Seizures

Question 1

classification of seizures?

Answer 1

epileptic
and
non-epileptic (NES)-these can be split into organic e.g. hypoglycaemia, syncopal, sleep disorders, TIAs and psychogenic-dissociative seizures, panic attacks, factitious seizures.

Question 2

most common type of non-epileptic seizure (NES)?

Answer 2

dissociative seizures-these are involuntary, pt has no control over them
some underlying psychological distress-body ‘dissociates’ from the brain in attempt to stop a part. distressing experience from entering the brain. physical response to an emotional reaction.

Question 3

what part. features of the seizure itself may suggest NES?

Answer 3

duration over 2 mins
gradual onset
fluctuating course
violent thrashing movements
side to side head movement
asynchronous movements
eyes closed
recall for period of unresponsiveness

Question 4

what endocrine blood substance rises in more than 90% of pts following a tonic-clonic seizure?

Answer 4

serum prolactin

Question 5

gold standard investigation for non-epileptic seizures?

Answer 5

video-EEG

Question 6

what is status epilepticus?

Answer 6

continuous seizure for 30 minutes or longer, or recurrent seizures without regaining consciousness lasting 30 minutes or longer.

Question 7

define provoked seizures?

Answer 7

seizures occurring within 1 week of an acute condition e.g. encephalitis, head injury, cerebral infarct, craniotomy and cerebral haemorrhage.

Question 8

indications for starting anti-epileptic drug treatment after a 1st seizure?

Answer 8

pt has a neurological defecit
brain imaging shows a structural abnormality
EEG shows unequivocal epileptic activity
pt or their family or carers consider the risk of having a further seizure unacceptable.

Question 9

which anti-epileptic drug treatment may exacerbate absence seizures?

Answer 9

carbamazepine

Question 10

recommended anti-epileptic drug for absence seizures?

Answer 10

ethosuximide or valproate

if CI or not tolerated, then lamotrigine

Question 11

recommended anti-epileptic drug for generalised tonic-clonic seziures?

Answer 11

sodium valproate (NOT in women of childbearing age) or lamotrigine

Question 12

recommended anti-epileptic drug for focal (partial) seizures?

Answer 12

carbamazepine

Question 13

define epilepsy

Answer 13

disease of the brain in which pt susceptible to recurrent, unprovoked seizures

• although unprovoked, there may be particular triggers e.g. flashing lights, alcohol, but these triggers would not cause seizures in people without epilepsy, unlike other organic problems e.g. hypoglycaemia, hyponatraemia.
  e. g. juvenile myoclonic epilepsy-type of primary generalised epilepsy, seizures and jerks often occur on a morning after waking and triggers include lack of sleep, alcohol and strobe or flickering lights.

Question 14

post stroke, what seziure activity may be seen?

Answer 14

acutely within 1st 24hr patient may develop continuous jerking movements in only the paretic limb, this is NOT epilepsy
can tx with anti-convulsants, but avoid sedating drugs e.g. BZDs as could be very risky alongside other complications pt susceptible to post stroke e.g. swallowing difficulty
long term patients may develop epilepsy

Question 15

which part of the brain is most susceptible to epileptic activity?

Answer 15

hippocampus

Question 16

what is a focal seizure?

Answer 16

also known as a partial seizure
sudden onset of electrical discharge restricted to a limited part of the cortex of 1 cerebral hemisphere. can be further characterised according to whether presence of:
aura-smell or auditory hallucination, visual distortion, deja-vu, fear, rising abdominal sensation, tingling. rapid onset contrasts with more gradual seen in migraine patients BUT there is the rarity of a rapidly evolving occipital seizure where aura can then be followed by a headache.
motor features e.g. 1 limb jerking (jacksonian seziure)
loss of awareness or responsiveness e.g. many temporal lobe seizures.

simple partial=pt retains consciousness
complex partial= may have aura. include automatisms e.g. lip smacking, unawareness of surroundings or may wander.

can evolve into bilateral convulsive seizure-secondary generalised seizure.

Question 17

features of a generalised seizure, and types?

Answer 17

involves both cerebral hemispheres simultaneously, always loss of awareness/consciousness
types:
tonic-clonic
clonic
tonic
myoclonic
absence (petit mal)
atonic-loss of motor tone and LOC, pt drops to the floor

Question 18

features of absence seizures on presentation and on EEG?

Answer 18

loss of awareness
vacant expression for less than 10s, eyelid fluttering, staring
typical attacks never due to acquired lesions e.g. tumours, feature of primary generalised epilepsy
EEG-3Hz spike and wave activity

Question 19

main pathology causing temporal lobe epilepsy?

Answer 19

hippocampal sclerosis
main RF=childhood febrile convulsions
changes often visible on MRI
1 of the more common causes of refractory epilepsy, may be amenable to surgery-resection of temporal lobe

Question 20

what RFs for epilepsy might we enquire about in the hx of a pt with seizures?

Answer 20

intracranial infection-meningitis, encephalitis
childhood febrile convulsions-cause hippocampal sclerosis=main pathology responsible for temporal lobe epilepsy. risk of epilepsy increased in patients with febrile convulsions if complex-focal, prolonged and repeated in the same illness
significant head injury
FH of epilepsy

Question 21

investigations in suspected epilepsy?

Answer 21

blood tests-FBC, U+Es, LFTs, glucose, Ca2+, Mg2+
serum prolactin
12 lead ECG-arrhythmias, QT interval-note px of pt with seizure following alarm clock going off
check drug levels of anti-convulsants in patients with hx of epilepsy
EEG, video-EEG
MRI brain-part. important in focal onset seizures-more likely struct. abnormality e.g. tumour, and in older patients-more likely cerebrovascular problems

Question 22

driving guidance for epilepsy?

Answer 22

patient must notify the DVLA and must not drive
pt must be seizure free for 1 year before reapplying for their licence
if pt has 1st one-off seizure, musn’t drive for 6 months
if pt has seizures whilst awake and asleep, may qualify for a licence if only attacks you’ve had in last 3 years have been when pt was asleep
if only have attacks when asleep, may qualify for a licence if it’s been 1 year or more since 1st attack
if attacks are not assoc. with LOC and these are the only ones you ever had, may qualify for licence if 1st 1 was 1 yr ago

if bus, coach or lorry licence:
more than 1 seizure, must show haven’t had a seizure and haven’t had any AEDs for last 10 years
if 1 off seizure, must show haven’t had a seizure and no AED for 5 years

If you had a seizure because your doctor changed or reduced your anti-epilepsy medicine, you can reapply when: the seizure was more than 6 months ago
you’ve been back on your previous medication for 6 months
you haven’t had another seizure in that time

Question 23

features of primary generalised epilepsies?

Answer 23

present in childhood and early adult life
brain structurally normal, but abnormalities in ion channels controlling neuronal firing, abnormalities in NT release and synaptic connections
polygenic with complex inheritence
e.g. childhood absence epilepsy, juvenile myoclonic epilepsy-myoclonic jerks, later followed by gen tonic-clonic seizures, triggers=sleep lack, alcohol, flashing lights.

Question 24

what additional treatment should be given to women thinking about becoming pregnant and who take anti-epileptic medication?

Answer 24

folic acid 5mg/day, well before pregnancy and throughout 1st trimester

Question 25

additional treatment during last month of pregnancy for women on phenytoin?

Answer 25

Vit K-to prevent clotting disorders in the newborn

Question 26

ADRs of sodium valproate?

Answer 26

teratogenic
weight gain
transient hair loss
hyponatraemia
convulsions
confusion
thrombocytopenia
tremor
can cause hepatic dysfunction and pancreatitis

Question 27

what is antiepileptic hypersensitivity syndrome?

Answer 27

rare but potentially fatal syndrome assoc. with some AEDs-carbamazepine, phenytoin, phenobarbitol, lamotrigine
symptoms between 1 and 8 wks of exposure: fever, lymphadenopathy, rash, also other systemic signs-haem, renal, liver complications, vasculitis
drug must be WD immediately and pt must not be exposed again

Question 28

what are interactions between antiepileptic drugs usually the result of?

Answer 28

hepatic enzyme induction or inhibition (CYP450)

Question 29

when is risk of AEDs used during pregnancy highest?

Answer 29

during 1st trimester

Question 30

what must women during 2nd half of pregnancy who have a seizure be assessed for before any AED treatment is changed?

Answer 30

eclampsia

Question 31

what notification is required for pregnant women with epilepsy?

Answer 31

whether taking AEDs or not, should be encouraged to notify the UK Epilepsy and Pregnancy register

Question 32

what types of seizures may carbamazepine exacerbate?

Answer 32

absence, myoclonic, tonic and atonic

Question 33

what serious reaction do we worry about when combining sodium valproate and lamotrigine?

Answer 33

serious skin rashes such as Stevens-Johnson syndrome

Question 34

what monitoring is required for a patient on levetiracetam during pregnancy?

Answer 34

fetal growth

Question 35

what congenital anomaly is phenytoin associated with?

Answer 35

cleft palate

Question 36

when can AED treatment be considered to be withdrawn?

Answer 36

if patient has been seizure free for more than 2 years

drugs will be stopped over 2-3months