To systematically quantify limb skin temperatures in patients with multiple system atrophy (MSA) and explore differences compared to healthy and diseased control groups.

As part of a prospective, longitudinal study of synucleinopathies we enrolled patients with early MSA (n=28), Parkinson’s disease (PD, n=14), Pure Autonomic Failure (PAF, n=37), and healthy controls (CON, n=15), and measured skin temperatures at 12 standardized sites per limb using a digital infrared temperature scanner under controlled ambient temperature. Patients were followed for up to 3 years and measurements were obtained annually. Proximal and distal measurement sites were averaged, and proximal-to-distal temperature gradients calculated. Subjects were also asked about symptoms of cold hands/feet.

At baseline, there were no significant temperature differences at distal sites between MSA, PD, and CON, and no difference in proximal-to-distal temperature gradients. In contrast, patients with PAF had significantly higher distal skin temperatures and lower proximal-to-distal temperature gradients compared to the other groups. These findings were virtually identical at last follow-up. In contrast, 59% of MSA vs. 23% of CON, 19% of PAF and 10% of PD patients reported symptoms of cold hands and feet.

While the majority of MSA patients reports symptoms of cold hands and feet, objective measurements do not reveal differences in distal skin temperatures compared to PD and CON. Cold hands and feet may therefore either be largely subjective, present only under certain circumstances, or limited to advanced disease stages, limiting its utility to support an early diagnosis. The higher distal skin temperatures in PAF are intriguing and may relate to peripheral autonomic denervation.