Seizures and Epilepsy Flashcards by Matthew Miller

How is epilepsy defined? Three definitions.

At least two unprovoked seizures occurring more than 24 hours apart (could be 60 years).
One unprovoked seizure and a probability of further seizures (i.e. tumor was due to a tumor, trauma, or stroke and will likely recur)
Diagnosis of an epilepsy syndrome

How well did you know this?

Not at all

Perfectly

How is resolution of epilepsy defined?

Remaining seizure-free for the last 10 years, with no seizure medication used for the last 5.

How well did you know this?

Not at all

Perfectly

How is drug resistant / medically intractable seizures defined?

Failure of seizure control after trying two anti-epileptic drugs which were tolerated well.

How well did you know this?

Not at all

Perfectly

What is the usual cause of epilepsy and what age groups get it most?

Bimodal distribution: highest prevalence in young children and older adults

Etiology: 65% idiopathic, but may be congenital, traumatic, degenerative, vascular, CNS infections, etc

How well did you know this?

Not at all

Perfectly

What are a few proposed mechanisms of seizure generation?

Enhanced glutamate / excitatory transmission, with impaired inhibition (GABA) -> higher basal activities to bring patients near seizure threshold in epilepsy

Lesions like scar tissues interrupting the macroenvironment -> i.e. mesial temporal sclerosis, or TBI scar

Abnormal glial function alters extracellular balance

Abnormal neural connections

How well did you know this?

Not at all

Perfectly

What is one cause of increased NMDA or AMPA receptor activation?

Non-ketotic hyperglycemia

-> upregulates glycine and modulates NMDA

How well did you know this?

Not at all

Perfectly

What vitamin should children be given in epileptic seizures?

Pyridoxine -> B6 is needed to convert glutamate to GABA

-> decreased GABA is thought to underlie problems of juvenile myoclonic epilepsy and angelman syndrome

How well did you know this?

Not at all

Perfectly

What are the new names for simple partial and complex partial seizures?

Simple partial = focal onset seizures without loss of awareness

Complex partial = focal onset seizures WITH loss of awarness

How well did you know this?

Not at all

Perfectly

What is a myoclonic vs tonic-clonic seizure?

Myoclonic - quick, repetitive jerks

Tonic-clonic - grand mal seizure if generalized -> alternating stiffening and jerking

How well did you know this?

Not at all

Perfectly

What is tonic vs atonic seizures? What can the latter be mistaken for?

Tonic - stiffening / sustained contraction of a muscle group

Atonic - “drop” seizures - complete loss of muscle tone. Can be mistaken for syncope since you fall to the floor.

How well did you know this?

Not at all

Perfectly

What is a versive seizure? What part of the brain is affected?

Forced head deviation to one side or the other

Frontal eye field (area 8) is affected -> seizure is contralateral to side you are turning your head towards.

How well did you know this?

Not at all

Perfectly

What is meant by the semiology of a seizure?

Clinical description of the progression of a seizure

> seizures are repetitive and stereotypic, always progressing the same way
> patient may able to describe an aura or warning sign before the seizure starts

How well did you know this?

Not at all

Perfectly

Why is it important to identify seizure type?

Primary generalized epilepsy syndromes (i.e. Absence) can worsen in response to Na+ channel blockers (i.e. carbamazepine) which are first line AEDs for other disorders.

How well did you know this?

Not at all

Perfectly

What is a Jacksonian march?

When a focal motor seizure marches up the homunculus starting from your fingers up your arm until you lose consciousness

How well did you know this?

Not at all

Perfectly

What side to automatisms happen in relation to where the seizure focus begins?

Will happen on ipsilateral side
-> i.e. seizure of right hemisphere will cause right-sided automatisms, since left side will be dystonic due to the seizure and the right side will “automatically” do things

How well did you know this?

Not at all

Perfectly

If one arm is extended and one arm is flexed during the tonic phase of a tonic-clonic seizure, which side did the seizure start on?

Generally seizure started on the contralateral side as the extended arm.

How well did you know this?

Not at all

Perfectly

What is the cause of a complex visual imagery hallucination aura vs flashes of light / color / scotoma aura?

Complex visual imagery - visual association cortex -> seizure likely starting in occipital-temporo-parietal junction

Flashes of light / color / scotoma -> occipital lobe (primary visual cortex)

How well did you know this?

Not at all

Perfectly

What anatomical defect is gelastic seizure most associated with?

Hypothalamic hamartoma

How well did you know this?

Not at all

Perfectly

What areas of the brain cause autonomic dysfunction auras? (palpations / feeling hot/cold)

Insula
Amygdala
Anterior cingulate gyrus

How well did you know this?

Not at all

Perfectly

Where does a hypermotor seizure arise from?

Frontal lobe -> precentral gyrus

What causes alteration of consciousness during a seizure?

Bilateral medial temporal lobe seizure activity (when seizure spreads to bilateral hemispheres)

Seizure is focal in medial temporal lobe, but opposite medial temporal lobe is damaged

What should you be thinking if a person says they can remember their bilateral tonic-clonic seizure? How is this diagnosed?

Think of a psychogenic non-epileptic spell
-> it is impossible to remember things during a tonic-clonic seizure

Diagnosed via video capture and EEG showing no abnormal electrical activity during the spell

What normally terminates a seizure and what are some common symptoms of a post-ictal state?

huge GABA surges from brain, or pharmacologic help

Confusion, disorientation, exhaustion, anterograde / retrograde amnesia

Rarer - post-ictal psychosis days after, Todd’s paralysis

When does Todd’s paralysis occur and what is it?

When there is a seizure of the premotor cortex

> post-ictal paresis contralateral to seizure side
> occurs due to depletion of glutamate during seizure

Where do primary generalized seizures generally start from?

Generally start from the thalamus, and spread nearly instantly through the commissures and corpus callosum leading to bilateral synchronous activity

Where does focal epilepsy generally start from and how does it spread?

Starts usually in medial temporal lobe, may spread outward through corpus callosum, commissures, and subthalamic structures

What else is on the differential diagnosis of seizures?

1. Movement disorders 2. REM sleep behavior disorder (may be mistaken for frontal lobe epilepsy) 3. Migraines with auras (vs simple partial seizures) 4. Limb-shaking transient ischemic attacks 5. Syncope 6. Hyperventilation syndrome 7. Psychogenic non-epileptic spells

What type of syncope mimics seizures? How is it told apart?

Convulsive syncope where patient can have myoclonus, hallucinations, automatisms, etc Syncope is precipitated by postural changes, has a long prodrome, is precipitated by emotion, pain, heat, is not associated with post-ictal confusion, and is commonly associated with cardiovascular signs

What is the most common epilepsy syndrome and what is the most common neuropathologic finding in patients when it is medically refractive?

Temporal lobe epilepsy | -> commonly caused by hippocampal sclerosis / mesial temporal sclerosis

What pathology is typically involved in mesial temporal sclerosis?

Neuronal cell loss and gliosis in the CA1/C3 region of the hippocampus (Ammon's horn) Also involved can be: Subiculum, dentate gyrus, amygdala, and entorhinal cortex (parahippocampal gyrus)

What predisposes to mesial temporal sclerosis and what is the treatment?

Finding is more likely if you had complicated febrile seizures before age 5 Treatment: temporal lobectomy or amygdallohippocampectomies of affected side

What is Benign Epilepsy with CentroTemporal Spikes (BECTS) and what is the prognosis?

Focal epilepsy syndrome characterized by epileptiform spikes on EEG Occurs in children age 3-13 years, can have hemifacial motor seizures and facial twitching which usually occurs at night -> may progress to bilateral tonic clonic No treatment is generally required because there will be remission by mid-teens

What type of seizure is "petit mal" and how is it diagnosed? What are the symptoms? Is there post-ictal confusion?

Primary generalized epilepsy - > absence seizure - > diagnosed via **3 Hz spike and wave** on EEG Symptoms: Mild tonic, clonic oral automatisms and eye fluttering. Last 10-20 seconds and there is no post-ictal confusion

What are the two general types of absence seizures and what is the treatment?

Childhood absence - usually between 4-8 years and spontaneously remits Juvenile absence - starting closer to puberty, may progress to a worse seizure disorder Treatment is ethosuximide

What seizures characterize juvenile myoclonic epilepsy (JME)? What precipitates them?

1. Myoclonic jerks of arms (usually early morning) 2. Generalized tonic-clonic 3. Behavioral arrest / staring spells Precipitated by sleep deprivation, alcohol use, and stress

What is the age of onset for JME, how is it diagnosed, and what is the prognosis?

Puberty to early 20s Diagnosed via 4-6 Hz spike and waves Wellcontrolled with medication, but will have seizures for life

What is the diagnostic triad of Lennox Gastaut syndrome? Prognosis?

1. Multiple seizure types (atonic, absence, tonic, generalized tonic-clonic) 2. Developmental delay 3. Slow 1-2.5 spike and wave on EEG as a baseline (not just during seizures) -> patient will have static encephalopathy with poor prognosis

What is an atypical absence seizure?

EEG spike and wave activity is more heterogenous than 3 Hz, and has more pronounced signs and automatisms than usual

What is EEG actually recording? And what is the gold standard for seizure diagnosis?

Summation of excitatory or inhibitory post synaptic potentials -> NOT action potentials Gold standard: Epilepsy monitoring unit -> video recording of seizure with EEG

What are the non-pharmacologic treatment options for focal seizures?

1. Resective surgery 2. Vagus nerve stimulator 3. Responsive neurostimulator device (i.e. deep brain stimulation) -> implanted near brain foci to terminate seizure

What are the non-pharmacologic treatment options for generalized seizures?

1. Vagal nerve stimulation | 2. Corpus callosum resection

What is the efficacy of pharmacotherapy in treating seizure disorders?

60-65% of patients can be controlled with one or two AEDs

What is the definition of status epilepticus? Can it occur with focal seizures?

Continuous seizures (5-30 minutes) without return to baseline (without regaining consciousness), or recurring seizures resulting in brain injury Yes, it can occur with focal seizures, not just generalized tonic-clonic

What do you want to do as a baseline before treating status epilepticus?

Assess patient's true status, assessing bloodwork (AED levels, CBC, chemistry), blood glucose, toxicology screen, vitals, respiratory state, etc

What is the first-line treatment for status epilepticus? SEcond line?

1st line: Benzodiazepines i.e. lorazepam or midazolam 2nd line: Fosphenytoin, phenytoin

What are the side effects of concern when adding phenytoin or fosphenytoin?

Hypotension and CNS depression May cause purple glove syndrome rarely: a thrombophlebitis which could require amputation (more common with phenytoin)

What are the thirdline treatments for status epilepticus?

Propofol, phenobarbital, possibly putting patient in a phenobarbital coma if patient is severely decompensating with lactic acidosis and hypoxia / hyperthermia

What two drugs should never be given together in status epilepticus?

Diazepam followed by phenobarbital -> may cause hypotension / severe respiratory depression