Motor planning in Parkinson patients (original) (raw)
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Journal of Neurology, Neurosurgery & Psychiatry, 1986
Compared with a group of age matched controls, patients with Parkinson's disease scored significantly lower in testing for ideomotor apraxia. Imitation of movement sequences was affected more severely than performance of single movements. The degree of impairment was not related to severity of motor disability, but correlated strongly with the results of tests that measured visuospatial and visuoperceptive abilities. It is suggested that defective encoding and central processing of visuospatial information impairs memory for movement which is necessary for correct imitation of movements. Enhanced vulnerability to interference between successively presented items may cause further deterioration of performance in the copying of movement sequences.
Journal of Neurology, Neurosurgery & Psychiatry, 1983
We studied the ability of Parkinsonian patients and controls to generate voluntary movements on a tracing task. Subjects were videotaped while tracing designs of increasing complexity, presented on a vertical, transparent screen. Some designs were presented in a degraded form and subjects filled in their missing sections. Subjects also received a constructional task and a test of general intellectual ability. The quality of errors on the tracing task differed in the Parkinsonian and control groups. Parkinsonian patients made two distinct types of errors. One probably related to the motor disorders of the disease, but another seemed to be related to a higher level of control over sequential and predictive movements. The latter correlated with performance on the constructional and general intellectual tasks. These results suggest that Parkinson's disease may affect basal ganglia structures that are necessary for voluntary movements which require sequencing or planning. Clinically this may be observed in perceptual motor tasks since they require both voluntary movement and sequential organisation of behaviour.
Planning and executing an action in Parkinson's disease
Movement Disorders, 1999
We evaluated the possible impairment in planning and executing an action in patients with Parkinson's disease (PD). The action considered in the present study was formed by two successive motor acts: reaching-grasping an object (first target) and placing it on a second target of the same shape and size. We examined the effects of extrinsic properties of the second target (that is, distance) on the various kinematic phases of reaching-grasping movements. Distance, position, and size of both stimuli were randomly varied across the experimental session. Movements were executed with and without visual control of both targets and arm. The performance of six patients with PD was compared with an age-matched control group. The kinematics of the initial phase of reaching was influenced by position and size of the first target and by distance of the second target in both patients and control subjects. In particular, peak acceleration was higher for farther position of the second target. However, in the subsequent phase patients, differently from control subjects, removed the effects of the sec-ond target distance by modifying their reaching kinematics. This was obtained by varying the duration of the acceleration phase. In summary, the patients reprogrammed the reaching component by taking into account only the properties of the first target. The decreasing influence of second-target distance on reaching kinematics of patients was more evident during movements executed under visual control. Moreover, their movements executed without visual control were slowed down from the beginning. The second target affected the grasping kinematics only of the control subjects. Globally, these results indicate that PD patients are able to compute the general program of an action that takes into account extrinsic properties of the final target. However, the finding that PD patients reprogrammed the movement during its execution suggests a decay of the program during its time course, that is, basal ganglia can be involved in storing the plan of an action and in controlling its correct execution.
Movement precues in planning and execution of arm movement in Parkinson's disease
The restructuring of planning processes during movement initiation and execution in 7 persons with Parkinson's disease (PD) off medication was compared to that of 7 older controls. Participants performed a two-stroke aiming movement on a digitizer. From a start position, they passed through a center box to one of two targets located to the left and right of the center box. A precue of the target position was presented prior to the imperative stimulus. In 80% of the trials the precue was correct (valid) and in 20% of the trials the precue was incorrect (invalid). Reaction time (RT), movement time (MT) and the fluency (normalized jerk, NJ) were analyzed. In both groups, RT was significantly longer when the invalid precue was presented. However, RT showed no significant group effect or Group x Precue interaction. In contrast, MT and NJ demonstrated a PD effect. For the first stroke of the two-stroke movement, both MT and NJ showed a significant interaction between Group and Precue....
Planning in Parkinson's disease: A matter of problem structure?
Neuropsychologia, 2008
Although the Tower of London (TOL) has been extensively used to assess planning ability in patients with Parkinson's disease (PD), the reported presence or extent of any planning deficits has been inconsistent. This may partly be due to the heterogeneity of the TOL tasks used and a failure to consider how structural problem parameters may affect task complexity. In the present study, planning in PD patients was assessed by systematically manipulating TOL problem structure. Results clearly disprove the identity assumption of problems with an equal number of minimum moves. Instead, substantial parts of planning performance were related to more subtle aspects of problem structure, such as subgoaling patterns and goal hierarchy. Planning in PD patients was not impaired in general but was affected when the information provided by the problem states was ambiguous in terms of the sequential order of subgoals, but not by increases in search depth.
Movement precues in planning and execution of aiming movements in Parkinson's disease
Experimental Neurology, 2005
Two experiments tested how changing a planned movement affects movement initiation and execution in idiopathic Parkinson's disease (PD) patients. In Experiment 1, PD patients, elderly controls, and young adults performed discrete aiming movements to one of two targets on a digitizer. A precue (80% valid cue and 20% invalid cue of all trials) reflecting the subsequent movement direction was presented prior to the imperative stimulus. All groups produced slower reaction times (RTs) to the invalid precue condition. Only the subgroup of patients with slowest movement time showed a significant prolongation of movement for the invalid condition. This suggests that, in the most impaired patients, modifying a planned action also affects movement execution.
2012
Personality differences based on fine motor precision performance were studied in early stage Parkinson’s patients and an age-matched control group under two different test conditions: Proprioceptive + visual information and proprioceptive information alone. A comparative data analysis for deviations of three measured movement types (transversal, frontal and sagittal) was done for both hands (dominant and non-dominant) with relation to personality di-mensions. There were found significant differences between the two groups in decision making dimension and emotionality. After splitting the data for gender subgroups, some significant differences were found for men but not for women. The differences in fine motor task performance varied, being better in some directions for the Parkinson’s patients and worse in others. The findings may suggest that medication has both positive and negative effects on motor per-formance and provoke personality changes, being more pronounced in men.
Motor control abnormalities in Parkinson's disease
Cold Spring Harbor perspectives in medicine, 2012
The primary manifestations of Parkinson's disease are abnormalities of movement, including movement slowness, difficulties with gait and balance, and tremor. We know a considerable amount about the abnormalities of neuronal and muscle activity that correlate with these symptoms. Motor symptoms can also be described in terms of motor control, a level of description that explains how movement variables, such as a limb's position and speed, are controlled and coordinated. Understanding motor symptoms as motor control abnormalities means to identify how the disease disrupts normal control processes. In the case of Parkinson's disease, movement slowness, for example, would be explained by a disruption of the control processes that determine normal movement speed. Two long-term benefits of understanding the motor control basis of motor symptoms include the future design of neural prostheses to replace the function of damaged basal ganglia circuits, and the rational design of r...