Epilepsy Flashcards
Definition
Recurrent spontaneous intermittent excessive electrical activity in part of brain causing seizure.
Aetiology
Often idiopathic, possibly due to channelopathies.
Structural- cortical scarring, developmental, SOL, stroke, sclerosis, vascular malformation.
Sarcoidosis, SLE
Symptoms
Various types of seizure, see other cards.
Sometimes triggers.
In general distrubed conciousness, behaviour, emotion, motor function, sensation.
Management
Drugs
Surgical resection
Acutely may need paralysis and intubation.
Partial seizure
One hemisphere, focal onset with site specific features.
- Simple- retain awareness, often precursor to larger seizure (aura). Focal motor, sensory, autonomic or psychic symptoms.
- Complex- lose awareness, odd behaviour eg lip smacking. Commonly temporal lobe= post ictal confusion.
- Secondary generalisation- electrical disturbance starts focal and spreads widely.
General symptoms eg amnesia, los bladder tone. Headache, drowsy.
Frontal lobe partial seizure
Abnormal head movement
Swearing and shouting
Unusual posturing
Repeated movements eg rocking
Temporal lobe partial seizure
Deja vu
Strange taste or smell
Rising sensation in stomach
Lip smacking, swallowing, chewing
Parietal lobe partial seizure
Abnormal sensation
Feeling like body part missing
Hallucinations
Cant understand language or reading
Occipital lobe partial seizure
Hallucinations
Disturbed vision
Eye pain
Nystagmus
Generalised seizure
Both hemispheres so cross corpus callosum. Simultaneous throughout cortex. Impaired conciousness.
- tonic clonic- LOC, stiffen, jerk, loss bladder control, tongue bite, respiratory arrest. Post ictal confusion and drowsy.
- atonic- sudden loss tone, no LOC.
- myoclonic- sudden jerking limb, face or trunk.
- absence- under 10 seconds. Unresponsive pause. May be blinking or slight jerking. Often in kids.
Diagnosis
Often clinical
Seizure characteristics
Triggers? Eg photic and hyperventilation.
EEG supports diagnosis only.
Check bloods, glucose, electrolytes, LFT, UE, ECG.
Management
AED depends on type
-VGSC blocker eg carbamazepine, phenytoin, lamotrigine.
-benzodiazepine GABA enhancement.
-valproate decrease GABA breakdown and increase synthesis.
Emergency management if over 5 mins-
buccal midazolam
ABCDE
Blood glucose
IV lorazepam, IV phenytoin.
Look for cause eg drug, withdrawal, electrolytes, infection.
Surgery if very severe.
Differentials
Syncope Arrhythmia TIA Migraine Sleep disorder Panic attack -Non epileptic causes- Trauma Stroke Haemorrhage RICP Alcohol or benzo withdrawal Hypoxia, electrolytes, glucose, urea Liver disease Infection eg meningitis, syphillis, HIV Drugs eg TCA, cocaine, tramadol, theophylline. Pseudoseizures.
AED in pregnancy
Lomotrigine safest, including during breast feeding.
Valproate teratogenic
AEDs by seizure type
-generalised tonic clonic- valproate or lamotrigine 1st line. Then carbamazepine.
-absence- valproate, lamotrigine, ethosuximide.
-other generalised eg atomic, myoclonic- same as tonic clinic but NOT carbamazepine.
-partial- carbamazepine 1st line. Then valproate, lamotrigine etc.
Aim for monotherapy. Start low dose.
Complications
Status epilepticus convulsions over 5 mins. Tx with IV lorazepam or phenytoin.
Brain dysfunction or damage.
Important benzo points
-benzodiazepines-
Lorazepam for status epilepticus
Clonazepam for absence ST
AE- sedation, tolerance, confusion, lack coordination, agression, dependance, withdrawal can trigger seizure.
OD reversed by IV flumazenil but this can trigger seizure or arrhythmia.
Important valproate points
Used for all types
Less severe AE eg sedation, ataxia, tremor, weight gain, transaminase increase, nausea.
Inhibited by antiDs and antipsychotics.
Aspirin competes binding.
Monitor plasma level, blood, hepatic and metabolism disorders.
Phenytoin important points
Not used for LT control
Not usd for absence
IV acutely as therapeutic level reached fast
AE- gingival hyperplasia, ataxia, dizzy, headache, nystagmus, anxiety, hypersensitivity, tremor, dysarthria, decreased intellect, depression.
Non linear PK, very variable dose responses.
Monitor plasma level.
Compete for binding with valproate, NSAIDs.
OCP decrseas, cimetidine increases.
Lamotrigine important points
1st choice in adults NOT paeds as ADRs Safer in pregnancy. Used for all types Less AE. Occasional rash and hypersensitivity, blurred vision, photosensitvity, tremor, vomiting, agitation, aplastic anaemia. No CYP induction Use with other AEDs Valproate binding completion. OTC decreases plasma level.
Carbamazepine important points
Not for absence
Contra indicated in AV conduction problems
AE include BP fluctuation, hypoNa, neutropenia, parasthesia, motor, blurred vision, diplopia, balance.
Induces own CYP metabolism.
Warfarin, phenytoin, OCP and systemic CS all decrease.
AntiD interfere
Monitor effect and adjust dose as levels fall.
Explanation
-Epilepsy is when you have seizures due to abnormal excitation in brain. The seizures can range from causing jerking involuntary muscle movements to just being short losses of alertness that can look like daydreaming.
-with treatment it can be well controlled. If not there is slight risk of brain damage with repeated seizures. Also risk of injury if tonic clinic seizure.
-you should carry with you emergency medicine and wear an alert bracelet. Also try to avoid any triggers if possible. Compliance to medication is important.
-
