A novel clinical sign to assess the risk of Parkinson’s disease in patients with isolated asymmetric arm swing

Introduction An isolated asymmetric arm swing can represent the beginning of Parkinson’s disease (PD) but also be related to physiological or non-specific musculoskeletal pathology. Patients and methods In this brief clinical observation including 15 patients with asymmetric arm swing, we provide a new clinical clue to evaluate the risk of subjacent parkinsonism. Results Among non-parkinsonian subjects, the immobilization of the contralateral arm, by asking the patient to put his hand on the contralateral shoulder, induced a clear increase in the amplitude of the arm swing, whereas in PD patients, the arm swing amplitude did not significantly vary when the contralateral upper limb was immobilized. Conclusions This novel clinical sign may be helpful when approaching patients with gait abnormalities and specifically reduced arm swing.