Impact of regional striatal dopaminergic function on kinematic parameters of Parkinson's disease.

Among the cardinal parkinsonian motor deficits, the severity of bradykinesia correlates with striatal dopamine loss. However, the impact of regional striatal dopamine loss on specific components of bradykinesia remains unknown. Using gyroscopes, we measured the amplitude, speed, and frequency of finger tapping in 24 untreated patients with Parkinson's disease (PD) and 28 healthy controls. Using positron emission tomography (PET) studies and [(18)F]-N-3-fluoropropyl-2-beta-carboxymethoxy-3-beta-(4-iodophenyl) nortropane (FP-CIT) in PD patients, we investigated the relationship between the mean values, variability and decrements of various kinematic parameters of finger tapping on one side (e.g. the mean, variability and decrement) and contralateral striatal FP-CIT binding. Compared with controls, PD patients had reduced amplitudes and speeds of tapping and showed greater decrement in those parameters. PD patients also exhibited greater irregularity in amplitude, speed, and frequency. Putaminal FP-CIT uptake levels correlated with the mean speed and amplitude, and caudate uptake levels correlated with mean amplitude. The variability of amplitude and speed correlated only with the caudate uptake levels. Neither caudate nor putaminal uptake correlated with frequency-related parameters or decrement in amplitude or speed. Reduced amplitude and speed of repetitive movement may be related to striatal dopaminergic deficit. Dopaminergic action in the caudate nucleus is required to maintain consistency of amplitude and speed. Although decrement of amplitude and speed is known to be specific for PD, we found that it did not mirror the degree of striatal dopamine depletion.

Cognitive dysfunction associated with falls in progressive supranuclear palsy.

BACKGROUND: Attentional and executive dysfunctions are associated with falls in community-dwelling elderly individuals and patients with PD. Frontal cognitive dysfunction and falls are frequent symptoms of PSP. We studied to identify the cognitive domains associated with recurrent falls in patients with PSP. METHODS: We performed a battery of neuropsychological tests in 59 individuals with probable PSP. We categorized patients into infrequent fall (≤one fall during the last 12 months, n=29) or recurrent fall (≥two falls during the last 12 months, n=30) groups. RESULTS: UPDRS subscores for axial deficits were significantly higher in the recurrent fall group than the infrequent fall group, but there were no significant differences in UPDRS total motor scores or subscores for bradykinesia, rigidity, and tremor. There was no difference between groups in MMSE scores. ANCOVA with adjustment for confounding factors showed that, recurrent falls were associated with abnormalities in alternating hand movement, alternating square and triangle, RCFT copying task, and ideomotor apraxia. Group difference of abnormalities in Stroop test was marginal (p=0.054). However, there were no group differences in the frequency of abnormalities in forward or backward digit span, motor impersistence, fist-edge-palm, contrast programming, go-no-go, Luria loop drawing, or Controlled Oral Word Association Tests. Recurrent falls were not associated with memory or language dysfunction. CONCLUSIONS: Recurrent falls in patients with PSP were associated mainly with executive and visuospatial dysfunctions, including (1) impaired coordinated alternating uni- and bimanual motor programming and execution, (2) deficit of attention and decision making in the presence of interference, (3) visuospatial misperception and (4) ideomotor apraxia.

Kinematic analysis in patients with Parkinson's disease and SWEDD.

BACKGROUND AND OBJECTIVES: The differential diagnosis between mild Parkinson's disease (PD) and Scan Without Evidence of Dopaminergic Deficit(SWEDD) is challenging. Progressive reduction in amplitude and speed of finger tapping (sequence effect) has been considered as the most useful sign for discriminating PD from SWEDD. However, a video analysis reported that sequence effect is a major confounding factor for the misdiagnosis of PD. Our objective was to perform a kinematic analysis of finger tapping to explore parameters for distinguishing between patients with PD and SWEDD. METHODS: We enrolled 14 patients with PD, 17 patients with SWEDD and 18 age- and sex-matched healthy controls. Amplitude, speed and frequency of finger tapping were measured using gyroscopes, and the means, decrement and variability in kinematic parameters for specific tapping duration were calculated. RESULTS: Compared to SWEDD group, PD group showed more decrement in amplitude and speed of the first 20 taps, more decrement in frequency after 20 taps and more variability in speed of 15 seconds of taps. However, none of parameters was a practically useful indicator distinguishing individual patients with PD from those with SWEDD. CONCLUSIONS: Analysis of finger tapping, even using an apparatus, is not useful for distinguishing mild PD and SWEDD.