Neuro Flashcards
Status epilepticus
a single seizure lasting >30 mins or recurrent seizures without recovery of consciousness between episodes
Effect of epilepsy on pregnancy
Increased risk of congenital anomaly, mainly secondary to use of AED during pregnancy
Increased risk of epilepsy in offspring
- 1 affected parent = 4%
- 1 sibling = 10%
- Both parents = 15%
Increased risk of fetal hypoxia with repeated or prolonged seizures
No difference in miscarriage or obstetric outcomes
Maternal death
Effect of pregnancy on epilepsy
Seizure frequency:
- Increased in 37% (highest risk in peripartum period)
- No change in 50%
Increased seizure frequency may be caused by:
- Hormonal influence
- Reduced serum AED level - Vomiting, malabsorption, increased clearance
- Emotional stress
- Sleep deprivation
- Non-compliance because of fear of teratogenic effects
- Hyperventilation during labour
- Lack of absorption from GIT during labour
Unknown whether pregnancy increased SUDEP
congenital anomaly rates of AED
Levotiracetam - 0.7 per 100
- But newer agent - need more data
Lamotrigine - 2 per 100
Carbamazepine - 3 per 100
Sodium valproate - 11 per 100
NTD
Cleft palate
Congenital heart defects
Minor - dysmorphic features, low IQ, ADHD, autism, abnormal nails
Pre-pregnancy and antenatal key points of management
for epilepsy
Consider AED withdrawal if >2y without seizure on minimal AED dose and negative EEG
- Should be done >6/12 prior to pregnancy,
Risk factors for relapse / deterioration in pregnancy:
- > 1 seizure / month
- Multiple seizure types
- Tonic-clonic or prolonged seizures
- Juvenile myoclonic seizure (AED should continue)
- Positive EEG
monotherapy at lowest dose
High dose folic acid for 12 weeks prior to conception
- Then continue throughout pregnancy because of small risk of folate-deficiency anaemia
Drug levels for carbamazepine and lamotrigine
- Anatomy scan at 18-20/40
- Fetal cardiac scan at 22/40
Serial growth
1-2% will have seizures in labour
Postpartum management of epilepsy
Neonates should have vitamin K 1mg IM to avoid coagulopathy
Breastfeeding is not contraindicated with AEDs
- Recommended to lower risk of neonatal withdrawal
Lamotrigine should not be initiated in breastfeeding mothers, but can continue
- Lamotrigine and phenobarbitone cross in significant amounts (30-50%) to breast milk
If AED increased during pregnancy, this should be gradually return to pre-pregnancy dose
Hepatic enzyme-inducing AEDs (phenytoin, primidone, phenobarbitone, carbamazepine) reduce contraceptive efficacy of oestrogens and progestogens
Depo Provera, Mirena and CuIUD are effective
Oestrogen can induce the metabolism of lamotrigine, so lowering drug levels
Effect of pregnancy on migraine
50-90% of women with pre-existing classical migraine improve during pregnancy
- worse in first, then improve
Pre-existing migraine is associated with an increased risk of PET and IUGR
Management of migraine
Paracetamol with metoclopramide
Other anti-emetics may be used
Codeine
NSAIDs - in short courses for acute attacks in first and second trimesters
Contraindicated:
- Ergotamine
Prophylaxis
- Aspirin (1st line(
- Propranolol 10-40mg tds
- Tricyclic antidepressants (amitriptyline 25-50mg nocte)
Incidence of Bell’s palsy
and clinical features
Occurs much more commonly in pregnancy - 10-fold increase
Incidence ~45 / 100,000 pregnancies
Unilateral lower motor neurone lesion of the facial nerve (cranial nerve VII)
Facial weakness
- Loss of power of frontalis muscle - cannot wrinkle forehead on the affected side
May be associated pain around the ear lobe or loss of taste on the anterior two-thirds of the tongue
Most cases occur around term
Peripartum - possibly related to swelling of the facial nerve within the petrous temporal bone
Management of Bell’s palsy
80-95% improve spontaneously
- May be slowly over a period of months
No evidence Bell’s palsy in pregnancy is associated with a worse outcome
Short (2 week) course of corticosteroids (prednisolone 40mg/day, tapered after first week) may speed or increase the change of recovery
- Needs to be started ASAP - preferably within 24-72h of onset of symptoms
Carpal tunnel syndrome
2-3% of women in pregnancy
Paraesthesia and numbness in thumb and lateral 2 1/2 fingers
Reassurance as likely to improve / abate after delivery
Wrist splints
- Avoid flexion of the wrist
Local steroid injection
Surgical division of the flexor retinaculum
CEREBRAL VEIN THROMBOSIS
- incidence
- pathophysiology
- features
- Incidence ~1 / 10,000
Associated with high mortality rate
Most cases in the puerperium
Hypercoagulable postpartum state
Possible trauma to the endothelial lining of cerebral sinuses and veins during labour
+/- infection and dehydration
Features:
- headache, seizures, raised ICP, vomiting, hemiparesis
CT or MRI venogram for diagnosis
HAEMORRHAGIC STROKE
- causes
PET / eclampsia
- vasospasm, loss of autoregulatory control and breakthrough of the vessel wall
Ruptured vascular malformations
AVMs are oestrogen sensitive and therefore tend to dilate in pregnancy
In untreated AVM, no advantage to vaginal delivery vs. CS
Risk of subarachnoid haemorrhage in pregnancy
Risk increased 2-3 fold during pregnancy
Risk increases 20-fold in the puerperium
Multiple sclerosis
- incidence and what it is
1 per 1000 population
Female : male = 2 : 1
Autoimmune disease resulting in multifocal demyelination of the CNS
85% have relapsing-remitting disease
