Aphasias Flashcards
Perisylvian aphasia syndromes
The hallmark of perisylvian aphasia syndromes is impaired repetition
- Broca’s aphasia (nonfluent)
- Wernicke’s aphasia (fluent)
- Conduction aphasia (fluent) - well preserved auditory comprehension (compared to Wernicke’s
- Global aphasia
Extrasylvian Aphasia Syndromes
a.k.a. transcortical aphasia syndromes
involve the borderzone region
Hallmark of extrasylvian aphasia syndromes is preserved repetition
- Transcortical motor aphasia (TMA) (nonfluent) - similar to Broca’s (motor) aphasia but intact repetition
- Mixed transcortical aphasia (MTA) (nonfluent) combines the motor and sensory forms of this disorder (global aphasia) except for preservation repetition
- Transcortical sensory aphasia (TSA) (fluent) - similar to Wernicke’s (sensory) aphasia but intact repetition
Subcortical Aphasia Syndrome
language disorders that may arise from lesions to the striatum, internal capsule, or thalamus.
Fluent or non-fluent
Impaired naming
if lesion only subcortical = prognosis good
if lesion both subcortical and cortical = prognosis poor
Alexia
Alexia refers to the inability to read
Alexia without agraphia (pure word blindness) - rare; selective
loss of the ability to read words without writing disturbance (cannot read own writing)
Alexia with agraphia - loss of ability to read and produce written language. Speech and comprehension may be intact, but an anomia may be present.
Pure Word Deafness
Rare; involves the loss of auditory comprehension of speech.
results from disconnection of Wernicke’s area from semantic regions of the anterior temporal lobe. This lesion prevents the speech signal from undergoing phonologic decoding in Wernicke’s area, but leaves intact sound decoding of nonspeech sounds.
Patients react to speech sounds as though they are deaf. They are
able to speak, read, and write, but are unable to repeat.
Writing is impaired in all aphasic syndromes except:
Really, it’s impaired in all but may be spared in subcortical aphasia
Nonfluent aphasias are associated with dysfunction within
anterior language centers
Fluent aphasias involve dysfunction of
posterior language areas.
Aphasic disorders without repetition difficulties are located in the
borderzone (extrasylvian) language areas
Aphasic disorders with repetition difficulties are located in the
perisylvian areas
Broca’s aphasia
a.k.a. motor, expressive, and anterior aphasia
- Nonfluent verbal output (sparse, effortful, dysarthric, dysprosodic, of short-phrase length, and agrammatic)
- Poor repetition
- auditory comprehension is spared
- Writing is usually impaired commensurate with speech.
- Naming is often impaired, but
contextual and phonemic cues can aid retrieval.
If lesion affects only cortex = good recovery
If lesion extended from cortex into BG or internal capsule = aphasia likely to be permanent
Areas:
- inferior frontal gyrus in the dominant hemisphere, just above the Sylvian fissure.
- Posterior portion of the inferior frontal gyrus of the left hemisphere
Associated features:
Right hemiparesis (arm more affected than leg)
Right facial droop
Wernicke’s aphasia
a.k.a. sensory, receptive, and posterior aphasia
- fluent verbal output with normal word count and phrase length
- impaired auditory comprehension
-word finding difficulty - Poor repetition
Speech described as empty or nonsensical because
there can be long syntactic strings replete with paraphasic errors, neologisms, and
circumlocutions.
Areas:
superior temporal gyrus in dominant hemisphere
Associated features:
Occasional superior quadrantopsia
Conduction aphasia
a.k.a. associative aphasia
- fluent speech
- intact comprehension (vs. Wernicke’s)
- impaired repetition
- paraphasias
- word-finding difficulties,
- impaired writing
- Poor naming
- Oral reading disturbed but reading comprehension intact
Areas:
Considered a disconnection syndrome because of damage to the arcuate fasciculus, thus disconnecting Broca’s area from Wernicke’s area
Associated features:
Common hemisensory defect and cortical sensory loss
Transcortical motor aphasia (TMA)
- anterior borderzone-related aphasia (anterior to Broca’s area in supplementary motor area)
- resembles Broca’s (nonfluent) aphasia BUT normal repetition
- comprehension is intact
Poor writing
Associated features:
Occasional right hemiparesis
Mixed transcortical aphasia (MTA)
Combines Broca’s and Wernicke’s (resembles global aphasia) BUT intact repetition
involves extensive borderzone damage (i.e., transcortical/extrasylvian).
nonfluent speech (motor aphasia)
Areas:
Essentially isolation or disconnection of the speech area; involves the entire vascular borderzone area in both the frontal and parietal zones
Associated features:
Common right hemiparesis and hemisensory defect
Common causes include hypoxic brain injury due to decreased
cerebral circulation, as in cardiac arrest, carbon monoxide poisoning, or in some
cases temporary occlusion/stenosis of the carotid artery.
Transcortical sensory aphasia (TSA)
posterior borderzone-related aphasia
resembles Wernicke’s aphasia BUT intact repetition
can feature paraphasia output and echolalia
Heard language is processed, allowing for repetition, but cannot be interpreted
Areas:
Usually at the junction of parietal, temporal, and occipital regions in the angular gyrus in the dominant parietal region, sparing Wernicke’s area
Associated features
Common hemisensory defect
Anomic aphasia
Primary problem is one of difficulty with
word finding –> causing multiple pauses, frequent circumlocution, and a somewhat stumbling verbal output
Intact repetition and comprehension.
Poor reading and writing
common residual disorder following improvement from other types of aphasia.
No specific location for the pathology, but it often involves the angular gyrus in the dominant hemisphere and disconnection between Wernicke’s area and intrasensory input areas in the parietal, temporal, and occipital lobes
Global aphasia
Perisylvian
severe disturbances in all major language functions
Typically Involves the entire perisylvian region in a typical middle cerebral artery pattern
Associated features:
Common right hemiplegia and right hemisensory defect
Aphasic syndrome chart
