types of aphasia
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Ling 411 – 05. Types of Aphasia. “Classifications are a necessary evil” Antonio Damasio (1998). Wernicke’s Aphasia. Impaired comprehension Result of failures in phonological discrimination Fluent verbal output Augmented verbal output Extra syllables at ends of words - PowerPoint PPT PresentationTRANSCRIPT
Types of Aphasia
“Classifications are a necessary evil”
Antonio Damasio (1998)
Ling 411 – 05
Wernicke’s Aphasia
Impaired comprehension•Result of failures in phonological
discrimination
Fluent verbal output Augmented verbal output
•Extra syllables at ends of words
•Extra words at ends of phrases
•Extra phrases at ends of sentences
Augmentations usually nonsensical Syntax otherwise not too bad Verbal paraphasia, including neologisms
Areas of damage in Wernicke’s aphasia
Always involved:•Posterior superior temporal gyrus
The classical core of Wernicke’s area
Usually also involved:•More of superior temporal gyrus•middle temporal gyrus•Temporal plane
Often also involved:•Angular gyrus•Supramarginal gyrus•Temporal-occipital junction area
Definitions of Wernicke’s area
1. Narrow definition Posterior superior temporal gyrus
2. Best definition• Posterior superior temporal gyrus and
adjacent temporal plane and superior temporal sulcus
3. Broad definition (used by some)• Includes also angular gyrus and/or
supramarginal gyrus• A.k.a ‘posterior language area’
Principal cortical gyri (schematic)Review
Subtypes of Wernicke aphasia
Not discretely different• Rather, spans along a scale
Type I• Damage is more anterior
• Phonological recognition most affected
• “Word deafness”
Type II• Damage is more posterior, incl. angular gyrus
• More word-blindness than word-deafness I.e., alexia
Intermediate types also occur “Obviously, all subtypes of Wernicke aphasia
are variations on a continuum…” •
(Benson&Ardila:144)
Extra-Sylvian Aphasic Syndromes
“Extra-Sylvian” (a.k.a. “Transcortical”) Extrasylvian motor aphasia
•Type I
•Type II
Extrasylvian sensory aphasia Sometimes just called ‘anomic aphasia’
•Type I
•Type II
Two Different Classification Schemes
Damasio Wernicke’s aphasia Broca’s aphasia Conduction aphasia Transcortical sensory
aph. Transcortical motor
aph. Global aphasia Anomic aphasia Alexia
Benson & Ardila Wernicke aphasia Broca aphasia Conduction aphasia Extrasylvian sensory
aph. Extrasylvian motor
aph. Global aphasia Anomic aphasia Wernicke II or
Posterior extrasylvian
Extra-Sylvian Aphasic Syndromes
In all perisylvian syndromes, repetition is faulty
In all extra-sylvian aphasic syndromes, repetition is intact
(why?) “Aphasia without repetition
disturbance almost invariably indicates pathology outside the perisylvian region” (B&A 1996:146)
Extrasylvian motor aphasia
Nonfluent output•Delayed initiation
•Terse, poorly elaborated utterances
• Incomplete sentences
•Verbal paraphasia
Good comprehension Good repetition
Extrasylvian motor aphasia, Type I
Left dorsolateral prefrontal damage•Anterior and superior to Broca’s area
Non-fluent output, but repetition good Articulation is normal Difficulty following commands
•Understand command but do not respond Damage anterior and superior to
Broca’s area (Brodmann areas 45, 46, and/or part of area 9) (B&A 1996:152)
Orientation terms (left hemisphere)
Dorsal
Ventral
RostralCaudal
Extrasylvian motor aphasia, Type II
Damage to supplementary motor area•Occlusion of left anterior cerebral artery
Non-fluent output, but good repetition Difficulty initiating speech Perhaps a purely motor disorder that
does not involve basic language functions•(in which case it isn’t really a type of
aphasia)
Principal cortical gyri
Superior parietal lobule
Supplementary motor area
Extrasylvian sensory aphasia
Speech is fluent Good repetition Comprehension is impaired Naming is impaired Paraphasia is frequent, even verbose
• Semantic substitutions
• Neologisms
Echolalia (patients repeat words of examiner)
Pointing is impaired Two subtypes
Extrasylvian sensory aphasia, Type I
Damage to temporal-parietal-occipital junction area• I.e., lower angular gyrus and upper area 37
Fluent spontaneous output Poor comprehension Naming strongly impaired Semantic paraphasia
Extrasylvian sensory aphasia, Type II
Damage to upper angular gyrus Fluent output Variable ability to comprehend speech Naming strongly impaired Few semantic paraphasias Repetition excellent Many circumlocutions
Anomic aphasia
Perhaps part of a continuum with extrasylvian sensory aphasia
Comprehension is good in many cases•Unlike extrasylvian sensory aphasia
Production and repetition are good Cannot be reliably localized
•Many different areas of damage can result in naming difficulty But different semantic categories may be
impaired with different areas of damage•Maybe not a true syndrome: Benson&Ardila
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