Blackouts Flashcards
What are causes of blackout/LOC?
Vasovagal syncope Situational syncope - cough, effort, micturition Carotid sinus syncope Epilepsy Stokes-Adams attacks Hypoglycaemia Orthostatic hypotension Anxiety Drop attacks Pseudoseizures/Factitious
What is vasovagal syncope?
Reflex bradycardia and peripheral vasodilation provoked by emotion, pain or standing too long - cannot occur lying
Onset is over seconds
Preceded by pre-syncopal symptoms (nausea, pallor, sweating, narrowing of visual fields)
Brief clinic jerking of the limbs may occur due to cerebral hypo perfusion - no tonic-clonic sequence
Urinary incontinence is uncommon and no tongue biting
LOC lasts for 2 mins and recovery is rapid.
What is situation syncope?
Clear precipitant of syncope:
Cough - paroxysm of coughing
Effort- exercise - underlying cardiac cause e.g. aortic stenosis, HCM
Micturition - happens during or after urination
What is carotid sinus syncope?
Hypersensitive baroreceptors cause excessive reflex bradycardia and vasodilation on minimal stimulation - head turning, shaving
What features suggest epilepsy
Attacks occur when lying down or asleep Aura Identifiable triggers Altered breathing Cyanosis Typical tonic-clonic movmeents Incontinence of urine Tongue biting Prolonged post-ictal drowsiness, confusion, amnesia and transient focal paralysis (Todd's palsy)
What is Stokes-Adams attack?
Transient arrhythmia (bradycardia due to complete heart block) cause reduced cardiac output and LOC.
Patient falls to ground often with no warning except palpitations.
Pale with slow or absent pulse
Recovery is in seconds, patient flushes, pulse speeds up and consciousness regained.
Anoxic clonic jerks may occur
Attacks may happen several times a day in any posture.
What doe you see before hypoglycaemia LOC?
Tremor, hunger, light-headedness
What is orthostatic hypotension
Unsteadiness or LOC on standing from lying in those with inadequate vasomotor reflexes: alertly, autonomic neuropathy, antihypertensive medication, overdiuresis, multi-system atrophy
What may suggest anxiety?
Hyperventilation, tremor, sweating, tachycardia, paraesthesiae, light-headedness
What are drop attacks?
Sudden fall to the ground without LOC
Mostly benign and due to leg weakness but may also be caused by hydrocephalus or narcolepsy
What important tests?
CVS - ECG urgently if associated with palpitations - long QT, 3rd degree AV block Lying standing BP Neuro Sleep EEG, EEG Echo CT/MRI
What are important factors in blackout history?
Loss of awaresness Do they injure themselves Does patient move?Stiff or floppy? Incontinency? Complexion change? (pale/cyanosis could be epilepsy, very pale could be syncope or arrhythmia) Bite tongue? Associated symptoms (palpitations, sweat, pallor, chest pain, dyspnoea) Duration of attack?
Before:
Warning? Aura?
Circumstances - triggers?
Can patient prevent?
During: see above
After:
How much does pt remember?
Muscle ache? (suggests tonic clonic)
Confused or sleepy? (epilepsy post-ictal)
BAckground When did they start? Frequency Anyone else in FHx Sudden death in FHx
What should you ask about prior to attack? After?
Before:
Warning? Aura?
Circumstances - triggers?
Can patient prevent?
After:
How much does pt remember?
Muscle ache? (suggests tonic clonic)
Confused or sleepy? (epilepsy post-ictal)
What should you ask about background?
BAckground When did they start? Frequency Anyone else in FHx Sudden death in FHx
