Paeds: Epilepsy (DrClarke) Management Flashcards Preview

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Flashcards in Paeds: Epilepsy (DrClarke) Management Deck (40):
1

Seizure

- Clear surrounding area
- Put into recovery position once it is over
- Pbserve for signs of breathing, aspiration, injury

2

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

3

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

4

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

5

Medical management 4 stages

1. Premonitory phase
2. Early status
3. Established status
4. Refractory status

6

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)

7

Early status

- Lorazepam bolus (4mg iv) - repeat once if necessary, after 10 mins

8

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

9

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

10

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.

11

3 basic mechanisms for the action of anti-epileptic drugs:

1. Suppression of sodium influx
2. Suppression of calcium influx
3. Potentiation of gamma-aminobutyric Acid (GABA)

12

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.

13

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.

14

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

15

examples of drugs that suppress calcium infux

this mechanism are preferred for absence seizures. Sodium valproate & ethosuximide act in this way.

16

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

17

Benzodiazepines
examples and action

e.g. diazepam
potentiate GABA, either by acting directly on GABA receptors

18

by promoting GABA release examples

gabapentin

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by inhibiting the enzyme that degrades GABA example

vigabatrin

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Benzodiazepines

diazepam: IV/rectal to control individual fits) & clonazepam (orally for prophylaxis usually taken with other drug) ↑ affinity of GABA for its receptor

21

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

22

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

23

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

24

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)

25

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.

26

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

27

Procedures available

1. Selective amygdalo hippocampectomy
2. Temporal lobectomy
3. Sub-pial resection
4. Hemispherectomy
5. Corpus callosotomy
6. Removal of a lesion e.g. tumour, cyst

28

Selective amygdalo hippocampectomy

hippocampectomy
Removal of 2 structures in temporal lobe which are the sites of seizure activity. Sometimes only hippocampus is removed.

29

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

30

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

31

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

32

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

33

COMPLICATIONS OF seizures:

1. Status epilepticus
2. Injruy
3. Aspiration
4. permanent brain damage/difficulty with learning
5. Anti-epileptics can cause birth defects

34

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!

35

Lifestyle and social issues

1. Driving
2. employment
3. Leisure
4. Pregnancy
5. Other

36

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.

37

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

38

• 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

39

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

40

• 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

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