Blackouts, Seizures + Epilepsy Flashcards
A blackout is a transient loss of consciousness. Collapse is an abrupt loss of postural tone (with our without transient LoC).
What is syncope?
- transient loss of consciousness (partial or complete)
- caused by global impairment of cerebral perfusion
- causing collapse
- spontaneous complete recovery
What are causes of blackout?
- neurological → epilepsy, stroke, TIA, tumour
- cardiovascular → vasovagal syncope, situational syncope, carotid sinus syncope, stokes-adams attack (arrythmias), orthostatic hypotension
- other → hypoglycaemia, anxiety, drop attacks, factitious, hyponatraemia + hypocalcaemia
What is a seizure?
- an acute change in neurological function produced by abnormal synchronous activity in the cerebral cortex
- epilepsy is having a predisposition to having seizures
- >more than 5 mins amnesia = strong marker
What are causes of seizures?
- infection → meningitis, encephalitis, cerebral abscess
- vascular → stroke, haemorrhage, venous thrombosis
- trauma → traumatic brain injury
- endo/met → hypoglycaemia, hypocalcaemia, hypomagnesaemia, uraemia, hyper/hypothyroidism
- toxic → alcohol, BDZ withdrawal, most rec drugs
What are acute provoked seizures?
- single seizures w/ underlying cause
- eg. trauma, hypoglycaemia, hyponatraemia, high fever, alcohol/drug abuse
What is the definition of epilepsy?
- at least 2 unprovoked (or reflex) seizures occurring more than 24hrs apart
Epileptic seizures may be classified as focal, generalised or unknown onset w/ subcategories of motor, non-motor (absence), with retained or impaired awareness for focal seizures.
The basic classification of epilepsy has changed in recent years. The new basic seizure classification is based on 3 key features.
What are these 3 key features?
- where seizures begin in the brain
- level of awareness during a seizure
- other features of seizures
What causes epilepsy?
- idiopathic → most common!
- structural → cortical scarring, SOL, developmental, stroke, tumour
- other → SLE, sarcoidosis, tuberous sclerosis
Generalised seizures affect your whole brain. During most of these seizures the person loses consciousness.
What are the two main types that generalised seizures can be classified into?
-
Motor onset:
- tonic-clonic + variants
- tonic
- atonic
- myoclonic
- myoclonic-atonic
- epileptic spasms
-
Non-motor onset:
- typical absence
- atypical absence
- myoclonic absence
- absence w/ eyelid myoclonia
What are tonic-clonic seizures?
- bilateral symmetric generalised motor seizures
- loss of consciousness
- tonic ⇒ bilateral increased tone (secs-mins)
- clonic ⇒ bilateral sustained rhythmic jerking
- tongue biting, incontinence, drowsy, confused, myalgia, headache
What are atonic seizures?
- sudden loss of muscle tone
- without apparent preceding myoclonic or tonic features
- very brief (<2seconds)
- may involve head, trunk, limbs
- often occur in indivdiuals w/ intellectual impairment
- can cause drop attacks
What is a myoclonic seizure?
- sudden jerk of limb, face or trunk
- may suddenly be thrown to the ground
- have violently disobedient limb
- tend not to black out
- occur in morning
What is an absence seizure?
- appear to be staring blankly into space
- unaware of surroundings + mildly confused after
- usually only last a few seconds
- eyelid fluttering + head flopping
- happen commonly in children + teenagers
- don’t usually continue into adulthood
- previously known as ‘petit mal’ seizures
Focal seizures originate within networks linked to one hemisphere and often are seen with underlying structural disease.
What is the new classification of focal seizures?
- aware or impaired awareness
- motor-onset
- non-motor onset
- focal to bilateral tonic-clonic seizure
Temporal lobe is the most common area for focal seizures. What are features if originating from the temporal lobe?
- automatisms: eg. funny hand movement, lip smacking
- dysphagia
- deja vu
- emotional disturbances
- delusional behaviour
- bizarre associations eg. cans make me pass out