Epilepsy

BY RUTENDO GANYANI AND SARAH FOLKERTS

Case

52 yr man brought to A&E

Wife witnessed: while standing at bus stop he fell to the ground & she was unable to rouse him

Breathing stopped for about 20s -> after that jerking movements affecting his arms & legs ~ 2mins

There was some urinary incontinence & his face became blue

After regaining consciousness he remained drowsy with a headache

No symptoms prior to episode

What are your main DDs?

What investigations would you perform?

- Syncope & epileptic fit are the main DDs - Syncope often while standing, stressful events & associated w/ arrythmia- Try to assess for prodromal & postictal symptoms

- Syncope -> dizziness & lightheadedness before- Epileptic fit -> confusion & sleepiness after

- Investigations: - FBC- U&E (exclude uraemia, hyponatraemia, hypoglycaemia & hypocalcaemia)- Also check gamma-GT for possible alcohol abuse- CT scan to exclude mass lesion or cerebrovascular event- Refer to neurologist for EEG

What is epilepsy?

Epilepsy is the most common neurological disorder.

Characterised by abnormal electrical activity in the brain.

Can be focal or generalised

What is it’s aetiology?

Changes in neuronal excitability!!!!

Reduction in GABA

Increase in Ach transmission

Increase in Na+ transmission

Decrease in K+ transmission

Mutations found in K+, Na+, Ach and GABA receptors (channelopathies)

How does it present?

PARTIAL SEIZURES!

• Symptoms depend on site of origin

• No loss of consciousness or post-ictal confusion

• What symptoms would you see if the seizure originated in the:

1. Temporal region?2. Parietal region?3. Frontal region?4. Occipital region?

ANSWERS

• Temporal: aura-smell/taste, déjà vu, jamais vu, emotional changes, oral automatisms, gestures eg dystonic or fidgeting

• Frontal: mainly motor, often bilateral e.g. kicking, cycling, violent.

• Parietal: Sensory, nausea, choking, sinking sensations, Illusions of body distortion

• Occipital: Visual hallucinations – simple or complex (shapes to scenes),Vision may black out, Visuo-spatial distortions, headache, nausea

• Altered consciousness, but may seem fully aware

• Symptoms: automatisms (chewing, swallowing, repeated displacement behaviour)

• Generally temporal lobe in origin, can progress to generalised

• Prior to onset may experience sense of déjà vu/jamais vu, perceptual changes, auras

• May have some post-ictal confusion

Question• So where is the main

difference between this type of seizure and a simple partial seizure?

GENERALISED SEIZURES!

• Also called Grand Mal seizures• Easiest to diagnose• N o warning of onset• Whole brain involved• Tonic phase -:

whole body stiffness breathing may stop (cyanosis) ask about this when taking a collateral Hx loss of bladder control patient may report that they were wet when they regained

consciousness. Ask about this when taking Hx. Also tongue biting• Clonic phase –:

muscle jerks• Post-ictal-: unconsciousness, muscle relaxation, slow regain of consciousness,

confusion, sleepy, headaches and aching limbs, no recall of episode ask about post-ictal symptoms when taking Hx eg tiredness

• Also called Petit Mal

• Rare in adults

• Generally start between 6-12 yrs

• Affect Girls > Boys

• Symptoms: seem to ‘switch-off’ (~10 s) but cannot be alerted or woken up

The in-betweener!

Partial with secondary generalised

Simple partial seizure, patient conscious and aware progressing to generalised (Grand-Mal)

Seizures becomes generalised when abnormal electrical activity hits the thalamus

The ‘simple’ part of the seizure depends on site of origin

‘Other’

psychogenic non-epileptic seizures

Myoclonic – sudden jerks (like when falling asleep), possibly familial

Clonic – repeated twitches and jerks no stiffness

Tonic – all muscle contract, whole body stiffness

Atonic – ‘drop attacks,’ muscle tone lost

TREATMENT OF EPILEPSY

Options

Pharmacological :

First line approach for seizures

Anticonvulsants

Surgical

removal of aberrant areas (found by MRI/CAT/electrical stim)

Implants

VNS – vagal nerve stimulation

Seizure type 1st line 2nd line

Simple PartialComplex partial

Partial with secondary

generalised

   CarbimazepineSodium Valproate

LamotrigineOxcarbazepine

Gabapentin Pregabalin Tiagabine

Topiramate etc

Tonic-Clonic Seizure (Grand Mal)

Sodium ValproateLamotrigine

Carbimazepine

ClobazamLevetiracetamOxcarbazepine

Topiramate

 Absence Seizures

(Petit Mal)

EthosuximideSodium Valproate

ClonazepamLamotrigine

 Status Epilepticus

(medical emergency)

IV Lorazepam (repeated after 10 mins)After 25 mins: phenytoin sodium, fosphenytoin, or phenobarbital sodiumAfter 45 mins: Anaesthetize with thiopental, midazolam or propofolBuccal Midazolam/Rectal diazepam (if resusc facilities not available, e.g. at home) Secure airway!

Anti-epileptic hypersensitivity syndrome

- 1-8 weeks from treatment initiation- Initial signs: fever, rash, swollen lymph nodes- Severe signs: Blood, liver, kidney abnormality, vasculitis & organ failure

- Withdraw drugs immediately- Topical steroids & antihistamines- Systemic corticosteroids?- Beware of rebound seizures activity

Be aware of this!

Sarah

GABAa targets

• Enhance activation of GABAA mediated channels via: Action at co-agonist sites Inhibition of GABA breakdown Inhibition of GABA uptake GABA mimetics

• Benzodiazepines: Act on GABAa receptor (γ subunit) to increase activity, thereby reducing neuronal transmission by enhancing inhibition.

• Barbiturates: as above but bind the β-subunit of the GABAa receptor

• GABA transporter inhibitors e.g. Tiagabine

• GABA transaminase inhibitors e.g. Vigabatrin

Side effects of Benzodiazepines and barbiturates• Short-term use only (< 12 weeks)• Tolerance and dependency can develop• Impaired motor coordination (↓muscle tone)• Impaired cognitive performance• Sedation• Disturbed sleep patterns• Retrograde amnesia• Withdrawal on termination

Benzo overdose: use

flumazenil

1. Sodium Valproate2. Ethosuximide3. Diazepam4. Carbamazepine

a. Ca-channel blockerb. Na-channel blockerc. GABA receptor modulator

1. Sodium Valproate – b. Na-channel blocker2. Ethosuximide – a. Ca-channel blocker3. Diazepam – c. GABA receptor modulator4. Carbarmazepine – b. Na-channel blocker

Any Questions???