Epilepsy: seizures and differentials Flashcards
What questions must be asked about the onset of a fall?
- What were they doing? Environment etc
- Light-head or other syncopal symptoms
- what did they look like?
- pallor, breathing
- posturing of limbs, head turning
What must be asked about the event of a seizure?
- type of movements
- tonic phase, clonic movements
- corpopedal spasms, rigor
- responsiveness and awareness thoughout
What must be asked about the events after a seizure?
- speed of recovery
- sleepiness/disorientation
- deficits
What are the epilepsy risk factors?
- birth
- development
- seizures in past (including febrile fits)
- head injury (including LOC)
- family history
- drugs
- alcohol
What examination is important if a patient develops syncope?
Cardiovascular examination and L&S BP
What investigations should be carried out in someone who has fallen?
ECG
Which patients get a CT scan acutely?
- clinical or radiological skull fracture
- deteriorating GCS
- focal signs
- head injury with seizure
- faiulre to be GCS 15/15 5 hours after arrival
- suggestion og other pathologh e.g. SAH
Which imagins can be undertaken in someone who has fallen?
MRIb or CTb
What is the advice regarding 1st seizures and driving?
6 months, 5 years for HGV/PCV
What is the advice for driving with epilepsy
1 year or 3 years (if during sleep), 10 years off medication for HGV/PCV
Describe generalised epilepsy?
- Most have genetic predisposition
- Present in childhood and adolescence, generalised spike wave abnormalities on EEG
- Tonic clonic, absence, myoclonic, clonic, tonic and atonic
When does primary generalised epilepsy present?
Childhood or teens
What is the treatment of choice for primary generalized epilepsy?
Sodium valproate
Lamotrigine if female of child bearing age
Juvenile myoclonic epilepsy presents with _____ _______ jerks, _________ seizures. The risk factors are _____ _______ and ______ ______
Juvenile myoclonic epilepsy presents with early morning jerks, generalised seizures. The risk factors are sleep deprivation and flashing lights
What is EEG useful for?
Identifying type of epilepsy
What is the underlying cause of focal onset epilepsy?
Underlying structural cause
Describe the progression of focal onset epilepsy?
Focal onset and can then generalise to secondary generalisation
What is the age of onset and treatment of focal onset epilepsy?
Onset at any age
Carbamazepine or lamotrigine (sodium valproate works as well)
What is often the result of focal onset epilepsy?
Complex partial seizures with hippocampal sclerosis
Describe the use of lamotrigine
Well tolerated in generalised and focal epilepsies
Takes a long time to titrate up
Describe the use of levetiracetam?
Very popular
Few interactions with other medications
Can cause mood swings
Descibe the use of topiramate
Sedation, dysphasia as side effects
Weight loss
Effective but not well tolerated
What anticonvulsants are more commonly used for neuropathic pain?
Gabapentin, pregabalin
Which anticonvulsants induce hepatic enzymes?
Carbamazepine, oxcarbazepine, phenobarbitol, phenytoin, primidone, topiramate
What is the issue with anticonvulsants that induce hepatic enzymes?
Can alter efficacy of combined oral contraceptive pill
Cannot use progesterone only pill
Morning after pill not adequate
What must be taken by epileptic women looking to conceive?
Folic acid and vitamin K
Balance risk of uncontrolled seizures vs teratogenicity
What is status epilepticus?
Recurrent epileptic seizures without full recovery of consciousness
Continuous seizure activity lasting more than 30 minutes
What are the types of status epilepticus?
- Generalised convulsive status epilepticus
- Non convulsive status
- Concious but in altered state
- epilepsia partialis conntinua
- continual focal seizures, consciousness preserved
What are the precipitants of status?
- severe metabolic disorders
- hyponatraemia, pyridoxine deficiency
- infection
- head traume
- sub-arachnoid haemorrhage
- abrupt withdrawal of anti-convulsants
- treating absence seizures with CBZ
*
Describe convulsive status
Generalised convulsions without cessation
How does convulsive status cause damage?
Excess cerebral demand and poor substrate delivery causes lasting damage
- respiratory insufficiency and hypoxia
- hypotension
- hyperthermia
- rhabdomyolysis
What is the management of convulsive status epilepticus?
- Stabilise patient
- ABC
- Must identify cause
- emergency blood tests +/- CT
- Anti-convulsants
- phenytoin (check levels)
- levatiracetam (keppra)
- valproate
- benzodiazepines
- if given need to go to ITU
What conditions are commonly confused with epilepsy?
- syncope
- non-epileptic attack disorder (pseudoseizures, psychogenic non-epileptic attacks)
- panic attacks/hyperventilation attacks
- sleep phenomena
List some DDx for epilepsy?
TIA
migraine
hypoglycaemia
Parasomnia
Paroxysmal movement disorder
cataplexy
periodic paralyses
tonic spasms of MS
What is an epileptic seizure?
Abnormal synchronisation of neuronal activity
- usually excitatory with high frequency action potentials
- sometimes predominantly inhibitory
Interruption of normal brain activity
- focal
- generalised
Why do epileptic seizures occur?
- too much excitation
- too little inhibition
changes;
- cell numbers/types
- connectivity*
- synaptic function*
- voltage gated ion channel function*
Genetic, acquired brain, metabolic, toxic and environmental factors
What are the types of partial epileptic seizures?
Simple: without impaired consciousness
Complex: with impaired consciousness
What are the types of generalised seizures?
- absence
- myoclonic
- atonic
- tonic
- tonic clonic
Describe the motor semiology of partial seizures?
Rhythmic jerking, posturing, head and eye deviation, other movements (e.g. cycling), automatosms (e.g. plucking), vocalisation
Describe the sensory semiology of partial seizures?
Somatosensory, olfactory, gustatory, visual, auditory
Describe the psychic semiology of partial seizures?
Memories, déjà vu, jamais vu, depersonalisation, aphasia, complex visual hallucinations
about __% are seizure free on monotherapy
about __% are seizure free with polytherapy
about __% have drug resistant epilepsy
about 55% are seizure free on monotherapy
about 10% are seizure free with polytherapy
about 35% have drug resistant epilepsy
Activity of _____-_____ ___ channels is inhibited by many AEDs, reducing pre-synaptic excitability and the ability of action potentials to spread.
Drugs include (10)
Activity of voltage-gated Na+ channels is inhibited by many AEDs, reducing pre-synaptic excitability and the ability of action potentials to spread.
- carbamazepine
- oxcarbazine
- esilcarbazepine
- phenytoin
- felbamate
- lacosamide
- lamotrigine
- rufiramide
- topiramate
- zonisamide
Activity of _____-_____ __ channels is enhanced by the AED ________, which opens these channels and stabilises the neurone- reducing excitability.
Activity of voltage-gated K+ channels is enhanced by the AED retigabine, which opens these channels and stabilises the neurone- reducing excitability.
Activity of the N-type ______-_____ ____channels that trigger neurotransmiter release is inhibited by the AEDs ______ and _______, and T-type ____ channels are inhibited by the AED ________.
Activity of the N-type voltage-gated Ca2+ channels that trigger neurotransmiter release is inhibited by the AEDs gabapentin and pregabalin, and T-type Ca2+ channels are inhibited by the AED ethosuximide.
The AED levetiracetam acts by binding to _____, interfering with _____ vesicles and inhibiting neurotransmitter ______.
The AED levetiracetam acts by binding to SVA2, interfering with synaptic vesicles and inhibiting neurotransmitter release.
Which AEDs enhance the response of GABAA receptor to GABA
Benzodiazepines, barbiturates, felbamate, topiramate
Which AEDs increase GABA levels
Tiagabine inhibits the GABA transporter, and vigabatrin is thought to inhibit GABA transaminase
What is the initial treatment for partial seizures?
Carbamazepine
Lamotrigine
Oxcarbazepine
Levetiracetam
Topiramate
Sodium Valproate
What are the add on drugs for partial seizures?
Gabapentin
Tiagabine
Pregabalin
Zonisamide
Vigabatrin
Clonazepam
Clobazam
What are the older drugs not commonly used for partial seizures?
Phenytoin
Phenobarbitone
Primidone
What is the treatment for generalised absence seizures?
Sodium Valproate
Ethosuximide
add on;
- topiramate
- levetiracetam*
What is the treatment for myoclonic generalised seizures?
Sodium valproate
Levetiracetam
Clonazepam
add on;
- lamotrigine
- topiramate*
What is the treatment for generalised atonic, tonic, generalised tonic clonic seizures?
sodium valproate
- levetiracetam
- topiramate
- lamotrigine
What is phenytoin used for?
For acute management only
Which drug used for focal onset seizures can make primary generalised epilepsies worse?
Carbamazepine
When do we give the drugs?
If the patient has epilepsy
If the patient had a single seizure but was at a high risk of recurrence
Only if the patient wants the drugs
