Ten-Second Cold Water Stress Test Differentiates Parkinson's Disease From Multiple System Atrophy: A Pilot Study

BackgroundPatients with Parkinsons disease (PD) often have cold hands and experience frostbite. The diagnostic criteria for multiple system atrophy (MSA) also describe cold and discolored hands, but in our clinical experience we have noticed that the hands are relatively warm. These symptoms are thought to be caused by autonomic dysfunction; however, the detailed mechanisms and differences in cold hands between MSA and PD remain unclear. ObjectivesTo identify an appropriate cold stimulation test to differentiate patients with PD and MSA using finger surface temperature (FST). MethodsWe included 27 and seven patients diagnosed with PD and MSA, respectively, at least 5 years after disease onset. After 15 minutes in a room with constant temperature and humidity, the patients hand was placed in cold water at 4{degrees}C for 10 seconds as the cold water stress test (10sec-CWST). FST was captured using a thermal imaging camera every minute for 15 minutes, and the recovery of FST was analyzed. The association between the clinical characteristics of each patient and the degree of FST recovery was examined. ResultsAll patients completed the 10sec-CWST without adverse events. Patients with PD showed a significantly slower recovery of FST after 7 minutes than that of those with MSA, with a maximum difference at 11 minutes (PD: 8.1{+/-}0.6{degrees}C; MSA: 10.5{+/-}0.3{degrees}C; p<0.01). FST recovery at 11 minutes was negatively correlated with the degree of resting hand tremor (r=-0.585, p<0.01). ConclusionsFST after 10sec-CWST may be safe and efficient test to differentiate PD and MSA.