Paeds: Epilepsy (DrClarke) Management Flashcards
Seizure
- Clear surrounding area
- Put into recovery position once it is over
- Pbserve for signs of breathing, aspiration, injury
Seizure
- if not confused or injured, no immediate action required Seek medical attention -> Investigation
- If confused/injured: wait with them and reassure them; do not attempt to give fluids/food/drug
- Call ambulance
Seizure
- If they recover from seizures: wait with them until fully recovered, may be worth noting any triggers, patterns etc, ? Consider meds review
- If they don’t: Medical emergency
Seizure >5-10 minutes: Immediate treatment
Treat and investigate source.
MEDICAL EMERGENCY:
-Immediate ->resuscitate measures ABC: airway maintained, oxygen given
- Control of seizure-anticonvulsant medication given.
- Identification of underlying cause - ?hypoglycaemia, electrolyte/cardiac/biochemical monitoring
Medical management 4 stages
- Premonitory phase
- Early status
- Established status
- Refractory status
Premonitory phase
Diazepam (10-20mg iv or rectally) - can be repeated once 15 mins later if status still dangerous OR iv bolus clonazepam (1-2mg)
Early status
- Lorazepam bolus (4mg iv) - repeat once if necessary, after 10 mins
Established status
Phenobarbitone bolus (10mg/kg 100mg/min) and/or phenytoin infusion (15mg/kg 50mg/min-ECG monitoring) - small risk of respiratory depression but can help obtain control
Refractory status
- If seizures continue or >30 mins despite Rx then general anaesthesia is given (thiopentone iv bolus then infusion) - artificial ventilation is likely to be necessary - the anaesthetic dose shouldn’t be tapered until >12 hrs after last seizure - EEG monitoring must be done as ventilated pt will be paralysed with muscle relaxants so may not have observable seizures
Long term management
Anti-epileptic drugs (AEDs) - generally after 2ndry seizure
- Monotherapy where possible
- review medication: aim to use minimum dose to maintain control and ideally seizure-free
- It may be possible for patients to come off medication (epilepsy remits in 70%) - obviously they need to have been well-controlled and seizure free for some time
- Important to consider the implications for the patient - depends on individual, their lifestyle, needs etc. i.e. someone who relies on driving may not wish to risk losing their license etc.
3 basic mechanisms for the action of anti-epileptic drugs:
- Suppression of sodium influx
- Suppression of calcium influx
- Potentiation of gamma-aminobutyric Acid (GABA)
Suppression of sodium influx process
The AED binds to sodium channels when they are in the inactive state, thus prolonging the inactive state ↓ ability of neurons to fire at high frequency. Seizures that depend on high frequency discharge are therefore suppressed.
Examples of drugs that suppresses of sodium influx and which seizures they are used in
Carbamazepine, phenytoin & lamotrigine exert their main action in this way & are effective in limiting the spread of a discharge from a focusRx of partial & 2o generalised seizures.
SUPPRESSION OF CALCIUM INFLUX.
The AED acts by inhibiting influx of calcium ions through T-type Ca channels. These calcium channels generate T-currents which usually play a minimal role in action potential generation, but in some neurons in the hypothalamus, T-currents cause action potentials. Absence seizures are caused by ↑ firing of hypothalamic neurons
examples of drugs that suppress calcium infux
this mechanism are preferred for absence seizures. Sodium valproate & ethosuximide act in this way.
POTENTIATION OF GAMMA-AMINOBUTYRIC ACID (GABA).
GABA is an inhibitory neurotransmitter that is widely distributed in the brain & causes a general ↓ in neuronal excitation drug examples: - Barbiturates e.g. phenobarbital - gabapentin - vigabatrin - Benzodiazepines e.g. diazepam
Benzodiazepines
examples and action
e.g. diazepam
potentiate GABA, either by acting directly on GABA receptors
by promoting GABA release examples
gabapentin
by inhibiting the enzyme that degrades GABA example
vigabatrin
Benzodiazepines
diazepam: IV/rectal to control individual fits) & clonazepam (orally for prophylaxis usually taken with other drug) ↑ affinity of GABA for its receptor
VALPROATE
- Indication
- recommended for which seizure type
- concerns
- 1st line if unable to classify type of epilepsy
- Broad spectrum
- Recommended esp. for generalised onset seizures
- Fewer pharmacokinetic problems
- Fewer adverse effects
- CONCERNS – foetal damage
CARBAMAZEPINE
- Indication
- recommended for which seizure type
- concerns/interactions
• Good general choice
• Recomm. esp. for partial seizures
• But acts on P450 system - interacts with OCP etc many drug
interactions
• Fewer side-effects than phenytoin
• Monitoring of levels helps determine optimum dose
PHENYTOIN
- Indication
- recommended for which seizure type
- concerns/interactions
- Narrow therapeutic window
- Significant variation in individual response
- Many drug interactions
- Zero order kinetics
- Monitoring of levels ESSENTIAL
- Avoid where possible
LAMOTRIGINE
- Best-established of the newer generation drugs
- Broad spectrum
- Works for almost all forms of epilepsy
- Reasonable safety profile but:
- Severe skin reactions in children
- Blood disorders
- Interaction with valproate
- Good choice for girls (i.e. re: pregnancy etc)
SURGERY
Surgery is an option in pts where there is a definite site of seizure onset with highly localised focus. Occasionally it can be used to reduce symptoms is patients with intractable epilepsy.
surgical management only beneficial in
focus – surgery can only help where there is a specific site at which seizures always start
• nature – surgery always carries risk therefore the benefits need to be significant – usually patients
with frequent, severe seizures, impacting on their QoL, despite treatment
• area – tests will be performed to accurately assess the area of brain involved and its function
Procedures available
- Selective amygdalo hippocampectomy
- Temporal lobectomy
- Sub-pial resection
- Hemispherectomy
- Corpus callosotomy
- Removal of a lesion e.g. tumour, cyst
Selective amygdalo hippocampectomy
hippocampectomy
Removal of 2 structures in temporal lobe which are the sites of seizure activity. Sometimes only hippocampus is removed.
Temporal lobectomy
A larger part of the temporal lobe is removed - usually the right side as the left side of the temporal lobe controls speech
Sub-pial resection
Fine cuts are made in the motor areas of the brain -they don’t affect motor function but do prevent the spread of seizures
Hemispherectomy
Sometimes used to treat very severe epilepsy in children with damage to one whole side of the brain - the damaged side of the brain is removed
Corpus callosotomy
Also sometimes used to treat children with very severe epilepsy (Atonic drop attacks) - the operation involves sectioning the fibres that connect the two halves of the brain
COMPLICATIONS OF seizures:
- Status epilepticus
- Injruy
- Aspiration
- permanent brain damage/difficulty with learning
- Anti-epileptics can cause birth defects
Status Epilepticus
(recurring seizures, w/o pt regaining consciousness b/t attacks, for 30 mins or
more. May permanent brain damage & death due to prolonged hypoxia) A MEDICAL
EMERGENCY!
Lifestyle and social issues
- Driving
- employment
- Leisure
- Pregnancy
- Other
Driving
must inform DVLA when diagnosed. Generally 1 year ban following a seizure (regardless of whether it occurs in the day or at night). Pt is then reviewed, & if they have been seizure free & are believed to be under good control then they will be allowed to drive again. If a person only has night seizures, they may be allowed to drive again even if they continue to have seizures.
If a pt is withdrawing from AEDs, they are advised not to drive during the withdrawal period or for the next 6 months and if they do have a seizure, they will be banned for 1 yr again.
Employment –
UK Disability Discrimination Act – only the Armed Forces are completely banned (by law). Other jobs may be restricted due to health & safety regulations (e.g. pilots, drivers, work that could be hazardous to the person or risk harm to others etc) – advisable to disclose epilepsy although there is no legal obligation to do so – if it is not disclosed, employers will not be liable for any harm should the employee have a seizure
• Leisure –
being active does not provoke seizures and may even be beneficial – safety is the important consideration – people with epilepsy should never swim alone (or be around water), should not perform activities e.g. climbing while epilepsy is uncontrolled – most activities are ok as long as person is sensible & always has a companion who knows what to do should they have a seizure – potential hazards include television (photosensitive epilepsy), computers (rarely), video games, theme parks, night clubs and of course water, heights etc
Pregnancy –
many AEDs reduce the efficiency of the pill need to consider type of medication & potentially other methods of contraception – also, when considering pregnancy, beneficial to have epilepsy under control before becoming pregnant (ideally) – need to think about medication/risks of malformation (give oral vit K a wk before deliver to preventneonatal haemorrhage causd by inhibition of transplacental transport) – after birth breastfeeding is usually not a problem
• Other –
ree prescription charges – exemption certificate FP92A (England)
Counselling – diagnosis of epilepsy can have substantial psychological impact – important to discuss with pt & family
Alcohol can provoke seizures so it may be necessary to provide advice and support on this Epileptics shouldn’t be alone e.g. when having a bath, bathing/looking after a baby so it really can impact greatly upon everyday life
