32 - Disorders of Language Flashcards
Aphasia
A disturbance in language as a result of neurological defect
Common causes of acute onset aphasia
Stroke, penetrating head injury, surgical resection
Common insidious, progressive causes of aphasia
Dementia, neoplastic changes
Common paroxysmal, episodic causes of aphasia
Focal seizures, migraine
Paroxysmal
Stereotypic symptoms between episodes
Commonality of language lateralisation in the brain
~95% of right handers and ~70% of left handers
Example of lateralisation of language
In people who have had a corpus collectomy, if show them an object in the left visual field (processed by right hemisphere), can’t name object, even though they know what it is, can use it, etc?
Aspect of speech that right hemisphere might play
Right hemisphere may play a role in nonpropositional
speech, prosody and paralingistic
aspects of speech
Artery important for parietal and temporal regions (superficial)
Middle cerebral artery (superior and inferior divisions)
Area supplied by superior middle cerebral artery
Dorsolateral prefrontal cortex, sensory, motor regions of brain
Area supplied by middle cerebral artery
Temporal, parietal regions.
Visual tracts
Basic divisions in language
1
2
Production (producing an appropriate output sequence of words)
Selection (choosing appropriate content, EG nouns)
Non-fluid language disorder
Deficits in language production Anterior lesions (superior middle cerebral artery) Loss of grammatical structure Intact selection of content EG Broca's aphasia
Fluid language disorder
Deficits in language selection Posterior lesion (inferior division of middle cerebral artery) Impaired selection of content Intact grammatical structure EG Wernicke's aphasia
Broca’s area
In prefrontal cortex.
Made up of two main gyri: pars triangularis, pars opercularis
Part of brain associated with language selection
Temporoparietal association neocortex
Temporoparietal association neocortex
Part of brain associated with language selection
Supramarginal gyrus.
Angular gyrus
Wernicke’s area
White matter tract thought to link Broca’s and Wernicke’s areas (among others)
Arcuate fasciculus
Wernicke's aphasia 1 2 3 4 5 6 7
1) Fluent jargonistic language output
2) Neologisms
3) Paraphasic errors eg. boap for boat
4) Impaired comprehension
5) Right quadrantanopsia (can’t see
6) No motor weakness
7) Often from a posterior lesion (inferior middle cerebral artery infarct)
Broca's aphasia 1 2 3 4 5
1) Non-fluent, highly effortful language output
2) Telegrammatic
3) Preserved comprehension
4) Right face and arm weakness
5) Often from a anterior lesion (superior middle cerebral artery infarct)
Conduction aphasias
1
2
3
1) Fluent aphasia, but more meaningful than Wernicke’s
2) Relatively intact basic auditory comprehension
3) Poor repetition of words
Transcortical motor aphasia
1
2
3
1) Non-fluent aphasia
2) Muteness at most severe
3) Repetition is preserved
Mechanisms of recovery
1
2
1) Contralateral transfer
2) Ipsilateral transfer
Contralateral transfer
1
2
3
1) Early Hemispherectomy
2) Neonatal infarction
3) Major developmental
anomalies
Ipsilateral transfer
1
2
1) Focal developmental anomaly
2) Adult-onset stroke
Appearance of brains of patients who have recovered from language deficits best
Both contralateral and ipsilateral plasticity
