Epilepsy Flashcards
What is an epileptic seizure
Paroxysmal and transient event in which changes of neurological processes are caused by excessive, hypersynchronous neuronal discharges in the brain
What is the clinical definition of epilepsy (criteria)
> 2 unprovoked seizures occurring >24h apart
What is a focal seizure
seizures that arise from a specific area, on one side of the brain
What is the most frequently recognised location of focal epilepsy
Temporal lobe origin
What are focal aware seizures
Remain conscious and typically recall the event
Characteristics of a focal impaired awareness seizures
- Loss of consciousness
- Memory loss of event
- Impaired responsiveness after event
Characteristics of a focal seizures affecting the temporal lobe
- Aura - deja vu, fear, strange smells
- Dysphasia
- Automatisms: Picking at clothes, Lip smacking
- rising Epigastric sensation
Characteristics of a focal seizure affecting the frontal lobe
- Jacksonian march - jerking starts in a specific muscle and spreads to surrounding groups
- Todd’s paralysis - unilateral paralysis of arms/legs
Characteristics of a focal seizure affecting the parietal lobe
- Paraesthesia
- Pain
- warmth
Characteristics of a focal seizure affecting the occipital lobe
Visual disturbances:
* Flashes/ floaters
* Change in colour vision
Give 5 RFs for focal seizures
- Febrile seizures
- Traumatic brain injury
- CNS infection
- Dementia
- Stroke
- tumour
What is the name for when focal seizures spread outside of one region
Bilateral tonic-clonic seizures
4 investigations for suspected epilepsy
- Blood glucose - exclude hypo/hyperglycaemia
- MRI brain - lobe abnormalities
- Electroencephalogram
- Serum electrolytes
- CT head - urgent if focal neuro deficits
What is the treatment for acute repetitive seizures
- Benzodiazepines - rectal/ IV diazepam or midazolam (community vs hospital)
How are focal seizures treated
- 1st line Anticonvulsant monotherapy
1) Lamotrigine or levetiracetam
2) Oxcarbazepine, Zonisamide or carbamazepine - 3rd line Anticonvulsant dual therapy
What are generalised seizures
- Both hemispheres of the brain are affected
- characterised by widespread motor manifestation
Describe a tonic seizure
- Sudden onset increased muscle tone - Stiff and flexed muscles
- Usually fall backwards
- LOC
Describe an atonic seizure
Referred to as ‘drop attacks’
* Sudden loss of muscle tone
* Often results in a fall
* Usually aware during episodes
Describe an absence seizure
- Blank, stares into space then abruptly returns to normal
- Unaware of surrounding and unresponsive during episodes
- Eyelids may flutter
- Usually seen in children
Describe a myoclonic seizure
- Sudden, brief muscle contractions - abrupt jump/ jolt
- Usually conscious
Describe a tonic-clonic seizure
- complete LOC
- Tonic (muscle rigidity) then clonic (muscle jerking)
- Tongue biting, incontinence, irregular breathing
- Prolonged post-ictal period
Describe the 4 phases of a seizure
- Prodromal: Mood changes days before a seizure - confusion & irritability
- Aura: warning feeling just before - deja vu, strange smells
- Ictal phase: the seizure
- Post-ictal: brain recovers from seizure - behaviour changes, amnesia, agitation, confusion
What is the treatment for tonic-clonic seizures
- 1st - Sodium valproate
- 2nd - Lamotrigine or levetiracetam (1st in woman and girls)
- girls aged under 10 years and who are unlikely to need treatment when they are old enough to have children or women who are unable to have children may be offered sodium valproate first-line
What is the treatment for myoclonic seizures
- 1st - Na valproate (CI = women/girls)
- 2nd - levetiracetam (1st line in women)
- 3rd - lamotrigine
What is the treatment for tonic/ atonic seizures
- 1st - Na valproate (CI = women/girls)
- 2nd - Lamotrigine (1st line in females)
- 3rd - Topiramate
What is the treatment for absence seizures
- first line: Ethosuximide
- 2nd line males: Na valproate
- 2nd line females: Lamotrigine/ levetiracetam
How is treatment-resistant epilepsy treated
- Surgical resection
- Vagus nerve stimulation
Mechanism of action of sodium valproate
- Increases the activity of GABA which has a calming effect on the brain
Why is sodium valproate avoided in females with childbearing potential
Teratogenic
* Causes neural tube defects and developmental delay
Apart from teratogenicity, give 3 side effects of sodium valproate
- Liver damage/ hepatitis
- Hair loss
- Reduced fertility
Give 3 side effects of carbamazepine
- Agranulocytosis
- Aplastic anaemia
- P450 inducer
What is status epilepticus
- a single seizure lasting >5 minutes, or
- > = 2 seizures within a 5-minute period without the person returning to normal between them
How is status epilepticus initially managed
- ABC approach
- Supportive care - high [O2], glucose if hypo, thiamine
- Benzodiazepines: rectal/ buccal prehospital or IV in hospital. This may be repeats once after 5-10 mins
How is status epilepticus treated if seizures continue despite 2 doses of benzodiazepine
Intravenous:
* Levetiracetam or
* Phenytoin or
* Na valproate
What are 3 options of benzodiazepines that are used in the initial management of status epilepticus
- Buccal midazolam
- Rectal diazepam
- IV lorazepam
Give 4 features that would indicate a non-epileptic seizure opposed to epilepsy
- Doesn’t occur in sleep
- Eyes tightly closed
- Longer (>3 mins)
- Asynchronous movements
Give 5 causes of non-epileptic seizures
- Autoimmune - SLE
- Metabolic - Low glucose/Na/Ca
- Drugs - cocaine
- Alcohol withdrawal
- Infection
What are the rules for patients who drive and have had seizures
- generally patients cannot drive for 6 months following a seizure
- For patients with established epilepsy they must be fit free for 12 months before being able to drive
