Language and Cognitive Communication Disorders

The left hemisphere is generally regarded as the language-dominant hemisphere.
Key cortical areas for language:
- Broca's area: involved in language production.
- Wernicke's area: involved in language comprehension.
- These areas are connected by the arcuate fasciculus.
The right hemisphere contributes to language and cognitive control of language.

The temporoparietal association cortex and inferior frontal gyrus play a role in communication, directing attention, and spatial cognition.

Aphasia results from damage to cortical language centers in the left hemisphere.
The primary cause is typically a stroke in the left hemisphere.
Aphasia impairs understanding and/or expression in verbal and written modalities.
The location and size of the lesion (stroke) determines the specific type of aphasia.

Characterized as a fluent aphasia with impairment of receptive language (spoken and written).
Damage occurs in the superior temporal gyrus, supplied by the middle cerebral artery (MCA).
Symptoms:
- Fluent, copious verbal output.
- Semantic paraphasia (word errors).
- Use of neologisms (made-up words).
- Impaired naming and repetition.

A non-fluent aphasia affecting expressive language (spoken and written).
Damage occurs in Broca’s area and surrounding areas in the inferior frontal gyrus, supplied by the left MCA.
Symptoms:
- Limited verbal output that is effortful and agrammatic.
- Relatively good auditory comprehension.
- Difficulty with naming.
- Poor repetition.
- Possible co-occurrence with motor speech disorders (dysarthria and apraxia) due to proximity to the motor cortex.

Lesion in the supramarginal gyrus and white matter pathways of the arcuate fasciculus.
Characteristics:
- Fluent speech with relatively intact receptive language.
- Poor repetition.
- Phonemic errors in spoken output.
- Naming difficulties (tip-of-the-tongue phenomenon).
- Awareness of errors.

Caused by extensive damage to frontal, temporal, and parietal regions, within the distribution of the MCA.
Severe receptive and expressive impairments.
Almost total absence of speech.
May have stereotypical utterances.
Possible expression through facial expression, intonation, and gesture.

Allied health professionals should create an accessible communication environment for people with aphasia.
Basic strategy: “ask, wait, and listen.”

Definition: Communication problems resulting from underlying cognitive deficits, rather than primary language or speech deficits.
Arise from disruption in one or more cognitive domains:
- Attention
- Memory
- Executive function (planning, problem-solving, reasoning)
Associated neurological conditions: traumatic brain injury, dementias, Parkinson’s disease, Huntington’s disease, multiple sclerosis.

Attention:
- Difficulty staying on topic.
- Decreased ability to follow complex media (TV, movies, books).
- Missing salient information during exchanges.
Memory:
- Difficulty accessing known information.
- Difficulty following directions; reduced comprehension of complex sentences.
- Difficulty learning new information, affecting rehabilitation and return to work/education.
Executive Function:
- Difficulties with turn-taking and social judgment.
- Difficulty adopting another’s perspective.
- Impaired self-regulation, leading to impulsiveness.
- Reduced informativeness in discourse (too much or too little information).
- Difficulty monitoring and repairing communication breakdowns.