Disorders of Language Flashcards
Define aphasia?
Disturbance in language as result of brain damage
What is the difference between language and speech disorders?
Speech disorders happen because of sensory and/or motor problems
What are some causes of acute onset aphasia?
Strok
Penetrating head injury
Surgical resection
What are some causes of insidious onset aphasia?
Dementia
Neoplastic change
What is the time course of insidious onset aphasias?
Progressive
What are some causes of paroxysmal aphasia?
Focal seizure if activity spreads to language cortices
Migraine
What is the time course of paroxysmal aphasias?
Episodic
Present same way each time
What are the corresponding Broddman’s areas of Broca’s area?
44 and 45
What is the hemispheric dominance in terms of language?
Right hemisphere for visuospatial function
Left hemisphere for language
What proportion of right and left handers have left lateralised language?
95% of right handers
70% of left handers
What might be the role of the right hemisphere in language?
Non-propositional speech
Prosody
Paralinguistic aspects
What are the divisions of the middle cerebral artery?
Superior
Inferior
What does the superior division of the middle cerebral artery supply?
Sensorimotor cortex
Ventrolateral prefrontal cortex
What does the inferior division of the middle cerebral artery supply?
Temperoparietal cortex
Visual tracts
What is the clinical significance of the relationship between which branch of the middle cerebral artery is affected and language?
Language disturbances depend on which branch is affected
Define language production
Producing appropriate output sequences
Define language selection
Choosing appropriate content
What part of language is affected in non-fluent language disorders?
Production
What part of language is affected in fluent language disorders?
Selection
Describe non-fluent aphasias
Anterior lesion
Loss of grammatical (sequential) structure
Intact selection of content
Eg: Broca’s aphasia
Describe fluent aphasias
Posterior lesion
Impaired selection of content
Intact grammatical (sequential) structure
Eg: Wernicke’s aphasia
Which division of the middle cerebral artery is affected in Broca’s aphasia?
Affects Broca’s area > superior division
Which division of the middle cerebral artery is affected in Wernicke’s aphasia?
Affects Wernicke’s area > inferior division
What is the function of the arcuate fasciculus?
Join’s Broca’s and Wernicke’s areas
Joins Wernicke’s area to premotor cortex
What does the dorsal language stream map?
Sound
What does the ventral language stream map?
Sound to meaning
What does damage to white matter tracts involved in the language system produce?
Very specific language disorders
Shows importance of systems rather than isolated areas
Describe Wernicke’s aphasia
Fluent jargonistic language output - Neologisms - Paraphasic errors - phonemic and semantic Impaired comprehension Right quadrantanopsia No motor weakness Affects written language too Often don't know that they don't make sense
What does an exam of language measure?
Output
Comprehension: easy > hard
Ability to follow instructions
Repetition
Describe Broca’s aphasia
Non-fluent, highly effortful language output
Telegrammatic
Preserved comprehension
Right face and arm weakness
Written language a little better than with Wernicke’s area
Usually good insight into their issues
Describe conduction aphasia
Fluent aphasia, but more meaningful than Wernicke’s
Relatively intact basic auditory comprehension
Poor repetition of words
Describe transcortical motor aphasia
Non-fluent aphasia
Muteness at most severe - lack motivation and effort to talk
Repetition preserved
What does ipsilateral versus contralateral transfer after recovery depend on?
Many factors, including
- Age
- Stage of recovery
- Size and location of lesion
On what side will recovery happen if you are young?
Younger the person, more likely of contralateral functional switch
Describe the way the roles of the two hemispheres change over time in adults, post-stroke
Controls - Left = a lot of activity - Right = a little activity Acute - Left = very little activity - Right = no activity Subacute - Left = a lot of activity - Right = a lot of activity > maybe to support other hemisphere Chronic - Left = a lot of activity - Right = moderate activity
What is the relationship between the size of the lesion and which side recovery happens on?
Larger lesions may mean more contralateral reorganisation
