Epilepsy med Flashcards
Define epilepsy
Epilepsy defines a group of brain disorders affecting individuals of all age groups, of varying and often of unknown cause, characterised by recurrent unprovoked seizures, or by one unprovoked seizure but with an “enduring predisposition” to further seizures. It may have significant consequences in terms of adverse educational, vocational, and psychosocial functioning, and physical morbidity (and potential mortality), especially in the one third of patients with drug-resistant epilepsy.
Epilepsy can be classified according to the type of seizure, each of which is associated with
different forms of brain pathology;; generalized, focal or provoked epilepsy
Define seizure
aka fits- manifestations of abnormal discharges of neurones in the brain.
A seizure results when a sudden imbalance occurs between the excitatory and inhibitory forces within the network of cortical neurons in favor of a sudden-onset net excitation
Classify epilepsy
General epilepsy- synchronous abnormal neuronal discharges. This usually commences in childhood with no particular cause.
Examples:
-Idiopathic(primary) i.e brain functions normally - juvenile absence AND juvenile myoclonic epilepsy
-symptomatic
-severe childhood epilepsy that is often a/w learning disability
Focal/Partial/Localised-discharges originate from a specific cortical
region, e.g. temporal lobe epilepsy, and can either
remain localised or spread to other regions.
Examples: temporal, frontal,occipital,parietal
lesional or non lesional (MRI negative)
Define juvenile myoclonic epilepsy
cornflake epilepsy- presence of myoclonic jerks that occur on awakening from sleep either in the morning or from a nap. They are typically described as shock-like, irregular and arrhythmic movements of both arms.
Define symptomatic a/ epilepsy
Underlying de novo mutation where mutation in protein affects brain development
Define juvenile absence epilepsy
occurs in childhood and adolescent - involves loss of awareness
Classification of seizures?
Generalized:
- Absence
- Myoclonic
- Tonic/Atonic
- Generalized tonic clonic convulsion
Focal/Partial:
- Simple Partial
- Complex partial
- Secondarily generalized tonic clonic convulsion
Difference between simple or complex partial seizures?
Compare absence vs complex partial seizures
Simple partial - patient is focally aware
Complex partial seizure: pt has impaired awareness - not fully conscious
Absence seizures:
lasts <10 seconds w simple automatisms, and a generalized spike and slow wave forms on EEG, normal imaging. Normal post event
Complex Partial seizures
lasts up to 2-3 mins w complex autonmatisms, and a focal sz onset for EEG, normal/lesion imaging. Fatigue post event
What is another name for tonic clonic convulsions?
Grand mal seizure which has the worst prognosis
Define tonic seizures
Define clonic seizures
Define atonic seizures
Tonic- tense/stiff arms or legs
-sudden-onset tonic extension or flexion of the head, trunk, and/or extremities for several seconds. These seizures typically occur in relation to drowsiness, shortly after patients fall asleep, or just after they awaken. Tonic seizures are often associated with other neurologic abnormalities
Clonic-rhythmic jerking motor movements with or without impairment of consciousness
Atonic- “drop attacks.” These seizures occur in people with clinically significant neurologic abnormalities and consist of brief loss of postural tone, often resulting in falls and injuries (hence, some patients need helmets)
Define myoclonic seizures
- muscle jerk
- brief arrhythmic jerking motor movements that last less than 1 second and often cluster within a few minutes.
List causes of epilepsies
- Unknown
- Genetic – hereditary
- Genetic – de novo mutations
- Acquired
- Cortical dysplasia
- Complicated febrile convulsions
- Meningitis / encephalitis
- Head trauma
- Stroke / vascular anomaly / tumour
List epidemiology of epilepsy
-Epilepsy is one of the commonest
serious neurological conditions, with around 350 000 affected patients in the UK.
-10 per 1,000 population.
Differential diagnoses for epilepsy
Non-epileptic (psychogenic) seizures
- Non-epileptic attack disorder (NEAD)
- Diagnosed by in-patient video EEG monitoring
Convulsive syncope
- About 8% of faints
- Syncope not a “top-order” diagnosis
How is epilepsy diagnosis
Epilepsy is primarily a clinical diagnosis
Importance of eye-witness account
Investigations may help to refine diagnosis, establish aetiology, guide treatment, and predict prognosis
Review / reconsider diagnosis in those with uncontrolled seizures
High diagnostic error rate
What general clinical evaluation questions would be asked ?
Demographics
Handedness
Early Risks for partial epilepsy eg meningitis
Family history
Other medical problems
What is the psychosocial impact of the epilepsy?
Driving?
What questions would be asked when evaluating seizures?
Age of onset of first unprovoked seizure
Seizure type(s) + aura
Seizure frequency
Seizure precipitants
Nocturnal Vs daytime
Injuries
Any history of status epilepticus
Define status epilepticus
a dangerous condition in which epileptic fits follow one another without recovery of consciousness between them
What medication history questions could be asked?
Current meds? Any prior AED? Side effects? Other meds? Folic acid? Compliance?
Which persons can conduct additional assessment
Multidisciplinary input
Epilepsy clinical nurse specialist
Education
Neuropsychology
Neuropsychiatry
Review imaging - ? need for repeat
What are some confirmatory investigative procedures
EEG studies
MRI - esp for suspected partial epilepsy
auxillary tests like tilt table test, ECG, lumbar puncture if p has suspected meningitis
What is the goal of tx for person with seizures?
seizure free and no side effects
freedom from convulsions and or drop attacks - severe epilepsy syndrome goals
Define intractable epilepsy
Generally taken to mean continued seizures despite treatment with two or more appropriate AEDs at tolerated and adequate doses
Consider epilepsy surgery if focal epilepsy
List management options for epilepsy
lifestyle/education attention to other med conditions antiepileptic drugs treatment of co morbidity eg depression epilepsy surgery vagal nerve stimulation ketogenic diet
When is epilepsy surgery typically done?
For refractory/unmanageable partial epilepsy most commonly temporal
consider early
Evaluation includes: Video EEG monitoring “Epilepsy protocol MRI” Neuropsychology Neuropsychiatry Functional imaging
What to do in the event of a single seizure ?
Look for and define cause
Risk of recurrence is up to 50%
Driving issues
Decision to treat is individualised::
Is there an underlying lesion on imaging?
Is there an epileptogenic pattern on EEG
What are the potential consequences of a further seizure?
pharm tx
t calcium channel blockers- ethosuximide, valproate (vec)
gaba a receptor enhancers- benzos
inhibiting repetitive sodium channel activation - cabamezapine, phenytoin
tx of absence seizures
ethosuximide
no carbamezapine-exacerbates seizure
tx for generalized / unclassified ?
focal onset?
valproate
monotherapy eg carbamezapine
tx for myoclonic/tonic/atonic
valproic acid
vagal nerve stimulation for tonic/atonic
