Aphasias

Question 1

What is aphasia?

Answer 1

A disturbance in language (not speech) as a result of brain damage

Question 2

List 3 categories of causes of aphasias, giving specific examples

Answer 2

Acute onset (stroke, penetrating head injury, surgical resection)
Insidious onset/progressive (dementia, neoplastic change)
Paroxysmal/episodic (focal seizures, migraine)

Question 3

Describe the lateralisation of language

Answer 3

The left hemisphere is dominant for language in ~95% of right handers and 70% of left handers

Question 4

What is the role of the right hemisphere in language?

Answer 4

Non-propositional speech
Prosody
Paralinguistic aspects of speech

Question 5

Describe the lateralisation of visuospatial function

Answer 5

The right hemisphere is dominant for visuospatial function

Question 6

What cortical regions does the superior division of the middle cerebral artery supply?

Answer 6

Sensorimotor cortex

Ventrolateral prefrontal cortex

Question 7

What cortical regions does the inferior division of the middle cerebral artery supply?

Answer 7

Temporoparietal cortex

Visual tracts

Question 8

Describe the location and predominant impairments of a Broca’s aphasia

Answer 8

Anterior lesion affecting Broca’s area
Non-fluent aphasia
Loss of grammatical (sequential) structure
Fluent jargonistic language output (neologisms and paraphasic errors e.g. boap for boat)
Impaired comprehension
Right quadrantanopsia

Question 9

Describe the location and predominant impairments of a Wernicke’s aphasia

Answer 9

Posterior lesion affecting Wernicke’s area
Fluent aphasia
Impaired selection of content
Non-fluent, highly effortful language output
Telegrammatic speech
Right face and arm weakness

Question 10

Describe the two aspects of the language system

Answer 10

Production (producing appropriate output sequences, putting words together in a meaningful way making appropriate use of grammar and context)
Selection (choosing appropriate content, picking the right word for the object)

Question 11

Which language structures are supplied by the superior division of the middle cerebral artery?

Answer 11

Broca’s area (composed of pars triangularis and pars opercularis)

Question 12

Which language structures are contained within the temporoparietal association neocortex?

Answer 12

Wernicke’s area
Angular gyrus
Supramarginal gyrus

Question 13

What results from a severing of the arcuate fasciculus?

Answer 13

Conduction aphasia

Question 14

What are the defining features of a conduction aphasia?

Answer 14

Fluent aphasia, but more meaningful than Wernicke’s
Relatively intact auditory comprehension
Poor repetition of words

Question 15

What are the defining features of a transcortical motor aphasia?

Answer 15

Non-fluent aphasia
Muteness at most severe
Repetition preserved

Question 16

What are the 2 main mechanisms of language recovery?

Answer 16

Contralateral transfer (better recovery)
Ipsilateral reorganisation

Question 17

Under what circumstances does contralateral transfer of language function tend to occur?

Answer 17

Following early hemispherectomy, in neonatal infarction or with major developmental abnormalities

Question 18

Under what circumstances does ipsilateral reorganisation of language function tend to occur?

Answer 18

With a focal developmental abnormality or in adult-onset stroke