Flashcards in Epilepsy Deck (35):
What is epilepsy?
A paroxysmal disorder in which cerebral cortical neuronal discharges result in intermittent, stereotyped attacks of altered consciousness, motor or sensory function, behaviour or emotion.
-recurrent tendency to siezures
what is the pathogenesis of epilepsy?
abnormal cortical neuronal communication
-increased connectivity (too many connections)
-increase in excitatory transmission (too many excitatory signals – glutamate)
-failure of inhibitory mechanism (GABA)
What are the causes of epilepsy
Primary (idiopathic): over 50%
Secondary: e.g. vascular/infection/neoplasia/drugs... etc
How are epileptic siezures classified?
-generalised (tonic clonic)
What is a partial seizure?
This is a seizure which begins focally, in a particular area giving specific s/s
Simple partial seizures:
Where consciousness is retained throughout the attack
Complex partial seizures:
Consciousness is impaired at any stage
They may become secondarily generalised where the patient loses consciousness with clinical evidence of spread across cerebral cortex e.g. bilateral convulsive movements
-Starts focally then loss of consciousness and have tonic-clonic seizures.
Generalised seizure - what is a:
Both cerebral hemispheres are involved from the start of the seizure
Tonic-clonic - grand mal
Tonic – increase stiffness and rigidity
Myoclonic – sporadic jerks
Absence – petit mal (blank stare and no post-ictal confusion)
Atonic – drop attacks: complete loss of tone
Primary generalised epilepsy:
-when does this onset?
-what kind of seizures?
Describe the nature of the tonic clonic seizures in primary generalised epilepsy:
-what happens before the attack
-what happens during the attack
-what happens after the attack
tonic-clonic seizures (grand-mal)
before an attack vague symptoms of dizziness/irritability
convulsion may begin with an epileptic cry – loss of consciousness and collapse
tonic phase – generalised muscle spasms occur
clonic phase – sharp repetitive muscle jerks
tongue biting, incontinence of urine and salivation may occur
when jerking stops patient is left unconscious for approx.. 30mins
confusion and drowsiness then occur for several hours
on recovery usually headache and stiffness or injury from the fall
muscular spasms can cause vertebral fractures
What is the treatment for primary generalised tonic-clonic seizures?
second line: Lamotrigine/carbamazepine
-when does this occur
-is it commoner in males or females
-always begin in childhood (4-8years)
-commoner in girls
-describe the attacks
-what is seen on EEG?
attacks occur without warning
child stares blankly into space and stops talking
eyes may flutter or roll up under lids
recovery occurs within seconds and there may be many daily attacks
absences are associated with characteristic EEG abnormalities (3-HZz generalised, symmetrical, spiked wave complexes)
What is the risk of seizures after absence seizures
Risk of seizures as an adult following this is 10%
What is treatment of absence seizures
sodium valproate or ethosuximide
sodium valproate particularly effective if co-existent tonic-clonic seizures in primary generalised epilepsy
Carbamazepine might make these worse
Describe the nature of temporal lobe epilepsy?
This is a complex partial seizure
aura of attack: fear or sensation déjà vu, hallucinations or rising sensation in epigastrium
patients may become confused/anxious and exhibit organised stereotyped movements – automatism
can be more complex and sometimes aggressive/violent
-where do these begin?
-what are these assoc. with?
-what happens after the attack?
-what is epilepsia partialis continua?
focal motor attacks that typically begin in corner of mouth, thumb, index finger or the great toe
movements spread across face or ascend up limb (jacksonian march)
generally associated with underlying organic brain disease
tumour in motor cortex
after attack the affected limb(s) may remain temporarily weak
epilepsia partialis continua is a rare form where the attack persists for days, weeks or even months
What are the treatment of partial seizures?
carbamazepine or lamotrigine
second line: sodium valproate
When should an MRI scan be used to investigate seizure?
-Clearly focal onset
-those that begin after 25yrs
When is prophylactic treatment considered for epilepsy?
Prophylactic treatment is mostly only considered after a second attack
What is the treatment for myoclonic seizures?
second line: clonazepam, lamotrigine
-what are the s/e?
-what are the side effect?
-what are the side effects?
-what are the side effects?
in pregnancy - what is sodium valproate assoc. with?
neural tube defects
in pregnancy which antiepileptics is considered the least teratogenic?
What is phenytoin assoc. with in pregnancy?
-It is advised that pregnant women taking phenytoin are given vitamin K in the last month of pregnancy to prevent clotting disorders in the newborn
What may need to change with the dose of lamotrigine in pregnancy?
studies to date suggest the rate of congenital malformations may be low. The dose of lamotrigine may need to be increased in pregnancy
Is breast feeding safe with antiepileptics?
Breast feeding is generally considered safe for mothers taking antiepileptics with the possible exception of the barbiturates
What is the general advice for contraception for women taking anti-epileptics?
consistent use of condoms, in addition to other forms of contraception.
For women taking:
phenytoin,carbamazepine, barbiturates, primidone, topiramate, oxcarbazepine: which contraceptive is:
UKMEC 3: the COCP and POP
UKMEC 2: implant
UKMEC 1: Depo-Provera, IUD, IUS
For women taking lamotrigine which contraceptive is:
UKMEC 3: the COCP
UKMEC 1: POP, implant, Depo-Provera, IUD, IUS
Describe the acute management of a seizure
If have IV access:
Give midazolam 0.05-0.1mg/kg up to 10mg IV
Diazepam 0.-0.2mg/kg up to 20mg IV
If don’t have IV access:
Midazolam 5-10mg intranasally/buccally
Diazepam 10-30mg per rectum
Reassess and wait for seizure to cease
If continuing Gain IV access and repeat dose
If it continues – status epilepticus
Start phenytoin infusion – 18mg per kg IV
Monitor heart – bradycardia and hypotensive
Intubate and ICU if still fitting
What is status epilepticus, what is the treatment?
Status epilepticus – if they have been having a seizure for more than 5mins treat
pre-hospital: diazepam 10-20mg PR or midazolam 10mg buccally
first line in hospital: lorazepam (or diazepam) IV
if benzo unsuccessful: phenytoin infusion 15-18mg/kg at a rate of 50mg/minute
officially status if more than 30mins or 3 seizure without regaining consciousness
Describe the driving rules for seizures and epilepsy
first seizure: 6 months off driving*.
For patients with established epilepsy they must be fit free for 12 months before being able to drive
If sleep-related, have to have an established pattern of seizures occurring only in relation to sleep during the previous 3 years
More stringent for heavy goods vehicles and passenger-carrying vehicles