What motor symptom of Parkinson's Disease may be exacerbated by cholinesterase inhibitors?

In Parkinson's Disease, cholinesterase inhibitors, which are typically used to treat symptoms associated with Alzheimer's disease and other forms of dementia, can sometimes exacerbate the tremor component of the disease. This is particularly relevant because while these medications are intended to increase levels of acetylcholine, which can improve cognitive function, they can have unintended effects on the dopaminergic system that is already compromised in individuals with Parkinson's Disease.

The tremor in Parkinson's is a result of dysregulation of motor pathways primarily influenced by dopaminergic neurotransmission. When cholinesterase inhibitors are used, they can potentially increase cholinergic activity, which might lead to a worsening of tremor in patients who are already experiencing motor symptoms. This can be counterproductive since tremors can significantly affect a patient's daily living activities and quality of life.

In contrast, akinesia/bradykinesia, rigidity, and postural instability are generally not worsened by cholinesterase inhibitors in the same way. While these symptoms are also hallmark features of Parkinson's Disease, they do not have the same relationship with cholinergic activity as tremors do, thus making tremor the correct answer in this context.