Syncope

Question 1

What is syncope? How does it differ from pre-syncope?

Answer 1

Syncope is a temporary loss of consciousness usually related to insufficient blood flow to the brain.

Pre-syncope is the sensation of near fainting or prodrome without actually passing out.

Question 2

Factors that effect cerebral blood flow?

Answer 2

MAP (how much pressure the heart/ vessels can exert to bring blood into the brain)

ICP (the pressure exerted on the vessels in the brain by the brain tissue, synovial fluids/ CSF and other brain structures

Question 3

What does the brain use to regulate blood flow?

Answer 3

The brain can alter resistance of the cerebral blood vessels. This depends on the pH and the PaCO2

O2 - only once things are really bad!

Question 4

Increased ICP - what emergency measures can you take?

Answer 4

Can use an osmotic like mannitol, and can hyperventilate to drop CO2 as much as possible (prevent cerebral vasodilation)

Can like theoretically drill a burr hole but…

Question 5

What is the most common type of syncope?

Answer 5

Vasovagal.

Question 6

What is reflex syncope and how is it triggered?

Answer 6

As a result of pressure on the baroRC of the carotid sinus - triggered by head rotation or tight collar.

Question 7

What triggers vasovagal syncope?

Answer 7

Stress, fear, noxious stimuli or heat exposure

Usually preceded by nausea, lightheadedness - has a prodrome

Question 8

What triggers situational syncope?

Answer 8

Post-micturition, exercise, postprandial, with GI stimulation.

Question 9

Criteria for orthostatic hypotension?

Answer 9

Decrease in systolic BP >20mmHg or diastolic >10mmHg within 3 minutes of standing from supine.

Question 10

Causes of autonomic failure?

Answer 10

Primary - Parkinson’s, MS, Wernicke’s encephalopathy

Secondary - DM, amyloidosis, uraemia, spinal cord injury and connective tissue diseases

Question 11

Drugs causing syncope?

Answer 11

Alcohol, insulin, anti-hypertensives, anti-diabetics, anti-depressants, anti-Parkinson’s

Question 12

Types of cardiac syncope?

Answer 12

Valvular - AS is the most common form
Structural - HOCM, Aortic dissection, acute MI
Arrhythmias - most common cause can be due to bradycardia, severe tachycardia

Question 13

Factor that might help distinguish syncope from seizure?

Answer 13

Post-ictal period, prodrome characteristic of a seizure, previous seizure hx, loss of bowel and urinary control, and tongue biting could be signs more of a seizure than syncope

Both can have myoclonus.

Syncope may have more an abrupt onset, be during exercise, postural, look at medications and past medical hx, age.

Question 14

Focal vs generalized seizures?

Answer 14

Focal only involve part of the body, the person’s awareness may not be impaired

Generalized onset involves the whole body, and awareness is impaired.

Question 15

Tonic vs clonic

Answer 15

Tonic - muscle contractions, rigidity

Clonic - jerking movements rapid

Question 16

Treatment for acute seizure?

Answer 16

Lorazepam, most resolve spontaneously in which case all that is needed is airway support, CBG for glucose, IV access

Question 17

Treatment for status epilepticus?

Answer 17

If the seizure does not resolve within 5 minutes, it is status, give lorazepam, and phenytoin, if this does not help switch to barbiturates. Final solution is sedation and intubation.

Question 18

Treatment for Orthostatic hypotension?

Answer 18

Discontinue aggravating medications, modify daily activities. Compression stocking and abdominal binders.

Question 19

Fitness to drive?

Answer 19

One vasovagal episode - no restrictions

Seizure - needs to be maintained without one and compliant to medical care for 6 months

Question 20

Carcinoid syndrome

Answer 20

Evaluate for serotonin (5-HIAA) in the urine, is a type of neuroendocrine tumour