Based on the available information, there is no definitive evidence that Lipitor use improves mental acuity in the elderly.

The first source, drugpatentwatch.com, provides information about Lipitor's patent but does not include data on its effects on mental acuity in the elderly [1]. The second source, a study published in the National Center for Biotechnology Information, focuses on the potential impact of statins (which Lipitor is a part of) on cognitive function in elderly women with a history of stroke [2]. The results suggest that statin therapy may be associated with better cognitive function in this specific population, but it does not establish a causal relationship.

The third source, an article from Harvard Health Publishing, discusses the controversy around the relationship between statins and dementia, stating that some studies have found an increased risk of dementia with statin use, while others have found no association or even a protective effect [3]. However, it does not specifically address the impact of Lipitor or statins on mental acuity in the elderly.

In conclusion, while some studies suggest a potential beneficial effect of statins on cognitive function in specific elderly populations, the evidence is not conclusive. Therefore, it cannot be stated that Lipitor use improves mental acuity in the elderly.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5830056/
[3] https://www.health.harvard.edu/staying-healthy/do-statins-increase-the-risk-of-dementia