You are working in ED reviewing Sharon Hazawa, a 28 year old lady who has been brought in by ambulance after having a witnessed seizure at a supermarket.
On arrival, she is febrile and GCS 10 (E2V3M5) – drowsy with eyes opening only to pain.
The paramedics report she had a self terminating 2 minute seizure in the ambulance. While you are reviewing her, she suddenly tenses up, then begins to have jerking, flexing movements of the upper and lower limbs.
List some possible differential diagnoses for this presentation
Seizure – in this case, status epilepticus
Pseudoseizure
Syncope
Myoclonus
Tics
Rigors
Movement disorders
> Tremors
> Dystonia
> Chorea
> Hemiballismus
> Athetosis
What other signs and symptoms makes the diagnosis of seizures more likely?
History
If available, also obtain a collateral history from someone who witnessed the seizure
The seizure
> Before: aura (e.g. strange smells, feeling of fear or doom – this could even happen days before the actual seizure event), trigger exposure (if known epileptic, e.g. flashing lights, loud noises), new medications (that can lower the seizure threshold or interact with anti-epileptics)
> During: loss of bowel or bladder continence, tongue biting, abnormal limb movements, loss of consciousness, progression of symptoms e.g. from one limb to another
> After: postictal state including confusion and drowsiness, recollection of the event, paralysis (Todd’s paresis)
Other important information: duration, any injuries sustained, previous seizures, relevant past medical history (e.g. previous CNS infection, space occupying lesion, traumatic brain injury)
Physical examination
There may not be any examination findings in the post-ictal state
During, observe for signs that may help classify the seizure e.g. which limbs are moving, in what way, if there is loss of consciousness and if there is any eye deviation
Tongue laceration (can help distinguish from pseudoseizure)
Injuries sustained e.g. posterior shoulder dislocation
What are some signs and symptoms that can characterise a pseudoseizure?
Variable character of seizures from one episode to the next
Resistance to eye opening
Intermittent, irregular movements
Gaze aversion
What is the definition of status epilepticus?
Prolonged or rapidly recurring convulsions lasting more than 5 min
> Previously, the definition was 30 minutes of continuous seizure activity.
> In the 1970s, an experiment was conducted in which bicuculline was injected into paralysed and ventilated baboos. Bicuculline is a competitive antagonist of GABA-A receptors. The neurons of these animals demonstrated ischaemic change after just 30 minutes of continuous seizures.
> Generally a seizure lasting more than 5 minutes is more likely to become prolonged and be associated with adverse outcome. Hence a seizure lasting more than FIVE minutes is now used as the definition and used as a threshold for commencing treatment.
> The longer you wait to treat a seizure, the harder it becomes to stop, partially because the benzodiazepine receptors are reduced by seizure activity
