Parkinson’s Disease May be Related to Dopamine Deficiency: AAN poster

Enterprise Reporting from the Annual Meeting of the American Academy of Neurology

                      Seniors Ride the “No-Dope Express”

by John Otrompke

Patients with Parkinson’s Disease (PD) miss medical appointments less frequently than other neurology patients, according to a poster presented at this year’s annual meeting of the American Academy of Neurology (AAN) in Los Angeles.

Neurologists previously hypothesized that PD is associated with personality traits such as increased conscientiousness and punctuality, but prior evidence was based on subjective questionnaires. Poster 60, “A Real-World Inquiry of the So-Called Parkinsonian Personality -- Comparing No-Show Rates of the Neurology Outpatients with and without Parkinson's disease (PD),” supplemented the existing data with real world evidence.

In the study, researchers from Virginia Tech's Carilion Clinic examined data from  medical records for all neurology appointments between January of 2010 and June of 2016. Of 19,501 patients, 400 had a diagnosis of PD, for whom the no-show rate was 3%, compared to 7.4% (p<0.001) among other neurology patients, according to the abstract.

In addition to punctuality, PD is associated with other characteristics thought to illustrate reduced novelty seeking, which in turn is thought to arise from a dopamine-deficient state. Examples of such personality characteristics include smoking and gambling (and maybe erectile dysfunction, as well- see below).

“Multiple studies show tobacco use is inversely associated with developing PD,” said Joseph Ferrara, MD, assistant professor at Virginia Tech Carilion School of Medicine in Roanoke, Virginia, who presented the poster. 

“People have associated lower smoking rates with reduced novelty-seeking, hypothesizing that the lower dopamine state makes it less likely people will begin smoking, and easier for them to quit. Gambling has also been looked at, because of problematic gambling that occurs in a minority of patients treated with dopamine agonists,” added Ferrara.

Another poster presented at AAN looked at another characteristic in some PD patients which may be associated with dopamine deficiency: erectile dysfunction.

Traumatic brain injury was not associated with an increased risk for alpha-synucleinopathy (including PD), but erectile dysfunction was, according to poster 63, “Traumatic brain injury and erectile dysfunction preceding clinically diagnosed alpha-synucleinopathies: a case – control study in Olmsted County, MN (1991-2010).” 

In the study, researchers from The Mayo Clinic examined data from all cases of alpha-synucleinopathies in Olmsted County, Minnesota from 1991 to 2010. Erectile dysfunction was found to be more common in patients later diagnosed with PD. The odds ration was 1.48 (p=0.051).