A. 6 - Types and localisation of aphasia Flashcards
what is aphasia?
speech disorder with an inability to comprehend and/or formulate language. It is caused by lesions of cortical speech centers and their connections.
where are the Brain regions related to speech located ?
in most people in the dominant (left)
hemisphere
what are the 2 Brain regions related to speech located?
Wernicke’s speech center
Broca’s motor speech
center
what is Wernicke’s speech center?
(Br22 + small part of Br39 and Br40) → comprehension of speech
○ Lies adjacent to the primary auditory cortex (in
the posterior 2/3 of the superior temporal gyrus
○ Connection with angular gyrus ensures coupling of perceptual and
learned memories with speech
what is Broca’s motor speech
center?
In the middle and inferior frontal gyrus + the lower part of the precentral gyrus (Br44)
○ Connected to the arcuate bundle with the angular and the supramarginal gyri + the Wernicke area
what are the Basic types of aphasia?
Motor:
(Broca’s, expressive, non-fluent, anterior type)
Sensory
(Wernicke’s, receptive, fluent, posterior type)
* Undercategories: conduction, transcortical sensory and amnestic aphasias
what are the Lesions of cortical speech centers?
Global aphasia
Motor (Broca’s) aphasia
Sensory (Wernicke’s) aphasia
what is global aphasia?
The entire distribution of the middle cerebral artery is affected, including both Broca’s and Wernicke’s areas.
what the lesion involves in global aphasia?
all aspects of language and severely impairs spoken communication.
Patient is unable to speak and understand language.
● Language automatism (repetition of gibberish) is a characteristic feature.
● Associated with severe hemiparesis – simultaneously destroy the motor and sensory speech centers
what is Motor (Broca’s) aphasia?
Disorder of coordination of the muscles of speech and the verbal elements of language.
what is the etiology behind motor aphasia?
May be due to an infarction of a branch of the middle cerebral artery
what imotor (broca’s) aphasia is characterised by?
severe impairment of spontaneous speech, while comprehension is not affected
● The patient can only speak with great effort (knows what he wishes to say, but unable to say it)
● Paraphasia: Substitutes one word for another
● Agrammatism: Grammatical errors in speech
● Telegraphic type: Gives responses with one word or simple sentences
● Agraphia: Writing is affected
● Patient is aware of disorder, and will be quiet
what is Sensory (Wernicke’s) aphasia?
Severe impairment of comprehension, while spontaneous speech remains fluent with a normal rhythm.
what is Sensory (Wernicke’s) aphasia caused by?
May be due to infarction of posterior temporal artery
(branch of middle cerebral artery).
what Sensory (Wernicke’s) aphasia is characterised by?
● Use of inappropriate words, generated nonsensical sentences and tends to speak too much with repetition of certain words.
● Paraphasia
● Agrammatism
● Neologism: Forming new and non-existent words, making speech incomprehensible
● The patient is typically unaware of his disorder
