Epilepsies

Question 1

Distinguish between the different types of childhood epilepsies

Answer 1

• Generalised: always LOC, no warning, symmetrical seizure, bilaterally synchronous discharge on EEG or varying asymmetry
  
  • ​Absence
  • Myoclonic
  • Tonic
  • Tonic-clonic
• Focal: relatively small group of dysfunctional neurones in one hemisphere, aura which affects site of origin, +/- change in conscious level or more generalised tonic- clonic seizure (simple vs. complex classification)
  
  • ​Frontal: motor or premotor cortex.
    
    • clonic movements moving proximally- Jacksonian march
    • asymmetrical tonic seizures
    • bizarre, hyperkinetic movements
    • atonic seizures (mesial frontal discharge)
  • Temporal lobe
    
    • ​MOST COMMON OF ALL EPILEPSIES​
    • aura with taste/ smell abormalities
    • distortions of shape and sounds
    • lip-smacking
    • automasisms (walking around with no purpose, plucking clothing)
    • Deja-vu
    • longer than absence and loss of consciousness can occur
  • Occipital
    
    • ​distortion of vision
  • Parietal
    
    • ​ckntralateral dyaestesias
    • distorted body image

Question 2

EEG/ MRI what can the can/ cannot show?

Answer 2

• EEG
  
  • unless seizure actually occuring, EEG does not add to diagnosis
  • people without epilepsy can have abnormal EEG activity
  • people with epilepsy can have normal EEG activity
  • sleep-deprived EEG/ 24h ambulatory or video telemetry if EEG normal
• MRI
  
  • ​not generally required for childhood epilepsies
  • indications: nerological signs between seizures, focal seizures, tumour or vascular lesion query

Question 3

Initial investigations in epilepsy

Answer 3

• Detailed history- diagnosed clinically (video, eye witness)
• EEG
• MRI- not always indicated
• Functional scans- PET/ SPECT
• Metabolic investigations
  
  • developmental regression (ID epilepsiy syndromes)
  • seizures related to feeds/ fasting
• Genetic studies
  
  • abnormalities of sodium or other channels- SCN1A

Question 4

Treatment options in epilepsy

Answer 4

• Anti-epileptics
  
  • ​can usually be discontinued after 2 years of seizure free
• Intractable seizures:
  
  • Ketogenic diet​
  • Vagal nerve stimulation
    
    • ​externally programmable stimulation of wire implanted around vagal nerve. Under trials.
  • Surgery
    
    • ​temporl lobectomy for mesial temporal sclerosis
    • hemispherectomy
    • other focal resections

Question 5

Know common anti-epilpetics and their side-effects

Answer 5

On seizure type:

• generalised
  
  • ​tonic-clonic: valproate, carbamaepine. Lamotrigine, topiramate.
  • absence: valproate, ethosuximide. Lamotrigine
  • myoclonic: valproate. Lamotrigine
• focal: carbamazepine, valproate, lamotrigine (slow titration). Topiramate, levetiracetam, oxycarazepine, gabapentin, tiagabine, vigbatrin​

Side effects (all may cause drowsiness and occassional skin rashes)

• valproate: weight gain, hair loss, rare idiosyncratic liver failure
• carbamazepine: rash, neutropenia, hyponatraemia, ataxia, liver enzyme induction
• vigabatrin: restriction of visual fields
• lamotrigine
• ethosuximide: nausea and vomiting
• topiramate: drowsiness, withdrawal and weight loss
• gabapentin: insomnia
• levetiracetam: sedation- rare
• benzodiazepines: sedation, tolerance to effects, increased secretions

Question 6

What is SUDEP and give advice to families?

Answer 6

• sudden unexpected death in epilepsy
• someone with epilepsy dies suddenly and unexpectedly, and no obvious cause of death can be found at autopsy
• with epilepsy, risk is 1 in 1000
• Risk factors: frequent tonic-clonic seizures (esp. during sleep),considered for epilpepsy surgery, drug and ETOH problem, depression, recent epilepsy related injury
• Preventing SUDEP: adhering to medications (controlling seizures), continual follow up, sleeping enough, avoiding alcohol and drugs, lifestyale and environmental changes for seizure prevention, epilepsy diary

Question 7

Febrile seizures

Answer 7

• seizure accompanied by fever in the absence of intracranial infection due to bacterial meningitis or viral encephalitis
• 3% children
• 6m- 6yrs
• genetic predisposition (10% risk if first degree relative has had a febrile seizure)
• clssically viral infection with rapidly rising temperature
• description of seizure: brief, generalised tonic clonic
• recurrence: 30-40%. More likely in younger child, onset of seizure from onset of infection short, lower the temp at seizure time and positive family history
• simple: do not cause brain damage. 1-2% of developing epilepsy.
• complex: focal, prolonged, recurrence in same illness- have increased risk of development of epilepsy (4-12%)
• Examination: find source of infection!
• Advice to parents: advice sheets. RIsks discussed. Anti-pyretics not been shown to reduce but still give in accordance to instructions. First aid- > 5 min seizure give rectal diazepam or buccal midazolam. Anti-epileptics are not given.

Question 8

Transient loss of consciousness

Answer 8

• breath holding attacks
  
  • ​upset toddlers
  • cries–> holds breath–> goes blue
  • brief LOC, rapidly fully recover
  • behaviour modification therapy (distraction) may help
  • resolve spontenously
• reflex anoxic seizures
  
  • ​occur in head trauma, eating cold food, fright and fever
  • infants/ toddlers
  • FHx of faints
  • pallor, drops to floor
  • hypoxia may induce a generalised tonic-clonic seizure
  • usually brief and child rapidly recovers
  • cardiac asystole due to vagal inhibition
• syncope
  
  • ​hot, stuffy environment; standing for hours; fear
  • clonic movements may occur
• migraine
  
  • ​unsteadiness/ light headedness
• benign paroxsymal vertigo
  
  • ​reccurent episodes of vertigo lasting several minutes
  • nystagmus, unsteadiness or falling
  • viral labarynthitis
• other
  
  • ​cardiac arrhythmias
  • TICS< day dreaming night terrors
  • self-gratification
  • NEAD- non-epileptic attack disorder
  • pseudoseizures
  • fabricated seizure
  • induced illness- NAI ? injecting insulin ?SDH
  • paroxysmal movement disorders (no LOC)

Question 9

Management of status epilepticus

Answer 9

1. ABC
2. BLOOD GLUCOSE- <3mmol/L give IV glucose
3. VASCULAR ACCESS? Lorazepam 0.1 mg/kg
4. NO VASULAR ACCESS? Rectal diazepam 0.5 mg/kg OR buccal midazolam 0.5 mg/kg
5. STILL FITTING (5 mins) Lorzaepam 0.1 mg/kg I.V.
6. STILL FITTING (10 mins) Paraldehyde 0.4 ml/ kg PR
7. STILL FITTING (10 mins) call for senoir help. Give phenytoin 18 mg/kg IV/IO over 20 mins or phenobarbital 15 mg/kg (if on PO phenytonin)
8. RAPID SEQUENCE INDUCTION with thiopental. Mechanical ventilation. Transfer to PICU.