Lesions of Brodmann's Areas

Question 1

what would occur if there was a UNILATERAL lesion in the primary auditory cortex?

Answer 1

small loss in the ability to detect sound

Question 2

what would occur if there was a BILATERAL lesion in the primary auditory cortex?

Answer 2

unable to detect sound (central/cortical deafness)

*rare

Question 3

what would occur if there was a lesion in the secondary auditory cortex?

Answer 3

auditory agnosia

• loss of ability to recognize or distinguish sounds (frequencies, pitch, etc)

Question 4

what would occur if there was a lesion in the posterior area 22 in the DOMINANT hemisphere?

Answer 4

Wernicke’s aphasia (sensory, receptive, or fluent aphasia)

• can’t comprehend but can speak
• difficulty interpreting the linguistic components of verbal communication

Question 5

what would occur if there was a lesion in the posterior area 22 in the NON-DOMINANT hemisphere?

Answer 5

sensory dysprosody

• difficulty or inability to interpret normal speech intonation and stress patterns (tone, pitch, rhythm, etc) of verbal communication
• can’t interpret “musical” or “emotional” components of verbal communication

Question 6

what would occur if there was a lesion in the primary visual cortex?

Answer 6

may experience cortical blindness
- inability to detect visual input

*complete loss of area 17 in one hemisphere will result in contralateral homonymous hemianopia

Question 7

what would occur if there was a lesion in the secondary visual cortex?

Answer 7

• visual agnosia
  - loss of ability to recognize or distinguish
  shapes, forms, colors, or spatial
  orientation and movement

Question 8

what would occur if there was a lesion in the primary somatosensory cortex?

Answer 8

contralateral hemianesthesia
- loss of ability to detect and localize somatosensory input (touch, proprioception, temperature, nociception) on OPPOSITE side of the body

Question 9

what would occur if there was a lesion in the secondary/associative somatosensory cortex?

Answer 9

astereognosis
- tactile amnesia
- loss of ability to judge the form of an object by touch

agraphesthesia
- difficulty recognizing a familiar form (number/letter) traces on the area of skin

Question 10

what would occur if there was a lesion in the primary motor cortex?

Answer 10

patient may experience contralateral hemiplegia/paresis

Question 11

what would occur if there was a lesion in the premotor cortex (PMC)?

Answer 11

may experience apraxia
- unable to perform learned skilled voluntary movements when asked

**loss is caused by inability to generate and send plan/sequence to motor cortex for activation

Question 12

what would occur if there was a lesion in the supplementary motor area (SMA)?

Answer 12

patient may experience incontinence

apraxia is possible, but not likely

Question 13

what would occur if there was a lesion in the frontal eye field?

Answer 13

horizontal gaze palsy - eyes deviate to the same side of lesion

*eyes cannot look to the side opposite of the lesion (i.e., if lesion is on left side, pt unable to look right)

Question 14

what would occur if there was a lesion in Brodmann’s areas 44/45 in the DOMINANT hemisphere?

Answer 14

Broca’s aphasia
- motor, expressive, or non-fluent aphasia
- can comprehend language but cannot speak

loss of ability to produce the linguistic components of verbal communication

Question 15

what would occur if there was a lesion in Brodmann’s areas 44/45 in the NON-DOMINANT hemisphere?

Answer 15

motor dysprosody

loss in ability to produce the normal variations in intonation, tone, pitch, rhythm, etc. of verbal communication

may speak in flat, monotone manner