EEG 1112 Midterm Exam

An aura of a smell of burning leaves would most likely cause you to closely watch which electrodes during the recording?

temporal leads (T7, T8)

Which location of the brain would more likely show a seizure beginning with a patient's leg?

Cz - central midline

To someone who is observing, what are some events that will look like a seizure?

behavioral events, syncope, body jerks when falling asleep

A patient has an aura of a prickly feeling in the right arm. Where is the most likely area of the brain to suspect an abnormality will occur?

parietal

Your patient tells you that he sees lights and sometimes pattern images with his seizure. Your EEG recording may show what?

occipital spikes or other abnormalities

If any employee has a lesion or weeping dermatitis, where should they report to?

Employee Health Services

Bed pans should be disposed of how?

emptied and then put into red biohazard bags

True or False: pulse ox, acceleometers, tape measures, and glue tips only need to be wiped down with alcohol

true

Pattern testing is used for what?

for patients who have photoparoxysmal response with photic

Oxyvir spray and wipes

1 minute

Sani wipes

5 minutes

abnormal brain-wave activity causing changes in behavior, sometimes as severe convulsions or epileptic fits

seizure

destruction of part of the brain due to blockage of blood flow caused by a clogged or ruptured blood vessel

stroke

Elements of a Report: Clinical interpretation

briefly describes EEG in a way that outside doctors can easily interpret what the EEG has shown

Elements of a Report: EEG Classification

describes the EEG findings in Mayo's classification system

Elements of a Report: Report

gives detailed description of the EEG

Special study reports: Short-term video

usually ordered for peds and spells patients in routine studies; most studies do use video now

Special study reports: pattern testing

completed to test pattern and/ or photosensitivity

Special study reports: Lens testing

for extremely photosensitive patients; may need colored glasses to prevent seizure onset

Special study reports: computer-assisted prolonged video EEG

EMU patients

A physician can order an EEG after hours for emergency reasons. What are some of these reasons?

diagnose and treat status epilepticus, active epileptic v. nonepileptic events, dx CNS conditions, determine electrocerebral inactivity

A physician may request EEG monitoring during surgical procedures. What are some of the reasons for this?

aortic aneurysm repair, carotid endarterectomy, electrode implantation, lobectomy, tumor removal

Mayo EEG Reporting: Normal / Essentially Normal

findings normal for pt's age and state of consciousness; minor variations

Mayo EEG Reporting: Abnormalities are classified according to what?

type, grade, and distribution/ localization

Mayo EEG Reporting: Dysrhythmia

refers to various abnormalities from slowing to specific waveforms

Mayo EEG Reporting: Dys. I

mild slowing of background; adults PDR 7-8 Hz; excess theta - diffuse or over temporals

Mayo EEG Reporting: Dys. II

moderate abnormalities; slowing to 5-6 Hz; excess theta and delta focal or generalized

Mayo EEG Reporting: Dys. III

specific waveforms or patterns; epileptiforms or seizure discharges, burst suppression, PLEDs, GPDs, triphasic waves, coma patterns, IRDA

Mayo EEG Reporting: Asymmetry Grade I

50% difference in amp between two sides

Mayo EEG Reporting: Asymmetry Grade II

75% difference in amplitude

Mayo EEG Reporting: Asymmetry Grade III

>75% difference; very rare

What montages do we flip through for routine EEG?

LAB, LAR, TAB, LCR, LAL, TAL

What montages do we use for patients in sleep?

LABDS, LGB-Ar, TAB, LCR, LAB-Ar

LFF for EEG

1 Hz

HFF for EEG

70 Hz

Sensitivity for EEG

7 uv/mm

Paper speed for EEG

30 mm/sec

Meningitis

inflammation of tissue surrounding the brain and SC

What causes meningitis?

bacteria or virus

What is thought to be the cause of SSPE?

measles virus

Symptoms of SSPE

memory loss, behavioral changes, motor dysfunction, some may have seizures and blindness

SSPE affects what population?

children and adolescents

What is the frequency of high-voltage slow waves associated with SSPE?

recur every 4-15 seconds

What does the background of a patient with SSPE look like?

normal early on; disease progression will show slow wave abnormalities

SSPE: Epileptiform activity may occur ________ or __________

focally, generalized

SSPE: Periodic complexes are usually generalized and bisynchronous. At times, they present in what fashion?

lateralized or focal

SSPE: Periodic complexes often _________ in sleep

persist

What is a characteristic feature of SSPE?

motor jerks or spasms that occur with periodic complexes

SSPE: In the final stages of the disease, there is an attenuation of the EEG activity and what?

disappearance of slow wave complexes

Reye's Disease

rare, serious condition that causes confusion, brain swelling, and liver damage

What causes Reye's disease?

minor infections like influenze

Symptoms of Reye's Disease

nausea, confusion, lethargy, stupor, coma

What group is affected by Reye's disease?

children and adolescents

Reye's Disease on EEG

reflects clinical state of patient; theta or delta slowing (better); burst suppression

The slower the frequency, the ____________ the abnormality

more severe

PDA: consists of polymorphic and arrhythmic delta slowing which _________________

persists throughout the record

PDA: shows little or no ________________ to afferent stimulation which usually indicates what?

reactivity; disturbance of cerebral function

PDA: It is primarily lesions involving _____________________ that produce delta slowing

subcortical white matter

PDA: Pure cortical lesions, on the other hand, produce a _______________________ of background activity on the side of the lesion

reduction in amplitude

IRDA

intermittent, rhythmic, and bilaterally synchronous slow-wave activity

IRDA shows reactivity to what?

eye-opening or alerting

What part of the homonculus covers most of the brain?

face

If input 1 is more negative than input 2, what is the deflection?

up

If input 2 is more negative than input 1, what is the deflection?

down

How do you check the integrity of a digital EEG machine?

utilize internal calibration

What is the most common cause of LPDs?

vascular lesions

What will the EEG show if someone has a localized brain tumor?

focal slow wave activity

Sharp wave duration

70-200 msec

Spike duration

20-70 ms

What is the most common cause of asymmetry of the amplitude of alpha activity in posterior head regions?

incorrect electrode spacing

What are two important variables to determine if EEG is normal or abnormal?

age and state of alertness

14 & 6 positive bursts occur most often in

adolescents; posterior temporals; light sleep

Rhythm at a distance is also known as:

projected rhythmic activity

If you see artifact on the EEG, what should you do?

try to eliminate it

Hypoatremia

impaired water excretion

A bipolar montage consists of electrodes connected in a ______________

series

What is the minimum amount of time acceptable for recording a baseline EEG during the waking state?

20 minutes

Alzheimer's shows what on EEG?

slowing in the early stages

Lewy body dementia shows what on EEG?

significant slow wave abnormalities

What would be considered abnormal response from HV?

spike and wave activity

The EEG has the least diagnostic value in which condition?

Parkinson's disease

An electrode pop is usually the result of:

an abrupt change of impedance

Slow wave abnormalities

OIRDA, FIRDA, TIRDA

What activity is usually associated with metabolic comatose patients?

generalized slowing

Abrupt withdrawal from drugs or alcohol may cause what changes on EEG?

epileptiform discharges

What are some medication effects that can be seen on EEG?

background slowing, increased beta, suppression

Some causes of epilepsy

trauma, infection, genetic factors

During HV, the CO2 level in the blood __________

decreases

Anterior Temporal Spikes

90-95%

Frontal Spikes

70-80%

Central Temporal Spikes

60-70%

Central Parietal Spikes

40-50%

Occipital Spikes

30-40%

What are some criteria to consider when localizing a focal abnormality?

state, area of brain, site of pathology, patient age

Which location of the brain or electrode would more likely show a seizure beginning with a patient's leg?

Cz

True or false: pulse ox, acceleometers, tape measures, and glue tips only need to be wiped down with alcohol

false

Sensitivity formula

S=V/D

Triphasic waves are known for what?

anterior to posterior lag

IRDA is also known as what?

distant rhythms; projected rhythms

When do you see LPDs?

following acute head injuries