EEG board prep 2020

Explain the modified nomenclature of the 10-10 system The modified nomenclature replaces T3/T4 and T5/T6 terms with T7/T8 and P7/P8 so that all electrode positions along the sagittal line have the same number (with exception of Fp1/Fp2 and O1/O2) and all electrodes along the same conronal line have the same letter What is the most valuable localizing feature in a bipolar montage? phase reversal What is the most valuable localizing feature in a referential montage? highest amplitude What causes cancellation (isoelectric phase reversal) in a bipolar montage? input 1 and input 2 being the same voltage What causes glossokinetic artifact and how do you monitor it? artifact from tongue movement, tip of tongue is negative and root is positive. monitor by placing one electrode above the mouth and one electrode below the mouth. ask patient to say "lilt" "la la la" to reproduce artifact. Describe respiration artifact and how to monitor it 1.)fairly rhythmic slow activity synchronous with body movement related to respiration 2.) slow or sharp wave occurring synchronously with inhalation or exhalation involving only the electrodes the patient is laying on. try to eliminate by re-positioning patient's head. Describe EKG artifact and how to monitor it no way to eliminate EKG artifact. Try to decrease by turning patients head relative to trunk, monitor by recording with 2 chest leads, one on each side Describe pacemaker artifact and how to monitor Seen as fast spike which is electrical stimulus delivered to the heart by an internal cardiac pacemaker. Pacemaker artifact will be seen in the channel monitoring EKG, should monitor EKG on every patient throughout the entire EEG recording. Describe tremor artifact and how to monitor it rhythmic theta activity with myogenic potentials (muscle artifact) superimposed that occursat 4 to 7 Hz as the head or body tremors; often seen in patients with Parkinson's disease. Monitor by placing electrode over extremity with tremor, can also be directly monitored by an accelerometer. An accelerometer is an elecromagnetic detector that records sudden movement and change in direction of movement. Describe electroretinogram artifact and how to eliminate it Seen during photic stimulation in Fp1 and Fp2. the artifact will match the frequency of the photic stimulation. Hold opaque card over eye to block photic stimulation flash from reaching retina What is the most common clinical feature of Dilantin toxicity? Ataxia What type of seizure begins with the head and eyes turning to one side? adversive seizure Dyarthria impaired speech homonymous hemianopsia The loss of the right or left half of the field of vision in both eyes. With rapidly increasing dosage, what medication will have the most sedative effect on a patient barbiturates used in treatment for only generalized seizures, commonly used for absence epilepsy treatment Ethosuximide Treatment for infantile spasms ACTH (adrenocorticotropic hormone) What is the effect of phenobarbital on EEG increase beta activity Bell's palsy is characterized by paralysis of facial muscles What clinic signs might be seen with a cerebellar hemorrhage? trunkal imbalance and poor coordination thiamin deficiency Wernicke's Syndrome Decorticate posturing is characterized by what? bilateral flexion at the elbows What can a lesion of the uncus result in? olfactory hallucinations What is the inability to perform purposeful movement though no muscular or sensory disturbance is present? Apraxia Subacute Panencephalitis(SSPE) is caused from what disease? Measles If a patient has a stroke involving the basilar artery, what clinical signs are expected to be seen? Dilopia Which of the following is most likely to be associated with a normal EEG? Cerebellar abscess Atrophy associated with Huntington's disease involves what area of the brain? basal ganglia What is the difference between a classical migraine headache and a common migraine headache? A classic migraine headache has an associated aura whereas a common migraine does not Sturge-Weber Syndrome has what? Neurocutaneous involvement What is the most common low-grade tumor detected in adults with epilepsy? Astrocytoma Patients with Rett's syndrome usually develop normally until what age? 6-18 months Name a disease that presents with an acoustic startle response within the first few months of life? Tay-Sachs disease Where is the cingulate cortex located in relation to the corpus callosum? Superiorly PLEDS are most likely to be seen in patients presenting with: Cerebral embolus The third ventricle is connected to the fourth ventricle by what? aqueduct of Sylvius Consciousness reticular formation Which of the following blood vessels is most frequently involved in strokes? middle cerebral artery Expressive asphasia may result from damage to where? Broca's area Epidural Hematoma an immediate threat to life Heschl's gyrus Auditory Aura Wernicke's area lies where? Posterior part of the superior temporal gyrus The most important source generator of the EEG is? pyramidal dendritic PSPs An EEG performed two days following a transient ischemic attack is most likely to show? normal activity A spike or sharp wave results from? synchronous activation of multiple neurons The pain of a migraine generally results from? Dilation of blood vessels Damage to Wernicke's area receptive, fluent aphasia PLEDs Acute cerebral infarction What is indicated by the presence of unilateral Babinski signs? pyradmidal tract dysfunction What is the etiology most commonly associated with LPDs/PLEDs? Ischemic Stroke A meningioma is usually what? encapsulated Where do most brain tumors occur in children? Posterior Fossa If the distance from the right preauricular to the right outer canthus measures 9cm, where should electrode T2 be placed 3 cm out from the right preauricular and 1 cm up Using the 10-20 electrode placement, if the distance from nasion to inion is 34cm, what is the distance from Fz to Oz 20.4cm