6. Types and localisation of aphasia Flashcards
Cause of aphasia
Lesions of cortical speech centers and their conncetions
Cortical speech center
- Wernicke’s speech center
- Broca’s motor speech center
Where is Wernicke’s speech center?
Left hemisphere, Br22
adjacent to prim. auditory cortex in post. 2/3 of the sup. temporal gyrus
Where is Broca’s motor speech center?
Left hemisphere, Br44 Br45. In middle and inferior frontal gyrus.
Basic types of aphasia
- Motor (Broca’s, expressive, non-fluent, anterior type)
- Sensory (Wernicke’s, receptive, fluent, posterior type)
Main causes of aphasia (3 types)
- lesions of the cortical speech centers
- dissociation syndromes
- subcortical aphasia
Types of lesions of cortical speech centers
- Global aphasia
- Motor (Broca’s) aphasia
- Sensory (Wernicke’s) aphasia
Types of dissociations syndromes
- Conduction aphasia
- Alexia (reading) without agraphia (writing)
- Auditory agnosia (process words)
- Transcortical motor aphasia
- Amnestic aphasia
Define subcortical aphasia
Damage to subcortical areas of the dominant hemisphere (mainly in cerebrovascular disorders) leading to aphasia. Lesions to basal ganglia, internal capsule and corona radiata
Define global aphasia
Lesion of entire distribution of middle cerebral artery, including Broca’s and Wernicke’s. Involves all aspects of language and severely impairs spoken communication. Patient unable to speak and understand language.
Characteristic feature of global aphasia
Patient unable to speak and understand language. Language automatism (repetition or gibberish).
Associated disease of global aphasia
Hemiparesis
Define motor (Broca’s) aphasia
Disorder of coordination of the muscles of speech and verbal elements of language.
Etiology of motor (Broca’s) aphasia
Infarction of a branch of the middle cerebral artery
Characteristics of motor (Broca’s) aphasia
Severe impairment of spontanous speech, while comprehension is not affected. The patient can only speak with great effort (pt. knows what he wants to say, but unable to do so)
