Aphasia and Other Disorders of Higher Cortical Function Flashcards
Aphasia is not the only cause of communication difficulties. What feature is a feature of essentially all aphasias that can be screened for in an exam?
anomia (impaired naming)
What is impaired in Broca’s aphasia? (of fluency, repetition and compression)
fluency and repetition are impaired
comprehension is preserved
What is a commonly associated neurological sign with broca’s aphasia?
right hemiparesis (especially of the face)
Where is the lesion in Broca’s aphasia?
broca’s area
posterior part of the inferior frontal gyrus in the language-dominant hemisphere
What is the most common cause of a broca’s aphasia?
an MCA stroke
What is impaired in Wernicke’s aphasia? (of fluency, repetition and comprehension)
fluency is preserved, but repetition and comprehension are impaired
What is a commonly associated neurological sign with wernicke’s aphasia?
right upper visual field cut
Where is the lesion in Wernicke’s aphasia?
Wernicke’s area
posterior part of the superior temporal gyrus in the dominant hemisphere
What is the most common cause of wernicke’s aphasia?
infarction of the inferior division of the MCA, many due to emboli from proximal locations like the heart or internal carotid
What is impaired in a conduction aphasia? (of fluency, repetition and comprehension)
repetition will be impaired, but fluency and comprehension will both be preserved.
Where is the lesion in a conduction aphasia?
the arcuate fasciculus ( white matter connection between broca’s and wernicke’s areas)
however, to actually much evidence to support this. really any lesion affecting the temporal or parietal lobes (but sparing wernicke’s area) can lead to this syndrome
If smoeone has a nonfluent aphasia, but with preserved repetition, where is the lesion? What is this aphasia called?
frontal lobe, but superior to Broca’s area (can also be from a lesion in the supplementary motor area or in the anterior portions of the basal ganglia)
a transcortical motor aphasia
If you have an aphasia with impaired comprehension but preserved repetition, where is the lesion? What is this aphasia called?
inferior portion of the left temporal lobe (lower than wernicke’s area)
transcortical sensory aphasia
What are the most common causes of transcortical sensory aphasias?
left PCA infarcts
small temporal lobe hemorrhages/contusions
Typically, reading deficits will occur in ___ aphasia, while writing deficits will occur in ___ aphasia.
reading deficit in Wernicke’s
writing deficit in Broca’s
so a patient with Broca’s may not be able to understand a spoken command, but may be able to understand if they read it.
Alexia without agraphia (or pure alexia) is characterized by an inability to read, despite a preserved ability to write. Where is the lesion?
dominant occipital lobe, but also the splenium of the corpus callosum
What is an apraxia?
an inability to carry out a learned motor task despite preservation of the primary functions needed to carry out the task
for example, someone with an apraxia may not be able to demonstrate how to hammer a nail even though they have the cognitive capacity to understand the command and the motor/sensory ability to do so
What are the three basic ways to test for an apraxia?
- pretend they are performing an action (may run their fingers through their hair when asked to demonstrate how ot use a comb)
- mimic the examiner performing an action
- use the actual object to perform an action
Where is the lesion in apraxia?
frontal or parietal lobs of the dominant hem
frontal - they tend to be able to recognize when someone else is doing the task correctly
parietal - can’t tell when someone is doing it correctly or incorrectly
What term is used to describe the inability to recognize objects?
agnosia
Where is the lesion in agnosias?
generally in the sensory association areas of the brain and will depend on which sensory modality is affected – a visual agnosia (unable to identify the object by sight, but may identify it by touch) will have a lesion in the occipitotemporal visual association cortex
Where is the lesion in prosopagnosia?
the fusiform face area in the right hemisphere
What syndrome will occur with lesions in the inferior parietal lobule of the dominant hemisphere (specifically in the angular gyrus)?
Gerstmann’s syndrome
What are the characteristics of Gerstmann’s syndrome?
agraphia
acalculia
finger agnosia
What is the most sensitive sign of neglect?
extinction to double simultaneous stimulation (so moving fingers on both sides on visual field screening)
Even though language is typically in the left hemisphere, how can right hemisphere lesions affect language?
can affect the prosody (of the infection/emotion) in one’s voice
Which hemisphere typically has a lesion in anosognosia?
right
