Blackouts Flashcards
What are the big 3 causes of blackout?
Epileptic seizure
Syncope - especially cardiac causes
Psychogenic non-epileptic seizure
What is a seizure?
Clinical manifestation of abnormal and excessive discharge of cerebral neurons
What can seizures be due to?
Epilepsy
First seizure
Acute symptomatic seizure
What is epilepsy?
A tendency to experience recurrent unprovoked epileptic seizures
How do epileptic seizures present?
Different clinical manifestations
Depends on - where the seizure arises and where it spreads to
What seizures have a focal onset?
Simple partial seizures (aura) - no LOC
Complex partial seizures
Secondary generalised tonic clonic seizures
Structural causes
What seizures have a generalised onset?
Generalised tonic clonic seizures
Myoclonic jerk
Absence
Idiopathic/genetic causes - affects ion channels
FHx
Early morning seizures - worse with sleep deprivation or alcohol
Photosensitivity
What is the definition of an absence seizure?
Associated with 3 second spike and wave on EEG
Otherwise use loss of awareness or vacant spell as lots of seizures can cause someone to briefly lose awareness, not just absence seizures
No focal manifestations or motor
Primary generalised epilepsy
What are the symptoms of an aura?
Depend on where seizure is taking place
Eg smells - temporal lobe
What is syncope?
Transient global cerebral hypoperfusion
What are the causes of reflex syncope?
Neurally mediated
- Vasovagal
- Situational
- Carotid sinus hypersensitivity
Cardiogenic
Orthostatic hypotension
- Drugs
- Autonomic failure
What can cause cardiac syncope?
Conditions predisposing transient tachyarrhythmias - will have abnormal ECG between events, cause sudden death in young people
Bradyarrhythmias
Cardiac ischaemia
Structural heart disease
Some types of heart block with high risk of progression to asytole
- Complete 3rd degree heart block
- Mobitz type II 2nd degree heart block
- Incomplete trifascicular block - RBBB, LAD, 1st degree heart block
Acute ischaemia causing syncope due to arrhythmia, output failure, or acute mitral regurg
Previous MI - scar related VT
Aortic stenosis - cardiac outflow obstruction
Hypertrophic cardiomyopathy - syncope during exertion
What is the most important investigation in a seizure clinic?
ECG
What is important to remember about blackouts occurring during exercise?
Cardiogenic until proven otherwise
ECHO
ECG and 24hr ECG
What is a psychogenic non-epileptic seizure?
Pseudo-seizure, non-epileptic attack disorder, dissociative seizures
Episodes of movement, sensation, or experience that resemble epileptic seizures but without ictal cerebral discharges
Physical manifestation of psychological distress
Associated with comorbid psychopathology and with childhood sexual abuse
What are the differential diagnoses of blackouts?
Epilepsy
Syncope
- Vasovagal (neurogenic)
- Cardiac
- Micturition
- Cough
- Postural hypotension
- Carotid sinus syndrome
Non-epileptic attacks
Hypoglycaemia
Acute hydrocephalus - obstruction of aqueduct
Basilar migraine
Severe vertigo
Cataplexy
Narcolepsy
Sleep paralysis
NOT stroke/migraine/TIA
What information is important to get in the patient account?
What were the circumstances of the event?
What do they recall beforehand?
What is the next thing they remember?
Did the attack cause injury or incontinence?
What information is important to get from the witness?
In what circumstances did the event occur?
What were the first signs of the attack?
What exactly happened during the attack?
- LOC
- Stiffening of trunk and limbs
- Movement of head, arms, legs
- Eyes open/closed
- Cyanosis/noisy breathing/vocalisation
How long did the event last?
What happened immediately after the event?
What other useful information can you get from the history in a seizure?
Previous possible unrecognised seizures
- Do you ever jerk?
- Do you ever have blank spells? - Miss fragments of TV/conversations even when concentrating?
- Over had other odd spells out of the blue - unexplained anxiety? Deja vu? Rising sensations?
What is important to get in the PMH for seizures?
Birth - premature/SCUB
Febrile seizures
CNS infections/significant head injury
Psychological comorbidity
What is important to get in the drug history?
Antidepressants
Tramadol
Any drugs lowering seizure threshold
What is important to ask in the social history in siezures?
Evidence of psychological comorbidity
Alcohol and drugs
Driving
What is important to ask about in the family history?
Seizures
Sudden cardiac death
Evidence of psychological comorbidity
What are the characteristic symptoms of generalised tonic-clonic seizures?
Circumstances - no trigger
Prodrome - may have aura
Witness - stiffening, jerking of limbs, vocalisation or grunting, breathing, cyanosis, eyes open
Duration - 1-2 mins
Post-ictal phase - profound confusion for around 20 mins, agitated, non-verbal, no recognition of family
Other phenomena - lateral tongue bite, urinary incontinence, injury (posterior dislocation of shoulder)
Other events - minor episodes consistent with unrecognised seizure, events are stereotyped
PMH - risk factors for seizure, febrile seizures, head injury, learning difficulties, autism
DH - tramadol
SH - alcohol or recreational drug use
FH - seizures
What is a characteristic history for syncope?
Circumstance - triggers for vasovagal, situational/postural exertion, no trigger for cardiac syncope
Prodrome - typical fainting prodrome
Witness- may have jerks especially if maintained upright posture, pallor,
Duration - brief
Post-ictal phase - none, rapid recovery
Other events - previous syncopal events
PMH - cardiac history
DH - hypotensive medications
FH - sudden cardiac death
What is a typical presentation of non-epileptic seizures?
Circumstance - may be situational
Prodrome - subjective seizure symptoms often discussed sparingly or by negotiation
Witness - eyes often closed, partially responsive, often wax and wane, may be emotional
Duration - often prolonged - think of it in cases of apparent status epilepticus
Post-ictal phase - variable, almost always tired/washed out
Other events - often variable non-stereotyped events
PMH - psychological comorbidity, other function illness - headaches, IBS, CFS
DH - antidepressants, other psychotropic medications
SH - psychosocial deprivation, domestic abuse, asylum seekers, ex-soldiers, early childhood trauma
FH - evidence of psychosocial deprivation, family trauma, family history of psychological morbidity
What investigations should you do in blackout?
ECG
Neuroimaging - CT, CT not indicated in syncope, MRI (investigation of choice)
EEG - normal EEG doesn’t exclude, not indicated in syncope
Recording event - home video, video EEG recording in hospital if frequent
What is vasovagal syncope?
Sudden reflex bradycardia with vasodilatation of both peripheral and splanchnic vasculature
Precipitants - common response to prolonged standing, fear, venesection, or pain
Prodrome - usually brief, dizziness, lightheadedness, nausea, sweating, feeling of heat, visual grey-out
Blackout - lie still but still jerking and twitching, pale, incontinence of urine and faeces can occur
Recovery - rapid, usually seconds, may be followed by feeling of general fatigue
What is cardiac syncope?
Potentially serious, often treatable
Little or no warning
Cardiac arrhythmias may be cause eg heart block, LV outflow obstruction
Often occurs during exertion
What is micturition syncope?
Syncope during micturition
Most often in men
Occurs most often at night
What is cough syncope?
When venous return to heart is obstructed due to severe coughing
What is postural hypotension?
Autonomic neuropathy in elderly
Drugs
What is carotid sinus syncope?
Vagal response caused by pressure over carotid sinus baroreceptors in neck eg tight collar or turning head
What is convulsive syncope?
Collapsing in propped-up position following syncope
Results in delayed restoration of cerebral blood flow leading to anoxic seizure following syncope
