Neuro Quizes Flashcards
A
Damage to the inferior parietal lobe of the dominant hemisphere results in the Gerstmann syndrome which includes right/left confusion, finger agnosia, acalculia and agraphia.
D
Patients with Wernicke’s or receptive aphasia cannot understand what is said to them. Their speech may be fluent but devoid of meaning.
C
A lesion in the dominant inferior frontal gyrus or Broca’s area would result in an expressive aphasia where comprehension is preserved but speech output is impaired. The resulting speech is nonfluent, telegraphic and often minimal.
C
Apraxia is the inability to perform a purposeful motor act on command. It can seen in lesions of the dominant parietal lobe.
B
The patient’s problem is with recent memory or making new memories which is a temporal lobe function.
A
The patient is having trouble with visual spatial sensory tasks. She is neglecting the left side of space which indicates dysfunction of the right parietal lobe.
D
These tests are tests for working memory and attention which are frontal lobe functions.
B
The eye cannot abduct so there is double vision when looking to the left. The false image is always the most peripheral image and is always from the abnormal eye. Covering the left eye eliminates the false or ghost image so it is the abnormal eye.
D
The right eye has limited range of motion for the muscles innervated by the 3rd nerve. The question is you mind should be why isn’t the right pupil dilated as well? If the 3rd nerve lesion was caused by compression of the nerve then the parasympathetic fibers which travel on the outer side of the 3rd nerve are involved and there is always a dilated unreactive pupil associated with the palsy. Diabetes can cause a pupillary sparing 3rd nerve palsy because of infarction of an endoneurial vessel which does not affect the parasympathetic fibers on the outside of the nerve.
C
The vestibuloocular system keeps an image steady on the fovea during head movements.
C
B
With a neurosensory hearing loss the vibration of the tuning fork placed on the forehead is perceived loudest in the normal ear. Air conduction is greater then bone conduction for both ears because there is no conductive hearing loss.
D
The patient has sparing of the frontalis muscle so this is an upper motor lesion affecting the left side of the face. The lesion is in the corticobulbar tract coming from the right cerebral cortex.
B
The tongue deviates toward the side of the abnormal 12th cranial nerve.
E
Because the optic tract is posterior to the optic chiasm the fibers that are contained in it “see” the same side of space although from different eyes. So a lesion of the right optic tract would result in a left hemianopsia that is present when testing each eye together or separately.
A
The jaw deviates toward the side of the lesion because of the unopposed action of the pterygoid muscle on the normal side.
B
With a lesion of the midbrain both the upper and lower extremities will be in extension. This is decerebrate posture. The explanation for this is that with a lesion of the midbrain the influence of the rubospinal tracts has been eliminated so the indirect brainstem motor control centers that reinforce extensor tone in both the upper and lower extremities (the reticulospinal and vestibulospinal tracts) are unmodulated and unopposed.
B
Only the lower extremity is effected and the sensory findings are on the opposite side of the body. In the spinal cord the ascending spinothalamic tract for pain and temperature sensation crosses almost immediately while the descending corticospinal tract has crossed at the level of the medulla.
A
The absence of triceps jerk and lower motor neuron signs of affected muscles in the upper extremity indicate a lesion at the C7 level. There are lower motor neuron signs at the level of the lesion and upper motor neuron signs below the level of the lesion.
A
Ankle clonus is often seen with an upper motor neuron lesion and the resulting spasticity. Hyperreflexia would be another finding seen in the upper motor neuron syndrome.
D
The patient has a crossed adductor sign which can be seen in spasticity or a lesion of the upper motor neuron. So one would expect to find hyperreflexia on the side of the body with the spasticity.
A
With one side of the face and the opposite side of the body involved then the lesion has to be in the brainstem. The side of the cranial nerve finding is usually the side of the lesion. Because vibratory and position sense are preserved then the medial lemniscus is spared which means that the lesion has to be below the upper pons where the tracts for the two sensory systems are close together and it has to be lateral if it is in the medulla so the medial lemniscus is spared. The best fit is the right lateral medulla.
D
This is the best anatomical fit for the lesion. At the level of the upper pons, the medial lemniscus and the spinothalamic tract are finally anatomically close together and close to the ventral trigeminothalamic tract so the sensory findings would be contralateral face and body with all somatosensory modalities being affected.
B
This is a case of a hemicord syndrome where the pain and temperature loss is on the opposite side of the body below the lesion and the dorsal column sensory loss is on the same side as the lesion. The key is to remember the level of crossing for the 2nd order axon for the two sensory systems is different with the spinothalamic crossing almost immediately and the DC-ML not crossing until the lower medulla.
C
The receptive fields on the fingertips, tongue and lips are the smallest for the body and these structures have the greatest cortical representation. On the fingertips one can recognize two points 2-4 mm apart.
B
This patient has agraphesthesia which indicates a lesion of the contralateral parietal lobe in the postcentral gyrus.
