Tool use in neurodegenerative diseases: Planning or technical reasoning?

Area of Science:

• Neuroscience
• Cognitive Neurology
• Gerontology

Background:

• Tool use impairment is known in stroke patients due to planning or technical deficits.
• These hypotheses remain underexplored in neurodegenerative diseases.
• Understanding these deficits is crucial for patient care and intervention.

Purpose of the Study:

• To compare planning skills, mechanical problem-solving, and real tool use in Alzheimer's disease (AD), semantic dementia (SD), and corticobasal syndrome (CBS).
• To identify the primary drivers of tool use deficits in these distinct neurodegenerative conditions.
• To inform disease-centered interventions for caregivers.

Main Methods:

• Patients with AD (n=32), SD (n=16), and CBS (n=9) performed tool selection/use tasks, mechanical problem-solving tests, and the Tower of London test.
• Motor function (Purdue Pegboard Test) and episodic memory (BEC96) were controlled.
• Data analysis included data transformation to avoid ceiling effects and single-case analysis of raw scores and completion time.

Main Results:

• All patient groups exhibited impaired or slowed tool use.
• Planning deficits were specific to the AD group.
• Mechanical problem-solving deficits were observed in AD and CBS groups.
• Tower of London performance predicted tool use in AD, suggesting general deficits.
• Motor dysfunction correlated with tool use in CBS; semantic loss explained deficits in SD.

Conclusions:

• Tool use deficits manifest differently across AD, SD, and CBS, linked to distinct cognitive and motor impairments.
• Planning abilities are key for tool use in AD, whereas motor function and semantic memory are relevant in CBS and SD, respectively.
• Findings support tailored interventions based on the specific neurodegenerative profile.