Aphasia

Global Aphasia

-Difficulty with both expression and understanding

Definition of Aphasia

-A speech or language disorder caused by damage to the parts of the brain that control speech and language: typically as the result of a cerebrovascular accident (CVA) or stroke

Prevalence of Aphasia

-Approximately 1 million people in the US are living with aphasia due to various brain traumas -Around 80,000 people acquire aphasia each year

Wernicke's (Fluent) Aphasia Symptoms

-Characterized by primary difficulty finding words: severely limited access to existing vocabulary -Severe circumlocution -"empty speech:" words have lost their paradigmatic meaning -Comprehension of language compromised -Words and their meanings appear to be disassociated: (*Ex- people can describe something and not think of the word for it or they are given a word and can't say what it means) -grammar appears to be spared

Transcortical Aphasia: Motor

-Damage to premotor cortex anterior and superior to Broca's Area -Nonfluent Aphasia -Extremely labored speech -Repetition is intact however -Auditory and reading comprehension are good -Syntax is better than Broca's

Transcortical Aphasia: Sensory

-Damage to the area surrounding and often including Wernicke's Area -Fluent Aphasia -Repetition is intact -All language modalities are impaired -Poor comprehension -Echolalic

What is damaged in Broca's (Nonfluent) Aphasia?

-Damage to the frontal lobe: inferior frontal gyrus

What is damaged in Wernicke's (Fluent) Aphasia:

-Damage to the posterior section of the superior temporal gyrus

Receptive Aphasia

-Difficulty understanding words and sentences

Expressive Aphasia

-Difficulty using words and producing words

Conduction Aphasia: Symptoms

-Fluent Aphasia -Good articulation -auditory comprehension is usually normal (wrenches' area = fine) -Poor repetition skills - area for comprehensions and expressions are not connected -poor sequencing of phonemes -results in paraphasia -anomia is common

Global Aphasia

-Like conduction aphasia, it is considered a "peripheral aphasia" -Damage to the fronto-temporo-parietal regions -Severe impairments in all modalities: speaking, listening, reading, and writing -Very limited speech output -nonfluent aphasia

Broca's (Nonfluent) Aphasia Symptoms

-Lose the ability to combine linguistic elements; grammar is severely restricted or absent (expressive language deficit) -Produce individual words or very short sentences: these are restricted, but often due to oral motor impairment known as apraxia of speech **-oral expression = very difficult/production of speech and language

Anomic Aphasia

-Naming difficulty -substitution of concrete nouns with indefinite pronouns (ex- thing, it stuff) -Very rare: not clear what part of the brain is affected -some consider it a mild form of Wernicke's

Subcortical Aphasia

-Nonfluent Aphasia -Lesions of the deep basal ganglia (frequently but not always) -Dysarthria (motor speech disorder) -Good comprehension

Conduction Aphasia: prevalence

-Not originally identified by the Boston Group -Occurs in fewer than 10% of aphasia

Paraphasias

-One word or phoneme is substituted for another

Hemiplegia

-Paralysis of one side of the body

Dysarthria

-The muscles of the mouth, face, and respiratory system may become weak, move slowly, or not move at all after a stroke or other brain injury, resulting in: -slurred speech -slow speech -limited movement of articulators -breathiness -abnormal intonation -difficulty chewing or swallowing

Classification System of Aphasia

-Varies widely: there are more than 20 currently -Systems vary primarily in terminology, but agree upon clinical classification of aphasias -2 classification systems that primarily guide our thinking: 1. Boston Group 2. Luria

Agnosia

-acquired disorder of recognition in some sensory modality (visual, auditory, tactile) -Ex: difficulty recognizing faces

What is damaged in Conduction Aphasia?

-damage to the arcuate fasiculus: a bundle of nerve fibers that lies below the supra marginal gyrus in the temporal lobe and connects Broca's and Wernicke's Areas -Both Broca's and Wernicke's Areas are left intact

Anomia/Dysnomia

-difficulty with word finding or naming

Apraxia

-disorder of learned, sequential motor movements in the absence of a motor, sensory, or coordination deficit

amnesic/anomic and nominal aphasias

-subtypes of Wernicke's -Involve impairment of semantic representations

circumlocution

-the use of many words where fewer would do, especially in a deliberate attempt to be vague or evasive. -talking around the word - definitions of the word are known but not associated

Boston Group (Primary Classification System)

1. Aphasias are fluent (Wernicke's) or non-fluent (Broca's) 2. Aphasias can be cortical, subcortical, or transcortical -cortical:external structure of the brain (wernicke's and broca's area are part of the cortex) -subcortical: deeper structure below the surface -transcortical: different area of the cortex

Related/Accompanying Disorders

1. Apraxia 2. Agnosia 3. Dysarthria 4. Hemiplegia

Nonfluent Aphasias

1. Broca's 2. Transcortical Motor 3. Globla 4. Subcortical Aphasia

All Fluent Aphasias

1. Wernicke's 2. Transcortical Sensory 3. Anomic 4. Conduction -can produce speech/language