Video Duration: 30 minutes
Sudden event in which changes of behaviour, sensation or cognitive processes are caused by excessive, hypersynchronous discharges in the brain
Epilepsy mechanism unknown - brain goes into seizure activity; excessive synchronisation. Resistance of excitatory neurone firing is decreased (ion channel changes/dysfunctioning inhibitory neurons).
Area where seizure develops is called 'seizure focus' (is needed for any surgical options - only 3% eligible). Another mechanism; possibly upregulation of excitatory circuits/downregulation of inhibitory circuits post-injury to brain. NB - BBB failure = toxin accumulations --> may cause epilepsy. Scarring from any infections, trauma, inflammation or surgery may cause epilepsy as well.
Febrile seizures, genetic factors, Infections/trauma
SEIZURES - 60% convulsive. 30-120 second duration. Positive ictal symptoms - movements, noise, tastes. Post-ictal symptoms - memory loss, temporary paralysis/unconsciousness. May occure from sleep (seperates from Non-epileptic seizures). May be associated with other brain pathologies - eg scarring.
Typical seizure phenomenon - lateral tongue biting, deja vu, jamais vu (opposite).
Can be primary or secondary. Focal point in brain determines type of seizure and symptoms seen.
Stereotypical seizures (patient knows usual pattern of events).
Focal - from specific part of the brain, may spread --> secondary globalised seizure.
Focal - preceded by isolated disturbance of cerebral function (aura - smell, taste, emotion).
eg - Left frontal seizure - with secondary generalisation = jerking of the foot, leg, trunk, arm , head.
Generalised - distorts activity of whole brain/ symmetrically.
Unclassifiable, provoked and acute.
Tongue biting, hypertonic, clonic (movement). Unconsciousness, memory loss, myotonic, atonic. Emotion (if limbic system affected). On examination - look for underlying cause as there may be one (eg - brain tumour), ask detailed history - previous injury.
EEG (interictal/ictal). Video EEG. MRI/CT.
SPECT (radioactive tracer for bloodflow detection in the brain).
PET - which sites take up glucose, where is metabolically active.
Invasive EEG recording (grid electrode - on exposed brain).
Wada test - barbiturate is introduced into each of the internal carotid arteries in turn in order to evaluate the other hemisphere; language and memory tests. (Prior to ablation for epilepsy surgery).
General for underlying cause
See investigations - MRI/CT/PET.
Education, epilepsy nurse, supportive, counselling - for employment, driving licence loss, etc.
Anti - epileptic drugs ; carbamazipine, sodium valproate, lamotrigine (warning - major side effect profile - caution in pregnant women/women of child bearing age as AEDs are usually teratogenic - cause harm to unborn fetus).
Specific drug regimen for different type of epilepsy/seizures. Monotherapy, maybe dual therapy. Try different drugs - titre up to lowest effective dose.
3% eligible - often curative, last resort.
Recurrent unprovoked seizures, which are abnormal excess activation of neuronal activity causing neurological dysfunction
Inc connectivity between neurons
Inc excitatory transmission
Dec inhibition (GABA)
50% no known cause
Neoplasia eg brain tumours
Focal - simple, complex or 2e generalised
Complex - tonic clonic, tonic, myoclonic, absence, atonic
Extensor plantar response
Check for infections
dec pO2, dec pH (checking for hypoxia induced seizure)
MRI/CT to exclude structural mass
ECG to exclude arrhythmia
EEG to confirm
Carbamazepine - focal and 2e generalised
Lamotrigine - broad spectrum
Sodium Valproate - broad spectrum
Phenytoin - tonic clonic and status epilepticus
Tumour excision if necessary