epilepsy Flashcards
what is status epilepticus
This means seizures lasting for >30min, or repeated seizures without intervening
consciousness. Mortality and the risk of permanent brain damage increase with the
length of attack. Aim to terminate seizures lasting more than a few minutes as soon
as possible (50%). Diagnosis of tonic–clonic status
is usually clear. Non-convulsive status (eg absence status or continuous partial
seizures with preservation of consciousness) may be more diffi cult: look for subtle
eye or lid movement. For other signs, see p489, p494-497. An EEG can be very helpful.
Could the patient be pregnant (any pelvic mass)? If so, eclampsia (OHCS p48) is the
likely diagnosis, check the urine and BP: call a senior obstetrician—immediate delivery
may be needed.
investigations in status epilepticus
Investigations
• Bedside glucose, the following tests can be done once has started: lab glucose,
ABG, U&E, Ca2+, FBC, ECG.
• Consider anticonvulsant levels, toxicology screen, LP, culture blood and urine, EEG,
CT, carbon monoxide level.
• Pulse oximetry, cardiac monitor.
treatment of status epilepticus
1 - Open and maintain the airway, lay in recovery position
Remove false teeth if poorly fi tting, insert oral/nasal airway,
intubate if necessary
2 - Oxygen, 100% + suction (as required)
3 - IV access and take blood:
U&E, LFT, FBC, glucose, Ca2+
Toxicology screen if indicated
Anticonvulsant levels
4 - Slow IV bolus phase—to stop seizures: eg lorazepam
2–4mg. Give 2nd dose of lorazepam if no response within 10min.
5 - Thiamine 250mg IV over 30min if alcoholism or
malnourishment suspected.
Glucose 50mL 50% IV, unless glucose known to be normal
Treat acidosis if severe (contact ICU)
6 - Correct hypotension with fl uids
7 - IV infusion phase: If seizures continue, start phenytoin,
15–20mg/kg IVI, at a rate of ≤50mg/min. Monitor ECG and BP.
100mg/6–8h is a maintenance dose (check levels).
Alternative: diazepam infusion: 100mg in 500mL
of 5% glucose; infuse at ~40mL/h as opposite
8 - General anaesthesia phase: Continuing seizures require expert help
with paralysis and ventilation with continuous EEG monitoring in ICU
what is epilepsy
Epilepsy is a recurrent tendency to spontaneous, intermittent, abnormal elec trical
activity in part of the brain, manifesting as seizures.1 These may take many forms,
but for each individual patient they tend to be stereotyped
what are convulsions
Convulsions are the
motor signs of elect rical discharges. Many of us would have seizures in abnormal
metabolic circum stances—eg Na+, hypoxia (eg refl ex anoxic seizures in faints): we
would not normally be said to have epilepsy. The prevalence of active epilepsy is ~1%.
elements of a siezure
A prodrome lasting hours or days may rarely precede the
seizure. It is not part of the seizure itself: the patient or others notice a change in
mood or behaviour. An aura is part of the seizure of which the patient is aware, and
may precede its other manifestations. The aura may be a strange feeling in the gut,
or an experience such as déjà vu (disturbing sense of familiarity), or strange smells
or fl ashing lights. It implies a partial (focal) seizure, often, but not necessarily, from
the temporal lobe. Post-ictally there may be headache, confusion, myalgia, and a
sore tongue; or temporary weakness after a focal seizure in motor cortex (Todd’s
palsy, p726), or dysphasia following a focal seizure in the temporal lobe.
siezure diagnosis
There are three key questions to consider:
1 Are these really seizures? A detailed description from a witness of ‘the fi t’ is vital
(but ask yourself: “Are they reliable?” In the heat of the moment many witnesses
report twitching when none took place. Tongue-biting and a slow recovery are
very suggestive. Not everything that twitches is epilepsy—refl ex anoxic convulsions
due to syncope are particularly diffi cult. Try hard not to diagnose epilepsy in error—
therapy has signifi cant side-eff ects, and the diagnosis is stigmatizing and has
implications for employment, insurance, and driving. See p464 for .
2 What type of seizure is it—partial or generalized? The attack’s onset is the key
concern here. If the seizure begins with focal features, it is a partial seizure, however
rapidly it then generalizes. See BOX.
3 Any triggers? Eg alcohol, stress, fevers, certain sounds, fl ickering lights/TV, contrasting
patterns, reading/writing? Does he recognize warning events (eg twitches)
so he can abort the fi t before it generalizes? TV-induced fi ts rarely need drugs.
In assessing a fi rst-ever seizure, consider also:
• Is it really the fi rst? Ask the family and patient about past funny turns/odd behaviour.
Déjà vu and odd episodic feelings of fear may well be relevant.
• Was the seizure provoked? (see ‘Non-epileptic causes’ above) Provoked 1st seizures
are less likely to recur (3–10%, unless the cause is irreversible, eg an infarct
or glioma); if it was unprovoked, recur rence rates are 30–50%.209 NB: provocations
are diff erent to triggers: most people would have a seizure given suffi cient provocation,
but most people do not have seizures however many triggers they are exposed
to, so triggered seizures suggest epilepsy. Triggered attacks tend to recur.
• Prompt investigation, eg with admission for 24h for bloods, drugs screen, LP (if
safe) , EEG—p496 CT/MRI + enhancement (or else infective causes, eg TB, may be
missed) .210 Admit to substantiate ideas of pseudoseizures, or for recurrent seizures.
