Epilepsy & seizures Flashcards
What is a seizure?
Occurence of signs/symptoms due to abnormal, excessive neuronal activity
What is epilepsy?
The tendency to have unprovoked seizures
What are the 2 major categories of seizures?
- Generalised
- Focal
Describe the types of Generalised seizures?
- Tonic-clonic
- Tonic
- Atonic
- Clonic
- Absence
- Myoclonic
- Myoclonic absence
- Eyelid myoclonia
Describe the different types of Focal seizures?
- Without impairment of consciousness or awareness
- With impairment of consciousness of awareness
- Evolving to a bilateral, convulsive seizure
- Tonic, clonic, tonic-clonic
Describe the pathophysiology of seizures?
- Imbalance between excitation and inhibition
- GABA is the inhibitory transmitter
- Glutamate and aspartate are the excitatory transmitters
How does GABA act as the inhibitory transmitter in the brain?
- Enhances chloride inflow
- Reduces chances of AP formation
How do glutamate and asparate act as the excitatory transmitters in the brain?
- Excitatory amino acids
- Allow influex of sodium and calcium
- Increase the chances of AP formation
Name some common triggering factors for seizures?
- Alcohol
- Flickering lights
- Sleep deprivation
- Recreational drug use
- Missed antiepileptic doses
What positive neurological symptoms will occur with an occipital onset of generalised tonic-clonic seizures?
- Visual changes
- Lights and blobs of colour
What positive neurological symptoms will occur with a temporal onset of generalised tonic-clonic seizures?
- False recognition
- Deja vu
Describe Focal seizures?
- Localised cortical activity
- Simple = retained awareness
- Complex = impaired awareness
- Localisation determined by symptoms
Describe Focal seizures with impairment of consciousness or awareness?
(Previously complex partial)
- Seizure spreads to temporal lobes which impairs awareness
- Patients stop and spare blankly +/-
- Blinking repetitively
- Smacking of lips
- Picking at clothes
- Period of drowsiness in post-ictal period
Causes of Focal seizures?
Describe Generalised tonic-clonic seizures?
- Initial aura
- Then patient becomes rigid and unconscious
- ‘Fall like a log’
- Jerky movements occur
- Tongue biting and urinary incontinece may occur
- Flaccid state of deep coma
What are the causes of generalised tonic-clonic seizures?
Describe Absence seizures?
- (petit mal)
- Start in childhood
- Shorter than focal seizures
- Can occur frequently during the day
Describe Myoclonic seizures?
- Brief, jerky movements in the arms
- Provoked by fatigue, alcohol or sleep deprivation
Describe Atonic Seizures?
- Brief loss of muscle tone
- Without loss of consciousness
- Result in falls
- Only occur in conjungation with other forms of seizure
Describe Tonic seizures?
- Increased tone and loss of awareness
- Usually part of an epilpesy syndrome
Describe Clonic seizures?
- Similar to tonic-clonic seizures
- With no preceding tonic phase
What are the common generalised epilepsy syndromes?
Describe the investigations which should be performed for someone who has experienced a single seizure?
- 12-lead ECG
- Cranial imaging
- CT/MRI
- EEG
- Where is the epilepsy arising?
- Standard and sleep EEGs
- Assesses prognosis after diagnosis confirmed
- Investigations for toxic, infective and metabolic causes
What are the indications for brain imaging in epilepsy?
- Epilepsy starting after 16
- Seizures with focal features
- Difficulty controlling seizures
- EEG showing focal seizure source
Describe first aid for someone having a seizure?
- Move person away from dnager
- Put in recovery position after convulsions cease
- Ensure the airway is clear
- If convulsions last > 5 minutes, seek additional medical help
Describe some lifestyle advice for someone with epilepsy?
- Avoid known precipitants of seizures
- Only have shallow baths
- Avoid prolonged cycle journeys
- Comply with driving regulations
- Describe UK driving regulations for epilepsy:
- Single seizure?
- Epilepsy?
- Withdrawal of anti-epileptic drugs?
- Single seizure
- Cease driving for 6 months
- Epilepsy
- Cease driving
- Licence restored after 1 seizure free year
- Licence renewal every 3 years until seizure free for 10 years
- Withdrawal of anti-epileptic drugs
- Cease driving during withdrawal period and for 6 months thereafter
Describe the guidelines for anti-epileptic drug therapy?
- Start with one drug
- Low dose then gradually increase until control achieved or side effects
Describe the treatment for focal onset and secondary generalised tonic-clonic seizures?
- 1st:
- Lamotrigine
- 2nd:
- Carbamazepine
- Levetiracetam
Describe the treatment for Generalised tonic-clonic seizures?
- 1st line:
- Sodium valproate
- Levetiracetam
- 2nd line:
- Lamotrigine
Describe the treatment for Absence seizures?
- 1st line:
- Ethosuximide
- 2nd line:
- Sodium valproate
Describe the treatment for myoclonic seizures?
- 1st line:
- Sodium valproate
- 2nd line:
- Levetiracetam
Describe some options for epilepsy surgery if pharmacological therapy fails?
- Surgical resection of epileptogenic tissue
- Vagal nerve stimulation
- Deep brain stimulation
Describe the withdrawal of anti-epileptic therapy?
- Considered after seizure-free period for > 2 years
- Most successful if epilepsy onsets in childhood
Describe the relation of anti-epileptics to contraception?
- Some AEDs induce hepatic enzymes which metabolise contraceptives
- Carbamazepine, phenytoin, barbiturates carry greatest risk
- Lowest risk in sodium valproate and levetiracetam
Describe epilepsy in pregnancy?
Describe Status epilepticus?
- Seizures which do not resolve spontaneously
- Recurrent seizures without complete recovery in between
Management of status epilepticus
- Benzodiazepines
- Diazepam
