Lecture 8-Aphasias Flashcards
What are the characteristics of Broca’s aphasia? (known as non-fluent or expressive aphasia)
- Major disturbance in speech production
- May retain use of nouns & verbs
- Loss of pronouns, articles, conjunctions
(“telegraphic”) - Effortful speech
- Comprehension intact
What is the role of Wernicke’s area in language processing? Where is it located?
Wernicke’s area, located in the posterior part of the first temporal gyrus, is essential for the storage of auditory word forms and is involved in language comprehension.
What are the characteristics of Wernicke’s aphasia? (Fluent receptive aphasia)
- Fluent speech, normal rhythm, and intonation
- Difficulty understanding spoken language
- Errors in word sounds and structures (non-sensical speech)
- Frequent misuse of words (Semantic paraphasias)
What is Wernicke syndrome linked to?
A single functional abnormality: the “abnormal representation of the sound pattern of words.” (Caplan)
What is conduction aphasia and what causes it?
Characterized by the inability to repeat words despite good comprehension and speech production, caused by a disconnection between Wernicke’s and Broca’s areas.
What are the hallmark symptoms of conduction aphasia?
Characterized by a patient’s inability to repeat words, the presence of phonemic paraphasias (sound errors), and occasionally word substitutions,
Which neural pathway’s damage leads to conduction aphasia?
Damage to the arcuate fasciculus, the tract between the language comprehension (werikness) and speech production (broca) areas of the brain.
Three principles underlying classic aphasic
syndromes (Caplan, 2003)
(1) Language processors are localized in specific brain areas, (2) Damage to one processor can cause multiple language deficits, and (3) The localization of these processors is related to primary sensory or motor functions.
- This essentially means that different parts of the brain are responsible for different language functions, so damaging one area can lead to multiple language deficits, and these language areas are located near areas responsible for basic sensory and motor functions.
What did Lichtheim propose about the localization of language processing?
Word meanings are stored in a specific area of the brain called the ‘concept center’, in the superior
portion of the parietal lobe
What does the intact Lichtheim’s Model represent?
Describe how language is processed in the brain, with a functioning motor speech area (M), auditory word form area (A) (language comprehension), and concept center (C).(meaning of words)
What is Broca’s Aphasia according to Lichtheim’s Model?
Broca’s Aphasia is characterized by damage to the Motor Speech Area (M) leading to reduced fluency of speaking,
reading, repeating, with comprehension in tact
What does Wernicke’s Aphasia entail in Lichtheim’s Model?
It entails damage to the Auditory Word Forms Area (A) resulting in fluent, often nonsensical speech and poor auditory comprehension.
What is Conduction Aphasia caused by in Lichtheim’s Model?
Conduction Aphasia is caused by damage to the pathway between the Motor Speech Area (M) and Auditory Word Forms Area (A), affecting repetition and spontaneous speech, with comprehension intact.
What is Transcortical Sensory Aphasia in Lichtheim’s Model?
Characterized by damage between the Auditory Word Forms Area (A) and Concept Center (C), causing impaired comprehension with preserved repetition ability.
What are the limitations of classical aphasia syndromes?
The classical syndromes are inconsistent, show varied deficits in people with the same diagnosis, exhibit similar deficits across different syndromes. Syndrome are not well correlated with lesion location, making them less useful for treatment planning.
