Fear among patients with Parkinson's disease and repeated falls: Analysis of skin conductance responses during simulated accidents

Abstract

IntroductionThe fear of falling (FoF) usually increases in patients with Parkinson’s disease (PD); however, it can decrease despite repeated falls for unknown reasons. This phenomenon is similar to the findings that the patients with PD show lower emotional responses in the decision-making during the Iowa gambling task (IGT) than of those without PD. The decision-making during the IGT is reportedly correlated with interoceptive accuracy. This phenomenon could be associated with decreased physiological reaction and interoception deficiency. This study aimed to investigate the factors associated with decreased FoF in patients with PD who fell repeatedly. MethodsWe recorded the skin conductance responses (SCR) during the task delivered by a virtual reality system and heartbeat perception task (HPT) as an interoceptive measure. We measured emotional self-awareness using visual analog scale (VAS) scores. We recruited 28 non-demented patients with PD and 24 age-matched Non-clinical population (NC) group. All patients with PD were grouped by FoF scale score and number of falls within the previous year into repeated falls without FoF, repeated falls with FoF, and no falls groups. ResultsThe SCR during all accident videos experienced by themselves were significantly lower in the repeated falls without FoF group than in the NC group (p < 0.01). The HPT was significantly lower in the repeated falls without FoF group than in the NC group (p = 0.007). ConclusionThe repeated falls without FoF group did not recognize recurrent falls as being problematic, possibly associated with decreased physiological reactions and interoception deficiency.