Adult Neurogenic Communication Disorders (Aphasia, Dysarthria, Apraxia)
This domain tests differential diagnosis of aphasia, dysarthria, and apraxia of speech after neurological injury.
Core rules
- Aphasia is a language disorder affecting comprehension, production, repetition, naming, reading, or writing. Classify by fluency, comprehension, and repetition.
- Broca aphasia: nonfluent, relatively preserved comprehension, impaired repetition. Wernicke aphasia: fluent, poor comprehension, impaired repetition. Conduction aphasia: fluent, good comprehension, markedly impaired repetition. Transcortical motor: nonfluent, good comprehension, preserved repetition. Global: severe across domains.
- Dysarthria is a motor speech disorder from weakness, spasticity, ataxia, or hypokinesia; articulation, voice, resonance, and prosody are affected. Apraxia is a planning/programming disorder with groping, inconsistent errors, and automatic-voluntary dissociation.
Worked example
A left middle cerebral artery stroke patient has sparse, effortful output, good yes/no comprehension, and cannot repeat a sentence. Naming is impaired, and the patient is aware of errors. This fits Broca aphasia, not dysarthria alone, because language domains beyond articulation are affected. If repetition were preserved, transcortical motor aphasia would be more likely. The plan includes supported conversation, word-retrieval treatment, and caregiver training, with dysarthria treatment added only if motor speech signs are documented.
Traps that cost marks
- Labeling all nonfluent speech as dysarthria.
- Ignoring repetition, which separates several aphasia syndromes.
- Missing apraxia when errors are inconsistent and groping.
- Not considering delirium, hearing loss, or language background.