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WorksheetsREVISION II
Total questions: 15
Worksheet time: 8mins
Why is averaging used when analysing repeated EEG signals?
To increase the size of the signal
To make the signals more complex
To combine different patients’ data into one graph
To reduce random noise and highlight consistent brain responses
Which of the following filter settings is not acceptable when performing EEG for ECI assessment?
Sensitivity at 2 µV/mm
Low-frequency filter at 1 Hz
High-frequency filter at 30 Hz
High-frequency filter at 70 Hz
What should be done if an artifact is detected during Video Telemetry Recording (VTR)?
Replace electrodes without any further analysis
Reanalyze the data after removing all artifacts manually
Immediately stop the recording and reset the equipment
Identify and isolate the source of the artifact for later correctio
What is the purpose of adjusting the sampling rate in long-term EEG monitoring?
To reduce the amount of data recorded
To improve the resolution of EEG waveforms
To synchronize the video recording with EEG data
To prevent electrode noise from appearing in the data
Which of the following describes the function of a referential montage in EEG?
It compares the potential difference between adjacent electrodes
It focuses on regional brain activity by isolating signals from different lobes
It uses a common reference electrode to evaluate brain activity across regions
It minimizes the effect of muscle artifacts by recording from all scalp regions simultaneously
What does "interictal" refer to in EEG terminology?
A normal brain pattern with no signs of seizure activity present
The time immediately after a seizure, when brain activity returns to baseline
The period between seizures, when abnormal brain activity may still be present
The initial onset phase of a seizure event, marked by a rapid increase in electrical activity
What is the role of the thalamus in generating EEG waves?
The thalamus regulates the generation of alpha waves during sleep and wake cycles
The thalamus directly produces delta waves by firing spontaneously without cortical interaction
The thalamus has minimal involvement in EEG wave generation, as it only transmits sensory information
The thalamus filters cortical signals, allowing high-frequency beta waves to be generated in the frontal cortex
What is the role of the ascending reticular activating system (ARAS) in EEG activity?
It suppresses cortical activity to generate alpha rhythms during rest
It activates the cerebral cortex to maintain wakefulness and alert EEG patterns
It produces delta waves by inhibiting thalamic relay neurons during deep sleep
It filters out sensory input during sleep, resulting in decreased cortical responsiveness
An EEG shows rhythmic 4–7 Hz theta activity localized to the temporal region in a drowsy adult. What is the most likely classification?
Normal finding during drowsiness in temporal leads
Diagnostic of non-convulsive status epilepticus in a wakeful adult
Indicative of generalized epilepsy with secondary bilateral synchrony
Suggestive of diffuse cortical dysfunction with frontal predominance
A 30-year-old patient presents with a history of focal seizures. The EEG shows intermittent sharp waves localized to the right temporal lobe. What does this EEG finding most likely suggest?
Normal finding in a seizure-free patient
Focal cortical dysplasia in the right temporal lobe
Generalized tonic-clonic seizures with focal onset
Non-epileptic seizures with no underlying brain abnormalities
What is the primary challenge of Video Telemetry Recording (VTR) when distinguishing between epileptic and non-epileptic seizures?
The EEG data is often too complex for accurate interpretation without prior video analysis
The challenge is in distinguishing sleep-related events from seizures, as both can present similarly on video
Video recordings often have too much noise, making it difficult to correlate the patient's behavior with EEG signals
Video alone may not differentiate non-epileptic events, requiring EEG patterns to confirm the presence of ictal activity
In a patient with suspected carpal tunnel syndrome, which muscle should be selected for EMG to assess median nerve function?
Flexor carpi ulnaris
Abductor pollicis brevis
First dorsal interosseous
Extensor digitorum communis
In a routine motor nerve conduction study, which parameter is most important when evaluating the median nerve?
F-wave latency recorded from the bicep
Conduction velocity across the thumb using surface electrode
Distal motor latency and amplitude recorded from the abductor pollicis brevis
Sensory latency recorded from the middle finger using antidromic stimulation
What is the most likely finding in visual evoked potentials (VEP) in a patient with multiple sclerosis (MS)?
Normal P100 latency with no waveform changes
Absent N135 waves, indicating optic nerve atrophy
Prolonged P100 latency due to demyelination of optic pathways
Decreased amplitude with sharp waves during the latency period
In a patient with acute ischemic stroke, which TCD finding would most likely correlate with impaired cerebral perfusion?
Increased MCA flow velocity with a normal PI, suggesting good perfusion
Low resistance and normal velocity in the anterior cerebral artery (ACA), indicating high perfusion
High velocity in the vertebral arteries with low resistance, indicating normal cerebral circulation
Decreased middle cerebral artery (MCA) flow velocity and elevated pulsatility index (PI), indicating poor perfusion
