Session Seven (Language and the Aphasias)

Question 1

Where is language located in the brain?

Answer 1

• Brain actually responds to language in a number of places, not one specific ‘centre’
• Different parts of the brain respond to different sorts of words e.g. social words, appearance words, fearful words
• However areas of the brain have been linked with language due to the effects of pathology at these locations e.g. Broca’s and Wernicke’;s

Question 2

What are the two different ways the brain clusters words?

Answer 2

• Semantic (to do with the meaning and context of words)

- Phonemic (to do with how a word sounds)

Question 3

What is Broca’s area?

Answer 3

Area of the brain associated with the motor element of speech, responsible for speech articulation

Question 4

What is Wernicke’s area?

Answer 4

Area of the brain associated with the comprehension of speech.

Question 5

What connects Broca’s to Wernicke’s area?

Answer 5

The Arcuate Faciculus

Question 6

What is Geschwind’s area?

Answer 6

• Area of the brain located in the inferior parietal lobe, somehow related to understanding the concept behind words e.g. left and right.
• Someone with pathology in this area will understand the question and be able to articulate their response but will get muddled up between things like left and right.
• Also possibly vital for development of speech in childhood

Question 7

What is the Anterior Temporal Lobe?

Answer 7

Area of the brain believed to be responsible for the memory component of speech

Question 8

What connects Broca’s area to the ATL?

Answer 8

Uncinate Faciculus

Question 9

What is meant by the term Peri-Sylvian anatomy?

Answer 9

Anatomy of the brain around the Sylvian fissure, contains areas of the brain implicated in speech. Includes Broca’s, Wernicke’s, Geschwind’s and ATL

Question 10

The Arcuate Faciculus connects the speech areas of the brain, but what are it’s subdivisions?

Answer 10

• Long segment, connects B’s to W’s

- Anterior and Posterior segments create an indirect route that goes via Geschwind’s area.

Question 11

What is the difference between a primary and a secondary aphasia?

Answer 11

Primary is inherent, likely caused by a developmental disorder e.g. autism

Secondary is an acquired condition e.g. from stroke

Question 12

What are some common causes of secondary aphasias?

Answer 12

• Stroke
• Brain injury
• Drugs
• Toxins
• Space Occupying lesions
• Infections
• Neurodegenerative diseases

Question 13

Define aphasia?

Answer 13

A disturbance to the reception and expression of language in which construction and formation of words is marked errors of form content and grammar

IMPORTANTLY: a language disorder not a speech disorder. Distinction between the two is aphasia affects both written and spoken language.

Question 14

What is Broca’s Aphasia?

Answer 14

Expressive aphasia, capable of thinking what to say but incapable of expressing it.

Question 15

What is Wernicke’s Aphasia?

Answer 15

Receptive aphasia, capable of expressing speech but incapable of comprehending and formulating an appropriate response.

Word salad.

Question 16

Broadly speaking how do we divide the aphasias?

Answer 16

• Fluent vs Non-Fluent.
• Basically divides them based on whether they can form sentences or not.
• Further subdivision can be done based on whether they are able to Comprehend speech, Name objects, Repeat sentences you’ve just said to them…..
• Based supposedly on which part of the brain has been affected

Question 17

When assessing someone with a suspected aphasia, what are the 4 things you need to deduce to classify which aphasia they have?

Answer 17

• Fluency
• Ability to comprehend a spoken sentence
• Ability to name objects
• Ability to repeat sentences spoken to them

Question 18

What are some associated features of the different aphasias?

Answer 18

• Right hemiparesis is very commonly seen in both Global and Broca’s aphasias?
• In Wernicke’s you often see Emotional disturbance, anxiety and agitation
• In Conduction aphasia you often see hemiparesis, hemisensory deficit

Question 19

What are the non-fluent aphasias?

Answer 19

• Global (LMA stroke, knocks out all 3 pathways involved in speech producing a total aphasia)
• Broca’s (comprehension intact but can’t articulate themselves)

Question 20

What are the two parts of a stroke visible on a CT?

Answer 20

Core and Penumbra

Question 21

What is AAA surgery for brain tumours?

Answer 21

Asleep-Awake-Asleep.

• Perform initial part of surgery under anaesthetic
• Wake patient up
• While they’re awake have them speak to you
• Touch their brain with a probe, testing which parts of the brain can be removed while preserving vital functions
• Put the patient back to sleep and only cut out non-essential parts.
• Especially useful if patient has a particular skill they’d like to preserve such as singing or playing an instrument.

Question 22

What modalities are used for studying aphasias?

Answer 22

• fMRI (can be done while performing a task to aid with pre-surgery planning)
• Resting State fMRI (mapping technology not as good as pure fMRI but a lot of potential)
• Diffusion Tractography Imaging (looks at connections in the brain,
• Transcortical Magnetic Stimulation (uses magnetic stimulation applied to specific areas to try and elicit speech or motor errors, more functionally relevant than fMRI but new and untested technology)
• EEG
• Lesion studies
• Myelin mapping

Question 23

What are the 3 types of pathways between areas of the brain?

Answer 23

• Association, within the same hemisphere
• Commissural, between the hemispheres
• Projection pathways, from the cortex down

Question 24

What are the differences between the Topological and Horological approaches to explaining impairments following brain injury?

Answer 24

Two different approaches to working out what damage where causes what:

• Topological approach says that the area of the brain all people with e.g. Broca’s aphasia have affected is the area responsible for that function.
• Horological approach is based more on disconnection, a patient’s symptoms are dependent on the white matter damage they experience more than anything else.
• Current taxonomy of aphasias is somewhere in the middle

Question 25

What part of the brain needs to get damaged to produce Wernicke’s?

Answer 25

W’s area (Superior Temporal Gyrus)

CLASSICAL MODEL, PERHAPS NOT TRUE

Question 26

What part of the brain needs to get damaged to produce Broca’s?

Answer 26

B’s area (Inferior Temporal Gyrus)

CLASSICAL MODEL, PERHAPS NOT TRUE

Question 27

What part of the brain needs to get damaged to produce Conduction aphasia?

Answer 27

• Damage to the frontal and parietal lobes
• Essentially needs to damage the arcuate fasciculus

CLASSICAL MODEL, PERHAPS NOT TRUE

Question 28

What part of the brain needs to get damaged to produce Global aphasia?

Answer 28

Left MCA territory, knocks out every speech component

CLASSICAL MODEL, PERHAPS NOT TRUE

Question 29

What part of the brain needs to get damaged to produce Transcortical motor aphasia?

Answer 29

Anterior to Broca’s or thalamus

CLASSICAL MODEL, PERHAPS NOT TRUE

Question 30

What part of the brain needs to get damaged to produce Transcortical sensory aphasia?

Answer 30

Dominant posterior, temporal-occipital area, watershed strokes

CLASSICAL MODEL, PERHAPS NOT TRUE

Question 31

The Wernicke-Broca’s… model of speech has been called overly simplistic, what is the evidence this is the case?

Answer 31

• If we compare what we think we know of the language system to systems we have a full mapping of (e.g. auditory or visual systems) its about a thousand times less complicated.
• Suggests we’re nowhere near close to understanding it.
• Furthermore, anatomically speaking Broca’s and Wernicke’s appear to have many different roles outside of language

Question 32

How true is the idea that speech is lateralised into one half of the brain?

Answer 32

Partially true, Catani et al showed that:

• 62.5% of people show strong lateralisation
• 20% of people were bilateral but still had most of their language activity on the left side
• 17.5% of people were totally bilateral

Question 33

What is the potential implication of differing levels of brain lateralisation?

Answer 33

It would appear to affect recovery from post-stroke aphasia:

• Forkel et al, 2014
• Looked at patients of a variety of ages who’d presented with aphasia following a stroke
• Found a correlation between how much of language activity occurred in the right part of the brain and how likely they were to recover speech function
• Better at predicting recovery than age, an 87 year old with a bilateral brain recovered when a 50 year old with a unilateral brain did not.

Question 34

What are some assessment methods used in Aphasias?

Answer 34

F-A-S, Western Aphasia Battery, Cinderella Story

Question 35

What sort of errors might you see in an aphasia assessment?

Answer 35

If the person has to say apple…
- Phonemic paraphasia (eliminations, substitutions and rearrangements of letters) e.g. affle, alppe
- Semantic paraphasia (substitutes that are related to target word) e.g. pear
- Semantic neologism (creates a new word because they can’t produce the target) e.g. bite-fruit
- Agrammatism (says the words but delivers the sentence in a super broken up way) e.g. yesterday me pick apple
- Paragrammatism (word salad)
- Set phrases (meaningless phrases repeated when the y can’t produce the phrase they want)
….