Epilepsy Flashcards
Causes of reflex syncope:
Vasovagal
Carotid sinus syndrome
Situational (cough, micturition)
Ictal (post-seizure/stroke)
Causes of orthostatic syncope:
Drug-induced
Autonomic failure
Cardiac cause of syncope?
Arrhythmias
Which lesions can cause tumours?
Hippocampal sclerosis
Glionruronal tumours
Focal cortical dysplasia
Arterio-venous malformation
Seizures attributable to genetics:
Childhood absence
Juvenile myoclonic
Juvenile absence
Adult seizures:
Post-traumatic epilepsy
Symptomatic partial epilepsies
Malignant gliomas (5% of adult presentation)
Substance abuse
Elderly: stroke, malignant gliomas and degeneration
How is epilepsy defined clinically?
Two or more unprovoked seizures in under 24 hours/1 event + abnormal CTH
Examples of acute symptomatic seizures:
Febrile convulsions
Alcohol withdrawal
Metabolic
Eclampsia
What is a focal seizure?
Affects only one part of the brain e.g. one hemisphere
Types of focal seizures:
Partial with retained awareness
Partial with loss of awareness - TLE, FLE
Partial progressing to full tonic clonic (whole cortex)
Generalised seizures:
Tonic clonic
Tonic
Absence
80% of seizures arise or involve which region due to the hippocampus?
Parietal lobe
Temporal involvement causes what?
Memory disturbances (deja vu) Emotional disturbances (fear/elation)
Effect of seizure in Broca’s area?
Asphasia
Insula is buried under frontal and temporal lobes. Its involvement in a seizure causes what?
Autonomic involvement
Epigastric sensations, salivation, change in HR, palpitations
Seizure in lateral temporal lobe causes what?
Hallucinations
Dream recollection
Illusions
What do occipital seizures (rare) cause?
Visual symptoms
What do parietal seizures (very rare) cause?
Vertigo and pain
Aura in temporal lobe epilepsy:
Epigastric sensation
Autonomic involvement (palpitations, salivation)
Deja vu
Pungent smell - burning/pencilin
Hallucinations if lateral temporal/parietal lobe
Features of Jacksonian epilepsy:
Spread of motor seizure up/down one side of the body
Somatosensory aura:
+ve symptoms
Jacksonian jerks
Pins and needles
Rarely pain
Visual hallucinations in epilepsy vs migraine:
Coloured mobile blobs in epilepsy
Sparkly white and black lines in migraine
Temporal seizure character:
Motionless stare then automatisms
Unresponsive and unconscious
Red in face
Features of tonic clonic seizure:
Go rigid and falls, cry as air squeezed out of lungs Lateral tounge bites (differential) Cyanosis Clonic jerks Salivation/frothing Post-ictal confusion/unconscious 1-2 minutes Occur after loss of sleep/alcohol
Features of dissociative seizures:
Stress/anxiety driven
Aware with bilateral directed movements, distractible
Back arches, thrashes, hits out, grabs
Need psychological intervention
History markers:
Lateral tounge bite Occur out of sleep Aura: epigastric rising, flashing lights Automatisms Rigid and violent jerks (not thrashing) Cyanosed/obstructed respiration Post-ictal unrousable/confused
Routine EEG procedure:
20-30 minutes
Photic stimulation and over breathing
Sleep EEG procedure:
60 minutes
Drug-induced sleep
Telemetry procedure:
Continuous
EEG with video/polysomnography
EEG of focal anterior temporal lobe seizures:
Spikes
EEG of generalised epilepsy:
Spike and wave at regular intervals
Diagnosis of epilepsy is…
Clinical
EEG is used for aetiology
When is epilepsy considered resolved?
Past age of age-dependent epilepsy
Seizure free for the last 10 years, off medication for last 5 years
Management of a provoked seizure?
Correct provoking factor
Benzos for alcohol withdrawal and delirium tremens
When are anti-epileptic drugs not indicated?
Prophylactically post-acute brain insult/neurosurgery
Concussive convulsions
Provoked
1st seizure with low risk of recurrence
1st seizure management:
Refer to first-fit clinic: EEG and MRI
Treatment for generalised seizures:
First line: VPA (mainstay as better tolerated than TPM and more efficacious than LTG)
Second line: LTG, CBZ, TPM
Contraindication of sodium valproate?
Teratogenic so avoid in young women
Treatment for focal seizures:
LTG (mainstay) CBZ GBP TPM OXC
VPA =
Valproate
LTG =
Lamotrigine (reduces efficacy of progesterone component of COC pill)
TPM =
Topiramate
CBZ =
Carbamazepine
GBP =
Gabapentin
OXC =
Oxcarbamazepine
Combination of VPA and LTG?
Synergistic function
What reduces the absorption of phenytoin?
Nasogastric tube
Interaction between VPA and PHT?
Compete as both bind to albumin
Which AEDs are enzyme inducing?
CBZ
PHB
PHT
(reduce efficacy of combined oral contraceptive pill but not progesterone only injectables)
Absence seizure medication:
VPA or ethosuximide
Myoclonic seizure medication:
VPA
Clanazepam, LTG
Risks of CBZ?
Will exacerbate absence and myoclonic seizures
Interactions of VPA?
Causes enzyme inhibition and will interfere with mainstay drugs e.g. warfarin
Does not affect oral contraception
Allergic hypersensitivity reactions more common with…
Aromatic AEDs: CBZ, PHB, PHT
also VPA
Chinese with HLA B1502 react to CBZ
Severe skin reaction to AEDs:
Steven’s-Johnson’s syndrome
What counts as an “attack”?
Any event: major/minor/aura
DVLA policy:
After attack stop driving for 1 year if causative factor with risk of recurrence
Otherwise 6 months after attack you can get a 3 year license
If seizure free for 5 years then a “til 70 group 1 license”
What is AED hypersensitivity syndrome?
Multi-organ damage especially liver following skin rash
MFM:
Normal chance = 1-2%
AED chance = 2-4% (don’t stop AED)
VPA chance = 6-9% (+ASD)
Pregnancy effects:
Slight association between AEDs and minor malformations and a drop in verbal reasoning IQ
Maternal seizures are associated with drop in verbal reasoning IQ, small for gest age and sudden death
Glucoronidation in pregnancy so most except CBZ decrease
Give vitamin K to mother in last 4 weeks and newborn
Breastfeeding and AEDs:
Recommended
PHT, CBZ and VPA are safe
Monitor withdrawal/sedation and slow metabolism of benzos in foetus
Surgical options:
Hemispherectomy, callostomy, multiple sundial transections are all resective
Vagal nerve stimulation is functional (better in children)
What is status epileptics?
Failure of termination/abnormally prolonged seizures
What do t1 and t2 indicate?
t1 = when treatment should be initiated t2 = when there are long-term consequences (neuronal damage at 30 minutes, spontaneous cessation unlikely after 5 minutes)
Stage 1 SE =
0-10 minutes
Stage 2 SE =
0-30 minutes
Stage 3 SE =
Established SE: 0-60 minutes
Stage 4 SE =
Refractory status: 30-90 minutes
Step 1 in treating SE =
Benzos in >5mins
IV lorazepam/diazepam
If not able then buccal/IM midazolam/rectal diazepam
Basic bloods, AEDs, glucose and pabrinex
Step 2 in treating established SE (no response within 10 minutes) =
PHT/levetiracetam/VPA/PHB (risk of resp failure with PHB)
Step 3 in treating refractory convulsive SE (no response to step 2 within 30 minutes) =
ICU admission
Anaesthesia - propofol, thiopentone, midazolam
Monitor for 24-48 hours and withdraw if no seizures
Side-effects of PHT:
Hypotension
Arrhythmia
Precipitation of crystals
