EEG BOARD EXAM SOLVED QUESTIONS
GRADED A+ COMPLETE PREPARATION
◉ Pulse.
Answer: Rhythmic slow waves in a single lead due to a close
pulsating vessel. Time locked but delayed after each QRS sample.
◉ Lateral eye movements.
Answer: Very slow out of phase derivations involving anterior
electrodes due to movement of the positively charged cornea. Best
appreciated in drowsiness and early sleep when patient experience
rolling eye movements.
◉ Muscle.
Answer: Extremely high frequency waves often generated from the
frontalis and temporalis muscles. Usually spares central leads.
Disappears in sleep.
◉ Glossokinetic.
Answer: Diffuse, low frequency discharges produced by movements
of the negative tip of the tongue. Can be induced by saying "la la la
la", chewing, or sucking.
,◉ Electrode pop.
Answer: Single or multiple sharp waves localized to a single
electrode without a surrounding field. Disappears by reapplying an
electrode.
◉ GRDA (generalized rhythmic delta activity).
Answer: Generalized in all leads, typically signifies global cerebral
dysfunction, such as in a severe encephalopathy, but is not to be a
risk factor for seizure or seizure tendency.
◉ Frontally dominant GRDA.
Answer: Can be seen with a variety of pathologies including
posterior fossa lesions, intracranial lesions, and increased
intraventricular pressure.
◉ LRDA (lateralized rhythmic delta).
Answer: Can be seen with focal lesions such a hemorrhage, tumor, or
stroke. Is associated with increased seizure risk/seizure tendency.
◉ LPDs (Lateralized periodic discharges).
Answer: Often seen with focal acute or subacute cerebral
dysfunction, such as with herpes simplex enchephalitis, stroke,
abscess, or subdural hematoma.
, ◉ GPDs (Generalized periodic discharges).
Answer: Felt to have highest seizure tendency of the 'ictal-interictal'
patterns. If seen clinically with rapidly progressive dementia it can
be strongly suggestive of Creutzfeldt-Jakob Disease.
◉ End stage liver disease.
Answer: This disease can present with hyperammonemia and
generalized periodic waves with triphasic morphology. They are
bilaterally synchronous and usually frontally predominant and
exhibit three phases (i.e. negative, positive, negative). Triphasic
waves can also be seen in ESRD and other forms of metabolic
encephalopathy.
◉ Subdural Hematoma.
Answer: Hemispheric asymmetry with the lower amplitude
discharges localizing to the affected hemisphere.
◉ HSV Encephalitis.
Answer: Due to the predilection for the temporal lobes, patients will
present with lateralized periodic discharges (LPDs) most prominent
in temporal leads.
◉ Stroke.
Answer: Shows focal irregular theta/delta activity with LRDA or
LPDs.
GRADED A+ COMPLETE PREPARATION
◉ Pulse.
Answer: Rhythmic slow waves in a single lead due to a close
pulsating vessel. Time locked but delayed after each QRS sample.
◉ Lateral eye movements.
Answer: Very slow out of phase derivations involving anterior
electrodes due to movement of the positively charged cornea. Best
appreciated in drowsiness and early sleep when patient experience
rolling eye movements.
◉ Muscle.
Answer: Extremely high frequency waves often generated from the
frontalis and temporalis muscles. Usually spares central leads.
Disappears in sleep.
◉ Glossokinetic.
Answer: Diffuse, low frequency discharges produced by movements
of the negative tip of the tongue. Can be induced by saying "la la la
la", chewing, or sucking.
,◉ Electrode pop.
Answer: Single or multiple sharp waves localized to a single
electrode without a surrounding field. Disappears by reapplying an
electrode.
◉ GRDA (generalized rhythmic delta activity).
Answer: Generalized in all leads, typically signifies global cerebral
dysfunction, such as in a severe encephalopathy, but is not to be a
risk factor for seizure or seizure tendency.
◉ Frontally dominant GRDA.
Answer: Can be seen with a variety of pathologies including
posterior fossa lesions, intracranial lesions, and increased
intraventricular pressure.
◉ LRDA (lateralized rhythmic delta).
Answer: Can be seen with focal lesions such a hemorrhage, tumor, or
stroke. Is associated with increased seizure risk/seizure tendency.
◉ LPDs (Lateralized periodic discharges).
Answer: Often seen with focal acute or subacute cerebral
dysfunction, such as with herpes simplex enchephalitis, stroke,
abscess, or subdural hematoma.
, ◉ GPDs (Generalized periodic discharges).
Answer: Felt to have highest seizure tendency of the 'ictal-interictal'
patterns. If seen clinically with rapidly progressive dementia it can
be strongly suggestive of Creutzfeldt-Jakob Disease.
◉ End stage liver disease.
Answer: This disease can present with hyperammonemia and
generalized periodic waves with triphasic morphology. They are
bilaterally synchronous and usually frontally predominant and
exhibit three phases (i.e. negative, positive, negative). Triphasic
waves can also be seen in ESRD and other forms of metabolic
encephalopathy.
◉ Subdural Hematoma.
Answer: Hemispheric asymmetry with the lower amplitude
discharges localizing to the affected hemisphere.
◉ HSV Encephalitis.
Answer: Due to the predilection for the temporal lobes, patients will
present with lateralized periodic discharges (LPDs) most prominent
in temporal leads.
◉ Stroke.
Answer: Shows focal irregular theta/delta activity with LRDA or
LPDs.
