Blackouts, Seizures and Epilepsy Flashcards
What is a seizure?
Transient occurrence of signs and/or symptoms due to abnormal, excessive or synchronous neuronal activity in the brain
What are the hallmarks of seizures?
- Prodome last hours or days
- Aura implies focal seizures
- Usually brief and self limiting
- Massive inter-individual variation
- Little intra-individual variation
- Recognised pattern and evolution
- Post ictal headache, confusion, myalgia
- Temporary weakness after a focal seizure in the motor cortex or dysphasia following a focal seizure in the temporal cortex
What is the investigation in suspected seizures?
THERE IS NO DIAGNOSTIC TEST
=> VERY THOROUGH HISTORY NEEDED
=> Look for provoking causes:
- Consider EEG
- Drug levels and drug screen
- MRI
- Lumbar puncture
How are seizures categorised?
=> DURATION:
- Self limiting
- Continuos (Status Epilepticus)
=> ONSET & SPREAD:
- Generalised
- Focal
=> CAUSE:
- Provoked
- Unprovoked
What is Status Epilepticus (Continuos seizure)?
A seizure which is unlikely to terminate and is associated with a risk of damage
What is Epilepsy?
Common neurological condition characterised by recurrent seizures
What conditions have the greatest association with Epilepsy?
- Cerebral palsy
- Tuberous sclerosis
- Mitochondrial diseases
Apart from Epilepsy, what are the other common causes of recurrent seizures?
=> Febrile convulsions
- Occurs in children aged 6 months - 15 years
- Typically early in viral infection
- Brief and generalised tonic/ tonic clonic in nature
=> Alcohol withdrawal seizures:
- Occurs in patients with history of alcohol excess who suddenly stop drinking
- Excess alcohol means high levels of GABA which act as inhibitory neurotransmitters. Sudden alcohol abstinence means there is a sudden overwhelming excitation the body is not used to, causing seizure
=> Psychogenic non-epileptic seizures:
- Patients may present with a history of mental health or personality disorders
How are seizures classified?
=> Focal seizures:
- Originating within networks linked to one hemisphere
=> Generalised seizures:
- Bi lateral distribution
=> Focal to bi-laterlal seizure:
- Seizures that start in one hemisphere then spread bi-lateral
What are the different types of Focal seizures?
=> Without impairment of consciousness:
- Focal motor, sensory, autonomic or psychic symptoms
- No post ictal symptoms
=> With impairment of consciousness:
- Most commonly arise from temporal lobe
- Post ictal confusion is a feature
What are the different types of Generalised seizures?
=> Tonic clonic (grand mal):
- Loss of consciousness
- Limbs stiffen (tonic) then shake (clonic)
- Post ictal drowsiness and confusion
=> Absence seizures (petit mal):
- Brief 10 seconds pause
- Common in childhood
=> Myoclonic seizures:
- Sudden jerk of face, limb or trunk
- Commonly described as an uncontrollable limb
=> Atonic seizures:
- No loss of consciousness
- Sudden loss of muscle tone causes a fall
=> Infantile spasms:
- Associated with tuberous sclerosis
What are the signs and symptoms of seizures?
- Tongue biting
- Urinary incontinence
- Post ictal drowsiness or tiredness for 15 mins
What are the investigations in a suspected seizure?
- EEG
- MRI
=> Thorough history of the seizure must be taken
What is the management of seizures?
- Medications are started after the 2nd neuro-epileptic seizure
=> Sodium Valporate is first line for Generalised seizures
=> Carbamazepine is first line for focal seizures
What is the effects of epilepsy on the lives of:
- Drivers
- People on other medication
- Women wishing to get pregnant
- Women taking contraception
=> Drivers:
- Cannot drive for 6 months
- For patients with established epilepsy they must be fit free for 12 months to drive
=> Patients on other medication:
- Antiepileptics can induce or inhibit P450 system therefore increasing or reducing metabolism of drugs
=> Women wishing to get pregnant:
- Antiepileptics are teratogenic
- Breastfeeding is generally considered safe
=> Women on contraception:
- Affect of antiepileptic and COCP on each other needs to be considered
