other aphasias Flashcards
damage to where causes subcortical aphasia?
damage to the subcortical regions of the brain (thalamus and basil ganglia)
damage to the thalamus and basil ganglia can result in:
aphasia and/or apraxia of speech, but specific roles are less defined than the cortical contributions
thalamus
(sensory relay nuclei)
- selectively gates the passing of sensory information to the cortex
- regulates the selective arousal of association cortex (reticular activating system)
passing of sensory information and regulation of selective arousal of association cortex
- thalamic lesion disrupts these functions; most typical result is lexical-semantic impairment
- can also damage thalamic-cortical connections… (understanding, putting the meaning to words)
characteristics of subcortical aphasia:
- non-thalamic strokes affect lenticulostriate arteries that feed the subcortical structures
- reduce blood flow to lateral cortex through the MCA
- depending on collateral circulation, get reduced functioning of affected cortex
- shows up on MRI but not CT
alexia without agraphia
reading impairment without and accompanying writing disorder
damage to where causes alexia without agraphia?
posterior and subcortical to angular gyrus; injury is to left visual cortex and splenium of corpus callosum
- usually related to a lesion in the angular gyrus
alexia with agraphia
reading and writing impairment without a significant deficit in oral expression or auditory comprehension
damage to where causes alexia with agraphia?
left angular gyrus
When alexia occurs without aphasia:
the lesion is posterior or vascular territory
the lesion is posterior:
left angular gyrus
left occipital
callosal
vascular territory
posterior MCA
pure word deafness
absent auditory comprehension with error-free spontaneous speech, naming, reading, and writing
auditory verbal agnosia
can’t understand the language that they hear, but can talk, write, and read OK
crossed aphsia
aphasia in right handed individuals who have had right hemisphere lesions
