Parallel plate model for trabecular bone exhibits volume fraction-dependent bias

Unbiased stereological methods were used in conjunction with microcomputed tomographic (micro-CT) scans of human and animal bone to investigate errors created when the parallel plate model was used to calculate morphometric parameters. Bone samples were obtained from the human proximal tibia, canine distal femur, rat tail, and pig spine and scanned in a micro-CT scanner. Trabecular thickness, trabecular spacing, and trabecular number were calculated using the parallel plate model. Direct thickness, and spacing and connectivity density were calculated using unbiased three-dimensional methods. Both thickness and spacing calculated using the plate model were well correlated to the direct three-dimensional measures (r(2) = 0. 77-0.92). The correlation between trabecular number and connectivity density varied greatly (r(2) = 0.41-0.94). Whereas trabecular thickness was consistently underestimated using the plate model, trabecular spacing was underestimated at low volume fractions and overestimated at high volume fractions. Use of the plate model resulted in a volume-dependent bias in measures of thickness and spacing (p < 0.001). This was a result of the fact that samples of low volume fraction were much more "rod-like" than those of the higher volume fraction. Our findings indicate that the plate model provides biased results, especially when populations with different volume fractions are compared. Therefore, we recommend direct thickness measures when three-dimensional data sets are available

Levodopa-carbidopa intestinal gel in advanced Parkinson's: Final results of the GLORIA registry

This registry evaluated the 24-month safety and efficacy of levodopa-carbidopa intestinal gel (LCIG) treatment in advanced Parkinson's disease (PD) patients under routine clinical care. Motor fluctuations, dyskinesia, non-motor symptoms, quality of life, and safety were evaluated. Observations were fully prospective for treatment-naïve patients (60% of patients) and partially retrospective for patients with ≤12 months of pre-treatment with LCIG (40% of patients). Hours of "On" and "Off" time were assessed with a modified version of the Unified Parkinson's Disease Rating Scale part IV items 32 and 39. Overall, 375 patients were enrolled by 75 movement disorder centers in 18 countries and 258 patients completed the registry. At 24 months LCIG treatment led to significant reductions from baseline in "Off" time (hours/day) (mean ± SD = −4.1 ± 3.5, P < 0.001), "On" time with dyskinesia (hours/day) (−1.1 ± 4.8, P = 0.006), Non-Motor Symptom Scale total (−16.7 ± 43.2, P < 0.001) and individual domains scores, and Parkinson's Disease Questionnaire-8 item total score (−7.1 ± 21.0, P < 0.001). Adverse events deemed to have a possible/probable causal relationship to treatment drug/device were reported in 194 (54%) patients; the most frequently reported were decreased weight (6.7%), device related infections (5.9%), device dislocations (4.8%), device issues (4.8%), and polyneuropathy (4.5%). LCIG treatment led to sustained improvements in motor fluctuations, non-motor symptoms particularly sleep/fatigue, mood/cognition and gastrointestinal domains, as well as quality of life in advanced PD patients over 24 months. Safety events were consistent with the established safety profile of LCIG