Epilepsy Flashcards
What are the the features of fall onset to explore in history?
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 are features of a fall itself to explore in the history?
Movement-Tonic phase, clonic movements, corpopedal spasms, rigor
Responsiveness and awareness throughout
what are features of a after a fall to explore in the history?
Speed of recovery, sleepiness/disorientation, deficits
what are the epilepsy risk factors to explore?
Birth, development, seizures in past (inc. febrile fits), head injury (inc. LOC), family history, drugs + alcohol misuse
what parts of the social history are important to explore in falls?
Driving, occupation
what other history is important in falls?
Collateral
which investigations are useful in falls?
ECG
Imaging - MRI CT
CT - acutely
EEG
what are the indications for CT in acute head injuries?
Clinical or radiological skull fracture Deteriorating GCS Focal signs Head injury with seizure Failure to be GCS 15/15 4 hours after arrival Suggestion of other pathology – eg SAH
What are the differentials of falls? (12)
Syncope, Non-epileptic attack disorder • Panic attacks / Hyperventilation attacks • Sleep phenomena • TIAs • Migraine • Hypoglycaemia • Parasomnias • Paroxysmal movement disorders • Cataplexy • Periodic paralyses • Tonic spasms of MS
what are rules about driving and seizures?
o 1st seizure – car = 6 months, 5 years for HGV/PCV
o Epilepsy – car = 1 year or 3years during sleep, 10 years off medication for HGV/PCV
what is the mechanism of syncope?
decrease in blood flow to the brain due to autonomic nervous system
what are the causes of syncope?
AF, murmurs, PE, aortic dissection
Reflex - postural hypotension
Neural - exposure to blood, pain, strong feelings or specific activity such as urination, vomiting or coughing
what are the risk factors associated with syncope?
fasting long hours, taking in too little food and fluids, low blood pressure, low blood sugar, high g-force, emotional distress, and lack of sleep
what is the underlying mechanism of neural causes of syncope?
when blood vessels expand and heart rate decreases inappropriately
what are the clinical features of syncope?
Loss of consciousness and muscle strength
Fast onset, Short duration
Spontaneous and quick recover
Fall
Prior - yawn, sweat, fast breathing, confusion, lightheadness, blurred vision, spots, ringing in ears
what is the management of syncope?
o Put into recover position
o Treat underlying cause
o CVS examination and L+S BP important
what is a non epileptic event?
Looks like seizures but not caused by electrical activity in the brain
what are the clinical features of non-epileptic events?
o Compared to epileptic seizure – coordinated movements
o duration >2mins
o gradual onset, fluctuating course
o violent thrashing movement, side-to-side head movement
o asynchronous movements
o eyes closed
o recall for period of unresponsiveness.
what are the physiological causes of non-epileptic events?
Syncope, paroxysms of acute neurological insults, paroxysmal toxic phenomena, non-toxic organic hallucinosis, non-epileptic myoclonus, sleep disorders, paroxysmal movement disorders, paroxysmal endocrine disturbances and transient ischaemic attacks
what are the psychogenic causes of non-epileptic events?
- Dissociative seizures
- Psychiatric conditions e.g. panic attacks
- Factitious seizures – e.g. Munchhausens sysndrome, fabricated or induced illness by carers
how are non-epileptic events investigated?
o EEG
o ECG
o MRI, Serum prolactin
what is the management of non-epileptic events?
treatment of underlying cause
what is the general mechanism of epilepsy?
- Too much excitation or Too little inhibition
* Changes in cell numbers/types, connectivity, synaptic function, voltage gated ion channel function
What is the main clinical feature of epilepsy?
Seizures
what are the before, during and after features of seizures in epilepsy?
Prior - anxiety/dread spread through body
During - Lie on ground, jerky, tight = during
After - woozy and drowsy, longer to recover
what is the main investigation for epilepsy?
EEG
what drugs worsen symptoms of epilepsy?
aminophylline/theophylline, analgesics e.g. tramadol, antibiotics e.g. penicillins, cephalosporins, quinolones, anti-erretcics e.g. procholrperazine, opioids e.g. diamorphone, pethidine
what are the two types of epilepsy?
Focal and Generalised?
what are the causes of focal epilepsy?
- trauma (penetrating head injuries)
- CNS infection
- Brain tumours
- stroke
what are the mechanisms of focal epilepsy?
structural abnormality
Imbalance of excitatory and inhibitory neurotransmitters and channels
Newer potential mechanisms
what is the consequence of a structural abnormality in focal epilepsy?
CNS insult sets up epileptogenic focus
what is the route of a focal seizure?
initiates as a focal seizure then evolves through the ipsilateral hemisphere. The ictal activity crosses the corpus callosum and then continues in the contralateral hemisphere (in addition to ipsilateral hemisphere)
what is involved in the neural imbalance in focal epilepsy?
imbalance between gamma-aminobutyric acid (GABA)-ergic (inhibitory) and glutaminergic (excitatory) neurotransmitters, voltage-gated sodium channels, T-type voltage-gated calcium channels, and an alpha-2-delta subunit of voltage-gated calcium channels.
what are the newer potential mechanisms involved in epilepsy?
alterations in gap junctions (connexins), SV2A synaptic protein vesicles, G-protein-coupled receptors, A or M voltage-gated potassium channels, and ionotropic glutamate receptors, among others.
what are the 2 types of seizure types?
Simple
Complex
what is a simple seizure?
seizure without impaired consciousness
what is a complex seizure?
seizure with impaired consciousness
what are the motor symptoms of focal epilepsy?
rhythmic jerking, posturing, head and eye deviation, automatisms, vocalisation. part of your body going stiff or limp, irregular jerks, Lip smacking, swallowing chewing, progression of jerking movements, repeated movements such as rocking, pedalling or pelvic thrusting
what are the Psychic symptoms of focal epilepsy?
memories, déjà vu, jamais vu, depersonalisation, aphasia, complex visual hallucinations, processing language
what are the sensory symptoms of focal epilepsy?
changes to somatosensory, olfactory, gustatory, visual, auditory, thermosensory, propioception
how else are focal seizures classified?
frontal, temporal, parietal or occipital
what often precedes a focal seizure?
an aura
what is the term Jacksonian mark?
seizures initiated and works down primary motor cortex
what are the features of EEG of focal seizures?
have only intermittent abnormalities
what is the 1st Line management of Focal Epilepsy?
Carbamazepine or Lamotrigine
what are the non first line drugs for focal epilepsy?
o Oxcarbazepine
o Levetiracetam
o Topiramate
o Sodium valproate
what are the add on drugs for focal epilepsy management?
Gabapentin, Tiagabine, Pregabalin, Zonisamide, Vigabatrin, Clonazepam, Clobazam
what are the older drugs used in focal epilepsy management?
o Phenytoin
o Phenobarbitone
o Primidone
what are the causes of generalised epilepsy?
genetics
metabolic
toxic and environmental factors
what part of the brain is affected in generalised epilepsy?
Global
what is the mechanism of global seizures?
o effects pathways that interconnect – corticothalamic circuitry
o thalamic generator source?
o begins immediately with hemispheric electrical discharges
what are the different types of generalised seizures?
absence myoclonic atonic tonic tonic clonic
what are the features of absence seizures?
long periods of clouding of consciousness with continuing ‘spike and wave’ activity on EEG
what are the features of myoclonic seizures?
sudden, brief, generalised muscle contractions
what are the features of tonic seizures?
body goes rigid
sudden sustained muscular contraction associated with immediate loss of consciousness
what are the features of tonic clonic seizures?
epileptic cry
tonic phase – rapid neuronal discharge
clonic phase – neuronal discharge slows
what is the EEG feature in generalised epilepsy?
more widespread than focal
what is the 1st line management of absence seizures?
sodium valproate or ethosuximide
what other drugs are used in management of absence seizures?
topiramate, levetiracetam
what is the 1st line management of myoclonic seizures?
sodium valproate, Levetiracetam, clonazepam
what other drugs are used in management of myoclonic seizures?
lamotrigine, topiramate
what is the 1st line management of Atonic, Tonic, Generalised tonic clonic seizures?
sodium valproate
what other drugs are used in the management of Atonic, Tonic, Generalised tonic clonic seizures?
levetiracetam, topiramate, lamotrigine
which drug should never be used in management of generalised epilepsy?
CARBAMAZEPINE
what are the risk factors to triggering seizures in juvenile myoclonic epilepsy?
sleep deprivation
flashing lights
what are the clinical features of juvenile myoclonic epilepsy?
early morning jerks
generalised seizures
what is the management of juvenile myoclonic epilepsy?
Sodium Valproate
Lamotrigine
what are the causes of status epilepticus?
o Severe metabolic disorders o Infection o Head trauma o Sub-arachnoid haemorrhage o Abrupt withdrawal of anti-consultants o Treating absence seizures with CBZ
what is the underlying mechanism of status epilepticus?
occurs when mechanisms that abort seizure activity fail. This failure can arise from excessive and abnormally persistent excitation or ineffective inhibition
what is the consequence of status epilepticus?
cerebral injury
o due accumulation of excitatory neurotransmitters, i.e. glutamate
o Other mechanisms include hyperthermia, hypoxia, lactic acidosis, and hypoglycaemia
what is the clinical feature of status epileptics?
o Recurrent epileptic seizures without full recover of consciousness
o Continuous seizure activity lasting more than ?30 minutes
what are the different types of status epileptics?
o Generalised convulsive
o Non Convulsive Status
o Epilepsia partialis continua
what are the features of Generalised convulsive status epileptics?
Can cause respiratory insufficiency and hypoxia
Hypotension Hyperthermia
Rhabdomyolysis
what are the features of non convulsive status epileptics?
conscious but in altered state
what are the features of Epilepsia partialis continua status epileptics?
continual focal seizures, consciousness preserved
what is the management of status epileptics?
ABCDE
Identify cause - bloods and CT
Anti Convulsant - Phenytoin, Keppra, Valproate, Benzodiazepines
ITU transfer within 1 hour
what are the channels involved in pre-synaptic excitability and neurotransmitter release?
voltage-gated Na+ channels voltage-gated K+ channels N-type voltage-gated Ca2+ channels T-type Ca2+ channels SV2A
what drugs inhibit voltage-gated Na+ channels in epilepsy management?
carbamazepine, oxcarbazepine, eslicarbazepine, phenytoin, felbamate, lacosamide, lamotrigine, rufinamide, topiramate, and zonisamide
what drugs inhibit voltage-gated K+ channels in epilepsy management?
retigabine
what drugs inhibit N-type voltage-gated Ca2+ channels in epilepsy management?
gabapentin and pregabalin
what drugs inhibit T-type Ca2+ channels in epilepsy management?
ethosuximide
what drugs inhibit SV2A in epilepsy management?
levetiracetam
what are the components of the GABA system?
the GABA system is made up of receptors, transporters and GABA transaminase
what drugs enhance the GABA receptor response in epilepsy management?
benzodiazepines, barbiturates, felbamate, topiramate
which drugs inhibit the GABA transporter in epilepsy management?
tiagabine
which drugs inhibit the GABA transaminase in epilepsy management?
vigabatrin
what are the side effects of sodium valproate?
weight gain, teratogenic, hair loss, fatigue
what is a side effect of topiramate?
Sedation, dysphasia, pyscosis, weight loss
which anti-convulsants induce hepatic enzymes?
Carbamazepine, oxcarbazepine, phenobarbital, phenytoin, primidone, topiramate
what is the effect of anti-convulsant on oral contraception?
reduce efficacy
