Ling 411 05 Types of Aphasia Classifications are

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 • 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 • middle temporal gyrus • Temporal plane § Often also involved: gyrus • Angular gyrus • Supramarginal gyrus • Temporal-occipital junction area

Definitions of Wernicke’s area Narrow definition 1. § 2. 3. • • • Posterior superior temporal gyrus Best definition Posterior superior temporal gyrus and adjacent temporal plane and superior temporal sulcus Broad definition (used by some) Includes also angular gyrus and/or supramarginal gyrus A. k. a ‘posterior language area’

Review Principal cortical gyri (schematic)

Subtypes of Wernicke aphasia § Not discretely different • Rather, spans along a scale • • • Damage is more anterior Phonological recognition most affected “Word deafness” • • Damage is more posterior, incl. angular gyrus More word-blindness than word-deafness § I. e. , alexia § Type II § 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 II § Extrasylvian sensory aphasia • • § Sometimes just called ‘anomic aphasia’ 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 Rostral Caudal Ventral

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 Supplementary motor area Sup erio r pa riet al l obu l e

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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