Speech centre

• Location
• Inferior frontal gyrus of dominant hemisphere
• Brodmann area 44
• Brodmann area 45

• Blood supply
• MCA

• Function
• Word formation (motor)
• Area 44
• Posterior part of the inferior frontal gyrus
• Seems to be involved in phonological processing and in language production as such;
• This role would be facilitated by its position close to the motor centres for the mouth and the tongue.
• Area 45
• (The anterior part of the inferior frontal gyrus)
• Seems more involved in the semantic aspects of language.
• Though not directly involved in accessing meaning
• Broca’s area therefore plays a role in verbal memory
• Selecting and manipulating semantic elements

• Deficit
• Expressive or motor aphasia
• Speech may be laboured and consist primarily of nouns, verbs or important adjectives. Speech takes on a telegraphic character.
• Difficulty with repetition
• Impairment in writing

• Location
• The posterior segment of the superior temporal gyrus in the dominant hemisphere.
• Broadmann's area 22

• Blood supply
• MCA

• Function
• Language comprehension: representation of phonetic sequences, regardless of whether the individual hears them, generates them himself or herself, or recalls them from memory.

• Deficit
• Fluent, grammatically correct speech with little meaning
• Poor comprehension
• Paraphasic errors:
• Calling a spoon a “fork” (semantic)
• Calling a spoon a “spood” (literal)
• Neologisms (or nonsense words)
• Global Aphasia
• Both Wernicke’s and Broca’s areas damaged
• All aspects of speech and language are affected.
• Patients can say a few words at most and understand only a few words and phrases.
• Cannot carry out commands
• Cannot name objects
• Cannot read or write
• Cannot repeat words

• Angular gyrus (area 39)
• Location
• Caudally located
• Which itself is bounded by the visual occipital areas (areas 17, 18, and 19),
• Function
• (Together with the posterior cingulate gyrus) seems more involved in semantic processing (process of finding meaning to words)
• Deficit
• Logopenic Primary Progressive Aphasia (lvPPA)
• Slowed speech with normal articulation,
• Impaired comprehension of sentence syntax
• Impaired naming of things
• Dyslexia (inability to read) without a deficit in understanding spoken language

• Supramarginal gyrus (area 40)
• Location
• Dorsally located
• Which arches over the end of the lateral sulcus, adjacent to the inferior portion of the somatosensory cortex
• Function
• Seems to be involved in phonological and articulatory processing of words

• Quality
• Dysarthria
• Neurologic damage to the motor components of speech, which may involve any or all of the speech processes, including respiration, phonation, articulation, resonance, and prosody
• Dysphonia
• Disordered sound production at the level of the larynx (hoarseness)

• Content
• Expressive function
• Broca's area

• Understanding:
• Receptive function
• Wernicke's area

---
config:
  layout: dagre
---
graph TD
    A[Types of Aphasia] --> B{Fluent?}
    B -->|No| C{Comprehends?}
    C -->|No| D{Repeats?}
    D -->|No| E["Global aphasia (Large territory infarct)"]
    D -->|Yes| F["Mixed transcortical aphasia (Watershed Infarct affecting speech areas)"]
    C -->|Yes| G{Repeats?}
    G -->|No| H["Broca's aphasia (Inferior frontal lobe. Telegraphic speech)"]
    G -->|Yes| I["Transcortical motor aphasia (Frontal white matter lesion)"]
    B -->|Yes| J{Comprehends?}
    J -->|No| K{Repeats?}
    K -->|No| L["Wernicke's aphasia (Posterior lesion. Paraphasias and neologisms)"]
    K -->|Yes| M["Transcortical sensory aphasia (White matter underlying Wernicke’s area)"]
    J -->|Yes| N{Repeats?}
    N -->|No| O["Conduction aphasia (Arcuate fasciculus damage)"]
    N -->|Yes| P["Anomic aphasia (Isolated word finding deficit; least localized)"]

    linkStyle 0 stroke:White,stroke-width:4px
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    linkStyle 14 stroke:green,stroke-width:4px

• Fluent (receptive): problems understanding
• Wernicke's ('fluent aphasia'/posterior aphasia)
• Impairment of the ability to understand the meaning of spoken words
• Abnormal but fluent speech
• Sentences do not hang together and irrelevant words intrude-sometimes to the point of jargon, in severe cases.
• Reading and writing are often severely impaired.
• Conduction
• Transcortical sensory
• Nominal

• Nonfluent (expressive): Trouble using words and sentences
• Broca's (non fluent form)
• Speech output is severely reduced and is limited mainly to short utterances of less than four words.
• Vocabulary access is limited and the formation of sounds by persons with Broca's aphasia is often laborious and clumsy.
• Understand speech relatively well and be able to read,
• Limited in writing.
• Global aphasia:
• Struggle with both using words and understanding
• Cannot read nor write.
• Most severe form of aphasia,
• Patients who can produce few recognizable words and understand little or no spoken language.
• Transcortical motor

• Define: Term used to describe an acquired loss of language that causes problems with any or all of the following:
• Speaking
• Listening
• Reading
• Writing
• Reading and writing are more impaired than talking or understanding.

• Anomic aphasia
• This term is applied to persons who are left with a persistent inability to supply the words for the very things they want to talk about-particularly the significant nouns and verbs.
• As a result their speech, while fluent in grammatical form and output is full of vague circumlocutions and expressions of frustration.
• Understand speech well
• Read well
• Difficulty writing

• Primary Progressive Aphasia (PPA)
• Pathology
• Normal role for the site of initial degeneration → Eventually problems spread throughout the broader language network
• Language capabilities become slowly and progressively impaired.
• Subtypes include
• Nonfluent primary progressive aphasia (nfvPPA),
• Semantic variant primary progressive aphasia (svPPA)
• Logopenic primary progressive aphasia (lvPPA).
• Unlike other forms of aphasia that result from stroke or brain injury, PPA is caused by neurodegenerative diseases, such as
• Alzheimer's Disease
• Frontotemporal Lobar Degeneration.
• PPA results from deterioration of brain tissue important for speech and language.
• Although the first symptoms are problems with speech and language, other problems associated with the underlying disease, such as memory loss, often occur later.

• Mixed non-fluent aphasia
• Sparse and effortful speech, resembling severe Broca's aphasia.
• However, unlike persons with Broca's aphasia, they remain limited in their comprehension of speech and do not read or write beyond an elementary level.

1. Inspection
1. Look for any scars, tracheostomy, PEG
2. Ask if the patient is right or left handed

2. Aphasia:
• What is your name and address? [tests understanding and fluency]

---
title: Transcortical motor aphasia (Normal comprehension, Non-fluent speech, Normal repetition)
---
graph LR
    A[Hearing]--> B["Wernicke's Area<br>('Recognising sounds'<br>Dominant hemisphere<br>supramarginal gyrus &<br>angular gyrus)"]
    B--> C["Concept Area<br>(Understanding words)"]
    B-- "<span style="color: white;">Arcuate fasciculus</span>" --> D["Broca's Area<br>(Br 44: Dominant<br>hemisphere between<br>pars operculairs and<br>pars triangularis)"]
    C--> D
    D--> E["Voice Production<br>and Articulation"]

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• Give command: with your right hand, touch your nose [tests understanding]

---
title: Transcortical sensory aphasia (Poor comprehension, fluent but meaningless speech, Normal repetition)
---
graph LR
    A[Hearing]--> B["Wernicke's Area<br>('Recognising sounds' Dominant hemisphere<br>supramarginal gyrus &<br>angular gyrus)"]
    B--> C["Concept Area<br>(Understanding words)"]
    B-- "<span style="color: white;">Arcuate fasciculus</span>" --> D["Broca's Area (Br 44:<br>Dominant hemisphere<br>between pars operculairs<br>and pars triangularis)"]
    C--> D
    D--> E["Voice Production<br>and Articulation"]

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• Assess whether speech is spontaneous
• Assess word finding:
• Name all the animals you can think of in 1 minute
• Name these 3 objects
• Assess repetition:
• Repeat: "the sun is shining"
• If able to repeat then wernicke’s area, broca’s area and arcuate fasciculus is not injured

---
title: Conductive aphasia (Normal comprehension, no repetition)
---
graph LR
    A[Hearing]--> B["Wernicke's Area<br>('Recognising sounds'<br>Dominant hemisphere<br>supramarginal gyrus &<br>angular gyrus)"]
    B--> C["Concept Area<br>(Understanding words)"]
    B-- "<span style="color: red;">Arcuate fasciculus</span>" --> D["Broca's Area<br>(Br 44: Dominant<br>hemisphere between pars<br>operculairs and<br>pars triangularis)"]
    C--> D
    D--> E["Voice Production<br>and Articulation"]

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    class Z crossStyle;
	  linkStyle 2 stroke:#ff0000,stroke-width:4px,color:#ff0000

3. Types of Aphasia:
• Global aphasia = lesion in both Broca's and Wernicke's areas
• Nominal aphasia = lesion in the angular gyrus
• Expressive dysphasia = lesion in the inferior frontal gyrus

---
title: Broca's aphasia (Normal comprehension, Non-fluent speech, no repetition)
---
graph LR
    A[Hearing]--> B["Wernicke's Area<br>('Recognising sounds'<br>Dominant hemisphere<br>supramarginal gyrus &<br>angular gyrus)"]
    B--> C["Concept Area<br>(Understanding words)"]
    B-- "Arcuate fasciculus" --> D["Broca's Area (Br 44:<br>Dominant hemisphere<br>between pars operculairs<br>and pars triangular)"]
    C--> D
    D--> E["Voice Production and<br>Articulation"]

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    class D crossStyle;
  

• Receptive dysphasia = lesion in the supramarginal gyrus of the temporal lobe

---
title: Wernicke's aphasia (Poor comprehension, fluent but meaningless speech, no repetition)
---
graph LR
    A[Hearing]--> B["Wernicke's Area ('Recognising<br>sounds' Dominant hemisphere<br>supramarginal gyrus &<br>angular gyrus)"]
    B--> C["Concept Area<br>(Understanding words)"]
    B-- Arcuate fasciculus --> D["Broca's Area (Br 44:<br>Dominant hemisphere<br>between pars operculairs<br>and pars triangular)"]
    C--> D
    D--> E["Voice Production<br>and Articulation"]

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    class B crossStyle;
  

4. Dysphonia:
• Ask the patient to cough
• Say 'eeeeeee'

5. Dysarthria (spastic/extrapyramidal/cerebellar/lower CN):
• Say "Yellow lorry"
• Say "Baby hippopotamus"

6. Examine other functions in the frontal and parietal lobe
• Check for field deficit
• Check for motor weakness
• Cranial nerve exam
• Examine reading and writing

• Anterior aspect of the left superior frontal gyrus:
• Suggested that the SMA has various superordinate control functions during speech communication and language reception, especially with increased task demands.
• SMA is subdivided into:
• Posterior region: Predominantly motor-related functions (SMA proper)
• Anterior part (pre-SMA): Involved in higher-order cognitive control mechanisms

• Intra-op symptoms:
• More difficult to start talking or appearing mute
• Single word responses rather than sentences
• Use of simple words rather than more complex or specific ones
• Talking less
• Less animated (lacking facial expression and gesture)
• Does not typically affect comprehension of language

• Post-op:
• "They don’t seem like they want to talk to me, they’re not talking much and don’t smile when they see me"
• Recovery is usually complete; improvement in 1st week but 2-9 weeks for complete recovery