Final answer:
The short form MMSE cannot differentiate between Lewy body dementia and Alzheimer's disease because it assesses cognitive functions affected in both, without specificity for distinguishing symptoms.
Step-by-step explanation:
The potential drawback of using the short form Mini-Mental State Examination (MMSE) in differentiating between Lewy body dementia (LBD) and Alzheimer's disease (AD) is that it cannot differentiate between LBD and AD. This is because the MMSE primarily assesses global cognitive functions such as memory, attention, and language, which are affected in both diseases. It is not sensitive to the specific symptoms that distinguish LBD from AD, such as visual hallucinations, Parkinsonian symptoms, and fluctuations in cognitive ability that are characteristic of LBD. While the MMSE can be indicative of the presence of cognitive decline and dementia in general, it lacks the specificity to pinpoint the exact type of dementia without additional diagnostic tools or assessments.