Cortical Lesions & Aphasia Flashcards
Major cognitive domains evaluated by MSE
Arousal and attention Memory Language Visuospatial function Mood and affect Complex cognition
Dysarthria
A disorder of speech due to motor system involvement
How is language lateralized?
90% of the population is right handed; 99% of right-handed people are left dominant for language
10% of the population is left handed; 67% of left handed people are left dominant for language
Ambidextrous people may have mixed language lateralization
How is aphasia diagnosed?
Assessment of 6 domains:
Spontaneous speech Auditory comprehension Repetition Naming Reading Writing
Mini-mental State Examination (MMSE)
AKA “The Folstein”
1-30 point scale
Abnormal score < 24
Montreal Cognitive Assessment (MoCA)
1-30 point scale
Abnormal score < 26
Alexia
An acquired disorder of reading
Reading is also organized in left perisylvian regions and so most patients with aphasia will also have alexia; reading aloud is more impaired with anterior lesions while reading for comprehension is more impaired with posterior lesions
Agraphia
Acquired difficulty with writing (must first rule out mechanical obstacles such as PD, arthritis, etc.)
Writing is organized in the left perisylvian regions and so most aphasias also have agraphia
Sparse, effortful writing is seen with anterior lesions; expansive, paragraphic writing is seen with posterior lesions
Broca’s area = Broadman’s area x?
44, 45
Broca’s aphasia - Clinical characteristics & Radiographic Findings
Effortful, non-fluent speech
Good auditory comprehension
Poor repetition
Poor naming
CT shows infarct in the left frontal region
Wernicke’s Aphasia - Clinical characteristics & Radiographic Findings
Fluent speech, may be paraphasic
Poor auditory comprehension
Poor repetition
Poor naming
CT shows ischemic infarct in the left superior temporal region
Wernicke’s Area = Broadman’s area X?
22 - Superior Temporal Gyrus
Paraphasias
AKA “paraphasic errors”
Unintended syllables or words of 3 types
- Literal (phonemic): substitution of phonetically similar words
- Verbal (semantic): substitution of words with related meanings (i.e. ‘wife’ becomes ‘mother’)
- Neologism (new and meaningless word insertion)
Conduction aphasia - Pathology
damage to the arcuate fasciculus, a white matter tract connecting Wernicke’s and Broca’s areas; may also see supramarginal gyrus damage
T2 MRI shows a focal ischemic region in the left hemisphere extending into the subcortical white matter (arcuate fasciculus)
Global Aphasia
The most severe form of aphasia, resulting from destruction of the entire perisylvian zone, usually due to middle cerebral artery infarct
Patients have essentially no language function in addition to right hemiplegia
