Epilepsy Flashcards
what is epilepsy
response to spontaneous, intermittent abnormal excitatory signals in the brain
inhibitory neurotransmitter in brain
GABA
what increases with GABA
Chloride
excitatory neurotransmitter in the brain
glutamate
what receptors does glutamate bind to
NMDA receptors
what increases with glutamate
Calcium
what are the 2 broad groups of seizures
generalized
focal (partial)
what are the 3 types of partial seizure
simple
complex
partial with secondary generalization
features of partial simple seizure
awareness intact
focal motor/autonomic/psychic or sensory (e.g. visual, olfactory) symptoms
no post-ictal symptoms
clinical features of partial complex seizures
awareness impaired
deja vu
lip smacking/jaw clenching/vertigo (automatism)
post ictal symptoms common
what lobe does complex partial seizures usually arise in
temporal
describe a partial seizure with secondary generalisation
electrical disturbance starts focally then spreads widely causing a typically convulsive seizure (pseudoseizure)
what are post ictal symptoms
headache
confusion
myalgia
sore tongue
seizures in frontal lobe
motor features - posturing, head/eye movements, peddling of legs dysphagia/speech arrest
seizures of parietal lobe
sensory disturbances - tingling, numbness
motor symptoms are rare - only if spread to pre-central gyrus)
seizures of occipital lobe
visual phenomena - spots, lines, flashes
1st line treatment for partial seizures
carbamazepine
2nd line treatment for partial seizures
sodium valproate
lamotrigine if woman of child bearing age
lamotrigine will diffuse into breast milk. True/false?
true - no harm to baby
what are the types of generalized seizures
absent (petit mal) tonic-clonic seizure (grand mal) myoclonic tonic atonic infantile spasms
brief (<10s) pauses e.g. suddenly stops talking mid sentence then carries on
absent seizures
typical EEG finding for absent seizures
3 hertz notch
when do absent seizures typically present
childhood
limbs stiffen then jerk with loss of consciousness
tonic-clonic
do you commonly get post-ictal symptoms in tonic-clonic seizures
yes
sudden jerk of a limb, face of trunk
may throw suddenly to ground
myoclonic
what drug should be avoided in myoclonic seizures
carbamazepine
sudden loss of muscle tone causing fall with no loss of consciousness (floppy)
atonic seizure
what condition is associated with infantile spasms
tuberous sclerosis
most common cause of seizures
idiopathic (often familial)
structural causes of seizures
cortical scarring (previous head injury) developmental space occupying lesion stroke hippocampal sclerosis ((after febrile convulsion) vascular malformations
non-epileptic causes of seizure
trauma stroke haemorrhage raised ICP alcohol/benzodiazepine withdrawal metabolic disturbances infection
what drugs can trigger seizures
cocaine
tricyclics
tramadol
theophylline
triggers for seizures
alcohol stress sounds/flashing lights drugs lack of sleep
most common time for epilepsy to present
childhood-adolescence
investigations of suspected seizure
ECG
MRI/CT - if suspected skull fracture, deteriorating GCS, focal signs, suggestion of other pathology
EEG - doesn’t always prove patient doesn’t have epilepsy
treatment of generalised tonic-clonic
1st - sodium valproate or lamotrigine
2nd line - carbamazepine or topiramate
treatment of absence seizures
sodium valproate
lamotrigine
ethosuximide
myoclonic seizures treatment
sodium valproate or lamotrigine 1st line
avoid carbamazepine
process of switching drugs
introduce new drug when still on old drug
only withdraw old drug when established on new drug
carbamazepine
action
SE
action - blocks voltage gated Na channels in pre-synaptic neuron which decreases excitable action potentials
SE: leucopenia, visual changes, impaired balance/drowsiness, rash
lamotrigine
action
SE
action - blocks voltage gated Na channels in pre-synaptic neuron which decreases excitable action potentials
SE: rash (toxic epidermal necrolyis,)hypersensitivity, visual changes, tremor, agitation, vomiting, aplastic anaemia
phenytoin
action
SE
action - blocks voltage gated Na channels in pre-synaptic neuron which decreases excitable action potentials
SE: visual changes, tremor, ataxia
Na valproate
action
SE
action: enhances GABA synthesis (increasing inhibitory signals) SE: VALPROATE Appetite (weight gain) Liver failure Pancreatitis Reversible hair loss Oedema Ataxia Teratogenic, tremor, thrombocytopenia Encephalopathy
levetiracetam SE
mood swings
topiramate SE
sedation
dysphagia
weight loss
advice for women with epilepsy planning a pregnancy
folic acid supplements 5mg/day
no valproate
most drugs present in breast milk (lamotrigine not thought to be harmful to infants)
what drugs are liver enzyme-inducing AEDs
carbamazepine
phenytoin
barbiturates
what is affected in enzyme inducing AEDs
morning after pill not adequate
affect contraceptive pill and Depo-Provera
rules for ordinary driving licenses with diagnosed epilepsy
can drive if had not had a seizure (on or off medication) for one year
only have seizures when asleep
have previously had awake seizures but have only had seizures when asleep for the last 3 years
rules for ordinary driving license with one -off seizure
can drive 6 months after seizure if:
only ever one seizure
clear EEG
don’t need to take AEDs
rules for HGV/PCV license in one-off seizure
can get license back after 5 years if :only ever one seizure
clear EEG
no AEDs
low risk of further seizures
rules for HGV/PCV with diagnosis of epilepsy
can get license if:
seizure free for 10 years
no treatment for 10 years
low risk of seizure in the future
seizure for >5 minutes
status elipticus
acute management of status elipticus
airway management and O2
benzodiazepine - IV lorazepam (if IV access)
if not - IM midazolam
what is non-epileptic attack disorder
happens for psychological reasons rather than physical ones
e.g. thoughts, feelings, past experiences
clinical findings on non-epileptic distress disorder
normal EEG
seizure like episodes
