Seizures Flashcards
Differential causes of seizures…
Trauma: haeomorrhage, diffuse axonal injury
Infection: meningitis, encephalitis
Metabolic: hypo/hyperglycaemia, hypo/hypernatraemia, hypo/hypercalcaemia, hypothyroidism
Neurological: epilepsy, raised ICP
Ischaemic: stroke
Toxins: alcohol withdrawal, drug overdose/withdrawal
Other: non-epileptic attack disorder, eclampsia
Important features of the history…
Before seizure:
- Pt activity
- Sx= sweating, light headedness, palpitations
- Focal neuro signs
- Aura
During seizure:
- Length of the seizure
- LoC
- Seizure movements - rigid/ jerking
- Tongue biting
- Incontinence
After seizure:
- Recall of the events
- Injury
- Confusion/ memory loss
Differentiating features of epilepsy, vasovagal syncope, cardiac syncope and NEAD…
Epilepsy:
- Aura present
- Sudden onset
- Lasts 1-3 mins
- Patient may go blue
- Incontinence
- Lateral tongue bite
- Prolonged post-ictal phase
Cardiac syncope:
- No prodrome
- Sudden onset
- Brief duration (<30s)
- No incontinence
- No tongue bite
- Almost instant recovery
Vasovagal syncope:
- Pre syncope sx e.g. light headedness, palpitations
- Gradual onset
- Lasts around 30s
- No incontinence
- No tongue bite
- Fatigue for few mins
NEAD:
- No prodrome
- Sudden onset
- Can last for hours
- No incontinence
- Bite tip of the tongue
- Eyes closed throughout
- Variable recovery
Investigations for first seizure…
Bedside:
- ECG - arrhythmia
- BP lying and standing
Bloods:
- FBC - raised WCC in infection
- Glucose - hypo/hyper
- U&E - electrolyte abnormalities
- LFTs - raised in liver failure
- Blood alcohol levels - withdrawal
- Drug levels - overdose
Imaging:
- CT/MRI to show structural abnormality
- EEG -only for second seizure
Management after first seizure…
- Patient to have neuro clinic follow up - first fit clinic
- Patient should have cardio clinic follow up if: ECG abnormiality, murmur, breathless, family history
- Inform DVLA : no driving for 6 months if first seizure
- Should avoid: swimming, having baths, operating machinery
Causes of epilepsy…
- Cerebrovascular disease: stroke
- Infection e.g. meningitis, cerebral abscess
- Malignancy / space-occupying lesion
- Trauma
- Medications can lower seizure threshold e.g. tramadol, TCAs
Different classifications of seizures:
Focal seizure = one specific area of the brain affected leading to specific focal neurological signs during seizure:
- Focal aware - consciousness maintained throughout
- Focal impaired awareness - reduced consciousness
Generalised seizure = dysynchronous activity occurs across both hemispheres leading to loss of consciousness and seizure affecting whole body:
- Tonic-clonic
- Tonic
- Myoclonic
- Atonic
- Absence
What are the characteristic features of different types of focal seizures?
Temporal lobe seizure:
- Pre-ictal: aura = deja vu, unusual smell, fear
- Ictal: fixed stare, lip smacking, pulling at clothes
Frontal seizure:
- Twisting, turning, grimacing
- Jacksonian march - movements from distal region then move more proximal
Occipital seizure:
- Distortion of vision
Parietal seizure:
- Sensory changes - warm , tingling sensation on one side
- Distorted body image
What are the characteristic features of different types of generalised seizures?
Absence seizure:
- Patient becomes vacant for seconds-minutes, then returns back instantly
- Automatism e.g. eye flickering
Myoclonic seizure:
- Single/ few jerking movements
- May involve all limbs
Tonic seizure:
- Involves prolonged spasm
Tonic-clonic seizure:
- Tonic phase = stiffening and contraction of limbs, become cyanotic
- Clonic phase = rhythmic jerking of limbs, incontinence, tongue biting
Atonic seizure:
- Complete loss of tone - causing patient to fall
Diagnosis of epilepsy …
> 2 unprovoked seizures within a year
Management of epilepsy
Medical - (start with monotherapy and gradually titrate up as required):
- Generalised seizures = sodium valproate 1st line
- Focal seizures = carbamazepine 1st line
If patient is seizure free for 2 years - can begin to taper down AED dose gradually.
Other:
- Inform DVLA - cannot drive for 12 months after last seizure
- Ketogenic diet (high fat, low carb and protein) - may be helpful
What options are available for drug resistant epilepsy?
- Vagus nerve stimulation: senses pre-ictal tachycardia and causes increased parasympathetic stimulation to prevent seizure
- Deep brain stimulation - electrodes placed deep in the affected parts of the brain and connected to a stimulator
- Surgery in refractory focal epilepsy - focal cortical resection, corpus callosotomy
What is SUDEP?
Sudden unexpected death in epilepsy:
Any death in an epileptic patient (excluding status) where post mortem has not found obvious physiological/ traumatic/ metabolic cause for death
Acute management of generalised seizure <5mins
General first aid priniciples apply... Protect from injury: - Cushion head - Move hazards away from around the patient that could harm them Do NOT restrain them When seizure stops, check airway and place in recovery position Examine for any other injuries Identify and treat precipitating cause
Acute management of generalised seizure >5mins…
Same first aid principles as for seizures <5 mins AND
- Buccal midazolam 10mg
- Rectal diazepam 10-20mg
- IV lorazepam 4mg
Get senior help!!
Then give usual AED if already on treatment
Acute management of focal seizure…
Protect from injury - moving harmful objects from around them
Do NOT restrain
Observe until full recovery is made
Reassure that they will be ok
Indications for CT head following seizure…
- Age >60
- Post-trauma
- Suspected infection - fever
- New onset neuro signs
- Persistent focal neuro signs
- Signs of raised ICP (papilloedema, bradycardia, hypertension)
- Suspected space-occupying lesion
- Confusion > 1 hr (prolonged post-ictal phase)
What is the definition of status epilepticus?
Seizure that lasts >5mins or multiple seizures within 5 min period where patient has not fully regained consciousness inbetween.
*Commonly caused by non-compliance to AEDs
Management of status epilepticus…
- Secure airway, high flow O2, IV access
- IV Lorazepam 5mg –> wait 10 mins for response, if still seizing give another 5mg
*If no IV access give buccal midazolam 10mg - If seizure has still not stopped - contact ITU and begin IV phenytoin infusion: 15-18mg/kg at a rate of 50mg/min
ECG and BP monitoring required - If patient is in refractory status epilepticus –> should be transferred to ITU after 30mins - need rapid sequence induction with propofol/midazolam then tracheal intubation
*EEG monitoring in ITU
What is non-convulsive status epilepticus?
Form of epilepsy syndrome where there are no obvious motor manifestations with impaired consciousness / diminished responsiveness
Difficult to diagnose -requires EEG for clinical diagnosis
Treatment of non-convulsive status epilepticus…
Maintenance of usual AED therapy or IV benzodiazepine
EEG monitoring required
Seizures with brain infection…
- Bacterial meningitis is associated with generalised seizures - h. influenzae is most common bacterium
- Viral encephalitis can lead to generalised and focal seizures - especially HSV
- Cerebral malaria can present with seizures
- Neurocysticercosis - parasitic infection which forms cysts in the brain leading to epileptic syndromes
Pathophysiology of post-traumatic seizures…
Early onset seizures after injury = direct reaction to the injury which stimulates brain tissue that has low threshold for seizure
Late-onset seizures = damage to the cerebral cortex, which may imply permanent brain changes predisposing to epilepsy
Side effects of common AEDs…
Carbamazepine = rash, neutropaenia, SIADH
Sodium Valproate = weight gain, hair loss, menstrual changes, teratogenic (neural tube defects)
Lamotrigine = allergic disorders, aplastic anaemia
Phenytoin = gum hypertrophy, acne, hirsutism, teratogenic
