Model-Based Deep Brain Stimulation Programming for Parkinson's Disease: The GUIDE Pilot Study.

BACKGROUND: Achieving optimal results following deep brain stimulation (DBS) typically involves several months of programming sessions. The Graphical User Interface for DBS Evaluation (GUIDE) study explored whether a visual programming system could help clinicians accurately predetermine ideal stimulation settings in DBS patients with Parkinson's disease. METHODS: A multicenter prospective, observational study was designed that utilized a blinded Unified Parkinson's Disease Rating Scale (UPDRS)-III examination to prospectively assess whether DBS settings derived using a neuroanatomically based computer model (Model) could provide comparable efficacy to those determined through traditional, monopolar review-based programming (Clinical). We retrospectively compared the neuroanatomical regions of stimulation, power consumption and time spent on programming using both methods. RESULTS: The average improvement in UPDRS-III scores was 10.4 ± 7.8 for the Model settings and 11.7 ± 8.7 for the Clinical settings. The difference between the mean UPDRS-III scores with the Model versus the Clinical settings was 0.26 and not statistically significant (p = 0.9866). Power consumption for the Model settings was 48.7 ± 22 µW versus 76.1 ± 46.5 µW for the Clinical settings. The mean time spent programming using the Model approach was 31 ± 16 s versus 41.4 ± 29.1 min using the Clinical approach. CONCLUSION: The Model-based DBS settings provided similar benefit to the Clinical settings based on UPDRS-III scores and were often arrived at in less time and required less power than the Clinical settings.

Comparison of knee motion on Earth and in space: an observational study.

BACKGROUND: Spaceflight has been shown to cause atrophy, reduced functional capacity, and increased fatigue in lower-limb skeletal muscles. The mechanisms of these losses are not fully understood but are thought to result, in part, from alteration in muscle usage. METHODS: Knee-joint angles and lower-extremity muscle activity were measured continually, via elecrogoniometry and surface electromyography respectively, from two subjects during entire working days of activity on Earth and onboard the International Space Station (ISS). RESULTS: On Earth the distribution of angular positions of the knee was typically bimodal, with peaks of >75 degrees of flexion and in almost full extension (<15 degrees of flexion). However, on the ISS, a single peak in the mid-range of the available range of motion was seen. The knee joint was also moved through fewer excursions and the excursions were smaller in amplitude, resulting in a reduced span of angles traversed. The velocities of the excursions in space were lower than those used on Earth. CONCLUSION: These results demonstrate that, in space, overall knee-joint motion is reduced, and there is a transformation in the type of muscle action compared to that seen on Earth, with more isometric action at the expense of concentric and particularly eccentric action.