neurology in pregnancy Flashcards
what is the incidence of epilepsy in woman of childbearing age
0.5%
what are the types of epilepsy
- primary generalised - tonic clonic, absences(petit mal, few seconds rapid onset and no post ictal, precipitated by hyperventilation) myoclonic jerks
- partial / focal (including temporal)
temporal is associated with an aura, lasts 1 minute or more, and have post seizure confusion
what is the ddx for seizures in pregnancy
Secondary causes - previous surgery to cerebral hemispheres, IC mass lesion (AVM, meningiomas)
Antiphospholipid syndrome
eclampsia
cerebral vein thrombosis
Stroke (4% have seizures)
Subarachnoid haemorrhage
Thrombotic thrombocytopenic purpura
hypoglycaemia - (diabetes, hypoadrenalism, hypopituitarism, liver failure)
Hypocalcaemia (MgSO4, hypoparathydroidism)
Hyponatraemia (Hyperemesis, hypoaldrenalism, pre eclapmsia)
Infection (TB and toxo)
Post dural puncture D4-7
Drug and alcohol withdrawal
Gestational epilepsy
Non epileptic seizure disorder - pseudoseizures ( no cyanosis, resistant no passive eye opening, down going plantars, biting cheek not tongue, positive conjunctival reflex
First seizure in pregnancy
What Ix need to occur
BP, urinalysis, Plt. coags, blood film
Blood glucose, calcium, Na urea Cr LFTs
CT/ MRI head
EEG
How does pregnancy effect epilepsy - seizures frequency
In most does not change the frequency of the seizures
2/3 same 1/3 different (half increased half decreased)
If poorly controlled or stops meds increased risk of seizures
Death from aspiration
SUDEP associated with high seizure frequency, no. of meds, IQ, early onset
What are reasons pregnancy could increase the seizure frequency
pregnancy itself
Stopping medications
N+V reducing drug levels
Increased plasma volume, increased hepatic and renal clearance, reduction in protein binding
Lac of sleep
Lack of absorption of oral meds in labour
hyperventilation during labour
what is the effect of epilepsy on pregnancy
no increase risk in miscarriage or obstetric complications unless seizure results in abdo trauma
risk is teratogenic AED
what is Status epilepticus
Status epilepticus is when a seizure lasts longer than 5 minutes or when seizures occur close together and the person doesn’t recover between seizures.
This is rare (<2% woman with epilepsy in pregnancy) and needs to be treated vigorously
What as the risk of the child having epilepsy if
Mum or dad has it
sibling affected
mum and dad has it
one parent 4-5%
sibling 10%
both parents 15-20%
increased risk if mum had it before the age of 10
all AEDs are teratogenic
what are the major + minor malformations and what drugs cause them
most drugs 5% risk, valproate 10%
Increased with polypharmacy Valproate lamotrigine and carbamezepine are dose dependent
Major
NTD - valproate
congential heart defects - phenytoin phenobarbitone and valproate
orofacial clefts - phenobarbitone
Minor - fetal anticonvulsant syndrome dysmorphic features including irregular teeth low set ears V shaped eyebrow, broad nasal bridge Hypertelorism (wide apart eyes) Hypoplastic nails and distal digits hypoplasia of midface
Valproate - impaired psychomotor development, reduced IQ, autism, ADHD
Management of pregnancy with epilepsy
prepreg can try to wean off valproate or reduce the dose. TDS or QID / modified release to reduce large peaks. monotherapy better
counselling around compliance
Folate 5mg 12/52 prepreg and throughout
(helps with folate def anaemia)
don’t change AED if seizures under control
counselling - shallow baths or showers, family aware to place in recovery position,
Prenatal screening, detailed anatomy including fetal echo
drug levels (increase plasma volume, increased hepatic and renal clearance, decrease drug binding) - drugs with little protein binding are more likely to need levels / dose adjustments eg carbamezapine and lamotrigine
Vitamin K in the last 4 weeks of pregnancy 10-20 mg to reduce the risk of haemorrhagic disease of the new born
Which AEDs need dose changes in pregnancy and why
carbamezapine and lamotrigine (may end up 2-3X higher) and also levetiracitam
drug levels reduce due to increased liver and renal function and haemodilution. They increase as less protein binding occurs and more free drug. Drugs with less protein binding therefore drop less and need to be uptitrated
lamotrigine is the only one that needs routine drug levels
what is the recommendation for Vit K
in the last 4 weeks of pregnancy woman on hepatic enzyme inducing AEDs should have 10-20 mg Vit K to reduce the risk of hemorrhagic disease of the newborn as Vit K dependent clotting factors in the neonate can be reduced
neonatal Vit K 1mg IM
intrapartum seizures
incidence
management
prevention
1-2 % of woman will epilepsy with seize in labour / 1-2% will seize within 24 hours of delivery Continue regular meds early epidural (prevent pain and anxiety)
Acute management
Oxygen
IV lorazepam 4 mg over 2 minutes
diazepam 10-20 mgPR or 10-20 IV 2mg / minute
What is the advice around breastfeeding and epilepsy
Recommended.
the drug is 3-5% concentration in BM (less then had in utero) (lamotrigine and phenobarbitone cross 50% + cannot be metabolised in the neonatal liver so can get accumulation - lamotrigine should not be started in breastfeeding mothers)
potential for withdrawal (esp phenobarbitone)
can plan feeds before not after dosing
