Missense mutation of Brain Derived Neurotrophic Factor (BDNF) alters neurocognitive performance in patients with mild traumatic brain injury: a longitudinal study

The predictability of neurocognitive outcomes in patients with traumatic brain injury is not straightforward. The extent and nature of recovery in patients with mild traumatic brain injury (mTBI) are usually heterogeneous and not substantially explained by the commonly known demographic and injury-related prognostic factors despite having sustained similar injuries or injury severity. Hence, this study evaluated the effects and association of the Brain Derived Neurotrophic Factor (BDNF) missense mutations in relation to neurocognitive performance among patients with mTBI. 48 patients with mTBI were prospectively recruited and MRI scans of the brain were performed within an average 10.1 (SD 4.2) hours post trauma with assessment of their neuropsychological performance post full Glasgow Coma Scale (GCS) recovery. Neurocognitive assessments were repeated again at 6 months follow-up. The paired t-test, Cohen’s d effect size and repeated measure ANOVA were performed to delineate statistically significant differences between the groups [wildtype G allele (Val homozygotes) vs. minor A allele (Met carriers)] and their neuropsychological performance across the time point (T1 = baseline/ admission vs. T2 = 6th month follow-up). Minor A allele carriers in this study generally performed more poorly on neuropsychological testing in comparison wildtype G allele group at both time points. Significant mean differences were observed among the wildtype group in the domains of memory (M = -11.44, SD = 10.0, p = .01, d = 1.22), executive function (M = -11.56, SD = 11.7, p = .02, d = 1.05) and overall performance (M = -6.89 SD = 5.3, p = .00, d = 1.39), while the minor A allele carriers showed significant mean differences in the domains of attention (M = -11.0, SD = 13.1, p = .00, d = .86) and overall cognitive performance (M = -5.25, SD = 8.1, p = .01, d = .66).The minor A allele carriers in comparison to the wildtype G allele group, showed considerably lower scores at admission and remained impaired in most domains across the timepoints, although delayed signs of recovery were noted to be significant in the domains attention and overall cognition. In conclusion, the current study has demonstrated the role of the BDNF rs6265 Val66Met polymorphism in influencing specific neurocognitive outcomes in patients with mTBI. Findings were more detrimentally profound among Met allele carriers

How effective is a powered toothbrush as compared to a manual toothbrush? A systematic review and meta‐analysis of single brushing exercises

Objectives: In adult participants, what is, following a single brushing exercise, the efficacy of a powered toothbrush (PTB) as compared to a manual toothbrush (MTB) on plaque removal?. Methods: MEDLINE-PubMed and Cochrane-CENTRAL were searched from inception to February 2019. The inclusion criteria were (randomized) controlled clinical trials conducted in human subjects ≥18 years of age, in good general health and without periodontitis, orthodontic treatment, implants and/or removable prosthesis. Papers evaluating a PTB compared with a MTB in a single brushing exercise were included. When plaque scores were assessed according to the Quigley-Hein plaque index (Q&HPI) or the Rustogi modified Navy plaque index (RMNPI). From the eligible studies, data were extracted. A meta-analysis and subanalysis for brands and mode of action being oscillating-rotating (OR) and side-to-side (SS) were performed when feasible. Results: Independent screening of 3450 unique papers resulted in 17 eligible publications presenting 36 comparisons. In total, 28 comparisons assessed toothbrushing efficacy according to the Q&HPI and eight comparisons used the RMNPI. Results showed a significant effect in favour of the PTB. The difference of Means (DiffM) was −0.14 (P < 0.001; 95%CI [−0.19; −0.09]) for the Q&HPI and −0.10 (P < 0.001; 95%CI [−0.14; −0.06]) for the RMNPI, respectively. The subanalysis on the OR mode of action showed a DiffM −0.16 (P < 0.001; 95%CI [−0.22, −0.10]) for the Q&HPI. For the SS mode of action using RMNPI, the DiffM showed −0.10 (P < 0.001; 95%CI [−0.15; −0.05]). The subanalysis for brands showed for the P&G OR PTB using the Q&HPI a DiffM of −0.15 (P < 0.001; 95%CI [−0.22; −0.08]) and the Colgate SS for RMNPI showed a DiffM of −0.15 (P < 0.001; 95%CI [−0.18; −0.12]). Conclusion: There is moderate certainty that the PTB was more effective than the MTB with respect to plaque removal following a single brushing exercise independent of the plaque index scale that was used