Neurological Disease Flashcards
What is the prevalence of epilepsy?
0.5% women of childbearing age
For a first seizure in pregnancy, what are the appropriate investigations?
BP, urinalysis, FBC, clotting screen, U+Es, LFTs (PET)
BSL
CT / MRI Brain
EEG
What is the effect of pregnancy on epilepsy?
For most women, no effect on seizure frequency
Those with poorly controlled epilepsy more likely to deteriorate
Highest risk of seizures postpartum
What is the effect of epilepsy on pregnancy?
No increased risk (unless seizure results in abdominal trauma)
Status epilepticus is dangerous for mother and fetus
Fetus relatively resistant to short episodes of hypoxia
What is the risk of a fetus developing epilepsy if
A) Either parent has epilepsy
B) Previously affected sibling
C) Both parents have epilepsy
A) 4-5%
B) 10%
C) 15-20%
What are the major congenital anomalies caused by anti-epileptics?
Neural tube defects
Orofacial clefts
Congenital heart defects
In epilepsy, what should be prescribed for women taking hepatic enzyme-inducing AEDs? And when?
Vitamin K
Last 4 weeks of pregnancy
Vitamin K clotting factors may be reduced
Risk of Haemorrhagic disease of the newborn is increased
When are women with epilepsy most at risk of having a seizure?
1-2% during labour
1-2% in the first 24h postpartum,
Therefore, women should not be left unattended in labour or for the first 24h postpartum
And should continue their regular AEDs in labour
When does the neural tube close?
Gestational day 26
What is relevant when considering contraception and epilepsy?
Women taking hepatic enzyme-inducing antiepileptics
Require higher doses of oestrogen to achieve adequate contraception
Same with the POP
Need double dose of ECP
Most headaches in pregnancy are due to…
Tension headache or migraine
What are the clinical features of a migraine?
Throbbing, unilateral severe headache
Prodromal symptoms: visual - transient hemianopia, aphasia, sensory symptoms
Nausea and vomiting
Photophobia or noise sensitivity
Hemiplegic migraine may rarely lead to cerebral infarction
What is the pathogenesis of tension headaches?
Muscle contraction
Often related to periods of stress
What is the pathogenesis of migraines?
Primary neurovascular disorder
Inflammatory component
Vasodilation of cerebral blood vessels, possibly related to platelet aggregation and serotonin release
What are the differential diagnoses of a headache in pregnancy?
PET Post-dural puncture headache SAH Meningitis Cerebral venous thrombosis Idiopathic (benign) intracranial hypertension Intracranial mass lesions Reversible cerebral vasoconstriction syndrome
Pre-existing migraine is associated with an increased risk of…
PET
Outside pregnancy: Stroke IHD VTE HTN Diabetes
What is the management for migraines in pregnancy?
LDA prophylaxis
Beta blockers (propranolol)
TCA: amitriptyline
What are the clinical features of Multiple Sclerosis?
Relapsing and remitting clinical course
Optic neuritis, diploid, sensory symptoms, weakness of the limbs
Variable course
What is the pathogenesis of Multiple Sclerosis?
Exact pathogenesis unknown
Multiple areas of demyelination within the brain and spinal cord
What is the effect of pregnanc on MS?y
Decrease relapse rate in 3rd trimester ? Decrease in cell mediated immunity
Neuropathic bladder: may have increased problems with UTIs
Rate of relapse increases in the first 3 months postpartum
How is a severe acute relapse of MS managed, in pregnancy?
High dose steroids
Is there any contraindication to epidural anaesthesia in MS?
No
What is the pathogenesis of Myasthenia Gravis?
IgG antibodies directed against post-synaptic antigens on the motor end plate
Block neuromuscular transmission
Causing weakness and fatigue or skeletal, but not smooth muscle
What is the effect of myasthenia Gravis on pregnancy?
Transplacental passage of antibodies
Fetal Arthrogryposis (can be fatal)
- contractures due to lack of movement
- polyhydramnios due to impaired swallowing
How is labour affected by Myasthenia Gravis?
First stage unaffected (uterus has smooth muscle)
Second stage may be impaired (maternal effort using voluntary striated muscle is required)
How is Myasthenia Gravis managed in pregnancy?
Measure thyroid function
Anticholinesterases
Immunosuppression
MgSO4 should be avoided for seizure prophylaxis in pre-eclampsia since it may precipitate a crisis
What is the effect of Myasthenia Gravis on anaesthesia?
More resistant to the depolarising neuromuscular blocking agents such as succinylcholine
Extremely sensitive to non-depolarising muscle relaxants
What % neonates born to mothers with Myasthenia Gravis may be affected by transient neonatal MG?
10-20%
Due to transplacental passage of IgG antibodies
What are the clinical features of benign intracranial hypertension?
Headache, often retro-orbital Obesity, rapid weight gain Diplopia Papilloedema CSF pressure increased
What is the effect of pregnancy on benign intracranial hypertension?
BIH tends to worsen in pregnancy, possibly related to weight gain
What is the management of benign intracranial hypertension?
Limitation of weight gain
Monitor visual fields and acuity - in severe cases, infarction of the optic nerve may occur, leading to blindness Any impairment of VF / VA, should prompt treatment with corticosteroids
Thiazide diuretics and acetazolamide (outside of pregnancy)
Repeated CSF drainage of insertion of a shunt
Most strokes associated with pregnancy occur in the distribution of…
The carotid and middle cerebral arteries
Most cases occur in the first week after delivery
What are the causes of stroke in pregnancy?
Unusual causes are more common in pregnancy
- Cardiac causes of arterial emboli, arrhythmia
- MV prolapse / disease
- Peripartum cardiomyopathy
- Infective endocarditis
- Paradoxical embolus
- Aortic / carotid artery dissection
- APS
- Sickle cell disease
- TTP
- PET / eclampsia
What is the pathogenesis of Haemorrhagic stroke in PET?
Cerebral vasospasm, loss of autoregulatory control and breakthrough of the vessel wall
What is the effect of pregnancy on AVMs?
AVMs are oestrogen sensitive and therefore tend to dilate in pregnancy
Possible cause of Haemorrhagic stroke
What does PRES stand for?
Posterior Reversible Encephalopathy Syndrome
What are the clinical features of PRES?
Transient neurological disturbance
Causing occipital lobe related symptoms
Headache, seizures, cortical blindness
In pregnancy, usually related to PET
What is the pathogenesis of PRES?
Vasogenic brain oedema
What are the MRI findings in PRES?
Bilateral involvement of white and grey matter in the posterior regions of the cerebral hemispheres
What is the increase in the incidence of Bell’s Palsy in pregnancy?
10x
What are the clinical features of Bell’s Palsy?
Unilateral LMN lesion of facial nerve
Facial weakness
And loss of taste on anterior 2/3 of tongue
Most cases in pregnancy occur around term
What is the pathogenesis of peripartum Bells’ Palsy?
Swelling of the facial nerve within the patrons temporal bone
May be related to oedema
What is the management of Bell’s Palsy?
Short course corticosteroids
NB: Important to examine the ear for vesicles prior to prescribing steroids (as they are contraindicated in Ramsay Hunt)
What are the clinical features of Carpal Tunnel Syndrome?
Paraesthesia and numbness in the thumb and lateral two and a half fingers
Tinel’s sign: Reproduction of symptoms on percussion over the carpal tunnel
Phalen’s sign: reproduction of symptoms on sustained flexion of the wrist
What is the pathogenesis of Carpal Tunnel Syndrome?
Compression of the median nerve at the flexor retinaculum
What is the management of Carpal Tunnel Syndrome?
Reassurance that the condition is likely to improve / abate after delivery
Wrist splints
If severe
- local steroid injection
- surgical division
What is Meralgia paraesthetica?
Numbness or pain in the distribution of the lateral cutaneous nerve of the thigh (anterolateral aspect of the thigh)
Caused by compression of this nerve
At the lateral aspect of the inguinal ligament
