epilepsy Flashcards
epilepsy
Epilepsy is associated with reduced GABA levels in the brain
- This leads to abnormal cell-cell message propagation
- Less stimulation for neuron to fire on a communication
- Abnoraml chain reaction set up
- Discharge of lots of neurons from one particular area of the brain or throughout brain
Abnormal discharge of neurons from brain
febrile seizure
- NOT EPILEPTIC*
- Same symptoms as tonic-clonic epilepsy
Only in children
- Once had one – likely to have another
Managed acutely – like other seizures
Usually when child has a fever
- Cool hot children (above 38o at risk of seizure)
- Ibuprofen
- Paracetamol
- Remove clothes
- Cool sponging
- Cool bath
2 classifications of epilepsy
generallised
partial
3 types of generalised epilepsy
tonic/clonic
absence (petit mal)
myoclonic /atonic
yellow arrow pointing at
Focal area within the brain with abnormal neuronal discharge – associated with epilepsy
3 types of partial epilepsy
simple partial
complex partial
simple sensory
possible epilepsy triggers
- Idiopathic – unknown
- Trauma - head injury
- CNS disease
- tumour, stroke (vascular degenerative diseases)
- CJD, meningitis, encephalitis
- Social
- Late nights, alcohol, hypoglycaemia – can be caused by alcohol overuse)
- Flashing lights
epileptic focus in generalised epilepsy
- Central focus sends signal out to all parts of cortex
- all parts of body involved in seizure
epileptic focus in partial epilepsy
- Focus closer to a particular part of cortex so primarily affects that area
- Any neural modality
- Motor, perception, sensation e.g. see, hear, smell, taste something that isn’t there due to seizure – consider when pt presents with symptoms with no obvious cause
- Any neural modality
electrical changes in generalised seizure seen on EEG
- Change from normal wave form to a larger more erratic pattern
tonic clonic seizures
prodromal aura
- awareness of change in their brain function, may not be able to communicate this but can see characteristic changes e.g. awareness, actions before seizure
loss of consciousness/continence
initial tonic (stiff)
- all voluntary muscles in body contract together – strain on skeleton – particular spine - damage possible
clonic - (contraction/relaxation)
- jerk, spasm
post-ictal drowsiness
- Usually spontaneously terminate in 1-3 mins
- Drowsy until consciousness
Status epilepticus possible
status epilepticus in tonic clonic seizures
recurrent seizures
Dangerous
- Normal breathing muscles cannot work during tonic-clonic seizures
hypoxic
petit mal (absence) seizures
may not be obvious unless closely watching
- short lived episodes (5-15 seconds)
- loss of awareness
- eyelids flutter, vacant stare, stops activity, loss of response, failed to respond
- CHILDHOOD usually
Can be multiple attacks in a single day
tonic-clonic seizures medical impact (2)
INJURY
asphyxia
tonic clonic seizures lead to injury
muscles uncontrolled, fall to ground – hit head
- protect where possible remove objects from around them, help control fall if possible
- Remove objects from the mouth IF POSSIBLE
tonic clonic seizures leading to asphyxia
no normal breathing during seizure - key worry in status epilepticus
management
- USE SUPPLEMENTAL OXYGENA
- GUEDEL airway IF POSSIBLE
- SUCTION any secretions
3 social impacts of tonic clonic seizures
pregnancy
sudden death
social
how does tonic clonic seizures impact pregnancy
- metabolism upset,
- Drug reactions
- sodium valproate
Balance risk of staying on medicine and small risk of teratogenic or stopping medicine and risk to pregnancy and pt of seizures
sudden death from tonic clonic seizures how?
- asphyxiation/aspiration
- acute lung damage
social impacts from tonic clonic seizures
driving (free of seizures for at least 1 year)
employment restrictions
tonic clonic seizures precipitators
most idiopathic
- withdrawal/poor medication compliance
- ask whether they actually take – as many don’t due to side effects
- epileptogenic drugs
- some GA agents
- alcohol
- tricyclics & SSRIs
- fatigue/stress
- Infection
- Menstruation
partial seizures are
focus located close to one area of brain
different types
- sensory
- simple partial
- complex partial
simple partial seizures
Motor localised to ONE region of the brain
- may move/spread to other motor areas
- E.g. Jacksonian seizure – wrist, up upper limb, shoulder, neck
sensory partial seizures
any sensory modality hallucinations
- visual, auditory, taste, smell
often aura & may involve déja vu
Distressing – cannot differentiate precipitators from real
complex partial seizures
automatism
- repetitive purposeless movements
- lip smacking, grimacing
- different muscles but area of brain stimulate linked movement affected by seizure
- lip smacking, grimacing
- Different areas of the brain affected and make connected movements*
- No awareness pt carrying out
- Stop at end of seizure*
preventative epilepsy treatment
- Anticonvulsant drugs
- Tonic–clonic
- Valproate, Carbamazepine, Phenytoin, Gabapentin, Phenobarbitone, Lamotrigine
- Absence
- Levetiracetam
- Tonic–clonic
emergency epilepsy treatment
- most require SUPPORTIVE treatment ONLY if UNCONSCIOUS - Airway & Oxygen
- Status epilepticus requires BENZODIAZEPINES
- Prolonged seizure produces hypoxia
epilepsy drugs
(4)
- GABA receptor actions
-
Valproate
- Gaba transaminase inhibitor
-
Benzodiazepines
- GABAA receptor action on Cl- enhanced
-
Valproate
- Sodium Channel actions
-
Carbamazepine
- Stabilises
-
Phenytoin
- ? Unsure of action
-
Carbamazepine
benefit of multiple epilepsy drugs
- Since they work on different aspects, allow them to be used in combination so pts may take 2/3 medications if not getting control from 1*
- Additive effects
valporate
GABA tranaminase inhibitor
drug with GABA receptor actions
benzodiazepines
GABAA receptor action on Cl- enhanced
drug with GABA receptor actions
cabamazepine
stabilses sodium channel actions
phenytoin
works on sodium channel actions
unsure of action
surgery for epilepsy
- Removal of focal neurological lesions
- Brain tumours (benign)
- Focal seizures
- Identifiable point of origin within the brain
- Not well controlled by medication
- Identifiable point of origin within the brain
Clearly identify focus that is poorly controlled prior
varying extent - lobes or just damaged area
determining epileptic focus site
- Identifying focus is key – damage, start or spread of seizure
- Stereotactic surgery in 3D to remove the focal point through craniotomy
complications of epileptic fits in dental setting
- oral soft tissue injury
- dental injury/fracture
Seizure in chair
- Risk injury
- Sharps around too
- KNOW EMERGENCY CARE
complications epileptic treatment
- gingival hyperplasia (phenytoin)
- bleeding tendency (valproate)
- folate deficiency (rare)
important before dental treatment assess risk of epileptic fit
- good & bad phases
- ask when last 3 fits took place
- how likely to have one that day
- distant less. Within last week - more
- how likely to have one that day
- ask about compliance with medication
- ask about changes in medication
- ask when last 3 fits took place
- Treat at times of ‘low risk’ if possible
