Neuro - Epilepsy Flashcards
What epilepsy questions might you have for a patient in A&E presenting with collapse with TLOC?
Previously well / any illness before event?
- illness can trigger seizures in those with epilepsy e.g. infection, dehydration, sleep deprivation, drug use
What was happening at the time of the TLOC?
- Precipitant? standing / sitting / lying / on standing upright
- TLOC triggered by postural change is likely vasovagal
Any warnings prior to event?
- Pre-syncope symptoms = light-headedness, nausea, sweating and ‘greying’ out of vision
- Epileptic seizure = unexplained smell, deja-vu, focal muscle jerking/twitching
First memory on waking up?
- Syncopal blackout = pt regains awareness / memory quickly
- Epileptic seizure = foggy or no memory before paramedics turn up / arriving in hospital
Any injuries, tongue biting, urinary / faecal incontinence?
- If yes to above –> more likely an epileptic seizure
- Beware! urinary incontinence can occur in syncope (especially women)
Any previous similar episodes?
What epilepsy questions might you have for an observer of a patient in A&E presenting with collapse with TLOC?
Any warning signs beforehand?
- focal onset seizure = focal twitching, a forced head turn, eye deviation or blank ‘staring’
- syncope = look pale, sweaty, complain of nausea / light-headedness
Did they fall stiffly or floppily?
- floppy = likely syncope
- stiffly = generalised seizure (tonic phase)
Did they shake + what did it look like?
- generalised seizure = rigid (tonic) phase + rhythmic clonic jerks afterwards, ↓ in amplitude + frequency
- syncope = a few brief myoclonic jerks, low amplitude + less rhythmic
Cyanosis?
- generalised seizure = blue lips (tonic-clonic involuntary muscle contraction prevents normal breathing)
Duration of LOC?
- syncope = < 1 min
- generalised seizure = 1-5 mins
Duration of shaking?
- generalised seizures = < 5 mins
- prolonged shaking = status epilepticus or NEAD
How long did it take to recover afterwards?
- syncope = speedy (few mins)
- seizure = drowsy for 15 mins
- prolonged unresponsiveness can be ‘pseudosleep’ of NEAD
How is a seizure managed acutely?
Airway: check + maintain airway - apply O2 if appropriate
Position: recovery position
Medication: benzodiazepines (if seizure is prolonged)
- Rectal diazepam 10-20 mg for adult (repeat once after 10-15 mins if needed)
- Midazolam oromucosal solution 10mg adult
What investigations would you do after an acute seizure?
BEDSIDE:
- Full neurological exam
- Cardiac exam
- Vital obs: (Temp, HR, BP, SpO2)
BLOODS:
- Blood glucose
- FBC - infection
- U+Es - hyponatraemia, hypocalcaemia
OTHER:
- ECG
- CT - if abnormal neurological findings or prolonged ↓ consciousness
A pt has a focal seizure of one of their temporal lobes - what symptoms might they experience?
HEAD mneumonic:
- Hallucination (auditory/gustatory/olfactory)
- Epigastric rising sensation / Emotional (e.g. fear)
- Automatisms (see below)
- Deja vu (memory disturbance) / Dysphasia post-ictal
Other symptoms:
- Fear
- Bizarre psychotic phenomena e.g. derealisation and depersonalisation or elation
- Automatisms (absent mindedly doing a simple action) e.g. plucking at clothes, lip-smacking, repetitive mumbling, repetition of a stereotypical phrase
- Impaired awareness - during/after in the case of ‘complex’ partial seizure
Besides the PC / HPC - what other specific questions are useful in a seizure history?
Significant head injuries
Hx of CNS infection - meningitis, encephalitis, cerebral abscess
FHx of epilepsy
Birth history:
- prematurity, difficulty delivery e.g. forceps, postnatal issues e.g. hypoxia or jaundice
- seizures in childhood / infancy
Medications - some can lower seizure threshold e.g. antipsychotics (worse with atypicals), quinolone Abx (ciprofloxacin or levofloxacin), antidepressants e.g. amitriptyline and some painkillers e.g. tramadol
Illicit drug use / alcohol use
What are febrile convulsions?
Seizures provoked by fever in otherwise normal children
Typical onset = 6 months - 5 years
Seen in 3-5% of children
Features:
- Viral infection causing pyrexia
- Seizure is brief ( < 5 mins) - if > 5 mins phone an ambulance (15-30 mins = complex febrile convulsion)
- Commonly tonic-clonic seizure
- Typically no recurrence within 24hrs
- Recover in < 1 hour
- Boys > girls
Prognosis:
- 1 in 3 have further febrile convulsions (depends on seizure risk factors)
- If further febrile convulsions –> teach parents how to use rectal diazepam or buccal midazolam
What is the link between febrile convulsions and epilepsy?
Majority of children who have febrile convulsions have no future issues, but a small proportion can develop epilepsy in later life!
Risk factors for developing epilepsy:
- FHx of epilepsy
- Complex febrile convulsions i.e. > 15 mins, focal not generalised, repeat episodes in < 24hrs)
- Background of neurodevelopmental disorder
0 risk factors = 2.5% risk of epilepsy
all 3 risk factors = ~ 50% risk of epilepsy
If pt goes on to develop epilepsy it tend to …
- originate from one of the temporal lobes
- associated with atrophy + scarring (gliosis) - seen on MRI –> called ‘mesial temporal sclerosis’ (MTS) - seen in attached image (high signal in R hippocampus + R atrophy = MTS)
What is sodium valproate?
Sodium valproate = anti-epileptic drug (AED), used in management of epilepsy and is 1st-line therapy for generalised seizures
MoA: voltage-gated Na+ channel blocker + ↑ GABA activity in brain (main mechanisms of action)
Women of childbearing age = AVOID!!
Other AED are often better for seizure control
Adverse effects:
- P450 inhibitor = ↓ drug breakdown, thus ↑ drug efficacy
- Nausea
- ↑ appetite + weight gain
- Alopecia
- Neuro: ataxia, tremor
- Organs: hepatotoxicity, pancreatitis, encephalopathy
- Thrombocytopaenia
- Hyponatraemia
- Teratogenic
What monitoring is required for sodium valproate?
Normally NONE!!
Poor clinical correlation between levels of serum valproate and efficacy (exception = phenytoin) –> thus blood tests aren’t done, except special circumstances
Special circumstances for valproate monitoring:
- Concerns about drug toxicity / OD
- Concordance or poor absorption (if these are concerns they could cause poor seizure control on valproate)
- Drug interactions e.g. P450
What concerns are there when swapping a pt from one AED to another?
Breakthrough seizures - as dose of original AED is lowered and the other AED increased the combination may not effectively prevent seizures
- Pt should be advised to avoid any dangerous activity during transition e.g. working at height, cycling in traffic, work with machinery, taking baths
Tolerability of new AED - will pt have bad side effect profile from new AED / combo of AEDs during transition
Interactions:
- Between AEDs
- Between new AED + other current medication e.g. P450 enzyme inducing impacting on COOP = ↓ contraceptive effect
Driving - if pt has breakthrough seizure = no liscence for 6 months (minimum)
- DVLA recommends (but doesn’t legally enforce) that during transition to new AED the pt stop driving during the transition + for 6 months thereafter
What is Lamotrigine and it’s side effects?
Lamotrigine = AED, 2nd-line for various generalised and partial seizures
MoA: sodium (Na+) channel blocker
Side effects:
- Common: sedation, dizziness, nausea and insomnia
- Rare: Stevens-Johnson syndrome (SJS = flu like symptoms progress to blistering red / purple rash) and toxic epidermal necrolysis (TEN) - type of severe skin reaction in which skin blisters leaving raw areas
How is pregnancy planned in patients taking AED for epilepsy?
↓ teratogenic risk - change AED e.g. sodium valproate (no AED is completely safe + risks for each AED are unknown)
Establish lowest therapeutic dose of AED
Prophylactic folic acid 5mg daily as soon as contraception is stopped (continue through 1st trimester)
Name factors which can ↑ an epileptic pt’s likelihood of having a seizure.
Illness e.g. LRTI or UTI
Poor concordance with AED medication
New medication interaction - some can lower seizure threshold e.g.
- antipsychotics (worse with atypicals)
- quinolone Abx (ciprofloxacin or levofloxacin)
- antidepressants e.g. amitriptyline
- some painkillers e.g. tramadol
Alcohol excess
Metabolic disturbances e.g. hypo-/hyper-natraemia, hypoglycaemia, hypocalcaemia (↓ Ca)
Disturbed sleep, jetlag, fatigue
GI disturbances which cause poor AED absorption
What is medically refractory epilepsy and how can it be managed?
Medically refractory epilepsy = epilepsy that has failed to be controlled by at least 2 AEDs (occurs in 20-30% of epilepsy)
Management:
- Further AEDs - tends to show ‘law of diminishing returns’ with each new AED being less likely to help
- 2 simultaneous AEDs - works for minority of pts (↑ risk of side effects)
- In some cases epilepsy surgery can be an option e.g. mesial temporal sclerosis
