The impact of nocturnal hypokinesia on supervised and unsupervised mobility in people with Parkinson’s disease

Abstract

Nocturnal hypokinesia (NH) is a disabling and underrecognized symptom of Parkinson’s disease (PD), affecting nighttime movements and sleep quality. However, its impact on daytime mobility remains unclear. This study investigated supervised and unsupervised mobility in propensity score-matched mild-to-moderate PD patients with (PD NH + ) and without NH (PD NH − ). Eighty-eight participants (44 PD NH+ and 44 PD NH-) underwent clinical assessments, mobility tests (i.e., 20-m forward walking, instrumented Timed-Up-and-Go and 3-metre backward walking test), and 5-day monitoring of average daily steps (AvDS) through a commercial activity tracker (Garmin Vivosmart 4). PD NH+ demonstrated worse functional mobility, reduced turning velocity, slower backwards walking, and fewer AvDS than PD NH-. Furthermore, NH severity correlated negatively with most supervised measures and with AvDS. However, sensitivity analyses controlling for fear of falling attenuated group differences in supervised mobility to non-significance, suggesting a preliminary nature of these findings. The association between NH severity and daily step count showed greater robustness. These findings suggest that NH could be associated with impaired daytime mobility and worse motor function. These findings highlight the importance of targeted interventions to address both nocturnal and diurnal mobility impairments in PD.