Epilepsy Flashcards
definition
a recurrent tendency to spontaneous, intermittent, abnormal electrical activity in part of the brain, manifesting as seizures
prevalence ~1%
elements of a seizure
prodrome - lasting hours or days may rarely precede the seizure. not a part of the seizure. patient or others notice a change in mood or behaviour
aura - part of the seizure in which the patient is aware, amy precede other manifestations. may be a strange feeling in the gut, deja vu, strange smells or flashing lights. implies a focal seizure, often (but not always) from the temporal lobe
post ictal Sx
headache
confusion
myalgia
sore tongue
temporary weakness following a focal seizure in the motor cortex
dysphasia following focal temporal lobe seizure
causes of epilepsy
2/3 are idiopathic (often familial)
structural:
cortical scarring (eg from injury years before onset)
developmental - dysembryoplastic neuroepithelial tumour or cortical dysgenesis
SOL
stroke
hippocampal sclerosis (eg after febrile convulsions)
vascular malformations
others: tuberous sclerosis sarcoidosis SLE PAN
non epileptic causes of seizure
trauma stroke raised ICP haemorrhage alcohol or benzo withdrawal metabolic disturbance - liver disease, hypoxia, deranged Na or glucose, low Ca, uraemia, infection
diagnosis
are these really seizures - detailed history. tongue biting and slow recovery are very suggestive
what type of seizure is it? focal onset = partial, however rapidly it then generalises
triggers? alcohol, stress, fevers, certain sounds etc
assessment of first ever seizure
consider:
is it really their first? detailed Hx from patient and others key. deja vu and odd episodic feelings of fear may well be relevant
was it provoked (eg non epileptic causes). provoked first seizures are less likely to recur (3-10%, unless the cause is irreversible - eg infarct or glioma. unprovoked have a recurrence rate of 30-50%
prompt investigation eg with admission for 24h for bloods, drug screen, LP (if safe), EEG, CT/MRI
partial seizure
focal onset
features attributable to one hemisphere. often seen with underlying structural disease
simple partial seizure
awareness unimpaired
focal motor, sensory, autonomic or psychic Sx
no post ictal Sx
complex partial seizure
awareness impaired
may have simple partial onset (=aura) or impaired awareness at onset
most commonly arise from temporal lobe
post ictal confusion is common in seizures arising form the temporal lobe
rapid recovery if origin is the frontal lobe
partial seizure with secondary generalisation
in 2/3rds of partial seizures, the electrical disturbance, which starts focally (as either simple or complex partial seizure), spreads widely
this causes a secondary generalised seizure, which is typically convulsive
primary generalised seizures
simultaneous onset of electrical discharge throughout the cortex
no localising feature attributable to one hemisphere
absence seizures
brief (<10secs) pauses
eg suddenly stops talking mid-sentence and then picks up where left off
present in childhood
tonic-clonic seizures
LOC limbs stiffen (tonic) then jerk (clonic) may have one without the other post ictal confusion and drowsiness
myoclonic seizures
sudden jerk of limb, face or trunk
patient may be thrown suddenly to the ground
may have a violently disobedient single limb
