Neurological Problems Flashcards
1
Q
What are the different types of neurological problems
A
- Epilepsy
- Migraines and headaches
- Multiple sclerosis
- Myasthenia Gravis
- Myotonic dystrophy
- Idiopathic intracranial hypertension (idiopathic)
- Stroke
- Bell’s palsy
- Subarachnoid haemorrhage
- Cerebral vein thrombosis
- Posterior reversible encephalopathy syndrome
- Entrapment neuropathies
2
Q
What is epilepsy?
A
- seizure (neurons synchronously active) disorder
- A neurological condition characterised by recurrent seizures
- Seizure are due to brief distributions in the electrical functions of the brain
- Caused by abnormal electrical discharge of cortical neurones (nerve cells)
- During a seizure clusters of neurons in the brain become temporarily impaired and starts to suddenly send excitatory signals over and over- paroxysmal.
- This occurs due to either too much excitation or too little inhibition.
3
Q
Why do epileptic fits happen?
A
- Idiopathic
- Physical causes: head injury, cerebral tumours, stroke, hypertension, infection
- Metabolic causes: hyperglycaemia, hypoxia, uraemia, fluid and electrolyte imbalance, hyper or hyponatraemia
o Metabolic anomalies: Alteration in cell membrane properties due to abnormal blood concentrations on various ions/electrolytes - Syndromes: Antiphospholipid, Alzheimer’s, Wernicke-Karsakoff (thiamine B1 deficiency), Wilson’s disease
- Congenital defects: cerebral palsy, intracranial cysts
- Infection
- Postdural puncture
- Gestational epilepsy (idiopathic)
- Pseydoepilepsy/ non-epileptic seizure disorder
- Eclampsia
- Cerebral Vein thrombosis
- Thrombotic Thrombocytopenic purpura (TTP)
- Stroke
- Subarachnoid haemorrhage
- Drugs and alcohol (withdrawal)
4
Q
What are the different types of fits?
A
Partial fits
- Simple partial
- Complex partial
- Secondary generalised
Generalised seizures: whole brain
- Absence
- Myoclonic
- Tonic
- Atonic
5
Q
What are the partial fits?
A
commonly affects temporal lobe
o Simple partial: remain conscious, experience and aura, change in the way things look, smell, taste or sound, pins and needles in the arm, déjà vu.
o Complex partial: change in awareness, loses memory of the event, rubbing of hands, smacking of lips: chewing, fiddling with objects.
o Secondary generalised: partial seizures begin in one part of the brain and spread to the whole brain and tonic clonic seizures occur.
6
Q
What are the generalised seizures?
A
o Absence: staring and blinking, daydreaming, mainly affects children and lose awareness for 5-20 seconds
o Myoclonic: brief muscle jerking or one or both arms and legs. Last a fraction of a second and remains conscious.
o Tonic: all muscles of the body contract causing falling but with convulsions. Lasts <20 seconds
o Tonic clonic: most common seizures with two stages: whole body convulse/twitch. Lasts 1-2 minutes with possible incontinence
o Atonic: all muscle tone lost very briefly; fall limpy to the ground. Head injury likely to occur. No confusion likely to get up after
7
Q
What are the precipitating factors for seizures?
A
- Sleep deprivation/physical exhaustion
- Emotional stress
- Increased body temperature
- Environmental factors: flashing lights
- Menstruation
- Metabolic disturbances
- Excessive alcohol/drug misuse
- Certain medication
- Non-compliance with drug therapy
8
Q
What are the key investigations?
A
- Clear history & eyewitness accounts of seizures (Most already with
- known history of epilepsy)
- Blood pressure measurement +obs, urinalysis
- Blood tests
o Haematology (FBC, platelets, coagulation screen, blood fil, thrombophilia screen)
o Biochemistry (U&Es, urate, glucose, serum calcium and sodium, LFTs)
o Toxicology screening - Computerised tomography scan (CT scan)
o Look for evidence of cerebral structural damage - Magnetic resonance imaging (MRI)
o More detailed view of brain structural changes - Electroencephalogram (EEG)
o Classifies seizure type by identifying origin of abnormal electrical discharge
o Gives you the diagnosis- tells you where the seizure is - Telemetry
o Uses video & EEG in order to observe & identify seizure type
9
Q
What are the managements of epilepsy?
A
- Aims to identify cause of seizures & prevent recurrence (if possible)
- Usually requires anti-epileptic drugs (AED) which may be lifelong; complete control gained in 70%+ of cases
- Majority treated with monotherapy; 5-10% require polytherapy; a few will require surgery
- Aim of therapy is to use lowest possible dose of AEDs in order to control seizures, as all drugs have side effects
- Dosage needs to be adjusted during weight gain (pregnancy) and weight loss (illness)
10
Q
What do you do when someone is having an epileptic fit?
A
- A –Assess the situation – are they in danger of injuring themselves? Remove any nearby objects that could cause injury
- C -Cushion their head (with a jumper, for example) to protect them from head injury
- T – Time, Check the time – if the seizure lasts longer than five minutes you should call an ambulance
- I – Identity, Look for a medical bracelet or ID card – it may give you information about the person’s seizures and what to do
- O –Over, Once the seizure is over, put them on their side (in the recovery position). Stay with them and reassure them as they come round
- N – Never restrain the person, put something in their mouth or try to give them food or drink
11
Q
What are anti-epileptic drugs?
A
- These are anticonvulsant drugs
- Usually they act by suppressing the hyperexcitability of neurons in the cerebral cortex
- Some act by enhancing the activity of the inhibitory neurotransmitter, GABA (gamma aminobutyric acid)
- Common side-effects of AEDs (dose-related)
- Drowsiness, irritability, vertigo, double vision, poor memory, loss of concentration, weight gain/loss
- Most people with epilepsy (70-85%) can control recurrent seizures adequately with these drugs
12
Q
Enzyme-inducing dugs
A
- Drugs that cause the liver to increase its production of certain enzymes
o Can result in increased rate of breakdown of drugs
o Can reduce effectiveness of oral contraceptive pill
Examples: - Carbamazepine (“Tegretol”)
- Phenytoin (“Epanutin”)
- Topiramate (“Topamax”)
- Primidone (“Mysoline”)
- Oxcarbazepine (“Trileptal”)
- Phenobarbitone
13
Q
Non-enzyme inducing drugs
A
- These drugs do not have the same effect on liver enzymes and are not thought to interfere with effectiveness of oral contraceptive pill Examples: - Sodium valproate (“Epilim”) - Gabapentin (“Neurontin”) - Clonazepam (“Rivotril”) - Vigabatrin (“Sabril”) - Zonisamide (“Zonegran”)
14
Q
What are the complications of epilepsy?
A
- Status epilepticus – repeated seizures without any recovery of consciousness
- Trauma – occurring at the time of the convulsion i.e. tongue biting, head trauma, hot water burns
- Cardio-respiratory failure – arising from status epilepticus where treatment was delayed
- Sudden Adult Death – Phenomenon whereby patient dies suddenly and no toxicological or anatomic cause of death is apparent
o Sudden unexpected death in epilepsy (SUDEP)
o High seizure frequency
o Polytherapy to control condition (> 3 drugs)
o Early-onset epilepsy
o Poor compliance/concordance with medication regime
15
Q
What is the pre-conception issues and care?
A
- All women should be offered preconception counselling
- Pregnancy deferred until seizure control is optimal
- Current medication should be reviewed and changed if necessary
- AEDs: Increased risk of folate deficiency and therefore neural tube defects= 5mg folic acid before and up to 12/40
- Women who have been seizure free for a minimum of 5yrs may consider withdrawing AEDs
- AEDs should be used at the lowest number and dose of drugs possible as polytherapy = ↑Major Congenital Malformations
16
Q
What are the effects of pregnancy on epilepsy?
A
- Usually, no effect on frequency of seizures
- If seizure free for many years → unlikely in pregnancy if good meds compliance
- Poorly controlled epilepsy → higher risk of deterioration
- If seizures of multiple types ↑ increase of frequency
- ↑ risk postpartum (3.5 % intrapartum)
17
Q
What are the possible reasons for perinatal deterioration?
A
- Hormonal changes of pregnancy
- Decreased plasma drug levels (pharmacokinetics and pharmacodynamics altered in pregnancy)
- Lack of sleep (end of pregnancy, during labour, postpartum)
- Lack of absorption of AEDs from the GI tract during labour
- Hyperventilation and stress
- Poor compliance with AED
- Change to less effective drugs because of the perceived lower risk of teratogenicity
- Decreased drug levels related to nausea and vomiting
- Pharmacokinetic changes with decreased plasma antiepileptic drug levels, particularly lamotrigine
- ↓ gastrointestinal absorption and ↑hepatic and renal clearance resulting in insufficient drug levels
18
Q
Effects on epilepsy on pregnancy
A
- Short episodes of hypoxia appear to be tolerable by the fetus (possible bradycardia, but no long-term effects)
- No increased risk of miscarriage or obstetric complications (unless trauma)
- Status epilepticus is rare, but dangerous for both mother and baby (1-2.5% of all pregnancies of WWE)
- ↑ of child to develop epilepsy, too
If another sibling is affected, the risk is 10%
o If both parents epileptic, the risk is 15-20%
o If mother with idiopathic epilepsy with early onset (less than 10y old), ↑ of child to develop epilepsy - ↑ of congenital anomalies due to meds
19
Q
Teratogenicity
A
- All cross the placenta and teratogenic
- Carbamazepine (2.2%), phenobarbitone, phenytoin (3.7%), sodium valproate (6.2% risk)
- The effects of newer anticonvulsants are not known as fully as for other medications - vigabatrin, gabapentin, lamotrigine (3% risk)
- Dose dependant teratogenic effects for SV and Lamotrigine
- Higher risk with polytherapy
20
Q
Complications in pregnancy
A
- Aetiology unclear - ?genetics, ? Seizures, ? AEDs
- Fetal abnormalities
- Spontaneous abortion
- Stillbirth
- Placental defects
- Placental abruption
- Pre-term labour
- Hypertensive disorders
- Haemorrhage
21
Q
What is the role as a MW
A
- Detailed history taking with emphasis on current drug therapy
- Referral to specialist care- consultant led
- Ongoing support
- Advice on safe self care and safe baby care
- Liaison with multidisciplinary team
- Foster positive partnership
- Be informed (CPD) and use evidence based approach
22
Q
Antenatal care
A
- 5mg folic acid up to 12/40 if not already
- Women taking sodium valporate should continue with 5mg FA for the remainder of the pregnancy
- Serum screening with AFP for neural tube defects
- Detailed USS at 18-22 weeks to screen for anomalies
- Women taking AEDs should receive 10mg Vit K PO from 36/40 or 4 weeks before delivery
- Adviced not to have a bath alone
- Encourage to register with UK Epilepsy and Pregnancy Register
- MDT care – obstetrician, neurologist, midwife
- Advise against hot baths and steamy environments
- Ascertain expectations and educate re potentially dangerous plans i.e. water births
23
Q
Intrapartum care
A
- Risk of seizures increase around the time of delivery
- Increased stress, lack of sleep, over breathing, pain, dehydration
- 2-3% will have a grand mal seizure
- Prolonged or repeated seizures = fetal hypoxia
- Pethidine is metabolised to norpethidine and may induce a seizure therefore its use should be avoided in labour
- Epidural (early)
- One to one care should be provided, do not leave alone in a single room
- Most women with epilepsy have normal vaginal deliveries and CS is only required if there are recurrent generalized seizures in late pregnancy or labour.
24
Q
What is the management of status epilepticus?
A
- Senior obstetric and anaesthetic staff to be present
- Maintain airway – recovery position, do not restrain
- Ensure safe environment
- Oxygen therapy – 6-10L/min via face mask
- Initial Rx magnesium sulphate (just in case eclampsia)
- Prolonged seizures – lorazepam 4mg (less sedative and longer acting than diazepam)
- Seek advise from neurologist if not effective
- Consider IV phenytoin with continuous EEG monitoring
- If not successful paralyse and sedate woman, ventilate mechanically
- Consider delivery of fetus at this point
- If CTG undertaken will initially be bradycardic, reduced baseline variability and decelerations for up to 30mins post seizure
25
Postnatal care
- During the 1st 24hrs 1-2% chance of grand mal seizures
- Physiological changes of pregnancy reversed = ↑AED levels
- AEDs interfere with Vit K metabolism in the neonate = possible haemorrhagic disease = 1mg Vit K IM at delivery
- Encourage BF: AEDs are secreted but less than therapeutic level for neonates and less that that received in utero
- Sedation, poor feeding, hypotonia and respiratory distress occasionally seen in neonates with increased AED levels
- Advise women how to minimise risks when caring for the baby in case of seizure; risk assessment
