Week 4: Seizure Disorders

Definitions

a seizure is a suddent, transient disruption in

brain electrical function

caused by exessive, abdnormal discharges of

cortical neurons

many conditions associated with seizures: 9

metabolic, congential, perinatal injury, postnatal trauma, myoclonic syndromes, infection, tumours, drugs, toxins

3 mechamisms

1. stim of CNS pathways

2. inhibition of inhibiotry pathways

3. withdrawal of long term CNS depressents

seizures may increase because 4

1. hypoglycemia, fatigue, stress

2. water high

3. antipsychotics mixed with alc

4. hyperventilation

Epilepsy are two unprovoked seizures more than

24 hours apart

epilepsy syndrome

abnormal findings on eeg and MRI, occur in pattern

convulsions are involuntary violent spamsms of

muscles in neck, arms, legs

all ____ are _______, but not all _____, are ______

convulsions are seizures, seizures are convulsions

young adult seizure onset probably causes 4

1. alc/drug withdrawal

2. brain tumour

3. idopathic

4. brain injury

older adult probbale causes 7

1. alc/drug withdrawal

2. timour

3. cerbreovascular disease; stroke

4. cns disease like alxhemie

5. depression

6. metabolic issues

7. brain injury

Seizure initiated by: hyperexictability of

neurons

Seizure initiated by: closure of

voltage dependent sodium channels

Seizure initiated by: long lasting

neuronal repolarization

Seizure initiated by: formation of

neurtitic plaques

PHASES OF A SEIZURE

Preictal, Ictus

PREICTAL

prodome or aura

PREICTAL: Prodoma

early manifestation, hours before, anxiety, depression, malaise, headache

PREICTAL: Aura

focal seizure, peculiar sensation imediatelt preceeds seizure, visual, smell, auditory expeeirnces, dizziness, funny feeling

ICTUS

seizure episode

Ictus includes 3

tonic clinic (relax then contract), bladder relax, airway maintain

ways to evalauate a seziure 7

1. clinical presentation

2. history

3. physical exam

4. CSF trsting

5. EEG

6. MRI

7. lab

What happens during seizure activity: cerebral blood flow

increases

What happens during seizure activity: cerebral oxygen consumtion

increased by 60%

What happens during seizure activity: glucose

depletion

What happens during seizure activity: accumalation of

lactate in brain tissues

3 ways to classify a seizure

1. orgion (focal vs generalized)

2. degree of awareness

3. level of body movement

FOCAL SEIZURES

begins in one area of brain, partial seizures and aura is common

FOCAL motor Tonic

tonic stiffining of muscles, has LOC

FOCAL motor atonic

sudden loss of muscle tone with falling, no LOC

FOCAL motor myoclonic

kers or twitches, may drop things, no LOC

FOCAL motor tonic clonic

abrupt LOC, stiffening (tonic) then shaking (clonic), cry, bladder loss, bites tounge, 2 mins

FOCAL motor hyperkinetic

pedal motor, kicking, clapping, hugging, sexual automatism

FOCAl Non-Motor sensory

numbness, tingling, burning, dlashing lights, audtory

FOCAl Non-Motor cognitive

aphasia, hallucinations, memory impairment

FOCAl Non-Motor emotional

fear, anger, cry, laugh, paranoia

FOCAl Non-Motor autonomic

blushing, pallor, up down HR, ventilation changes, nausa

FOCAL WITHOUT loss of awareness

recall, responsive, conscious

FOCAL WITH loss of awareness

complex focal seizure, dream like state

FOCAL to Bilateral Tonic Clonic

begins one part, then spreads, then tonic clonic and loss of consciousness

Generalized Seizures

both sides od brain, DOES have LOC

Generalized MOTOR

tonic clonic, tonic, atonic, myoclonic, myoclonic-atonic,

Generalized NONMOTOR

typical, asence seisures, eyelid myoclonus

Epileptic Spams

onset 3-12 months of age

epileptic spasms: possible causes 4

idopathoc, genetic, metabolic, CNS insult

epileptic spasms: episodes of sudden flextion or extention wth

neck, trunk and extemeities, head nods to violent contractions

epileptic spasms: occur in clusters

5-150 times per day

epileptic spasms: seizure activity increases in intensity

loss of developmental milestones

epileptic spasms: treatment

anticonvulsant or surgery

Status Epilepticus

●       Abrupt discontinuation of antiseizure drugs but also may occur in untreated or inadequately treated persons with seizure disorders (MORE THaN 5 MINS) TONIC CLONIC, REPEATED< OR MORE THAN 30 MINS

Status Epilepticus: is a medical emergency

admin 02

Status Epilepticus: can cause long term

disability, dementia, brain damage, aspriation

EPILEPSIES AND CLASSIFICATIONS

what is epilepsy: interaction of complex

genetic mutations

epilepsies can cause: abnormailites in

synamptic transmission

epilepsies can cause: imbalance in

brains neurotranmitters

epilepsies can cause: alterations of

receptors and ion channels

epilepsies can cause: development of abnromala

nerve connections or loss of nerves

corticol exication in tonic phase

exictatory neurons react to corical stimulation, firew more frequently

corticol exication in clonic phase

inhibitory neurons react, seizure is disrupted

6 factors for epilespy

1. genetic

2. strictural

3. metabolic

4. immune

5. infection

6. unknown

different genetic/developmental seizures 5

1. absence epilepsy syndrome

2. lennon gastaut syndriome

3. juvenile myoclonic epilepsy

4. unclassfied seizures

5. pseudoseziruees

Childhood Absence Epilepsy Syndrome

4-8 years of age, eye movements, chewing, blank stare 20 seconds antiepiletic drug

Lennon-Hastaut Syndrome

1-5 years

tonic-clonic, atonic, akntic, absence, myoclonic

slow spike and wave

delays intelect and motor

drugs and ketogenic diet

Jevenile Myoclonic

adolecence

jerks of neck, shoulder, arms

lack of sleep or alc

early morning

drugs presceibed for life

Unclassfied epileptic seizures

unknown

Psuedoseziures

nonepiletic but look like it

frequent with child abuse

Simple Febriile

3 monthjs - 5 years, hgenerlized tonic 38*, less than 5 minutes

Complex Febrile

more than 15 minutes, focal seizure, 1 in 24 hours

PHARMACOTHERAPY

barbiturates

phenobarbital

benzodiazepines

diazepam

hydantoins

phenytoin

phenytoin like, acid derrivitives

valproic acid

succinimides

ethosucimide

goal of drugs

stop reptivie firing, start on low dose and gradually increase, withdrawan over 6-12 weeks

mechanism 1: stimulated influx of chloride which increases GABA

barbiturate (phenobarbital) and benzodiazepines (diazepam)

mechanism 2: delay influx of soduum ions

phenotoin and valorapte acid

mechanism 3: delay influc of calciuym

ethosuximide

at resting state, neruons surrdonded by b

high concentration of sodium, calcoum, amndf choloride

influx of sodium or calcium

enhances neuronal activity

influx of chloride

supresses neuronal actiivity

Phenobarbital Indication

seizures, tonic-clonic, febrile

Phenobarbital MOA

enhances GABA

Phenobarbital Desired

supressed abnormal neuronal discharge ( sedates and anti-seiure med)

Phenobarbital Adverse 6

1. Breathtaking - resp depression, larygospams, low BP leading to coma and death

2. barbie keeps talking makign you Sleepines drowsiness

3. barbie has fans evevryehere (depdence/tolerance) and your love is (long lastong)

4. barbie can deplete your vit d, b12, and folate

5. going out can give tou a rash (steben johnsons)

6. thrombophebitis because standing too long waiting for her

Phenobarbital Teaching 3

barbie goes out at night

cannot abruptly stop withdrawal symoykms (nightmares, tremors, hallucinations)

drinking alc can lead to cardia arrest

Diazepam Indications

short term seizure control

Diazepam MOA

binds to gaba inhibtory receptors to intensify GABA actions

Diazepam Desired

supression of nueronal foci, calming, reduced seixure

Diazepam Adverse 6

1. hypotension

2. resp depression

3. dizziness

4. HA

5. blurred vision

6. constipation

Diazepam should not be taken with

alc or depressents

Drugs that supress sodium influx

●       Phenytoin

●       Valproic Acid

Phenytoin: Indications

most seizures EXCEPT absence

Phenytoin: MOA

delays sodium influx inton neurons

Phenytoin: desired

prevent spread of disruptive charges

Phenytoin: Advserse

P: P450 inhibitor

H: hirsutism and headace

e: enlarged gums

ny: nystagmis

t: teratogenicity (fetal birth defects)

o: ostemomalcia and osteppenia (impairs Ca absorption)

I: inference with folic, vitamin K, b 12

n: neuropathies (veritgo, ataxia, heachace)

s: skin rash (dermatitis and steven johnsons)

Phenytoin Signs of Toxicity NASTI

nystgmus

ataxia

slurred speech

twitching

insomnia

Phenytoin Preggnancy

can cause harm, but may be considered if pros benefit risks