Neurology - Epilepsy Flashcards
(34 cards)
1
Q
Why does epilepsy occur?
A
- This is a group of conditions that happens because of abnormal discharge of neurons within the brain
- Epilepsy is associated with reduced GABA levels in the brain
- This leads to abnormal cell-cell message propagation
- So it takes less stimulation for a neuron to fire and pass the message onto another cell
2
Q
What is a febrile seizure?
A
- These are seizures - the patient will have the same symptoms as someone having tonic/clonic epilepsy
- The difference is that these largely happen in children and they only happen when the child has a fever - this is usually above 38 degrees but can be much higher than that when they are initiated
- If a child has a febrile seizure once it will likely have a febrile seizure again
- This however does not mean the child is epileptic it just means that they are prone to febrile seizures
- These are managed acutely
3
Q
What are the signs and symptoms of a febrile seizure? (5)
A
- Fever
- Face may turn blue or red
- Eyes rolling upwards
- Loss of consciousness
- Muscles and limbs jerk in unnatural movements
4
Q
Febrile seizures occur in children with a temperature above 38 degrees - this puts them at risk. How can we reduce the chance of them having a seizure? (5)
A
- Paracetamol
- Ibuprofen
- Remove clothes
- Cool sponging
- Cool bath
5
Q
What is anti-pyretic medication?
A
- Medication which reduces fevers
6
Q
What are the 2 general groups of epilepsy?
A
- Generalised
- Partial
7
Q
What are the different types of generalised epilepsy? (3)
A
- Tonic/clonic
- Absence (petit mal)
- Myoclonic/atonic
8
Q
What are the different types of partial epilepsy? (3)
A
- Simple partial
- Complex partial
- Simple sensory
9
Q
What are the possible triggers of epilepsy? (4)
A
- Idiopathic
- Trauma - head injury
- CNS disease
- Social (environmental stimuli)
10
Q
What are possible CNS diseases that can trigger epilepsy? (5)
A
- Tumour
- Stroke
- CJD
- Meningitis
- Encephalitis
11
Q
What are possible social stimuli that can trigger epilepsy? (4)
A
- Late nights
- Alcohol
- Hypoglycaemia
- Flashing lights
12
Q
Explain the epileptic focus in terms of generalised and partial?
A
- Epilepsy can be generalised or partial
- When there is generalised epilepsy there is often a central focus which then spreads the signal out to all parts of the cortex which means all parts of the body are involved in the seizure
- If the focus is much closer to one particular part of the cortex it will primarily be the part that is affected by the partial seizure - this can affect any neural modality in the body - it can affect motor (most often) but it can also affect perception and sensation
- So the patient can hear, see, smell and taste something that is generated within the brain by epileptic focus and not present in the environment - this is important to realise when considering reasons why patients are presenting with symptoms without any obvious cause
13
Q
What does an ECG look like in a person who is having a generalised seizure?
A
- In epilepsy (generalised) the ECG changes from the normal wave form to a very much larger and more erratic pattern
14
Q
What is a Petit mal (absence) seizure?
A
- Patient may not appear to have any obvious changes unless you are watching them
- They are short lived episodes (5-15 seconds)
- Loss of awareness (eyelids flutter, vacant stare, stops activity, loss of response)
- Childhood usually
- Can be multiple attacks in a single day
15
Q
What are the indications for a tonic/clonic seizure?
A
- Prodromal aura
- Loss of consciousness/continence
- Initial tonic (stiff) - where all the voluntary muscles of the body contract together (this puts a tremendous strain on the skeleton and on the spine and can lead to damage)
- Clonic (contraction/relaxation)
- Post-ictal drowsiness (in most cases the seizure will spontaneously end in 1-3 minutes and the patient will remain drowsy until they gradually return to full consciousness)
- Status epilepticus - recurrent seizures
16
Q
What is prodromal aura?
A
- The patient has an awareness in the change in their brain function (this might not be something that they can easily report to you) but there will be changes such as change in awareness or change in actions that the patient will do before they properly start the seizure
17
Q
What is the problem with recurrent tonic/clonic seizures?
A
- Sometimes the tonic clonic reaction will be followed by a short period of post-ictal drowsiness and will then restart again - if this process goes on for a significant period of time it is very dangerous for the patient as the normal voluntary breathing muscles cannot operate during the tonic clonic seizure and the patient will become significantly hypoxic
18
Q
What are the medical complications of tonic/clonic seizures? (2)
A
Injury:
- Protect where possible
- Remove objects from the mouth if possible
Asphyxia:
- Use supplemental oxygen
- Guedel airway if possible (use of an airway adjunct)
- Suction any secretions
19
Q
What are the social complications of a tonic/clonic seizure? (3)
A
Pregnancy:
- Metabolism upset, drug reactions
- If a young person wishes to become pregnant the medications that are used to control epilepsy can be very harmful
- This is true with sodium valproate
- Usually patient has to stay on the medications and accept the small risk to the baby
Sudden death:
- Asphyxiation/aspiration
Social:
- Driving, employment
- Patient must be free of seizures for at least a year before they are allowed to apply for a drivers licence
- Employment can be restricted
20
Q
What are precipitators for tonic/clonic seizures? (5)
A
- Withdrawal/poor medication compliance (sometimes the doctor will stop the medication before putting the patient on a new one and this is a high risk time for the patient)
Epileptic drugs: (there are some drugs that precipitate seizures)
- Some GA agents
- Alcohol
- Tricyclics & SSRI’s
- Fatigue/stress
- Infection
- Menstruation
21
Q
What is a partial seizure?
A
- Motor localised to one region of the brain
- May move/spread to other motor areas
22
Q
What is a Jacksonian seizure?
A
- Part of a partial seizure
- Patient will start with a small tremor at the extremity of the upper limb and it will progressively move up towards the elbow, shoulder and then into the neck
23
Q
What are sensory partial seizures?
A
- Any sensory modality (visual, auditory, taste, smell)
- Often aura & may involve deja vu
24
Q
What are complex partial seizures?
A
- These happen when different areas of the brain are affected which produce connected movements
- Automatism:
- Repetitive purposeless movements
- Lip smacking, grimacing
- They become automatic and the patient has no awareness that they are being carried out
- At the end of the seizure the movements will stop
25
What is possible preventative treatment for epilepsy?
Anticonvulsant drugs:
Tonic/clonic:
- Valporate, Carbamazipine, Gabapentin, Phenobarbitone, Lamotrigine
Absence:
- Levitiracetam
26
What is possible emergency treatment for epilepsy? (2)
- Most require supportive treatment only if unconscious - airway & oxygen
- Status epilepticus: benzodiazepines
27
What are 2 types of drugs we can use to treat epilepsy?
- GABA reception actions
| - Sodium channel actions
28
Give examples of drugs which have GABA receptor actions and what are their actions? (2)
Valporate:
- GABA transaminase inhibitor
Benzodiazepines:
- GABA(A) receptor action on Cl- enhanced
29
Give examples of drugs which have sodium channel actions and what are their actions? (2)
Carbamazepine:
- Stabilises
Phenytoin:
- Unsure of action
- There is still a lot of uncertainty with these medicines as to how exactly they work, however the fact that they work on different aspects of the systems allows them to be used in combination and patients who are finding difficulty in controlling with a single medicine may take 2 or even 3 different medicines which will have additive effects between different pathways in the brain
30
When can we do surgery for epilepsy?
- Can do this when there is a single focus which is clearly identified and poorly controlled
- Removal of focal neurological lesions:
- Brain tumours (benign)
- Focal seizures:
- Identifiable point of origin within the brain
- Not well controlled by medication
31
Why is it important to determine the focus site prior to surgery?
- Identifying the focus is the key
- But if there is a single area within the brain where there is damage and is causing the start or spread of the seizure then stereotactic surgery in 3 dimensions to remove that through a craniotomy can be helpful
32
What are dental complications of epileptic seizures (complications of fits)? (3)
- Oral soft tissue injury
- Dental injury/fracture
- A patient sitting in the dental chair has a risk of injury not only from the seizure but also from many sharp pieces of equipment in the dental environment and therefore it is always sensible to treat patients during quiescent phases
- Asking patients all about seizures can be helpful - what kind, do they take drugs, compliance etc
- Also helpful to ask when their last seizure was
- KNOW EMERGENCY CARE
33
What are dental complications of epileptic seizures (complications of treatment)? (3)
- Gingival hyperplasia (phenytoin)
- Bleeding tendency (valporate)
- Folate deficiency (rare)
34
How do we assess an epileptic patient to determine when is the best time to treat them? (5)
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Assess risk of fit:
- Good & bad phases
- Ask when last 3 fits took place (will give an idea of how likely they are to have one today)
- Ask about compliance with medication
- Ask about changes in medication
treat at times of 'low risk' if possible
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