EEG MCQ Quiz Questions

Triphasic refers to a wave with three components alternating about the baseline. In this context, it means that the wave has three distinct phases or segments that alternate in a cyclical pattern. This term is commonly used in medical and physiological contexts to describe certain types of electrical or physiological waveforms, such as in muscle activity or nerve conduction.

Diphasic refers to a waveform or signal that has two distinct phases or components. In this context, it suggests that there are two components present in the waveform that are on opposite sides of the baseline. This means that the waveform has both positive and negative components, indicating a change in direction of polarity. The other options, such as sinusoidal, triphasic, epileptiform, and sharp transient, do not necessarily imply the presence of two opposite components, making them incorrect answers.

Theta waves are a type of brainwave that occurs during light sleep or deep relaxation. They have a frequency range of 4-7 Hertz, which means they oscillate at a rate of 4 to 7 cycles per second. This frequency range is associated with increased creativity, deep meditation, and enhanced memory. Frequencies below 4 Hertz are typically associated with delta waves, which occur during deep sleep, while frequencies above 7 Hertz are associated with alpha waves, which occur during wakefulness and relaxation. Therefore, the correct answer is 4-7 Hertz.

Sinusoidal waves are regular waves that closely resemble sine waves. They have a smooth, repetitive pattern with a consistent frequency and amplitude. Sinusoidal waves are commonly found in various natural phenomena, such as sound waves, electromagnetic waves, and water waves. In the context of the given options, sinusoidal is the most appropriate term to describe regular waves that resemble sine waves.

A wave with a single deflection either up or down from the baseline is described as monophasic. This means that the wave has only one phase or direction of deflection. It does not have multiple phases or deflections like the other options (transient, polyphasic, paroxysmal, epileptiform).

Delta waves are a type of brainwave that are associated with deep sleep and unconsciousness. They have a frequency range of less than 4 Hertz, which means they occur less than 4 times per second. This frequency range is characteristic of the slowest and highest amplitude brainwaves. It is important to note that delta waves are typically only present in adults during deep sleep or certain brain disorders, and they are more commonly observed in infants and young children.

A wave with a single deflection either up or down from the baseline is referred to as monophasic. This means that the wave only has one phase or direction of movement. It does not have multiple phases or deflections like in polyphasic waves. Transient refers to something that is temporary or short-lived, paroxysmal refers to sudden and intense episodes, and epileptiform refers to waveforms resembling those seen in epilepsy.

The correct answer is "Meninges". The meninges are the three protective membranes that cover and protect the brain. They consist of the dura mater, arachnoid mater, and pia mater. These membranes help to cushion and protect the brain from injury, as well as provide support and nutrition to the brain.

Diphasic refers to a waveform or signal that has two distinct phases or components. In this context, the two components mentioned in the question are on opposite sides of the baseline. Therefore, diphasic is the correct answer as it accurately describes the waveform with two phases.

Polyphasic refers to a wave that has 2 or more components of a different direction. This means that the wave consists of multiple phases or components that are moving in different directions. It is the only option that accurately describes a wave with multiple components of different directions, making it the correct answer.

The unit used to describe amplitude is microvolts. Amplitude refers to the maximum value of a waveform, and it is typically measured in volts. The prefix "micro-" indicates one millionth, so microvolts represent a very small unit of voltage. Kilowatts, univolts, hertz, and gigawatts are not units used to describe amplitude.

The term "epileptiform" refers to waveforms that are characteristic of epilepsy or seizure activity. These waveforms can be observed on an electroencephalogram (EEG) and are typically abnormal in nature. They are often associated with clinical seizure manifestations, such as convulsions or loss of consciousness. In contrast, waveforms without clinical seizure manifestations are considered normal or non-epileptiform. Therefore, the term "epileptiform" is the most appropriate choice to describe waveforms associated with clinical seizure manifestations.

High amplitude slowing refers to a pattern seen on an electroencephalogram (EEG) where there is a decrease in the frequency and increase in the amplitude of brain waves. Hyperventilation is a technique that involves rapid and deep breathing, which can cause changes in the blood chemistry and lead to high amplitude slowing on the EEG. Drowsiness, on the other hand, is a state of reduced alertness and can also be associated with high amplitude slowing on the EEG. Therefore, both hyperventilation and drowsiness can elicit high amplitude slowing.

Polyphasic refers to a wave that has 2 or more components of a different direction. This means that the wave consists of multiple phases or components that are moving in different directions. It could be a combination of positive and negative phases or waves that are moving in opposite directions. This term is commonly used in the context of brain waves or electrical activity in the brain, where polyphasic waves may indicate abnormal or pathological activity.

The term "ictal" refers to the period of time during a seizure, when abnormal electrical activity occurs in the brain. It is characterized by various patterns, including sharp transient and irregular activity. The other options, interictal and epileptiform, describe different types of electrical activity that can occur outside of a seizure. Therefore, the correct answer is "Ictal" because it specifically refers to the seizure period.

Transient refers to something that is temporary or short-lived. In the context of the given question, an event that stands out against the background is likely to be something that occurs briefly or momentarily, making the term "transient" the most suitable answer.

The three main parts of the brain are the medulla, cerebrum, and cerebellum. The medulla is responsible for controlling vital functions such as breathing and heart rate. The cerebrum is the largest part of the brain and is responsible for higher cognitive functions such as thinking, memory, and perception. The cerebellum is involved in coordinating movement and maintaining balance.

Paroxysmal refers to a sudden and intense occurrence or event. In the context of the given statement, it suggests that the waves described exhibit a sudden onset, peak rapidly, and then abruptly disappear. The term "paroxysmal" accurately describes this characteristic of the waves, making it the correct answer.

The term "epileptiform" refers to waveforms that are characteristic of epilepsy or seizure activity. These waveforms can be observed during an electroencephalogram (EEG), which is a test used to diagnose and monitor seizures. Epileptiform waveforms are abnormal electrical discharges in the brain that are often associated with clinical seizure manifestations, such as convulsions or loss of consciousness. Therefore, the term "epileptiform" is the most appropriate choice to describe waveforms associated with clinical seizure manifestations.

Eye-opening and closing affects the Posterior Dominant Rhythm. The Posterior Dominant Rhythm is an electrical brain activity pattern that is most prominent in the posterior regions of the brain. It is typically observed when a person is awake with their eyes closed, and it becomes less prominent when the eyes are opened. Therefore, the pattern is affected by eye-opening and closing.

Epileptiform activity refers to abnormal electrical activity in the brain that is associated with epilepsy. It is characterized by sharply contoured waveforms, such as spikes and sharp waves, that are distinct from normal brain activity. These waveforms can be observed on an electroencephalogram (EEG), a diagnostic test that measures brain activity. The presence of epileptiform activity on an EEG can help to confirm a diagnosis of epilepsy and guide treatment decisions.

The average human brain weighs 3 pounds.

Infantile spasms is the correct answer because it is a disorder characterized by multifocal epileptiform discharges observed using the EEG. This condition typically presents in infancy and is characterized by brief, symmetric muscle contractions that occur in clusters. The EEG findings in infantile spasms often show a hypsarrhythmia pattern, which is characterized by high-amplitude, disorganized, and chaotic brain wave activity. This pattern is indicative of abnormal brain function and is commonly associated with the diagnosis of infantile spasms.

The term "Ictal" refers to the period during a seizure when the abnormal electrical activity in the brain causes the characteristic symptoms of a seizure. This includes the actual seizure activity itself, which can be observed on an electroencephalogram (EEG) as an electrographic seizure pattern. The other options, such as "Interictal" (between seizures), "Sharp transient" (a type of EEG waveform), "Irregular Activity" (a general description of abnormal brain activity), and "Epileptiform" (abnormal EEG patterns associated with epilepsy) are not specific to the ictal period.

Beta waves are neural oscillations in the brain that are associated with alertness, concentration, and active thinking. They typically have a frequency range of 13 to 30 Hertz.