CEREBRAL CORTEX Flashcards Preview


Flashcards in CEREBRAL CORTEX Deck (15)

1. A55-year-old right-handed veteran received a small shrapnel wound in the hed during the Vietnam War. Within 1 year of recciving his wound, the man complained of seizures and was treated with seizure medication. The medication was not effective, and a section of the anterior corpus callosum was performed successfully, Which of the following neurologic successfully. Which of the following neurologic deficits is most likely.
A. Slexia
B. The inability, with Closed eyes,
to indentify verbally an object held in the left hand
C. Gait dystaxia
D. Loss of binocular vision
E. Sympathelie aprexia in the left hand

1-B Transection of corpus callosum result in the inability, when blindfolded, to indentify verbally an object held in the head (dysnomia). The left hemisphere is dominant for language and naming object. Alexia is found in lesions of the inferior parietal lobule. Gait dystaxia may man’s visual pathways are not affected. Transsections of callosal fibers adjacent to the left promotor cortex produces a right hemiparesis, a motor (Broce) dysphasia, and a sympathetic dyspraxia of the left. Nomparalyzet, arm


2. A 70-year-old hypertensive man suddenly experiences numbness on the right side of his body. When asked to raise his left hand, he raises his right hand. The lesion is most likely in the
A. right frontal lobe D. left temporal lobe
B. left pariental lobe E. right enternal capsule
C. right parietal

2-B The right hemiparesis points to a lesion on the left side involving the conricospinal tract. Left-reght confusion is seen in Gerstmenn syndrome along with finger agnisoa. This syndrome results from destruction of the left anguler gyus.


3. A 45-yaer old farmen complains of hedeches Neurologic examination reveals pronator drift and mild hemiparesis on the left side and papilldema is visible on the left side. The lesion is most likely in which of the following cortices.
A. Frontal Insuler D. Parietal
B. Insular E. Temporal
C. Occipital

3-A The certical center for lateral conjugate gazed in are 8 of the frontal lobe. Destruction of this area results in turning of the head and eyes toward the side of the lesion. Stimulation of this area results in contralateral turning of the eyes and bead : pronator drift and hemi paresis are frontal lobe signs.


4. An 80-year old microbiologist has a cerebral infraction. His speech is limited to expletives, he cannot write but does respond to questions by shaking his head, and he has lower facial weakness on the right side. The lesion is most likely in the
A. left frontal lobe D. right pariatel lobe
B. right frontal lobe E. left temporal lobe
C. left parietal lobe

4-A Lower fecial weaknes is a localizing neighborhood sign. The Broca speech area is located in the posterior part of the inferior frontal gyrus (Brodmann areas 44 and 45).


5. A lesion resulting in a nonfluent expressive aphesia would most likely be found in the
A. temporal lobe D. occipital lobe
B. parietal lobe E. limbic lobe
C. frontal lobe

5-C A nonfluent. Expressive motor aphesia (broca aphesia) results from a lesion in the posterior inferior frontal gyrus (area 44 and 45) of the dominant frontal lobe.


6. Broca aphesia is frequently associated with
A. auditory hallucinations
B. finger agnosia
C. construction aprexia
D. an upper motor neuron (UMN) lesion
E. visual field deficits

6-D Broca aphesia is frequently associated with an upper motor neuron (UMN) lesion of the leg. Broca speech area lies just anterior to the motor strip : both broca speech area and the motor strip are irrigated by the superior division of the middle cerebral artery (prorelandic and rolendic arteries). Broca aphasia is frequently associated with a “both sympatheric aprexia, “an aprexia of the numparalyzed left hand.


7. Alexia without agraphia and aphasia would most likely result from occlusion of the
A. lest anterior cerebral artery D. left posterior cerebral artery
B. right anterior cerebral artery E. right posterior cerebral artery
C. left middle cerebral artery

7-D Alexia without agrephia and aphasia from acelusium of the left prosterior cerebral artery, which supplies the left visual cortex and callosal fibers (within the splenium) from the right visual association cortex. Interruption of bilateral visual association fibers en route to the. Left angular gyrus results alexia. Because the angular gyrus and Wernicke area are spared, the patient will not be agraphie or dysphasic.


8. Agraphia and dyscalculia would most likely result from a lesion in the
A. left frontal lobe D. left temporal lobe
B. left parietal lobe E. spenium of corpus callosum
C. right occipital lobe

8-B Lesions of the angular gyrus of the dominant hemisphere may result in Gerstmann syndrome. Which consists of agraphia, dyscaleulia, finger agnisia, and left right confuse


9. A patient is asked to bisect a horizontal line thought the middle to draw the face of a clock and to copy a cross. The patient bisected the horizontal line to the clock on the right side, and did not complete the cross on the left side, the most likely lesion site for this deficit would be in the.
A. left frontal lobe D. right temporal lobe
B. right parietal lobe E. left occipital lobe
C. left parietal lobe

9-B The inability to draw a clock face or bisect a line through the middle is called construction apraxia.lesions of the right (nondominant) parietal lobe result in construction apraxia, dressing apraxia, anosognosia, and sensory heminegleet.


10. A lesion of the dominant inferior parietal lobule could result in all of the following deficits EXCEPT
A. the inability to perform calculations
B. the inability to identify fingers
C. the inability to write from dictation
D. right-left diroserientation
E. difficulty in dressing

10-E Dressing apraxia is a symptom of the nondominant parietal lobe. A lesion of the dominant angular gyrus is known as Gerstmann syndrome, which includes finger agnosia (autotopagnosia or somatotopagnosia), rght left confusion, agraphia, and dyscalculia. Alexia may be associated with Gerstmann syndrome


11. All of the following statements concerning the parietal lobe are correct EXCEPT
A. it contains the primary somatosensory area
B. it contains the angular gyrus
C. it contains the supramarginal gyrus
D. it contains the visual radiation
E. it contains the Wernieke speech area

11-E Wernicke speech area (included in Bredmann area 22) is found in the posterior part of the superior temporal gyrus of the dominant hemisphere, Wrrnicke speech area includes the planum temporal, which lies on the lower bank of the lateral sulcus


12. All of the following statements concerning the layers of the neocertex are correct EXCEPT
A. layer I has the highest numerical call density in the neocortex
B. layer III is the external pyramidal layer
C. layer IV in the occipital lobe receives input from the lateral geniculate body
D. layer V contains the giant cells of Betz
E. layer VI is the major source of cortieothalamic fibers

12-A Layer I is characterized by a paucity of neurons, the horizontal cells of Cajal. (Layer II contains small granular cells). Layer III contains pyramidal cells that are myelinated within the cortex; they course in the white matter as projection, association, or commissural fibers. Layer IV, the major sensory receiving station of the neocortex, receives input from the ventral posterolateral and ventral posteromedial nuclei. Layer V, the internal pyramidal layer, gives rise to the corticonuclear and corticospinal fibers and also contains the giant cells of Betz; the largest neurons of the cortex, the Betz cells are located in Brodmann area 4 of the precentral gyrus and in the paracentral lobule. There are 40.000 Betz cells in a single hemisphere. Finally, layer VI is the major source of corticothalamic fibers


13. Lesions of the frontal lobes may give rise to all of the following EXCEPT
A. ocular signs
B. upper motor neuron (UMN) lesion signs
C. gait aprexia
D hemianopiah
E. sucking groping, and grasping statements

13-D Frontal lobe lesions may affect the frontal eye field, the motor cortex, and the promotor and prefrontal cortices (gait apraxia). Sucking, groping, and grasping reflexes are seen in frontal lobe lesions. Hemianopias result from lesions of the visual pathway. The visual pathway is not found in the frontal lobe


14. All of the following statements concerning the primary motor cortex are correct EXCEPT
A. it is found in the para central lobule
B. it is located in the frontal lobe
C. it contains the giants cells of Betz
D. It corresponds to Brodmann area 4
E. abletion results in a permanent flaccid paralysis

14-E The primary motor cortex, the motor strip (area 4), is located in the precentral gyrus and in the anterior part of the paracentral lobule, both of which are found in the layer V of the motor cortex. Ablation of the motor strip initially results in flaccid paralysis, which becomes a spastic contralateral hemiparesis with Babinski sign.


15. All of the following statements concerning the paracentral lobule are correct EXCEPT
A. it is found in two lobes of the brain
B. it contains giant cells of Betz
C. it is iriganted by two arteries
D. its infarction results in loss of vibration sense in the contralateral foot
E. its infection results in a contralateral extensor plantar reflex

15-C The paracentral lobule is perfusec by the anterior cerebral artery; the territory of the anterior cerebral artery extends a centimeter over the crest of the lateral convexity and perfuses the hip area of the motor and sensory strips. The giant cells of Betz are largest in the paracentral lobule.