Lecture 7: Production And Comprehension Disorders

Question 1

Anatomy of stroke

Answer 1

• middle cerebral artery is the most common affected blood vessel in the brain, running along the Sylvian fissure.
• blockage in posterior cerebral artery and anterior cerebral artery also result in stroke and aphasia

Question 2

Types of stroke

Answer 2

• ischemic stroke
• haemorrhagic stroke
• transient ischemic attack

Question 3

Ischemic stroke

Answer 3

Blocked artery (85% of strokes)

Question 4

haemorrhagic stroke

Answer 4

Ruptured artery

Question 5

Transient ischemic attack

Answer 5

Not long-lasting interruption of blood supply

Question 6

Language recovery post-stroke. When is the plateau of language function after stroke?

Answer 6

6-9 months

Question 7

3 main approaches to studying aphasia and language

Answer 7

1. Cognitive neuropsychological approach
2. Syndromes approach
3. Lesion-deficit correlation approach

Question 8

Cognitive neuropsychological approach

Answer 8

Comprehensive case studies of individual patients focused on functional architecture of language rather than neuroanatomy

Question 9

Syndromic approach

Answer 9

Investigation of groups of individuals sharing a clinical syndrome of feature

Question 10

Lesion-deficit correlation approach

Answer 10

Imaging of damaged brain regions and association to language deficits

Question 11

What underlies the quick recovery immediately after stroke?

Answer 11

• reperfusion of key language regions post-stroke
• inflammation decreased

Question 12

What underlies the quick recovery in the first few weeks and 3-6 months after stroke?

Answer 12

• Degeneracy
• Variable neuro-displacement

Question 13

Anatomical division of LIFG (Left Inferior Frontal Gyrus)

Answer 13

• Pars triangularis
• Pars opercularis
• Pars orbitalis

Question 14

Pars triangularis

Answer 14

Verbal working memory, semantic and thematic coherence

Question 15

Pars opercularis

Answer 15

Coordination of the speech organs, phonological processing

Question 16

Pars orbitalis

Answer 16

Semantic processing, phonological processing and syntax

Question 17

Dysarhria

Answer 17

• loss of control over articulatory muscles
• classified as motor speech disorder
• difficulties to produce clear speech and to regulate loudness, pitch and rhythm

Question 18

Apraxia of speech

Answer 18

• deficits in the ability of program articulation
• classified as speech sound disorder

Question 19

Dronkers, 1996: lesion-deficit correlation approach to Broca’s aphasia conclusions

Answer 19

• double dissociation across patient groups
• damage to left anterior insula
• anterior insula likely involved in articulatory planning and essential for coordinating speech articulation

Question 20

Wernicke’s aphasia

Answer 20

• receptive aphasia
• paragrammatic

Question 21

Conduction aphasia

Answer 21

Malfunction in repetition

Question 22

Geschwind’s model of language processing: visual input

Answer 22

Visual input -> visual areas -> angular gyrus -> Wernicke’s area where meaningful sequence is generated -> transmission to Broca’s area via arcuate fasciculus -> translation to motor commands conveyed to speech muscles for articulation

Question 23

Geschwind’s model of language processing: auditory input

Answer 23

Auditory input -> parietal-temporal-occipital association cortex (angular gyrus) -> Wernicke’s area for phonological representation-> transmission to Broca’s area via arcuate fasciculus -> word representations activate related concept and auditory comprehension is realized -> translation to motor commands conveyed to speech muscles for articulation

Question 24

Atomic aphasia

Answer 24

• written and spoken production
• difficulties with retrieving known words
• early sign of primary progressive aphasia

Question 25

Lesion of anomic aphasia

Answer 25

LH in left angular gyrus

Question 26

Two levels of word retrieval difficulties of anomic aphasia

Answer 26

- semantic level: patients show category-specific problems - speech-output level: errors are dependent on usage of frequency of words

Question 27

Global aphasia

Answer 27

- production and comprehension - impairment of receptive and expressive - most severe subtype

Question 28

Lesion of global aphasia

Answer 28

Stroke in middle cerebral artery

Question 29

Pure word deafness

Answer 29

- auditory comprehension - behavioral disorder with severe spoken language comprehension deficit (also named *auditory agnosia*)

Question 30

Lesion of pure word deafness

Answer 30

Bilateral lesions in the superior temporal gyrus

Question 31

*disconnection theory* about pure word deafness

Answer 31

- Lesion disconnects LH Wernicke’s area from auditory cortex - Sounds can be heard but not analyzed

Question 32

Pure alexia

Answer 32

- visual comprehension - inability to read or comprehend written language - patients can write but cannot read what they have written

Question 33

Lesion of pure alexia

Answer 33

- often occurs with stroke in posterior cerebral artery - connected to lesions to **left occipital cortex** and to posterior sector of the *corpus callosum* called **splenium**

Question 34

Agraphia

Answer 34

- complete loss of previous ability to write - malfunction in **angular gyrus**

Question 35

Atrophy of PPA

Answer 35

Commonly found in *anterior temporal lobes, dorsal and ventral white matter tracts between frontal and temporal areas*

Question 36

Three variants of PPA

Answer 36

1. Non-fluent/agrammatic PPA 2. Semantic PPA 3. Logopedic PPA

Question 37

Atrophy of non-fluent PPA

Answer 37

Inferior frontal gyrus and prefrontal/premotor regions

Question 38

Semantic PPA

Answer 38

Disorder of semantic memory

Question 39

Atrophy of semantic PPA

Answer 39

Anterior parts of the temporal lobes

Question 40

Logopenic PPA

Answer 40

Impaired single-word retrieval in spontaneous speech and naming

Question 41

Atrophy of logopenic PPA

Answer 41

Left temporal-parietal regions