Epilepsy Flashcards
3 definitions of epilepsy (clinical definitions)
- 2 or more unprovoked/reflex seizures occurring more than 24 hrs apart
- One unprovoked/reflex seizure and a probability of further seizures similar to the general recurrence risk (>60%) after 2 unprovoked seizures occurring over the next 10 years
- Diagnosed epilepsy syndrome
3 subtypes of seizures
- Focal
- Generalised
- Unknown origin
Define seizure
Transient occurrence of signs/symptoms due to abnormal excessive or synchronous neuronal activity in the brain
Describe status epilepticus
- Life-threatening
- > 5 minutes - continuous seizure or repetitive seizures without regaining consciousness
- Subtype = generalised convulsive SE
Describe generalised seizures - adults
- These types of seizures are found in many types of epilepsy
- Tonic-clonic (GTCS)
- Involves LoC
- Phasic tonic stiffening - followed by repetitive clonic jerking
- Subtype = grand-mal epilepsy
- Usually self-limiting without intervention
What does one see on an EEG during a generalised seizure
- Bisynchronous epileptiform activity in both cerebral hemispheres
Describe generalised seizures - children
- Recurrent generalised seizures in children are classified epilepsy
- Common
- Treat with anticonvulsants, ketogenic diets, vagus nerve stimulation and lifestyle
Risk factors for generalised seizures in children
- Genetic
- Family history
- History of febrile seizures
- Head trauma
- Abnormal nervous system
Describe febrile seizures
- In infants and children - 3 months to 5 years
- High fever with no infection or defined cause
- LP to exclude other causes
- Usually self-limiting
Describe absence seizures
- Abrupt cessation of activity/responsiveness
- Minimal associated movements
- Staring
- 5-10 seconds - several times daily
- Tends to disappear into adulthood
- Treat with anticonvulsants
What are absence seizures precipitated by
- Hyperventilation
- Photic stimulation
Describe focal/partial seizures
- Electrical and clinical manifestations
- Arise from one portion of the brain
- Temporal lobe most common site
- 2 subgroups - focal aware and impaired awareness
- May lead to secondary generalised seizures
- Treat with antiepileptic medication
Difference between syncope and seizure
SYNCOPE - vasovagal and cardiac syncope can have twitching and jerking
EPILEPSY - rhythmic jerking of all limbs, loss of bowel and bladder control, postictal confusion
What defines someone as epilepsy resolved
- Seizure free 10 years
- No antiepileptic medication for 5 years
Epilepsy epidemiology
3-3.5% of Australians
40% of epileptics are children - many grow out of it
What % of aetiologies are unknown
50%
Aetiology of epilepsy
- Genetic
- Head trauma
- Stroke or brain haemorrhage
- Lack oxygen
- Degenerating conditions
- Brain infection
- Tumours
Subtyping focal seizures
- Motor and non-motor
- Aware and impaired awareness
Subtyping generalised seizures
- Motor = tonic-clonic and others
- Non-motor
What % of people with epilepsy have focal seizures
60%
Simple focal seizure
Preserved consciousness
Complex focal seizure
- Memory loss
- Impaired responsiveness at time of event
What amount of seizures have a known aetiology
1/3
Define kindling in regards to seizures
Repeated seizures lead to increased seizure duration and severity
Focal seizure epidemiology
- Incidence highest before 20 and after 60
- M > F
- Prevalence 4-8/1000
Clinical presentation focal seziure
- Movement of one side of the body
- Premonitory sensation/experience
- Automatisms (eg. smacking lips)
- Temporary aphasia
- Postictal focal neurological deficit
Risk factors for focal seizures
- Febrile seizures
- CNS infection
- Brain tumour
- Dementia
- Head trauma
- Stroke
- Mental retardation
- Family history
- Vascular malformations
Acute management focal seizure
- Lorazepam/Diazepam + airway management
- Phenytoin
- Phenobarbital/Propofol + Midazolam
Ongoing management focal seizures
- Antiepileptic monotherapy = Carbamazepine/Lamotrigine/Lacosamide/Valproic Acid
- Alternative antiepileptic monotherapy
- Polytherapy
- Surgery
Epidemiology GTCS
- 25% of epileptic patients have GTCS
- No age/sex/ethnicity association
Investigations for seizure
- EEG (to differentiate focal and generalised)
- BGL, FBC, electrolytes, toxicology, CT head, serum prolactin, serum CK
Acute management of GTCS
- Benzodiazepine and supportive care
2. Phenytoin
Ongoing management of GTCS
- Anticonvulsant monotherapy
- Alternative monotherapy
- Dual anticonvulsants
