Cortical Lesions

Question 1

What area of the cortex is phylogenetically older?

Answer 1

The hippocampus

Question 2

The cerebral cortex comprises how many cells?

Answer 2

20 billion

Question 3

Each cortical neuron connects to _________ other neurons.

Answer 3

20,000

Question 4

There are diffuse and focal disorders of cortical dysfunction. Describe some examples.

Answer 4

Diffuse: neurodegenerative disorders (like Alzheimer’s); metabolic disorders

Focal: stroke; contusion; neoplasm

Question 5

Benign tumors damage the brain by ___________, while malignant tumors damage the brain by ___________.

Answer 5

mass effect; infiltration

Question 6

What are the functions of the frontal lobes?

Answer 6

Voluntary movement
Comportment
Prosody
Executive function 
Motivation
Language production

Question 7

What are the functions of the temporal lobes?

Answer 7

Audition
Language comprehension
Sensory prosody
Memory 
Emotion

Question 8

What are the functions of the parietal lobes?

Answer 8

Tactile sensation
Visuospatial reasoning
Attention 
Reading
Writing 
Calculation

Question 9

What are the functions of the occipital lobes?

Answer 9

Vision

Question 10

Prosody is primarily controlled by ____________.

Answer 10

the inferior gyrus of the nondominant frontal lobe

Question 11

Someone who presents with perseveration may have lesions to ____________.

Answer 11

the frontal lobes (this is a form of executive dysfunction)

Question 12

Because of the experience of H.M., surgeons now do what for temporal lobe epilepsy?

Answer 12

They remove only one lobe, not both.

Question 13

Temporal lobe epilepsy results from _____________.

Answer 13

focal cortical lesions in the temporal lobe

Question 14

Patients with temporal lobe epilepsy often develop what personality changes?

Answer 14

Hyperreligiosity
Deepened emotional states
Hypergraphia

Question 15

Hemineglect most often presents after lesions to the ________ lobe.

Answer 15

right parietal

Question 16

What is the pathophysiologic basis of hemineglect?

Answer 16

The right parietal lobe can attend to both sides of the visual field, but the left can only attend to the right. As such, a lesion to the left will not produce hemineglect of the right, but a lesion of the right will produce hemineglect of the left.

Question 17

Prosopagnosia results from lesions to what brain region?

Answer 17

right occipitotemporal lobe

Question 18

What is alexia without agraphia?

Answer 18

A syndrome in which the patient is able to write but not read (also called pure alexia)

Question 19

What area, if lesioned, can produce inability to understand the prosody of speech?

Answer 19

Right Brodmann 22 (the analogue of Wernicke’s area)

Question 20

Bilateral occipitoparietal lesions can lead to a condition in which multiple inputs are not understood. What is this called?

Answer 20

Simultanagnosia

Question 21

What brain area is usually damaged in pure alexia?

Answer 21

The splenium of the corpus callosum and the left occipital lobe

Question 22

Motivation is mediated by the _________________.

Answer 22

medial frontal cortices

Question 23

Left occipitotemporal lobe lesions produce ______________, while right occipitotemporal lobe lesions produce _______________.

Answer 23

object agnosia; prosopagnosia

Question 24

Describe the presentation of conduction aphasia.

Answer 24

Normal comprehension, but poor ability to repeat phrases. Speech inflected with paraphasias.

Question 25

What effects can be seen with disconnection of the corpus callosum?

Answer 25

Left hand apraxia, anomia, and agraphia