Other Causes Of Blackout

Question 1

What is syncope?

Answer 1

transient loss of consciousness due to global cerebral hypoperfusion with rapid onset, short duration and spontaneous complete recovery

Question 2

What is a neurocardiogenic syncope (vasovagal)

Answer 2

Due to sudden reflex bradycardia with vasodilation of both peripheral and splanchnic vasculature
Triggered by emotion, pain or stress. Often referred to as ‘fainting’
Person feels nauseas, dizzy, sweaty and vision greys out and they lie still with little twitches, over in seconds

Question 3

Name two other types of situational reflex syncope.

Answer 3

Cough and micturation syncope

Question 4

Orthostatic syncope

Answer 4

primary autonomic failure: Parkinson’s disease, Lewy body dementia
secondary autonomic failure: e.g. Diabetic neuropathy, amyloidosis, uraemia
drug-induced: diuretics, alcohol, vasodilators
volume depletion: haemorrhage, diarrhoea

Question 5

What is a non-epileptic seizure (pseudo seizure)?

Answer 5

Attacks may look like generalised fits
Usually bizarre thrashing and non synchronous limb movements
Serum prolactin does not rise

Question 6

What is narcolepsy and what is it associated with?

Answer 6

associated with HLA-DR2 and low levels of orexin (hypocretin), a protein which is responsible for controlling appetite and sleep patterns
early onset of REM sleep
typical onset in teenage years

Question 7

Main clinical features of Narcolepsy

Answer 7

EXCESSIVE DAYTIME SLEEPINESS : frequent irresistible sleep attacks
CATAPLEXY: sudden loss of muscle tone leading to head droop or even falling with intact awareness
HYPNAGOGIC/ HYPNOPOMPIC HALLUCINATIONS: dream-like hallucinations occuring while falling asleep
SLEEP PARALYSIS : paralysis on waking or falling asleep due to intrusion of REM atonia while waking

Question 8

Investigation for narcolepsy

Answer 8

multiple sleep latency EEG

Question 9

Management for narcolepsy

Answer 9

Daytime stimulants (e.g. modafinil) and nighttime sodium oxybate