 DDx of epilepsy?

Answer 37

1) Breath holding spell (cyanotic)
- precipitated by noxious, painful stimuli, surprise
- crying → stop breathing → cyanosed, limp, unresponsive + tonic/clonic jerks
- rapid recovery

2) Breath holding spell (pallid)
- may not cry but with abrupt LOC and limpness