Effects of Medication on Turning Deficits in Individuals with Parkinson's Disease

Abstract

Background and Purpose People with with Parkinson disease (PD) often have difficulty executing turns. To date, most studies of turning have examined subjects ON their anti-Parkinson medications. No studies have examined what specific aspects of turning are modified or remain unchanged when medication is administered. The purpose of this study was to determine how anti-Parkinson medications affect temporal and spatial features of turning performance in individuals with PD. Methods We examined turning kinematics in 10 people with PD who were assessed both OFF and ON medication. For both conditions, participants were evaluated with the UPDRS motor subscale, rated how well their medication was working on a visual analogue scale (VAS), performed straight-line walking and 180 degree in-place turns. We determined average walking velocity, time and number of steps to execute turns, sequence of yaw rotation onsets of the head, trunk, and pelvis during turns, and amplitudes of yaw rotation of the head, trunk, and pelvis during turns. Results Medication significantly improved UPDRS scores (p = 0.02), VAS ratings (p = 0.03), and walking velocity (p = 0.02). While improvements in turning were not statistically significant, medication did reduce the time and number of steps required to to turn, slightly increased the amplitudes of yaw rotation of the various segments, and increased the rotation of the head relative to the other segments. Medication did not improve the timing of segment rotations, which showed “en bloc” turn initiation in both the OFF and ON medication conditions. Discussion and Conclusion These results suggest that only certain aspects of turning may be responsive to anti-Parkinson medications. As such, additional rehabilitative approaches to address turning are needed, as turning may not be effectively addressed by pharmacological approaches. These results should be interpreted cautiously given the small sample size.

A narrative review of turning deficits in people with Parkinson’s disease

“…Whilst this paper does highlight the influence of axial rotation on turning performance, it is unlikely that this is a result of improvements in axial rigidity particularly, as levodopa has since been shown to be ineffective at improving specific axial deficits during turning [13]. However, when considering the components of the KCH rating scale for axial rotation, also include measures of perpendicular performance, such as rising from a chair and whole body bradykinesia, this again suggests the influence of levodopa on secondary compensations only; highlighting the need to address axial rotation deficits specifically as the disease progresses and turning becomes more challenging.…”

“…The axial deficits include segment rigidity [4,13,24,25,38], altered trunk segment co-ordination [6,8,18,22,27,29,38,39] and timing [6,8,9,14,19,25,26,32,33], reduced segment rotation [9,14,22,27] and altered posture [2,5,7] (Table 2). Each deficit, alongside their interactions and clinical implications, will be discussed in this review.…”

“…Such motor deficits commonly lead to poor performance in measures of balance and functional tasks, and have been associated with generalised deficits of attention and falls [3]. Difficulties with turning around the longitudinal axis are a common and early feature of PD, and can be present while lying recumbent [4], seated [5], standing [6][7][8][9][10][11][12][13][14][15] or walking [9][10][11][12][13][14][15][16][17][18][19].…”

Saccadic Eye Movements are Related to Turning Performance in Parkinson Disease

“…Levodopa therapy, the most common treatment for those with PD, provides minimal improvement in both turn performance and voluntary saccade performance. 36,37 However, DBS of the STN in persons with PD has shown considerable efficacy in improving motor performance, including gait and performance of voluntary and reflexive saccades. 38–40 .…”

Pharmacological treatment in Parkinson's disease: Effects on gait

“…Whereas turning in place does not seem to benefit from dopaminergic treatment [38, 63], making a turn to change walking direction does. Turning speed and number of steps to complete the turn improved with levodopa [38, 59], but to a lesser extent than parameters of straight walking [59].…”