Epilepsy Neuro Revision Flashcards
what is a seizure?
short episode of symptoms caused by a burst of abnormal electrical activity in the brain
what is epilepsy?
tendency to have recurrent seizures
2 types of seizure?
focal
generalized
what is a focal seizure?
the abnormal electrical activities tend to stay in one part of the brain
patients tend to have focal symptoms
what is a generalized seizure?
the burst of electrical activity is generalised to all the brain and unlike focal seizures, awareness is always impaired
can progress from focal seizures
what is an aura in relation to a seizure and what can it indicate?
sensation before a seizure
can take various forms such as deja-vu, change in vision, smell or taste etc
when present, regarded as focal aware seizures/simple focal seizures
symptoms of a focal aware seizures in the frontal lobe?
causes motor signs such as stiffness, twitching or spasm
jacksonian march = phenomenon where a focal aware seizure spreads from the distal part of the limb towards the ipsilateral face
symptoms of a focal aware seizure in the parietal lobe?
causes sensory menifestations which can take the form of tingling or numbness or pain
symptoms of a focal aware seizure seizures in the occipital lobe?
causes visual phenomena such as flashing lights, colours or hallucinations
symptoms of a focal aware seizures in the temporal lobe?
causes changes in mood or behaviour
rising epigastric sensation is a common manifestation
what is a focal impaired awareness seizure (complex focal seizure)?
type of focal seizure where the patient is not aware of his/her surroundings or what they are doing
usually arise in the temporal lobe in most cases
most common cause of mesial temporal lobe epilepsy which is typically associated with complex partial seizures?
hippocampal sclerosis
3 distinct components of a complex partial seizure?
the aura the absence (loss of consciousness) automatism (repetitive stereotyped movement)
features of automatism?
lip smacking, chewing, fiddling, walking, whistling etc
patient usually doesnt remember doing it
what is post ictal confusion?
post seizure confusion
what is an absence seizure?
abrupt sudden loss of consciousness and of all motor activity
type of generalised seizure
features of absence seizures?
loss of consciousness
loss of motor activity
tone preserved
no fall
attack ends as abruptly as it started
previous activity is resumed as if nothing happened with no post-ictal confusion
patient usually unaware of attack afterwards
how long to absence seizures usually last?
around 10 seconds
when do absence seizures usually develop>
childhood and adolescence
EEG characteristic of absence seizure?
3 Hz spike wave pattern
what is a myoclonic seizure?
type of generalised seizure
brief contraction of a muscle group or several muscle groups resulting in a small twitch or severe jerk
what is juvenile myoclonic epilepsy?
subtype of idiopathic generalised epilepsy
features of juvenile myoclonic epilepsy?
characteristic seizures which are brief myoclonic jerks (sudden, shock-like jerks affecting mainly shoulders and arms)
usually occur in the first hour or so after waking
when does myoclonus develop in juveline myoclonic epilepsy?
between 12 and 18 yrs old
what also often occurs with juvenile myoclonic epilepsy and when does this happen?
generalised tonic clonic seizures
usually occur months or years after the onset of myoclonus
how well does juvenile myoclonic epilepsy respond to therapy?
complete response to treatment in 80-90% of cases
lifelong therapy may be needed
what is a clonic seizure?
type of generalised seizure
seizure involving spasm and jerking of muscles
the elbows, legs and head will flex rapidly
which age group are clonic seizures most common in?
neonates and young children
features of a tonic seizure?
type of generalised seizure
causes a brief loss of consciousness
patient falls to the ground and often there is extension of the neck with upturning of the eyes and arching of the back
most common form of generalised seizure?
tonic-clonic
features of a tonic clonic seizure?
tonic phase
- patient quickly loses consciousness and skeletal muscles become stiff)
clonic phase
- muscles start to contract and relax rapidly, tongue might be bitten from strong jaw contractions
- may have cyanosis and incontinence
how is epilepsy diagnosed?
clinical history
EEG is a helpful adjunct to confirm type in some cases however it can be normal in some people
what imaging is used in epilepsy?
generally not used
however, when requested an MRI is first line
when is imaging used in epilepsy?
in those who develop epilepsy before age 2
any suggestion of a focal onset
in people who’s seizures continue despite use of first line medication
4 principles of anti-epileptic drug treatment?
establish diagnosis and epilepsy type
use one drug at a time (monotherapy)
initial titration should be to low maintenance doses and any upward/downward titration should be in slow stepped doses
polytherapy used if 3 types of monotherapy have failed
first line drugs in tonic clonic generalised seizures?
sodium valproate
lamotrigine
2nd line in tonic clonic generalised seizures?
levetiracetam
topiramate
clobozam
first line drug in absence generalised seizures?
ethosuximide
sodium valproate
1st line in myoclonic generalised seizures?
sodium valproate
2nd line in myoclonic generalised seizures?
levetiracetam
first line in focal seizures?
carbamazepine
lamotrigine
first line in unclassified seizures?
sodium valproate
2nd line in unclassified seizures?
lamotrigine
topiramate
general treatment for generalised seizures?
sodium valproate or lamotrigine
mechanism of carbamazepine?
Na channel inactivation
adverse effects of carbamazepine?
diplopia
ataxia
blood dyscrasias teratogenic
hyponatraemia
mechanism of phenytoin?
na channel activation
adverse effects of phenytoin?
nystagmus diplopia ataxia sedation gingival hyperplasia hirsutism peripheral neuropathy megaloblastic anaemia teratogenic (cleft palate and cardiac defects)
mechanism of lamotrigine?
blocks voltage gated na channels
side effects of lamotrigine?
rash
steven johnson syndrome
may exacerbate myoclonic seizures
can lamotrigine be used in pregnancy?
yes
mechanism of ethosuximide?
blocks thalamic T-type calcium channels
side effects of ethosuximide?
GI upset fatigue headache urticaria stevens-johnson syndrome
mechanism of sodium valproate?
Na channel inactivation with increased GABA concentration
side effects of sodium valproate?
GI upset liver failure neural tube defects tremor weight gain
who is valproate never used in?
women and girls of child bearing age
can be used if its the only thing that works and theyre definitely not pregnant
what is status epilepticus?
convulsive seizure which continues for a prolonged time (>5 mins)
or when convulsive seizures occur one after the other with no recovery time in between
first line treatment in status epilepticus in the community?
buccal or rectal midazolam
first line treatment of status epilepticus in hospital?
IV lorazepam
overall treatment for status epilepticus?
10mg benzodiazepines then wait 5 mins
another 10mg if unresolved then wait another 5 mins
if still unresolved then administer IV phenytoin or phenobartital
driving rules for single seizure while awake?
stop driving for 1 year
driving rules for seizure during sleep?
can drive but only if there is no awake seizures for 3 years
driving rules for seizure while awake but not affecting consciousness?
may still qualify for liscence if these are the only type of attack youve ever had and the first one was 12 months ago
HGV rules for epilepsy?
one off seizure = stop driving for 5 years
more than 1 seizure = must be seizure free and medication free for 10 years
