Reisert: Seizures Flashcards by Setha Treadwell

Paroxysmal event due to abnormal CNS discharge with resultant manifestations depending on area involved

seizure

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5-10% of population in lifetime

More prevalent in early childhood and later in adulthood

Seizure

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Patient with reccurent seizures

0.3-0.5% of population

Epilepsy

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Two types of seizures?

Partial and Generalized

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Deranged area of cerebral cortex often due to a structural anomaly

Consciousness is preserved

Simple partial seizure

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Third type of partial seizure?

Partial seizure secondarily generalized

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partial seizure where consciousness is impaired

complex partial seizure

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Diffuse region of brain firing simultaneously

Often a widespread problem:

Cellular disorder (mental retardation)

Biochemical disruption (low sodium)

Structural issue (brain tumor)

Generalized seizure

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Motor, sensory, autonomic psychic but without loss of consciousness. Often clonic with repetitive flexion/extension

Example: hand tremor on opposite side of abnormal brain activity

______ partial seizure

Simple

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EEG shows abnormal impulses in focial area of brain

Simple partial seizure

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Jacksonian March

Todd’s paralysis

Epilepsia partialis continua

Variations of simple partial seizures

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Motor activity begins distally, like fingers, and spreads to whole extremity

EEG: spike waves

Which variation of simple partial seizure?

Jacksonian March

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Local paresis lasting minutes to hours

What variation of simple partial seizure?

Todd’s paralysis

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Continues hours to days

What variation of simple partial seizure?

Epilepsia partialis continua

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Changes in somatic sensations (paresthesias)

Change in vision (flashing lights, hallucinations)

Changes in equilibrium (falling, vertigo)

Autonomic changes (flushing, sweating)

Odd feelings (déjà vu)

Sx of what type of seizures?

Simple partial seizures

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Focal activity progresses to loss of contact with environment (ictal stage)
- Stare and amnesia
Often begins with aura stereotypical for patient –> feel funny
Followed by ictal stage
- involuntary behaviors
- chewing, picking
Post inctal confusion
Lasts seconds to hours

Signs/Sx of _______ partial seizures?

Complex

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EEG between spells (inter ictal) usually normal or brief discarhge of spikes

Complex partial seizures

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electrical discharge spread and both hemispheres become involved

Results in tonic-clonic seizure

Common when partial seizures in frontal lobe –> look like generalized seizures

Partial seizures with secondary generalization

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Arise in both cerebral hemispheres simultaneously

Look like focal seizure that secondarily generalized though not associated with specific focal onset event

generalized seizures

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Absence seizures and tonic-clinic seizures

These are included in ______ seizures?

generalized

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Brief loss of consciousness without postural control that lasts a few seconds

No post ictal confusion

Other subtle findings include: eye blinking, chewing, clonic movements of hands

Absence seizures (petit mal)

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Onset: typically childhood - 4-8 y/o or early adolescence

15-20% of childhood seizures

May occur all day long –> daydreaming appearance

Absence seizures

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EEG shows symmetrical discharge

Spike and wave

Start stop with inter-ictal normal EEG

Worsens with hyperventilation manuever

Absence seizures

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_________ seizures may be associated with T-C seizures

Absence

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What % of cases of absence seizures remiss in childhood?

60-70%

Similar to absence but symptoms last longer and have more motor features May have brain abnormality such a mental retardation/developmental delay Harder to tx than absence seizures

Atypical absence seizures

Which seizures are considered grand mal?

Generalized tonic-clonic seizures

10% of patients with epilepsy Most common type when seizures are due to metabolic derangement

Generalized tonic-clonic seizures

Episodes often of sudden onset May have prodrome but less so than aura in focal seizures that secondarily generalize

Generalized tonic-clonic seizures

Tonic phase: increased muscle tone Often moan or cry Change in respiration: secretions pool, cyanosis, jaw clenches, bite tongue Sympathetic sx: increased BP & HR, pupil dilation Characteristics of what type of seizure?

T-C seizures

Clonic activity: muscles relax and contract, usually lasts about a minute Post-ictal state: unresponsive, flaccid, salvation or airway obstruction, bowel/bladder incontinence May last min - hours before awakening Post seziure: HA, fatigue, muscle aches Characteristics of what type of seizures?

T-C seizures

Tonic phase: Increased low voltage fast activity with high amplitude polyspike discharges Clonic phase: spike and wave activity develops Post-ictal: slowing then recovery EEG for what type of seizures?

T-C seizures

\_\_\_\_\_\_\_\_\_ and ________ are variations of T-C seizures

Atonic and Myoclonic seizures

1-2 sec lose motor tone brief loss of consciousness no post-ictal confusion associated with other epileptic syndromes

Atonic seizures

When are you at risk of atonic seizures?

After head injury

Brief contraction or jerk similar to when you fall asleeo and you twitch

Myoclonic seizures

Myoclonic seizures are seen in _______ injury

brain

Bilateral jerk with maintained consciousness Worse with awakening, sleep deprivation Seen in adolescence

Juvenile myoclonic epilepsy

benign good response to meds may spontaneously remit

Juvenile myoclonic epilespy

Seen in children Usually impaired cognitive function Associated with CNS disease: developmental delay, trauma, infection, neural injuries EEG: slowing and spike waves Often difficult to control

Lennox Gastaut syndrome

Difficult to control partial epilepsy with characteristic features MRI shows hippocampal sclerosis

Mesial temoral lobe epilepsy

Shift in balance of excitation and inhibition in CNS

Etiology of seizures

Change in seizure threshold (fevers in children) Genetic role Traumatic brain injury Other events including strokes, infection Mechanisms of \_\_\_\_\_\_\_\_\_

seizures

Stress Sleep deprivation Menses Medications

precipitating factors of seizures

* A burst of electrical activity * Influx of extracellular calcium * Excitatory molecules such as NMDA (N-methyl-D-aspartate) may further calcium influx * Influx of sodium * Under influence of GABA (Gamma-aminobutyric acid) or potassium channels * Spike discharge * Inhibitory neurons overwhelmed by calcium and potassium * Propagation of action potentials * Channel problems may be source of genetic epilepsy

seizure

Birth injury Hypoxemia Congenital abnormalities Drugs (maternal) Cause seizures in what age range?

Neonates

Febrile seizures seen in which age range?

Early childhood

What % of children have febrile seizures?

3-5%

3mo-5 years Most commonly 18-24 mo

Febrile seizures

Otitis media Respiratory infection Gastroenteritis Infections seen with which type of seizure?

Febrile seizures

Early on in febrile illness T-C activity Can be simple (one event) or complex (repeated activity) NOT epilepsy Recurrence about 1/3 of patients

Febrile seizures

Age where epilepsy becomes apparent

Childhood

Think trauma Worse the trauma, worse the seizures

Seizures in adolescence

Cerebrovascular disease (50% new onset seizures) Trauma CNS tumor Degernative disease Medical (Hypo/hyperglycemia, renal failure, liver dx, drugs)

Seizures in adulthood

\_\_\_\_\_\_ is key (observe/bystander) when diagnosing a seizure disorder

History!

ASAP to measure brain activity: awakeness/activity Burst of action potentials Baseline alpha wave (8-13 Hz) with eyes closed Faster beta activity (\>13 Hz) increase with activity /eye opening Slower theta activity (4-7 Hz) and delta (\<4 Hz)

EEG to diagnosis seizure disorder

Awake/sleep Eyes open/closed or with photo stimulation Hyperventilation Sleep deprivation \_\_\_\_\_ situations assessed for seizure disorder

EEG

Abnormal activity that starts/stops abruptly or abnormal acitivty during T-C seizure

EEG key findings with seizure disorder

Inter-ictal may see spikes or sharp waves in \_\_\_\_% of cases (worse prognosis)

40%

* EEG * Imaging * Most get * MRI best * Blood tests * Usually normal * May see elevated prolactin level in first 30 mins.

Work up for seizures

Diff dx with seizures Tired, sweaty, tunnel vision May have 10 sec of convulsive activity

Syncope

Diff diagnosis with seizures Non-epileptiform behvaiors that resembles seizures Seen with stress/conversion reaction Head turning, shaking, twitching, no LOC, pelvic thrust that waxes and wanes

Psychogenic seizures

* Basic life support * Vital signs, CPR * Treat cause if identified * Infection, tumor, drugs * Cerebrospinal fluid tap? * Imaging (MRI preferred) * Meds if more than one episode or high risk * 31-71% risk of second seizure in one year * Assess for likelihood of recurrence * Are meds needed long term? * 2 year trial on meds? * Safety * Work * Driving

Seizure treatment

\_\_\_\_\_\_ meds are first line seizure meds \_\_\_\_\_\_ meds are second line

Older Newer

If the patient is low risk One seizure and then seizure free Normal exam (no developmental delay, head injury, etc) Normal EEG DO SLOWLY

When you can consider stopping seizure drugs

Some say if more than 15-30 mins Others if \> 15 seconds May range from T-C seizure to more subtle May need EEG to verify

Contiuous seizure

Cardiovascular implications Hyperthermia Metabolic derangements CNS injury These are conconsidered a _________ in status epilepticus

Medical emergency!

Metabolic problems Drug toxicity CNS infection or tumor Head injury Refractory epilepsy Causes of \_\_\_\_\_\_

Status epilepticus

* Metabolic work up * Benzodiazepine (Lorazepam (Ativan®), diazepam (Valium®), midazolam (Versed®) [More water soluble than diazepam] others * Phenytoin (Dilantin®) * Phenobarbital * Anesthesia * Phenobarbital coma?

Treatment of status epilepticus

Which type of seizure do you primarily use surgical treatment?

Refactory epilepsy

Temporal lobectomy Focal lesion removal Corpus callosotomy

Surgical procedures for seizures

Place bipolar electrode in left vagus nerve Generator delivers a pulse May take a while to work MOA: may simply increase seizure threshold

vagal nerve stimulator

* Developmental delay/mental retardation * Parenting * Stigma * 2-3x greater death rate * Work? Driving? * Menstrual cycles may increase risk * Pregnancy * Seizures may worsen or improve in half of pts * May alter drug levels * Tx may cause birth defects * May affect contraception

Other issues seen with seizures

What % of people with seizure like sx get CT?

100%!

Seizure tx Blocks voltage dependent calcium channels, modulating excitatory neurotransmitter release Safe Sedation and dizziness MC S/E

Gagapentin

Tx for seizures Binds alpha2-delta subunit of calcium channels reducing neurotransmitter release producing anti-nociceptive and antiseizure effects Safe Sedation and dizziness MC S/E

Pregabalin

Treatment for partial seizures, post herpetic neuralgia, neuropathic pain in diabetes and spinal cord, and fibromyalgia

Pregabalin

Carbamazepine Phenytoin Lamotrigine Valproic acid Tx for ______ seizures?

Partial

Valproic acid Iamotrigine Carbamazepine Phenytoin Tx for ____ seizures?

Generalized

Treatment for partial seizures, post herpectic neuralgia and neuropathic pain

Gabapentin

EEG, Video EEG Neuroimaging SPRCT or PET scans (functional) Electrical mapping

Requirements for surgical treatment of seizures

What is it important to monitor with seizure medications?

Adverse drug reactions Effectiveness Levels LFT Blood counts