Epilepsy Flashcards
Epilepsy definition
a condition characterised by an increased susceptibility to spontaneous epileptic seizures
Epileptic seizure definition
transient episode of abnormal neurological function caused by sudden excessive or hypersynchronous cortical neuronal activity
What are the 2 main seizure types?
focal (partial)
generalised
Where does a focal seizure affect?
affects on hemisphere
Name some subtypes of generalised seizures
absence (petit mal)
myoclonic
tonic
clonic
tonic clonic (grand mal)
atonic
Describe absence seizures (petit mal)
sudden onset
behavioural arrest
unresponsive
staring
minor blinking
duration = seconds
quick recovery
characteristic EEG
Describe myoclonic jerk seizures
brief jerks
usually involving upper limbs
may affect limbs and trunk
may show diurnal variation
Myoclonic seizure EEG sign
4-6 irregular polyspike wave
Describe tonic seizures
sudden onset
muscle contraction - limbs, axial muscles
consciousness usually impaired
may result in forceful sudden falls
common during sleep
Describe atonic seizures
sudden onset
loss of muscle tone
consciousness usually impaired
lasts 1-2 seconds
may result in sudden falls
What are some alternative diagnoses to seizures?
syncope
non-epileptic attack disorder
transient ischaemic attack
narcolepsy
cataplexy
transient global amnesia
Describe some differences between syncope and seizure
syncope:
- prodromal symptoms
- pallor
- fall
- hypotonia
- brief duration
- no post-ictal confusion
seizure:
- variable warning
- fall
- initial tonic phase
- cyanosis
- clonic jerking
- duration = minutes
- tongue biting
- incontinence
- post-ictal confusion
What causes epileptic seizures?
things that affect brain structures:
- developmental abnormalities
- brain trauma
- stroke
- tumours
- infections
- immune-mediated inflammation
things that affect the brain’s metabolic or electrophysiological function:
- alcohol withdrawal
- drugs
- hypoglycaemia
- other biochemical disturbances
Describe childhood absence epilepsy
onset in childhood
girls>boys
frequent absence seizures
characteristic EEG (generalised 3HZ spike and wave discharges, hyperventilation induced seizures)
+ve FH of epilepsy
usually remits at puberty
responds well to ethosuximide or sodium valproate
Describe Juvenile myoclonic epilepsy
age-related onset of absences, jerks, generalised tonic clonic seizures
absences begin 5-16y
myoclonic jerks follow 1-9y later
GTCS about same time as myoclonus
