Electroencephalogram

Question 1

What does EEG stand for?

Answer 1

Electroencephalogram

An EEG is a test that detects electrical activity in the brain.

Question 2

What is the primary function of neurons in the cerebral cortex?

Answer 2

To send and receive nerve impulses

Neurons are responsible for transmitting information throughout the brain and nervous system.

Question 3

How many electrodes are typically used in an EEG?

Answer 3

21 electrodes

Electrodes are placed on the head to record brain activity.

Question 4

What do odd-numbered electrodes represent in an EEG?

Answer 4

Left side of the head

Each electrode is numbered based on its position.

Question 5

What is the frequency range for alpha waves in an EEG?

Answer 5

8-13 Hz

Alpha waves are typically observed when a person is awake with eyes closed.

Question 6

What type of brain activity do beta waves represent?

Answer 6

When awake

Beta waves are associated with active thinking and alertness.

Question 7

What is the frequency range for delta waves?

Answer 7

1-5 Hz

Delta waves are typically seen in deep sleep.

Question 8

What is the purpose of an EEG?

Answer 8

To diagnose and investigate epilepsy and other brain disorders

EEGs help identify abnormalities in brain activity.

Question 9

What may sudden changes in electrical activity on an EEG indicate?

Answer 9

An epileptic seizure or interruption in normal brain activity

Sudden changes can signal acute neurological events.

Question 10

True or False: EEGs provide a conclusive diagnosis of brain disorders.

Answer 10

False

EEGs indicate areas of brain activity problems but do not diagnose conclusively.

Question 11

Fill in the blank: Each electrode in an EEG is identified by a _______ and a number.

Answer 11

letter

The letter indicates the brain area where the electrode is placed.

Question 12

What are the four types of brain wave rhythms recorded in an EEG?

Answer 12

• Alpha
• Beta
• Delta
• Theta

Each type has distinct frequency and amplitude characteristics.

Question 13

What does a delta wave occurring in an awake adult indicate?

Answer 13

Abnormal brain activity

Delta waves are not expected in awake adults and signal potential issues.

Question 14

Explain one factor that can affect brain activity.

Answer 14

Sleep disorders

Conditions like insomnia or sleep apnea can alter normal brain function.

Question 15

What is the amplitude range for alpha waves?

Answer 15

20-200 µV

Amplitude reflects the strength of the electrical signals detected.

Question 16

What is the typical presentation of theta waves?

Answer 16

Young children and adults in deep sleep

Theta waves are commonly associated with light sleep and the early stages of sleep.