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