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ABPN Clinical Neurophysiology study materials
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ABPN Clinical Neurophysiology practice questions

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Question 1EEG and Epilepsy Monitoring

A 24-year-old woman is referred after a single witnessed generalized tonic-clonic seizure. Which EEG finding most strongly predicts recurrence and supports starting antiseizure medication?

  1. Mu rhythm attenuating with contralateral hand movement
  2. A posterior dominant rhythm of 9 Hz
  3. Frontal intermittent rhythmic delta activity
  4. Epileptiform discharges on a routine awake EEG Correct answer.

Explanation

Epileptiform discharges (spikes, sharp waves, spike-and-wave) on an interictal EEG increase the risk of seizure recurrence after a first unprovoked seizure and inform treatment decisions. Normal background rhythms and benign variants do not carry this prognostic weight.

Question 2EEG and Epilepsy Monitoring

In the 10-20 system, which electrode is placed at the midline between the nasion and inion, 20% above the inion?

  1. Cz
  2. Pz
  3. Fz
  4. Oz Correct answer.

Explanation

The midline electrodes are Fz, Cz, Pz, and Oz, spaced at 20% intervals from nasion to inion. Oz sits 20% above the inion, and Pz sits centrally between Cz and Oz.

Question 3EEG and Epilepsy Monitoring

A 3 Hz generalized spike-and-wave discharge that begins and ends abruptly and is activated by hyperventilation is most characteristic of which epilepsy syndrome?

  1. Benign rolandic epilepsy
  2. Childhood absence epilepsy Correct answer.
  3. Lennox-Gastaut syndrome
  4. Juvenile myoclonic epilepsy

Explanation

Childhood absence epilepsy is defined by frequent, brief absences with a bilateral synchronous 3 Hz spike-and-wave pattern that is often provoked by hyperventilation and occurs on a normal background.

Question 4EEG and Epilepsy Monitoring

During a routine EEG, the technologist asks the patient to hyperventilate for three minutes. Which normal change is expected in most young adults?

  1. Flattening of the background to a suppression-burst pattern
  2. Diffuse high-amplitude slowing with a buildup over time Correct answer.
  3. Onset of 3 Hz spike-and-wave discharges
  4. Appearance of 14 and 6 Hz positive bursts

Explanation

Hyperventilation normally produces a gradual buildup of diffuse, high-amplitude slowing that resolves with rest, reflecting cerebral vasoconstriction and mild hypocapnia.

Question 5EEG and Epilepsy Monitoring

A 6-year-old boy has nocturnal seizures with drooling and facial twitching. His EEG shows high-amplitude diphasic sharp waves in the centrotemporal region that are activated by drowsiness. What is the most likely diagnosis?

  1. Electrical status epilepticus in sleep
  2. Juvenile absence epilepsy
  3. Panayiotopoulos syndrome
  4. Self-limited epilepsy with centrotemporal spikes Correct answer.

Explanation

Self-limited (benign) epilepsy with centrotemporal spikes presents with sleep-related orofacial seizures and characteristic centrotemporal sharp waves that are activated by drowsiness and sleep.

Question 6EEG and Epilepsy Monitoring

Which finding on an EEG performed during a prolonged unresponsive episode most strongly supports nonconvulsive status epilepticus?

  1. Generalized polymorphic delta activity
  2. Continuous rhythmic 3 Hz spike-and-wave with evolution Correct answer.
  3. Bilateral independent temporal slowing
  4. Intermittent rhythmic delta activity without evolution

Explanation

Nonconvulsive status epilepticus is supported by continuous or near-continuous epileptiform activity that evolves in frequency, amplitude, or morphology, often with rhythmic spike-and-wave.

Question 7EEG and Epilepsy Monitoring

Which EEG pattern is a normal variant seen during drowsiness and consists of brief bursts of sharply contoured waves over the posterior head regions?

  1. Wicket spikes
  2. POSTS (positive occipital sharp transients of sleep) Correct answer.
  3. FIRDA
  4. Breach rhythm

Explanation

Positive occipital sharp transients of sleep are surface-positive, sharply contoured waves over the occipital regions that appear in drowsiness and light sleep and are a normal finding.

Question 8EEG and Epilepsy Monitoring

A 45-year-old man is being evaluated for temporal lobe epilepsy. Which interictal EEG finding most supports a mesial temporal focus?

  1. Bitemporal independent slowing
  2. Left anterior temporal spikes Correct answer.
  3. Diffuse beta activity
  4. Occipital sharp transients of sleep

Explanation

Interictal spikes that are maximal at the anterior temporal electrodes (F7/T3 or F8/T4) strongly support a temporal lobe focus and help lateralize the epileptogenic zone.

Question 9EEG and Epilepsy Monitoring

During a video-EEG admission, a patient's stereotyped events are captured. Which feature most reliably distinguishes an epileptic seizure from a psychogenic nonepileptic event on the EEG?

  1. Ictal EEG change that evolves in frequency and amplitude Correct answer.
  2. Patient reports of an aura
  3. Elevated heart rate during the event
  4. Rhythmic movement artifact during the event

Explanation

An evolving ictal EEG pattern that changes in frequency, amplitude, and morphology is the strongest electrographic evidence of an epileptic seizure.

Question 10EEG and Epilepsy Monitoring

Which EEG feature is most characteristic of Lennox-Gastaut syndrome?

  1. Three Hz spike-and-wave with a normal background
  2. Fourteen and six Hz positive bursts
  3. Slow spike-and-wave at 1.5-2.5 Hz with a slow background Correct answer.
  4. Centrotemporal spikes with a normal background

Explanation

Lennox-Gastaut syndrome is characterized by slow spike-and-wave discharges (1.5-2.5 Hz), a slow background, and multiple seizure types including tonic and atypical absence seizures.

Question 11EEG and Epilepsy Monitoring

A patient's EEG shows a burst of generalized spike-and-wave followed by brief diffuse attenuation and then return of the background. This sequence is best described as which pattern?

  1. Suppression-burst
  2. Hypsarrhythmia
  3. Generalized spike-and-wave with post-burst attenuation Correct answer.
  4. Burst-suppression with burst duration exceeding suppression

Explanation

The described sequence reflects an ictal or interictal generalized discharge followed by post-burst attenuation, a common pattern in generalized epilepsies.

Question 12EEG and Epilepsy Monitoring

A 70-year-old man with recent cardiac arrest is comatose. His EEG shows a continuous generalized pattern of sharply contoured triphasic waves at 1.5 Hz. Which interpretation is most appropriate?

  1. Definite nonconvulsive status epilepticus requiring immediate escalation
  2. Normal sleep architecture
  3. Metabolic encephalopathy pattern that may warrant correlation with clinical context Correct answer.
  4. Focal temporal lobe epilepsy

Explanation

Triphasic waves are typically associated with metabolic encephalopathy and are not by themselves diagnostic of status epilepticus. Clinical correlation and consideration of the underlying cause are required.

Question 13EEG and Epilepsy Monitoring

Which EEG montage is most useful for detecting phase reversals that localize a focal spike?

  1. Longitudinal bipolar (double banana) montage Correct answer.
  2. Laplacian montage
  3. Transverse bipolar montage
  4. Referential montage

Explanation

In a longitudinal bipolar montage, a focal spike produces a phase reversal at the electrode where the maximum negativity is located, aiding localization.

Question 14EEG and Epilepsy Monitoring

A patient with suspected psychogenic nonepileptic events has an event captured on video-EEG. Which finding most supports a nonepileptic etiology?

  1. Postictal generalized slowing
  2. Side-to-side head turning with closed eyes and asynchronous limb movements Correct answer.
  3. Rhythmic 5 Hz theta activity that evolves in amplitude
  4. A well-formed 3 Hz spike-and-wave discharge

Explanation

Features such as side-to-side head turning, closed eyes during the event, and asynchronous or out-of-phase limb movements are more consistent with psychogenic nonepileptic events.

Question 15EEG and Epilepsy Monitoring

Which EEG pattern is most consistent with a diagnosis of infantile spasms (West syndrome)?

  1. Centrotemporal spikes
  2. Hypsarrhythmia Correct answer.
  3. Slow spike-and-wave
  4. Three Hz spike-and-wave

Explanation

Hypsarrhythmia is a chaotic, high-amplitude, disorganized background with multifocal spikes and is the classic EEG pattern of infantile spasms.

Question 16EEG and Epilepsy Monitoring

A patient is being monitored for presurgical evaluation. Which finding on an interictal EEG is most helpful for lateralizing a temporal lobe focus?

  1. Bilateral independent temporal slowing
  2. Right-sided anterior temporal spikes Correct answer.
  3. Generalized 4 Hz theta activity
  4. Occipital positive transients of sleep

Explanation

Anterior temporal spikes that are consistently lateralized to one side help identify the epileptogenic temporal lobe and guide surgical planning.

Question 17EEG and Epilepsy Monitoring

Which feature on an EEG recording indicates that a spike is likely a genuine epileptiform discharge rather than an artifact?

  1. A transient that appears only on a single electrode
  2. A sharp transient that is time-locked to the ECG
  3. A sharply contoured wave that persists unchanged with eye opening
  4. A sharp wave that is followed by a slow wave and disrupts the background Correct answer.

Explanation

Genuine epileptiform discharges typically disrupt the background and often consist of a spike followed by a slow wave, with a field extending across adjacent electrodes.

Question 18EEG and Epilepsy Monitoring

A patient with juvenile myoclonic epilepsy undergoes routine EEG. Which finding is most characteristic?

  1. Slow spike-and-wave at 2 Hz
  2. Four to six Hz polyspike-and-wave discharges with photosensitivity Correct answer.
  3. Centrotemporal spikes
  4. Periodic lateralized epileptiform discharges

Explanation

Juvenile myoclonic epilepsy is characterized by 4-6 Hz polyspike-and-wave discharges, often with photosensitivity and a normal background.

Question 19EEG and Epilepsy Monitoring

Which EEG finding is most consistent with periodic lateralized epileptiform discharges (PLEDs)?

  1. Diffuse fast activity
  2. Frontal intermittent rhythmic delta activity
  3. Generalized 3 Hz spike-and-wave
  4. Lateralized sharp waves recurring at about 1 Hz over one hemisphere Correct answer.

Explanation

PLEDs consist of lateralized sharp waves or spikes recurring at roughly 0.5-2 Hz over one hemisphere and are associated with acute structural lesions such as stroke or infection.

Question 20EEG and Epilepsy Monitoring

A patient with refractory focal epilepsy is evaluated with an intracranial EEG. Which finding is most useful for defining the seizure onset zone?

  1. Interictal spikes that are widespread
  2. Occipital positive transients of sleep
  3. Diffuse background slowing
  4. A focal area of rhythmic fast activity that precedes clinical onset Correct answer.

Explanation

The seizure onset zone is best identified by a focal region showing rhythmic fast activity or other evolving ictal patterns that precede clinical seizure onset.

Question 21EEG and Epilepsy Monitoring

During a hyperventilation activation, a patient develops a generalized 3 Hz spike-and-wave discharge with impaired awareness that resolves when hyperventilation stops. Which diagnosis is most likely?

  1. Juvenile myoclonic epilepsy
  2. Childhood absence epilepsy Correct answer.
  3. Lennox-Gastaut syndrome
  4. Temporal lobe epilepsy

Explanation

Hyperventilation-provoked 3 Hz spike-and-wave with brief impaired awareness is the hallmark of childhood absence epilepsy.

Question 22EEG and Epilepsy Monitoring

A patient's EEG shows a breach rhythm over the right frontotemporal region. What is the most appropriate interpretation?

  1. A focal epileptiform abnormality requiring treatment
  2. An artifact from the ECG
  3. A sign of nonconvulsive status epilepticus
  4. A normal variant related to a skull defect Correct answer.

Explanation

Breach rhythm refers to mu-like or beta activity that appears over a skull defect and is a normal variant that should not be mistaken for epileptiform activity.

Question 23EEG and Epilepsy Monitoring

A comatose patient after cardiac arrest shows a burst-suppression pattern on EEG. Which statement best describes this pattern?

  1. It is diagnostic of absence status epilepticus
  2. It is associated with severe cortical dysfunction and poor prognosis Correct answer.
  3. It is a normal sleep stage
  4. It indicates a good prognosis with full recovery

Explanation

Burst-suppression reflects severe cortical dysfunction and is associated with a poor prognosis after cardiac arrest, particularly when it persists.

Question 24EEG and Epilepsy Monitoring

A 30-year-old woman has episodes of unresponsiveness with eyelid fluttering and 3 Hz generalized spike-and-wave on EEG. She also has occasional generalized tonic-clonic seizures. Which feature most strongly argues for juvenile absence epilepsy rather than childhood absence epilepsy?

  1. Three Hz spike-and-wave on EEG
  2. Hyperventilation-induced discharges
  3. Age of onset in adolescence Correct answer.
  4. Presence of eyelid fluttering

Explanation

Juvenile absence epilepsy typically begins in adolescence and is often accompanied by generalized tonic-clonic seizures, distinguishing it from childhood absence epilepsy, which begins in early childhood.

Question 25EEG and Epilepsy Monitoring

A patient with suspected nonconvulsive status epilepticus has an EEG showing continuous generalized rhythmic delta activity at 2 Hz without spikes or evolution. Which interpretation is most appropriate?

  1. This pattern is a normal variant
  2. This is diagnostic of nonconvulsive status epilepticus
  3. This pattern indicates a focal temporal seizure
  4. This pattern is nonspecific and does not establish status epilepticus Correct answer.

Explanation

Continuous rhythmic delta activity without spikes or evolution is a nonspecific encephalopathic pattern and does not by itself establish nonconvulsive status epilepticus.

Question 26EEG and Epilepsy Monitoring

A routine EEG is performed on a healthy 22-year-old while awake with eyes closed. Which finding is considered a normal posterior dominant rhythm?

  1. A 14 Hz anteriorly dominant rhythm that blocks with eye closure
  2. A 9 Hz sinusoidal rhythm over the occipital regions that attenuates with eye opening Correct answer.
  3. A 3 Hz generalized spike-and-wave discharge lasting several seconds
  4. A 6 Hz rhythmic temporal theta activity that persists after eye opening

Explanation

The normal posterior dominant rhythm in an awake adult is an 8-13 Hz sinusoidal activity over the occipital regions that attenuates with eye opening. Faster anterior rhythms and persistent focal slowing are not normal adult awake background features.

Question 27EEG and Epilepsy Monitoring

An EEG technician notes a rhythmic 60 Hz artifact across multiple channels. Which measure is most appropriate to confirm and reduce this artifact?

  1. Checking the ground and impedance of the recording electrodes Correct answer.
  2. Switching the reference electrode to the contralateral ear
  3. Increasing the sensitivity from 7 to 3 microvolts per millimeter
  4. Changing the low-frequency filter to 1 Hz

Explanation

Line-noise artifact at 60 Hz commonly arises from poor electrode impedance or a faulty ground. Verifying ground and impedance is the appropriate first step to confirm and reduce it. Filter changes and sensitivity adjustments do not address the source.

Question 28EEG and Epilepsy Monitoring

Which EEG pattern is characteristic of stage N2 sleep in an adult?

  1. Vertex sharp transients occurring in trains
  2. Continuous generalized polymorphic delta
  3. Positive occipital sharp transients of sleep
  4. Sleep spindles and K complexes Correct answer.

Explanation

Stage N2 sleep is defined by the presence of sleep spindles and K complexes against a mixed-frequency background. Vertex sharp transients and positive occipital sharp transients of sleep are features of N1, and continuous polymorphic delta indicates encephalopathy or deeper sleep.

Question 29EEG and Epilepsy Monitoring

A patient has a focal spike over the left temporal region. On a bipolar longitudinal montage, which feature best localizes the spike's maximum negativity?

  1. A phase reversal between adjacent electrodes sharing the focus Correct answer.
  2. A generalized attenuation of background activity
  3. A single-channel discharge without involvement of neighboring electrodes
  4. A widespread field with equal amplitude in all channels

Explanation

In a bipolar montage, a focal negative discharge produces a phase reversal between the two adjacent electrodes that share the focus, with the channels pointing toward each other. This phase reversal is the primary localizing feature.

Question 30EEG and Epilepsy Monitoring

Which EEG finding is most consistent with a diagnosis of absence epilepsy during a hyperventilation activation?

  1. Focal temporal rhythmic theta activity
  2. Generalized 3 Hz spike-and-wave discharges with abrupt onset and offset Correct answer.
  3. Generalized polyspike discharges with associated myoclonus
  4. Periodic lateralized epileptiform discharges

Explanation

Absence epilepsy is characterized by generalized 3 Hz spike-and-wave discharges with abrupt onset and offset, often provoked by hyperventilation. Focal rhythmic theta and PLEDs indicate focal pathology, and polyspike discharges with myoclonus suggest juvenile myoclonic epilepsy.

Question 31EEG and Epilepsy Monitoring

A patient with a history of febrile seizures in childhood is being evaluated for mesial temporal sclerosis. Which MRI finding would most strongly support this diagnosis?

  1. Enlargement of the temporal horn contralateral to the seizure focus
  2. Bilateral symmetric hippocampal volumes
  3. Diffuse cortical thickening in the frontal lobes
  4. Hippocampal atrophy with increased T2 signal on the affected side Correct answer.

Explanation

Mesial temporal sclerosis is characterized by hippocampal atrophy with increased T2 signal and often loss of internal architecture on the affected side. Symmetric volumes and contralateral changes do not support the diagnosis.

Question 32EEG and Epilepsy Monitoring

Which EEG finding is characteristic of a generalized tonic-clonic seizure during the tonic phase?

  1. Low-voltage fast activity evolving into generalized rhythmic 10 Hz activity Correct answer.
  2. Periodic sharp waves occurring every 1 to 2 seconds
  3. Focal rhythmic delta slowing
  4. Generalized rhythmic 3 Hz spike-and-wave

Explanation

The tonic phase of a generalized tonic-clonic seizure typically shows low-voltage fast activity that evolves into generalized rhythmic 10 Hz activity, often with muscle artifact. Rhythmic 3 Hz spike-and-wave characterizes absence seizures.

Question 33EEG and Epilepsy Monitoring

A patient is being evaluated for possible brain death. Which EEG finding would be most consistent with this clinical state?

  1. Electrocerebral inactivity with no recordable cortical activity at high sensitivity Correct answer.
  2. Continuous generalized rhythmic delta activity
  3. Intermittent generalized spike-and-wave discharges
  4. Sleep spindles and K complexes during a drowsy state

Explanation

Electrocerebral inactivity, defined as absence of recordable cortical activity at high sensitivity, is the EEG correlate of brain death. Rhythmic delta, spike-and-wave, and sleep features all indicate preserved cortical function.

Question 34EEG and Epilepsy Monitoring

A patient with known epilepsy has an EEG showing a burst of generalized spike-and-wave discharges lasting 2 seconds, followed by a brief period of diffuse attenuation, then return of background activity. What is the most appropriate interpretation?

  1. This represents a generalized seizure with postictal suppression
  2. This is a normal variant of drowsiness
  3. This is an interictal epileptiform discharge with brief post-burst attenuation Correct answer.
  4. This represents an artifact from eye movement

Explanation

A brief generalized spike-and-wave burst followed by diffuse attenuation and rapid return of background is an interictal epileptiform discharge with post-burst suppression, not a sustained electrographic seizure. Seizures typically evolve in frequency and amplitude and last longer.

Question 35EEG and Epilepsy Monitoring

An EEG performed on a 65-year-old man after a cardiac arrest shows a continuous generalized pattern of sharply contoured theta and delta waves at 1 to 2 Hz. What does this pattern most likely represent?

  1. A focal temporal lobe seizure focus
  2. A normal aging variant
  3. A benign rolandic discharge
  4. A severe encephalopathy with poor prognosis Correct answer.

Explanation

Continuous generalized sharply contoured theta and delta activity after cardiac arrest indicates severe diffuse encephalopathy and is associated with a poor prognosis. It is not a normal variant or a focal epileptiform pattern.

Question 36EEG and Epilepsy Monitoring

A patient with suspected psychogenic nonepileptic events has an event captured on video-EEG. Which finding most strongly supports a nonepileptic cause?

  1. Focal rhythmic theta evolving to delta during the event
  2. Postictal generalized EEG suppression
  3. Eyes closed with rhythmic pelvic thrusting and normal EEG during the event Correct answer.
  4. Generalized 3 Hz spike-and-wave during the event

Explanation

Nonepileptic events often feature eyes closed, pelvic thrusting, and lack of electrographic seizure activity during the event. Generalized spike-and-wave, evolving focal rhythms, and postictal suppression support an epileptic seizure.

Question 37EEG and Epilepsy Monitoring

An EEG in a 6-month-old infant shows hypsarrhythmia. Which clinical syndrome is most strongly associated with this pattern?

  1. West syndrome with infantile spasms Correct answer.
  2. Juvenile myoclonic epilepsy
  3. Benign rolandic epilepsy
  4. Childhood absence epilepsy

Explanation

Hypsarrhythmia, a chaotic high-amplitude disorganized background with multifocal spikes, is the characteristic EEG pattern of West syndrome with infantile spasms. The other syndromes have different characteristic patterns.

Question 38EEG and Epilepsy Monitoring

A patient is being monitored for presurgical evaluation. Which interictal EEG finding is most helpful for lateralizing the epileptogenic zone?

  1. Diffuse background slowing
  2. Bilateral independent temporal spikes
  3. Reproducible unilateral temporal spikes with a consistent field Correct answer.
  4. Generalized spike-and-wave discharges

Explanation

Reproducible unilateral temporal spikes with a consistent field help lateralize the epileptogenic zone. Bilateral independent spikes, generalized discharges, and diffuse slowing provide less reliable lateralizing information.

Question 39EEG and Epilepsy Monitoring

A spike is noted on EEG. Which feature most strongly suggests it is a genuine epileptiform discharge rather than an artifact?

  1. A single sharp deflection in one channel without a field
  2. A dipole field with a physiologic distribution across adjacent electrodes Correct answer.
  3. A waveform that occurs only when the patient blinks
  4. A 60 Hz oscillation overlying the spike

Explanation

Genuine epileptiform discharges typically show a dipole field with a physiologic distribution across adjacent electrodes. Single-channel deflections, blink-locked waveforms, and 60 Hz oscillation suggest artifact.

Question 40EEG and Epilepsy Monitoring

A patient with juvenile myoclonic epilepsy undergoes a routine EEG. Which interictal finding is most characteristic?

  1. Periodic lateralized epileptiform discharges
  2. Hypsarrhythmia
  3. Focal temporal spikes
  4. Generalized polyspike-and-wave discharges at 3 to 6 Hz Correct answer.

Explanation

Juvenile myoclonic epilepsy is characterized by generalized polyspike-and-wave discharges at 3 to 6 Hz, often provoked by sleep deprivation or photic stimulation. Focal spikes, PLEDs, and hypsarrhythmia are features of other conditions.

Question 41EEG and Epilepsy Monitoring

An EEG shows periodic lateralized epileptiform discharges (PLEDs) over the right hemisphere. Which clinical context is most commonly associated with this finding?

  1. Juvenile absence epilepsy
  2. Normal aging without neurologic disease
  3. Acute focal cerebral injury such as stroke or herpes encephalitis Correct answer.
  4. Chronic well-controlled epilepsy

Explanation

PLEDs are most commonly associated with acute focal cerebral injury, including stroke, infection such as herpes encephalitis, and tumor. They are not a feature of well-controlled epilepsy or normal aging.

Question 42EEG and Epilepsy Monitoring

A patient with refractory focal epilepsy is evaluated with intracranial EEG. Which finding is most useful for defining the seizure onset zone?

  1. Widespread interictal spikes across all electrodes
  2. A focal region showing low-voltage fast activity at seizure onset Correct answer.
  3. Diffuse background slowing
  4. Generalized spike-and-wave discharges

Explanation

A focal region showing low-voltage fast activity at seizure onset is a reliable indicator of the seizure onset zone on intracranial EEG. Widespread interictal spikes and diffuse slowing are less localizing.

Question 43EEG and Epilepsy Monitoring

A patient's EEG shows a breach rhythm over the right frontotemporal region after a craniotomy. What is the most appropriate interpretation?

  1. It indicates acute encephalitis
  2. It represents a generalized seizure pattern
  3. It represents an underlying epileptiform focus requiring treatment
  4. It is a normal variant caused by skull defect and does not itself indicate epilepsy Correct answer.

Explanation

Breach rhythm is a normal variant caused by a skull defect, producing increased amplitude and sharper contour over the region of the craniotomy. It does not itself indicate epilepsy or infection.

Question 44EEG and Epilepsy Monitoring

A comatose patient after cardiac arrest shows a burst-suppression pattern on EEG. Which statement best describes this patient's prognosis?

  1. It is a normal sleep pattern
  2. It indicates a good prognosis with likely full recovery
  3. It is associated with a poor prognosis and severe cortical dysfunction Correct answer.
  4. It indicates a focal seizure disorder

Explanation

Burst-suppression after cardiac arrest reflects severe cortical dysfunction and is associated with a poor prognosis. It is not a normal sleep pattern or a focal seizure disorder.

Question 45EEG and Epilepsy Monitoring

A 30-year-old woman has episodes of unresponsiveness with eyelid fluttering and 3 Hz generalized spike-and-wave on EEG. Which syndrome is most likely?

  1. Childhood absence epilepsy Correct answer.
  2. West syndrome
  3. Juvenile myoclonic epilepsy
  4. Temporal lobe epilepsy

Explanation

Childhood absence epilepsy is characterized by brief episodes of unresponsiveness with eyelid fluttering and 3 Hz generalized spike-and-wave discharges. Juvenile myoclonic epilepsy features myoclonus, temporal lobe epilepsy is focal, and West syndrome shows hypsarrhythmia.

Question 46EEG and Epilepsy Monitoring

An EEG performed during a prolonged unresponsive episode shows continuous generalized rhythmic delta activity without clear evolution. Which interpretation is most appropriate?

  1. This is diagnostic of nonconvulsive status epilepticus
  2. This indicates a focal temporal seizure
  3. This pattern is nonspecific and may reflect encephalopathy rather than status epilepticus Correct answer.
  4. This represents a normal drowsy pattern

Explanation

Continuous generalized rhythmic delta activity without evolution is nonspecific and may reflect encephalopathy rather than nonconvulsive status epilepticus. Status epilepticus typically shows evolving frequency and amplitude.

Question 47EEG and Epilepsy Monitoring

A patient with refractory focal epilepsy is being evaluated for surgery. Which EEG finding would most strongly suggest a poor surgical outcome if resected?

  1. A single focal spike within the planned resection zone
  2. Bilateral independent temporal spikes with a dominant focus Correct answer.
  3. Reproducible unilateral temporal spikes
  4. Focal rhythmic theta at the seizure focus

Explanation

Bilateral independent temporal spikes suggest bilateral epileptogenicity and are associated with a poorer surgical outcome. A single focal spike, reproducible unilateral spikes, and focal rhythmic theta are more favorable localizing findings.

Question 48EEG and Epilepsy Monitoring

An EEG shows a pattern of generalized periodic discharges at 1 to 2 Hz in a patient with altered mental status after prolonged status epilepticus. Which statement best describes this pattern?

  1. It may represent an ictal-interictal continuum pattern requiring clinical correlation Correct answer.
  2. It is diagnostic of brain death
  3. It is a normal variant seen in drowsiness
  4. It indicates a focal temporal lobe seizure

Explanation

Generalized periodic discharges at 1 to 2 Hz in a patient after status epilepticus may represent an ictal-interictal continuum pattern and require clinical correlation to determine whether treatment is warranted. They are not a normal variant, brain death, or focal seizure pattern.

Question 49EEG and Epilepsy Monitoring

A patient with suspected nonconvulsive status epilepticus has an EEG showing continuous generalized rhythmic delta activity that evolves in frequency and amplitude over time. Which interpretation is most appropriate?

  1. This pattern supports an electrographic seizure Correct answer.
  2. This represents a burst-suppression pattern
  3. This represents a benign normal variant
  4. This indicates a focal temporal seizure

Explanation

Evolution in frequency and amplitude over time is a key feature that supports an electrographic seizure rather than a static encephalopathic pattern. Benign variants, focal seizures, and burst-suppression have different characteristics.

Question 50EEG and Epilepsy Monitoring

A patient with a known temporal lobe epilepsy focus has an EEG showing a spike over the left temporal region. Which additional feature would most increase confidence that the spike is a true cortical discharge rather than an artifact?

  1. The spike is time-locked to the cardiac cycle
  2. The spike occurs only during eye blinking
  3. The spike appears in a single channel with no field
  4. The spike has a dipole field with a consistent voltage gradient across adjacent electrodes Correct answer.

Explanation

A dipole field with a consistent voltage gradient across adjacent electrodes supports a true cortical discharge. Time-locking to the cardiac cycle suggests pulse artifact, blink-locking suggests eye artifact, and a single-channel discharge suggests electrode artifact.