Electroencephalogram EEG - PowerPoint Presentation

Slide1

Electroencephalogram

EEG Slide2

Outline;

EEG Overview.

Purpose

Indications

Type of EEG Tests

Nursing Interventions;

*

Patient Preparation.

*

Patient and Family Teaching.

Normal / Abnormal Results

Common Factors affecting EEG Recording

Complications.Slide3

Objectives

At the end of the lecture, the students will be able to

Understand EEG procedure.

Discuss nursing management.Slide4

Diagnostic Tests for Neurological Diseases

Brain scans

Cerobrospinal

fluid analysis

Computed Tomography (CT scan)

,

Echocardiogram

Electroencephalography (EEG)Slide5

The Electroencephalogram (EEG

)

Definition:

Is a medical test used to measure the electrical activity of  the brain, via electrodes applied to scalp

or through microelectrodes placed within the brain tissueSlide6

Electrodes

are attached to multiple sites on the scalp to provide a recording of electrical activity that is generated in the cerebral cortex.

Electrical impulses

are transmitted to an electroencephalograph, which magnifies and records these impulses as brain waves on a strip of paper.Slide7

PURPOSE

It

provides a physiologic assessment of cerebral activity.

for

diagnosing and evaluating seizure

disorders, epilepsy,

coma, or organic brain

syndrome, sleep disorders.

Used in making

a determination of brain

deathused

in intensive care units for brain function monitoring non-convulsive seizures/non-convulsive status

epilepticus

effect

of sedative/anesthesia in patients in medically induced coma (for treatment of refractory seizures or increased intracranial

pressure) secondary brain damage in conditions such as subarachnoid hemorrhage Slide8

Where is it performed?

room with no electrical interference;

bedside

-

comatose patient

(

using a portable unit.)

The

test takes about 1 to 2 hour.

completely painless , no need for shaving the  hair.

Provides

information about the timing of events.

Indication:

epilepsy,

coma,

sleep disorders,

confirmation of brain death

Tumors, brain abscesses, blood clots, and infection may cause abnormal patterns in electrical activity. Slide9

For a baseline recording

,

the patient

is instructed to

lie

quietly with both eyes closed

(

resting phase)

hyperventilate for 3 to 4 minutes and then look at a bright, flashing light for stimulation.

( activation procedures)

to evoke abnormal electrical discharges, such as seizure potentials. Slide10

During the recording, a series of activation procedures may be used. These procedures may induce normal or abnormal EEG activity that might not otherwise be

seen. (hyperventilation

, photic stimulation (with a strobe light), eye closure, mental activity, sleep and sleep

deprivation).

A sleep EEG

may be recorded after sedation because some abnormal brain waves are seen only when the patient is asleep. Slide11

Types of EEG test

:

Routine EEG tests -

EEG test done

at an outpatient’s appointment at the

hospital (

lasts about one

hour)

2. Ambulatory

EEG

test- recording the activity in the brain over a few hours, days or weeks, allowing

more time for the test to pick up any unusual electrical activity in the brain, the electrodes are plugged in to a small monitor that records the

results.

3. Sleep

EEG

tests - an EEG test is done while the patient is asleep, usually done in hospital, using a routine EEG machine. Before the test, the patient may be given some medicine to induce sleep. The test lasts for one to two hours or up to 8 hours Patient goes home once he wakes up 4. Sleep-deprived EEG tests - done when a patient had less sleep than usual. Before a sleep-deprived EEG test, the patient is advised not to go to sleep at all the night before, or just to wake up much earlier than usual. A patient tries to fall asleep or doze while the EEG is still recording the activity in the brain. The test lasts for a few hours. Patient goes home once he wakes upSlide12

Types of EEG test

:

5. Video-telemetry tests – a patient wears an ambulatory

EEG usually

carried out over a few days

. All

movements are recorded by a video camera.

The patient

need to stay in

hospital

This is done if a patient have already been diagnosed with epilepsy to determine the following:

To determine the type of seizuresThe reason / cause why anti-epileptic drugs are not working

well

Other

possibility that

the seizures are caused by other etiology than epilepsy.considering having epilepsy surgery.Slide13

Nursing Interventions

A- Patient Preparation;

Explain the procedure to the patients, emphasizing the importance of cooperation.

Withhold

Antiseizure

agents, tranquilizers, stimulants, and depressants medications for 24 to 48 hours before an EEG (alters the EEG wave patterns or mask the abnormal wave patterns of seizure disorders)

NO coffee, tea, chocolate, and cola drinks in the meal before the test (stimulants)Slide14

Have regular meal before the EEG

( to avoid alteration of blood glucose level. Low blood sugar can cause changes in the brain wave patterns and change the EEG result)

Assure the patient that the procedure does not cause an electric shock and that the EEG is a diagnostic test, not a form of treatment.

Patients with seizures do not stop taking their

antiseizure

medication prior to testing.

Assist the patient to wash the hair before and after the test.Slide15

B- Patient and Family Teaching

The test takes about 1 to 2 hour.

The test is painless and will be performed while sitting in a comfortable chair or lying on a stretcher.

The electrodes are applied to the scalp with a thick paste.

During the test, the patient will first be asked to breathe in and out deeply for a few minutes. Then, close her eyes while a light is flashed on them and, finally, the patient will lie quietly with her eyes closed.

After the test, the nurse will help the patient wash the paste out of the patient’s hair.Slide16

Normal Results

Brain

electrical activity has certain frequencies (the number of waves per second) that are normal for different levels of consciousness. For example, brain waves are faster when the person is awake

, and slower when

he/she is

sleeping.

There

are also normal patterns to these waves.

The

frequencies and patterns are what the EEG reader looks for.

Note: A normal EEG does not mean that a seizure did not occurSlide17

Abnormal

Results

Abnormal results on an EEG test may be due to:• An abnormal structure in the brain (such as a brain tumor)

• Attention problems

• Tissue death due to a blockage in blood flow (cerebral infarction)

• Drug or alcohol abuse

• Head injury

• Inflammation of the brain (encephalitis)

• Hemorrhage (abnormal bleeding caused by a ruptured blood vessel)

• Migraines (in some cases)

• Seizure disorder (such as epilepsy or convulsions)• Sleep disorder (such as narcolepsy)Slide18

Common factors affecting EEG recording ( artifacts

)

The biggest challenge with monitoring EEG is artifact recognition and elimination.

There

are patient related artifacts (e.g. movement, sweating, ECG, eye movements

)

technical artifacts

(cable

movements, electrode paste-related), which have to be handled differently.

Common

factors are:• Radio frequency (RF) waves• Electromagnetic interference • Eye movement

• ECG

• Head movement

• Muscle 

• Sweating• Electrode Slide19

Complications

EEG is a safe test with

no side effects.

However, a person with epilepsy may experience a seizure, triggered by the various stimuli used in the procedure, including the flashing lights.

This is not seen as a 'complication' by medical staff, because a seizure during an EEG can greatly help in diagnosis.)Slide20