Language disorders Flashcards
Aphasia definition
impairment of language produced by brain dysfunction
differentiated from: dysarthria (disorders of articuation), auditory disorders, psychiatric illnesses
Language anatomy
Hemispheric specialization
Dominant hemisphere: L in >95% of R-handed, 70% of L-handed people
Non-verbal aspects processed in non-dominant hemisphere (tone, prosody)
Broca’s area
Wernicke’s area
Broca’s area
production of language
interacts with many surrounding areas in frontal cortex
Wernicke’s area
comprehension of language
interacts with many surrounding areas in temporal and parietal cortex
including angular and supramarginal gyri
Arcuate fasciculus
connects Broca’s and Wernicke’s areas
Corpus callosum
Connects to non-dominant hemisphere
Examinable components of speech
Articulation Fluency Effort Word finding Paraph
Dysarthria
dysarthria is not a language disorder, per se can be due to: UMN/LMN lesions NMJ lesions cerebellar extrapyramidal etc
Phonemic paraphasias
literal
sound substitutions
e.g. cable instead of table
Semantic paraphasias
word substitution
e.g. hat instead of coat
Neologisms:
made-up words
Prosody
intonation of speech
convey emotion
disorder - dysprosody/aprosody, can be caused by lesions in non-dominant hemisphere
Auditory comprehension
Yes/no, MC questions
Point to objects and parts
Commands (simple/complex)
Complex syntax
Naming impairments
can be impaired in absence of any other language problem (pure anomia)
Classification of aphasias
use a 3-step approach: 1) fluency 2) comprehension 3) repetition do NOT simply say receptive/expressive
Global aphasia characteristics
non-fluent, poor comprehension
poor repetition/naming
Mixed transcortical aphasia characteristics
non-fluent, poor cmprehension
poor naming
good repetition
Global aphasia cause
Usually due to damage of both Broca’s/Wernicke’s (MCA)
Mixed transcortical aphasia cause
damage to areas that communicate with Broca’s & Wernicke’s
but Broca’s , Wernicke’s, articulate fasciculus are spared individually
MCA/PCA, MCA/ACA watershed territories
Broca’s aphasia
non-fluent with good comprehension
poor repetition and naming
Transcortical motor aphasia characteristics
non-fluent with good comprehension
good repetition
poor naming
Transcortical motor aphasia causes
damage to other areas of frontal lobes that communicate with Broca’s area
Wernicke’s aphasia
Fluent speech with poor comprehension
poor repetition and naming
Transcortical sensory aphasia characteristics
fluent speech with poor comprehension
Good repetition
Poor naming
Transcortical sensory aphasia causes
damage to other areas of temporal/parietal lobes that communicate with Wernicke’s area
Conduction aphasia characteristics
fluent speech with good comprehension
poor repetition
poor naming with frequent paraphasias
Conduction aphasia cause
damage to peri-Sylvian areas affecting articlate fasciculus
Anomic aphasia characteristics
fluent speech with good comprehension
good repetition
Poor naming with occasional paraphasias
Anomic aphasia cause
anatomically non-specific
usually due to smaller lesions
Naming in aphasia
poor in ALL aphasias
good screening to test naming
Agraphia without aphasia
impaired writing without other language impairments
due to lesions to angular gyrus
Gerstmann’s syndrome
Gerstmann’s syndrome
lesion to inferior parietal lobule, including angular gyrus 4 components: agraphia acalculia R/L disorientation finger agnosia
Alexia without agraphia
Lesions in L occipital cortex/posterior corpus callosum = PCA
Information from L visual field –> R occipital lobe, then should cross over to L angular gyrus and Wernicke’s to permit reading
Disconnection syndrome
Apraxia
lack of ability to execute learned purposeful movements
Not due to primary motor/sensory deficit
Comprehension, attention, motivation intact
Types of apraxia
ideomotor apraxia
ideational apraxia
apraxia of speech
most due to lesions in dominant hemisphere (frontal/parietal association cortices)
Ideomotor apraxia
commonest
failure to perform skilled/learned motor sequences on command, or to imitation
brush teeth, comb, salute, hammer nail (limb)
whistle, blow match, suck straw (bucco-facial)
bow, stand like a boxer (trunk)
intent of movement usually still recognizable
Ideational apraxia
conceptual deficit
difficulty performing sequence of steps to complete a task
loss of knowledge to select tools/objects
usually bilateral parietal lobes affected
Apraxia of speech
difficulty translating motor plans into speech output
general buccofacial praxis intact
speech effortful, but not due to aphasia (writing intact)
trial and error, groping for words
Lesion in dominant prefrontal areas near Broca’s
