1. Questions from Week 9 lecture
Exam content
Apraxia/Dyspraxia (disturbance/difficulty)
Apraxia Model
Differentiating Apraxia/Aphasia
Prosopagnosia vs. Variant of Prosopagnosia in Semantic dementia

2. LH lesions destroy motor programs stored in inferior parietal lobe:
In most patients ideomotor apraxia is associated with left hemisphere (LH) lesions
LH lesions destroy motor programs stored in inferior parietal lobe:
Supramarginal or Angular Gyrus
Or disconnect the flow of information from motor programs to premotor or motor areas necessary to initiate complex movement
When asked to carry out a command with the right hand this pathway is used
To carry out a command with the left hand, information must be carried to the right premotor cortex through Corpus Callosum and then conveyed to motor areas
Unilateral (left) apraxia follow lesions located anterior Corpus Callosum

3. Prosopagnosia vs Semantic dementia variant of Prosopagnosia
Lesion:
Bilateral occipital vs anterior right temporal
Deficit:
Faces not categorised as familiar (face recognition units function as a memory store); able to identify facial features; retains knowledge if given person’s name vs progressive difficulty with face recognition/and or naming (semantic knowledge about person is lost)

4. Aphasia

5. Aphasia is defined as a loss or impairment of language function caused by brain damage (language content, comprehension, reading and writing)
Aphasia/Dysphasia (disturbance/difficulty of language) used interchangeably
Language is the complex symbolic signal system used by individuals to communicate with each other
Language not only involves the content of speech but communication also occurs by reading and writing
Language is intertwined into what it is to be human

6. Language and Speech production: Speech
Speech is the co-ordinated muscle activity required for oral communication
Speech is the neural process involved in language
Language is the content of speech
Dysarthria
Dysarthria is the impairment of the processes involved in speech production (tongue, throat, lips)
May include subsystems of respiration, phonation, resonance, prosody (pauses, slow rate) and articulation
Dysarthria and aphasia can coexist but one is often seen without the other

7. Speech apraxia
Disruption of motor program which determines the sequence of muscle contractions required to produce individual sounds and words (multisyllabic words e.g. caterpillar)
Difficulty in speaking reflects a lesion that prevents execution (voluntary and on command) of the complex sequence of muscle contractions involved in speaking
Manifests primarily as errors in articulation of speech and secondarily what are thought to represent compensatory alterations of prosody
Prosody refers to the melody, pauses, intonation stresses/accents that enhance and liven speech
Some consider speech apraxia to be a variant of Broca’s aphasia rather than a disorder of speech

8. Aphasia is a disorder of Language
Dysarthria and Speech Apraxia are disorders of (the motor control) of Speech

9. Phonemic Paraphasias – speaking a word with an error in letter sound
Aphasia results from a breakdown in the linguistic components/content of language:
Phonemic Paraphasias – speaking a word with an error in letter sound
Phonology – term applied to sound pattern of language
Phoneme is the smallest segment of spoken language (phoneme = ‘k’ in kiss, ‘p’ in pencil). Sounds/phonemes are ordered to produce words
Patients may be impaired in their ability to organise letter sounds in sequence which results in phonemic paraphasias (word is distorted with unintentional sound)
An error occurs in a letter sound ‘f’ - ork
Real word approximations e.g. pipe = “hike, no, pike, no pipe”; snail for stale
Neologisms e.g. fencil for pencil, poot for suit
Phonemic decoding critical for language comprehension
Necessary to distinguish pear from bear, fit from bit

10. One word, usually related semantically, replaces another
2. Semantic Paraphasias – speaking an incorrect word semantically related to the target word
Semantics – meanings of words e.g. mother, aunt; canary is a small yellow bird
Breakdown in understanding referential meaning of words – linking sound to meaning
One word, usually related semantically, replaces another
Results in semantic paraphasias
orange for apple, sister for brother, him for her
animal for giraffe
Unintended and distinct from word-finding/naming difficulty (e.g. “it’s that green thing you eat with fingers” [asparagus])

11. 3. Agrammatism/Paragrammatism
Syntax – words strung together to form phrases or sentences in a complex way that obeys grammatical rules
A loss of syntactic production results in agrammatism:
Broca’s Aphasia
Speech is simplified, reduction in prepositions (e.g.“on” ) articles (“the”, “a/an”), inflections - ing, verbs, tense, person, plurals
The production of sentences with incorrect use of syntactic elements results in paragrammatism
Wernicke’s Aphasia
Running or increased speech production, with a tendency to acceleration. Content lacks information-conveying nouns and verbs. Phrases do not make sense together because abnormal syntactic inflections produced or due to paraphasias including neologisms
Paragrammatism sometimes called “word salad”

12. Dementias – rarely cause classical aphasic syndromes
Causes of Aphasia: Neuroanatomical location of lesion rather than the aetiology that essentially determines the nature of the language deficit
Focal lesions
CVA (stroke) usually middle cerebral artery territory infarct or haemorrhages
Abrupt onset
Aphasia most pronounced at time of onset – or shortly thereafter
Recognisable syndromes usually emerge after acute phase
Intracranial tumours and other space occupying lesions (SOL) (cerebral abscess) with symptoms worsening as SOL increases
Traumatic brain injury
Dementias – rarely cause classical aphasic syndromes
Alzheimer’s Disease
Frontotemporal lobar degeneration: semantic dementia, progressive non-fluent aphasia

13. Mutism:
Mutism is a complete failure of language or speech output. May be due to
Severe aphasia
Acute global aphasia: severely impaired comprehension, reading and writing
Acute Broca’s aphasia: comprehension relatively normal, writing may be unaffected
An articulation (speech) disorder
Aphemia (pure word mutism): comprehension, repetition and reading/writing normal
Psychiatric condition

14. Disorders of articulation:
Causes of mutism:
CVA (Stroke)
Disorders of articulation:
CVA (Stroke, Motor neurone disease, poliomyelitis, Lyme disease, Tumour)
Degeneration of the basal ganglia (Huntington’s Disease, Parkinson’s Disease)
Psychiatric disorders
Catatonia in Schizophrenia, Severe depression and PTSD
Hysterical aphonia (Psychogenic voice disorder)
Elective mutism

15. Left hemisphere and language: the left hemisphere is strongly dominant for language in most humans Language is generally located in the left hemisphere
Hemisphere
Language
Dominance
Handedness
Left
Right
Bilateral
50-70%
15-19%
15-20%
96% 4%

16. Classical Aphasic syndromes:
Aphasic syndromes proposed by Lichtheim (1885) drawn from work of Broca and Wernicke
Two cortical areas within the dominant (left) hemisphere were identified as having specialised language function
Anterior or motor language (Broca’s) area
Posterior or sensory language (Wernicke’s) area

17. Anterior or motor language (Broca’s) area
Broca (1861) described a patient “Leborgne” whose language output was non-fluent and limited to the word “tan”. He could understand spoken language, non-verbal communication and could communicate through gestures and facial expression
Lesion: center of the lesion was the inferior frontal convolution of left hemisphere
Broca related the lesion to the patient’s expressive language dysfunction

18. Leborgne’s (Tan’s) brain on autopsy

19. 2. Posterior or sensory language (Wernicke’s) area
Wernicke (1874) described a patient with fluent language output that contained words with sound errors (phonemic paraphasias) and semantic errors, who did not understand spoken language
Lesion: posterior part of the superior temporal gyrus
Proposed that receptive language processing was localised adjacent to primary “sensory” cortex and expressive language processes was adjacent to primary “motor” cortex.

20. Classification of Aphasia Syndromes
Terminology, classification schemes vary
Initially dichotomous classification scheme
Expressive, non-fluent, motor, anterior or Broca’s aphasia
Receptive, fluent, sensory, posterior or Wernicke’s aphasia
Lichtheim (1885) developed seven syndromes linked to the lesion sites of Broca and Wernicke:
Broca’s aphasia
Wernicke’s aphasia
Pure motor speech disorder – articulation disorders
Pure word deafness – auditory word recognition disorder
Transcortical motor aphasia
Transcortical sensory aphasia
Conduction aphasia

21. Classification system of lesion based aphasia syndromes
Three additional syndromes described by Benson (1979):
Anomic aphasia
Global aphasia
Isolation of the language zone (Isolated aphasia)
Neuroanatomical model developed further by Geschwind (1965) to include the anatomical link between Wernicke’s and Broca’s area – white matter tract “arcuate fasciculus”

22. Comprehension
Of spoken language: When you hear a word spoken, auditory information is transmitted to the primary auditory cortex and subsequently relayed to Wernicke’s area/inferior parietal lobe in the dominant hemisphere for translation
Of written words: Visual impulses transmit to the primary visual cortex in the occipital lobe are relayed to the angular gyrus from which it is sent to Wernicke’s area

23. Expression
Following translation the information is passed to Broca’s area via the arcuate fasciculus (subcortical white matter tract)
Broca’s area passes information to the primary motor cortex of each hemisphere. Instructions are sent via the motor pathways to the muscles of the speech organs to produce a verbal response

25. Boston Aphasia Classification System
Major Classification System (Benson, 1979)
Recognises eight subtypes of aphasia
Assess: Boston Diagnostic Aphasia Examination
Broca’s Aphasia. Lesion of the expressive speech area
Wernicke’s Aphasia. Lesion of the receptive speech area
Conduction Aphasia. Disconnection of the expressive and receptive areas
Global Aphasia. Extensive lesion involving both expressive and receptive areas

26. Boston Aphasia Classification System
5. Transcortical Motor Aphasia
6. Transcortical Sensory Aphasia
7. Isolated Aphasia
8. Anomic Aphasia

27. Boston Aphasia Classification System
Syndromes 1 to 4
Associated with lesion of the central speech areas or their connections
Aetiology: Most likely to result from CVA involving one or more of the branches of the middle cerebral artery

28. Boston Aphasia Classification System
Syndromes 5 to 8
Associated with lesions surrounding the central speech areas
‘Watershed’ or ‘Border-zone’ area
Aetiology: Infarction between anterior and middle cerebral arteries, and between the middle and posterior cerebral arteries
Repetition: Disordered in groups 1 to 4, intact in groups 5 to 8

29. Blood supply: Blue = Anterior Cerebral Artery Pink = Middle Cerebral Artery Yellow = Posterior Cerebral Artery

30. Boston Aphasia Classification System
Each syndrome associated with particular cluster of language symptoms (not all of which need to be present for categorisation)
Clusters of certain symptoms have shown discriminant validity between cases of Broca’s, Wernicke’s, conduction and anomic aphasia (Strauss, Sherman & Spreen, 2006)
Scale profiles aid in classification but a large range of aphasics patients are not classifiable because they have mixed symptomatology

31. Some cautions with the lesion based classification systems of aphasia:
1. Level of description of language deficit:
Classical syndrome language abnormalities reflect the patients ability to perform entire language tasks (fluent/non-fluent speech, comprehension, repetition, naming) – do not examine the linguistic details of language impairment (phonology, semantics, syntax, prosody). Both Broca’s and Wernicke’s may have problems with expression.
2. Do not cover all patients symptoms:
There may be heterogeneity of deficits across patients with the same syndrome (e.g., Broca’s – comprehension of speech may be normal in some, moderately disturbed in others; Benson & Geschwind, 1971)
May result in a large number of patients showing mixed rather than pure symptomatology

32. 3. Syndromes may not localise to expected lesion site:
general correlation between lesion site and syndrome
classical syndromes are related to lesion sites in cases of rapidly developing lesions e.g., stroke (but not applied to acute and subacute phases of illness)
in chronic phase at least 15% of patients have lesions not predictable from their syndromes
Broca’s aphasia requires larger lesion to sylvian fissure encompassing much of the left fronto-parietal opercula, insula and white matter in territory upper middle cerebral artery

33. Site of damage causing Broca's aphasia
Site of damage causing Broca's aphasia. The areas infarcted in 14 patients, all diagnosed as suffering from Broca's aphasia. All 14 lesions were then superimposed, indicating a focus of damage in the posterior part of the left inferior frontal gyrus.
From Kertesz A, Lesk D, McCabe P: Arch Neural 34:590.

34. Site of damage causing Wernicke's aphasia
Site of damage causing Wernicke's aphasia. The areas infarcted in 13 patients, all diagnosed as suffering from Wernicke's aphasia. All 13 lesions were then super­imposed, indicating a focus of damage in the posterior part of the left superior temporal gyrus.
From Kertesz A, Lesk D, McCabe P: Arch Neurol 34:590.

35. Classifying aphasia syndromes Four aspects of language
1. Fluency
Divides syndromes into those associated with anterior (non-fluent) vs posterior (fluent) lesions
Non-fluent: slow, laborious, lack of melody/rhythm, poor articulation, shortened phrases, preferred use of verbs and nouns
Lesion: anterior to sylvian fissure
Fluent: normal rate, preserved rhythm/melody good articulation, normal phrase length
Lesion: posterior to sylvian fissure in Wernicke’s area or basal temporal lobe

36. 2. Repetition Defective repetition:
Lesion: perisylvian area in the territory of the middle cerebral artery, incorporating Broca’s area, insula and Wernicke’s area, and arcuate fasciculus in between them
Preserved repetition (cf spontaneous speech):
Lesion: sparing of primary language areas (Broca’s and Wernicke’s); lesion is outside of sylvian areas
Syndromes associated with sparing of repetition are termed transcortical (transcortical motor or transcortical sensory)

37. Comprehension Deficits on gross examination associated with:
Lesion: Damaged temporal lobe
Note** If syntactic comprehension tests are used most dysphasic patients (regardless of site of lesion) will have some comprehension deficit
e.g. “Pick up the blue circle OR the red square” (2 step command from the Token Test)
“Put the pen on top of the book then give it to me” (3 step command from Western Aphasia Battery)

38. Naming
Ability to name objects, or line drawings is impaired in most aphasic patients to some degree 3
30. harmonica…… (musical instrument)
Copied from Boston Naming Test for educational purposes

39. Broca’s Aphasia
Non-fluent speech
Impaired repetition
Comprehension relatively intact
Naming poor – improves with phonemic cues, and multiple choice
Speech:
- Slow and effortful; phonemic paraphasias
Agrammatic and telegrammatic (containing a predominance of content words)
Writing:
- Misspellings, letter omissions, perseverations, agrammatic sentences
- Copying better than to dictation

40. Reading:
- Reading aloud poor
- Comprehension relatively spared
Frequent Associations
- Speech apraxia
- Dysarthria
- Right Hemiplegia (paralysis) or hemiparesis (weakness) – most notable in the arm and face
Ideomotor apraxia
Neuropathology
Extensive damage to fronto-parietal region to area supplied by anterior branch of middle cerebral artery
Evolves over time from global aphasia

41. Spontaneous Language: ‘Cookie jar theft’: Boston Diagnostic Aphasia Examination
Copied for educational purposes

42. youtube.com broca’s aphasia

43. 2. Wernicke’s Aphasia
Fluent speech
Repetition poor
Comprehension impaired
Naming impaired – not aided by phonemic cues or multiple choice
Speech:
- Content: Word substitutions (phonemic and semantic paraphasias) and combinations, sometimes neologistic jargon
Incapable of monitoring own output
Sentences meaningless and cannot be understood by others
Writing:
- Legible – letters formed (rarely have a concomitant hemiplegia)
- Content: Aphasic, disjointed, repetitive text, few nouns and verbs

44. Reading:
Reading aloud and reading comprehension both disturbed (occasional patients may have superior reading ability)
Associated deficits:
- Often none
- Visual field defect - Quadrantanopia may be evident
Neuropathology
Destruction of Wernicke’s area
Damage to superior posterior temporal lobe

46. youtube Wernicke’s aphasia

47. 3. Conduction Aphasia
Fluent speech paraphasic (mainly phonemic)
Repetition highly abnormal – strings of phonemic approximations
Comprehension relatively intact
Naming often disturbed
Speech:
Hesitation due to word finding difficulties (dysprodic speech)
- Writing:
- Spelling poor with omission, reversal and substitution of letters
- Words often interchanged and misplaced

48. Reading:
Reading aloud similar to repetition highly abnormal
Silent reading may be good
Frequent Associations:
- Often none
- Hemianesthesia (loss of sensation down one side of the body)
- Visual field defects (hemianopia or quadrantanopia)
Neuropathology:
- Severing of the arcuate fasciculus in classical syndrome
- More commonly results supramarginal gyrus lesion
- Conduction aphasia often occurs in recovery from Wernicke’s aphasia

49. 4. Transcortical Aphasias
Early aphasiologists postulated a transcortical pathway linking auditory language and verbal motor centre bypassing meaning – now used descriptively
4a) Transcortical Motor Aphasia
Shares many qualities with Broca’s aphasia
Non-fluent speech: reduction in the quality and complexity of spontaneous speech (non-fluent) and dysarthric
Few paraphasic errors
Repetition: preserved
Comprehension: very good
Writing: similar to spoken output
Lesions: dominant frontal lobe anterior and superior to Broca’s area generally due to anterior cerebral artery infarction

50. 4b) Transcortical Sensory Aphasia
similar to Wernicke’s aphasia
Fluent speech: contaminated by semantic paraphasias
Comprehension: defective at level of linking sound to meaning
Repetition: words and long sentences intact but cannot extract meaning from language
Reading and writing: similar to Wernicke’s aphasia (disturbed)
Lesion: border zone of parieto-temporal junction

51. 5. Anomic Aphasia
- Anomia (the inability to name to confrontation) common to most aphasic patients
- When most prominent feature of the aphasia the condition is referred to as anomic aphasia
- Common syndrome
- Often the end point of recovery from other aphasic conditions
Speech
- Fluent but empty due to lack of substantive words
May be circumlocutory (providing a description of the word) or abrupt cut-offs (trying to find word) in mid sentence
Writing: Near Normal
Neuropathology:- Non-localising; Acute onset suggests lesion temporo-parietal area

52. 6. Global (total) Aphasia
All major language functions seriously disturbed
Neuropathology:
Typically extensive left hemisphere damage
Syndrome has been reported even in cases where Wernicke’s area is spared
May result from subcortical syndromes which functionally isolate Broca’s area

53. 7. Isolation (mixed-transcortical) Aphasia
- Rare
- Intact repetition in association with marked reduction of spontaneous speech and poor comprehension
- Voluntary aspects of language lost (spontaneous speech, initiation of speech)
- Resembles global aphasia except for preservation of repetition
Neuropathology:
Anterior and posterior parts of watershed area

54. Tests of Language: Spontaneous language: Confrontation naming:
Open questions (Western Aphasia Battery)
How are you?
Have you been here before?
Tell me a little about whyy ou are here?
Complex picture description:
‘cookie jar theft’ picture from Boston Diagnostic Aphasia Examination
Confrontation naming:
line-drawings (Boston Naming Test)

55. Word-picture matching tests:
Comprehension:
Increasingly syntactically complex commands
one step, two step, three step commands
Token Test, Western Aphasia Battery)
Word-picture matching tests:
single-word (semantic) comprehension (Peabody Picture Vocabulary Test)
Aphasia batteries:
Boston Diagnostic Aphasia Examination
Western Aphasia Battery
Psycholinguistic Assessment of Language Processing in Aphasia (PALPA)