RS510 Chap.7 Aphasia, Apraxia and Disorders of Skilled Movement
Aphasia, Apraxia and Disorders of Skilled Movement
Classifying aphasia
The practical session classifies aphasia by fluency, then comprehension, then repetition, with a typical lesion for each type. Broca's, global, transcortical motor and mixed transcortical aphasia are non-fluent; Wernicke's, conduction, transcortical sensory and anomic aphasia are fluent.
Repetition separates types that share fluency and comprehension, because lesions inside the perisylvian zone impair it and those outside spare it. Phonemic, semantic and neologistic paraphasias and semantic or empty circumlocution are the errors to name.
Movement without weakness
The motor system is guided by a praxic programme for how to move and an intentional programme for when to move.
Motor impersistence, motor extinction, continuous and recurrent perseveration and the apraxias, ideomotor, ideational, limb-kinetic and task-specific, can all appear in a person whose limbs are strong.
Why this matters for a programme
Language and motor disorders change how every other assessment should be read.
A person with poor comprehension may fail a memory test because the instructions were not understood, and a person with apraxia may fail a construction task for reasons that have nothing to do with visuospatial skill. The practical session's factors list makes the same point about comprehension.
Recognising these disorders early lets you choose tests that do not depend on the impaired channel and write recommendations, such as demonstration rather than verbal instruction, that the rest of the team can use.
What this chapter covers
- 01
Aphasia types by fluency, comprehension and repetition
- 02
Lesion sites inside and outside the perisylvian zone
- 03
Phonemic, semantic and neologistic paraphasia
- 04
Semantic and empty circumlocution
- 05
Praxic and intentional motor programmes
- 06
Motor impersistence and motor extinction
- 07
Continuous and recurrent perseveration
- 08
Ideomotor, ideational, limb-kinetic and task-specific apraxia
Worked example · free
Tell ideational from ideomotor apraxia at the bedside
- 3Classify patient A with the reason.
- 3Classify patient B with the reason.
Key terms
- Conduction Aphasia
- A fluent aphasia with good comprehension but poor repetition and phonemic paraphasias, linked to the supramarginal gyrus and arcuate fasciculus.
- Anomic Aphasia
- A fluent aphasia with good comprehension and repetition in which word-finding difficulty is the main sign.
- Semantic Paraphasia
- A speech error in which a wrong word related in meaning replaces the intended one, such as girl for boy.
- Motor Extinction
- Failure to move the limb opposite a lesion when the limb on the same side moves at the same time, a mild kind of motor neglect.
- Ideational Apraxia
- An inability to conceptualise and sequence the actions of a task even though the tools are recognised.
- Limb-kinetic Apraxia
- A loss of fine, separate yet coordinated finger and hand movements, a motor dexterity impairment.
Aphasia, Apraxia and Disorders of Skilled Movement FAQ
How do you tell Broca's aphasia from transcortical motor aphasia?
Test repetition. Both are non-fluent with good comprehension, but Broca's aphasia impairs repetition because its lesion in the left inferior frontal gyrus lies inside the perisylvian language zone, while transcortical motor aphasia preserves repetition because its lesion lies anterior or superior to Broca's area.
What is the difference between continuous and recurrent perseveration?
Continuous perseveration, Luria's efferent type, keeps a movement going after the task has been completed. Recurrent perseveration, which Luria called inertia of program action, repeats the old movement when the task requirements have changed and a new motor programme is needed. Both are linked to frontal and basal ganglia dysfunction.
Where are the lesions that cause apraxia?
Mainly in the left hemisphere: the motor planning areas of the premotor cortex, the inferior parietal lobe including the supramarginal and angular gyri, and the inferior frontal gyrus; the supplementary motor area; and white matter tracts that connect parietal and frontal regions, such as the arcuate fasciculus.
What is motor impersistence?
An inability to sustain a simple motor activity, such as holding a posture, although the person has the physical ability to do it. It is commonly associated with frontal damage, particularly on the right, appears after stroke and brain injury and in dementia and neurodegenerative disorders, and involves disruption of attention networks and motor control.
Assessment move
Build a one-line description of each aphasia type from the three questions, fluent, comprehension, repetition, and add the lesion. Then practise on speech samples you write yourself; classifying from a sample, not from a name, is what the practical session asks you to do.
