Olfaction is our oldest sense. When we lose our sense of smell, it can signal the beginning of Parkinson's, Alzheimer's and or a pituitary tumor.
I have patients try to identify coffee, cinnamon and or peanut butter during the sniff test. If they fail to identify the smell, I make sure to refer out for further imaging.
Loss of smell might be the first clinical sign of a disease years before it becomes more degenerative. A Swedish study found 61% of hyposomic (couldn't smell) adults with DAT deficit developed Parkinson's after 4 years. Not everyone who has a decrease in sense of smell goes on to develop Parkinson's. That is why additional imaging is important to confirm the diagnosis. If loss of smell is documented and imaging is reflexively ordered then treatments can be used earlier before there is severe pathological changes in the brain. Early diagnosis equals better prognosis.
My clinical experience with patients with Parkinson's has been good. I have worked with several cases over the past 20 years and used my environmental medical approach. When patients followed the environmental detoxification protocols and made critical lifestyle changes they achieved clinical remission. I treat Parkinson's aggressively with nutraceuticals, clinical nutrition and I.V. therapies.