Friday, 8 September 2017

A nose for detection

There is a nice editorial coming out in Neurology highlighting the strength of the finding of poor smell (known as anosmia or hyposmia) in those at high risk of developing PD.

Poor smell due to any reason (i.e. trauma, chronic nose/sinus infections or neurodegeneration) is common when tested - between 1 in 4 to 1 in 6 American adults. When people are asked about their smell, however, less than 1 in 10 say they have poor smell. In Parkinson's disease, 9 in 10 people have poor smell.

The editorial highlights the possible pathological processes that link anosmia and Parkinson's. It also alludes to links between smell, normal physiology and potential sources for the disease to start. For instance, poor smell leads to a reduction in the digestive processes controlled by the brain and nervous system, which in turn changes the acidity of the stomach and gut, which in turn leads to a change in the bacteria which live in the gut. This bears direct relevance for the hypothesis that changes in the gut microbiome is involved in the initiation of PD, and also has relevance to the debate from 2015 regarding the risk reduction after truncal vagotomy.

Regardless of the cause and effect of anosmia, it is a significant finding, and we will continue to look for it in the participants of PREDICT-PD