In an 84‑year‑old man with Parkinson disease responsive to low‑dose carbidopa/levodopa who can perform daily activities but has difficulty mastering new violin pieces, which function is most likely impaired: episodic memory, working memory, procedural memory, semantic memory, perceptual‑motor function, or balance?

Working Memory Impairment in Parkinson's Disease

The most likely impaired function affecting this patient's ability to master new violin pieces is working memory. 1

Rationale for Working Memory as the Primary Deficit

Working memory—the ability to hold and manipulate information in real-time—is characteristically impaired in vascular and subcortical cognitive impairment patterns, which overlap substantially with Parkinson's disease cognitive profiles. 1 This patient demonstrates:

• Preserved procedural memory: He maintains his ability to play the violin at a basic level and performs all usual daily activities independently, indicating intact motor skill execution 1
• Intact semantic memory: He appears cognitively intact for general knowledge and language function 1
• Preserved episodic memory: He independently performs instrumental activities of daily living, suggesting he can recall recent events and personal experiences 1

Why Working Memory Specifically Affects New Music Learning

Learning new musical pieces requires simultaneous processing of multiple elements—reading notation, translating it to finger positions, maintaining rhythm, and integrating these components in real-time. 1 This demands substantial working memory capacity. The patient's difficulty is specifically with new music, not familiar pieces, which distinguishes this from:

• Procedural memory deficits: Would impair all violin playing, including previously learned pieces 2, 3
• Perceptual-motor dysfunction: Would affect basic motor execution and daily activities, which he performs independently 1
• Balance problems: Would interfere with standing to play but not specifically with learning new repertoire 1

Executive Dysfunction Pattern in Parkinson's Disease

Parkinson's disease characteristically produces executive dysfunction with prominent working memory impairment due to frontostriatal circuit involvement. 1 The NINDS-Canadian Stroke Network standards specifically identify that subcortical pathology produces:

• Slowed information processing 1
• Impaired ability to hold and manipulate information (working memory) 1
• Difficulty shifting between tasks 1

These deficits are especially evident on timed tasks requiring simultaneous processing—exactly what sight-reading new music demands. 1

Clinical Distinction from Dementia

This patient does NOT meet criteria for dementia or even mild cognitive impairment (MCI), as he maintains independence in all functional abilities and instrumental activities of daily living. 1 The NIA-Alzheimer's Association criteria specify that MCI requires preservation of independence in daily function, and dementia requires significant impairment in social or occupational functioning 1. This patient has neither.

His difficulty is a domain-specific cognitive challenge (working memory) within the context of treated Parkinson's disease, not a progressive dementing illness. 1

Why Other Options Are Less Likely

• Episodic memory: Would impair recall of recent events and learning of all new information, not just complex musical tasks; his independence in IADLs argues against this 1
• Procedural memory: Research demonstrates that even patients with severe hippocampal damage can learn new musical pieces through procedural learning 2, 3; this patient's difficulty is with the cognitive complexity of new music, not motor execution
• Semantic memory: Would affect general knowledge and language, which are intact 1
• Perceptual-motor function: Would impair basic motor tasks and ADLs, which he performs independently 1
• Balance: Would affect ambulation and standing stability, not cognitive processing of new musical information 1

Clinical Pitfall to Avoid

Do not attribute all cognitive complaints in elderly Parkinson's patients to "normal aging" or assume dementia is developing. 4 Domain-specific executive and working memory deficits can occur in well-controlled Parkinson's disease without progression to dementia, and these deficits particularly affect complex, multi-step cognitive tasks like learning new music while sparing simpler procedural skills. 1, 2