Music Attenuates Excessive Visual Guidance of Skilled Reaching in Advanced but Not Mild Parkinson's Disease

Parkinson's disease (PD) results in movement and sensory impairments that can be reduced by familiar music. At present, it is unclear whether the beneficial effects of music are limited to lessening the bradykinesia of whole body movement or whether beneficial effects also extend to skilled movements of PD subjects. This question was addressed in the present study in which control and PD subjects were given a skilled reaching task that was performed with and without accompanying preferred musical pieces. Eye movements and limb use were monitored with biomechanical measures and limb movements were additionally assessed using a previously described movement element scoring system. Preferred musical pieces did not lessen limb and hand movement impairments as assessed with either the biomechanical measures or movement element scoring. Nevertheless, the PD patients with more severe motor symptoms as assessed by Hoehn and Yahr (HY) scores displayed enhanced visual engagement of the target and this impairment was reduced during trials performed in association with accompanying preferred musical pieces. The results are discussed in relation to the idea that preferred musical pieces, although not generally beneficial in lessening skilled reaching impairments, may normalize the balance between visual and proprioceptive guidance of skilled reaching

The use of rodent skilled reaching as a translational model for investigating brain damage and disease

Neurological diseases, including Parkinson's disease, Huntington's disease, and brain damage caused by stroke, cause severe motor impairments. Deficits in hand use are one of the most debilitating motor symptoms and include impairments in body posture, forelimb movements, and finger shaping for manipulating objects. Hand movements can be formally studied using reaching tasks, including the skilled reaching task, or reach-to-eat task. For skilled reaching, a subject reaches for a small food item, grasps it with the fingers, and places it in the mouth for eating. The human movement and its associated deficits can be modeled by experimental lesions to the same systems in rodents which in turn provide an avenue for investigating treatments of human impairments. Skilled reaching movements are scored using three methods: (1) end point measures of attempts and success, (2) biometric measures, and (3) movement element rating scales derived from formal descriptions of movement. The striking similarities between human and rodent reaching movements allow the analysis of the reach-to-eat movement to serve as a powerful tool to generalize preclinical research to clinical conditions

The reach-to-grasp movement in infants later diagnosed with autism spectrum disorder: a high-risk sibling cohort study

Abstract Background Although autism spectrum disorder (ASD) is characterized by impairments in social communication and the presence of repetitive behavior and/or restricted interests, there is evidence that motor impairments may be a contributing factor to the ASD phenotype. The purpose of this study was to examine the motor act of reaching-to-grasp in children at high risk (HR; with an older sibling diagnosed with ASD) and low-risk (LR; no family history of ASD) for ASD. Methods Children were compared for differences in reaching-to-grasp based on sibling status and diagnostic outcome. Children were enrolled between 6 and 12 months of age and the reach-to-grasp movement was scored at 6, 9, (where available) 12, 15, 18, 24, and 36 months of age using the qualitative Skilled Reaching Rating Scale to determine the presence of any group-, age-, or sex-related differences in the mechanics of the reach-to-grasp movement using a Mixed Models analysis. At 36 months, all children underwent a gold-standard diagnostic assessment, which resulted in three outcome groups: HR children diagnosed with ASD (HR-ASD; n = 10), HR children not diagnosed with ASD (HR-N; n = 10), and low-risk children not diagnosed with ASD (LR; n = 10). Results The group of children who were later diagnosed with ASD (HR-ASD group) showed higher (worse) total scores on the reach-to-grasp movement, as well as higher scores on the components of Orient, Lift, and Pronate compared to children in the LR and HR-N groups. Conclusions Our results support the growing literature indicating that children who are later diagnosed with ASD show impaired early motor performance. These results highlight the importance of early surveillance of children who are at elevated risk for ASD, and early initiatives should focus on early signs of the phenotype, including both movement and sensory differences (prodromal signs) prior to the emergence of diagnostic characteristics

Time (mean and standard error) to complete advance and withdrawal for the four experimental groups.

<p>▒ = advanced PD>YAC; * = advanced PD>OAC; ## = advanced PD>mild PD and # ps<0.001.</p

Reach duration (top) and engagement duration (bottom) difference for all experimental groups (no music-music); mean and standard errors.

<p>Note that the time to complete total reach duration was not affected by accompanying music, whereas time to complete total engagement duration was decreased for advanced PD subjects.</p

Movement element score (mean and standard error) for the four experimental groups.

<p>▒ = advanced PD>YAC; ▒▒ = advanced PD>OAC; * = advanced PD>mild PD.</p

Time to complete engage to move and grasp to disengage (mean and standard error) for the four groups at baseline (left) and with preferred musical pieces (right).

<p>▒ = advanced PD>YAC at p<0.001; * = advanced PD>OAC at p<0.001; # = advanced PD>mild PD at p<0.05.</p

Time to complete advance and withdrawal (mean and standard errors) for the four experimental groups.

<p>* = different from visual condition (*<0.05; **<0.01; ***<0.001). Note for the advanced PD group both advance and withdrawal shows a significant change.</p

Experimental set-up.

<p>The white dots represent light reflective markers on the subject (left) and the food target (right). The head set is for eye-tracking. Food is placed on the pedestal and the subject begins the first reach with hand open on the lap.</p