Visual recovery after perinatal stroke evidenced by functional and diffusion MRI: case report

BACKGROUND: After perinatal brain injury, clinico-anatomic correlations of functional deficits and brain plasticity remain difficult to evaluate clinically in the young infant. Thus, new non-invasive methods capable of early functional diagnosis are needed in young infants. CASE PRESENTATION: The visual system recovery in an infant with perinatal stroke is assessed by combining diffusion tensor imaging (DTI) and event-related functional MRI (ER-fMRI). All experiments were done at 1.5T. A first DTI experiment was performed at 12 months of age. At 20 months of age, a second DTI experiment was performed and combined with an ER-fMRI experiment with visual stimuli (2 Hz visual flash). At 20 months of age, ER-fMRI showed significant negative activation in the visual cortex of the injured left hemisphere that was not previously observed in the same infant. DTI maps suggest recovery of the optic radiation in the vicinity of the lesion. Optic radiations in the injured hemisphere are more prominent in DTI at 20 months of age than in DTI at 12 months of age. CONCLUSION: Our data indicate that functional cortical recovery is supported by structural modifications that concern major pathways of the visual system. These neuroimaging findings might contribute to elaborate a pertinent strategy in terms of diagnosis and rehabilitation

Evaluation of crown-root angulation of lateral incisors adjacent to palatally impacted canines

BACKGROUND: The objective of this study is to explore differences in crown-to-root angulation between lateral incisors adjacent to palatally impacted canines (PICs) and lateral incisors adjacent to normally erupted canines (NECs). METHODS: Orthodontic records of 100 subjects (51 with PICs and 49 with NECs) were reviewed. Crown-to-root angulations of all lateral incisors were measured manually on the final panoramic radiographs. Also, three experienced orthodontists were asked to visually inspect the morphology of the lateral incisors on the panoramic radiographs. A mixed model was used to test the difference in crown-to-root angulation of the lateral incisor between the experimental and the control groups. The association between the examiners' observations and the presence of a canine impaction was assessed by means of a chi-square test. All analyses were performed at the 0.05 level of statistical significance. RESULTS: A significant (p = 0.009) difference of 2.3° in crown-to-root angulation was found between groups. Also, 66.7% of the lateral incisors that were identified as “abnormal” by the panel of orthodontists were adjacent to a PIC. A percentage of 65.2 of lateral incisors that were identified as “normal” were located adjacent to NECs. CONCLUSIONS: The root of lateral incisors adjacent to PICs is angulated more mesially compared to lateral incisors adjacent to NECs. In addition, clinicians are somewhat able to predict if a canine is palatally impacted by visually observing the crown-to-root angulation of the adjacent lateral incisor. Evaluating the crown-to-root angulation of a lateral incisor on a panoramic image might facilitate an early diagnosis of palatally impacted canines

Brain energy rescue:an emerging therapeutic concept for neurodegenerative disorders of ageing

The brain requires a continuous supply of energy in the form of ATP, most of which is produced from glucose by oxidative phosphorylation in mitochondria, complemented by aerobic glycolysis in the cytoplasm. When glucose levels are limited, ketone bodies generated in the liver and lactate derived from exercising skeletal muscle can also become important energy substrates for the brain. In neurodegenerative disorders of ageing, brain glucose metabolism deteriorates in a progressive, region-specific and disease-specific manner — a problem that is best characterized in Alzheimer disease, where it begins presymptomatically. This Review discusses the status and prospects of therapeutic strategies for countering neurodegenerative disorders of ageing by improving, preserving or rescuing brain energetics. The approaches described include restoring oxidative phosphorylation and glycolysis, increasing insulin sensitivity, correcting mitochondrial dysfunction, ketone-based interventions, acting via hormones that modulate cerebral energetics, RNA therapeutics and complementary multimodal lifestyle changes

Acute action of rotenone on nigral dopaminergic neurons--involvement of reactive oxygen species and disruption of Ca2+ homeostasis

Abstract Rotenone is a toxin used to generate animal models of Parkinson’s disease; however, the mechanisms of toxicity in substantia nigra pars compacta (SNc) neurons have not been well characterized. We have investigated rotenone (0.05–1 lm) effects on SNc neurons in acute rat midbrain slices, using whole-cell patch-clamp recording combined with microfluorometry. Rotenone evoked a tolbutamide-sensitive outward current (94 ± 15 pA) associated with increases in intracellular [Ca2+] ([Ca2+]i) (73.8 ± 7.7 nm) and intracellular [Na+] (3.1 ± 0.6 mm) (all with 1 lm). The outward current was not affected by a high ATP level (10 mm) in the patch pipette but was decreased by Trolox. The [Ca2+]i rise was abolished by removing extracellular Ca2+, and attenuated by Trolox and a transient receptor potential M2 (TRPM2) channel blocker, N-(p-amylcinnamoyl) anthranilic acid. Other effects included mitochondrial depolarization (rhodamine-123) and increased mitochondrial reactive oxygen species (ROS) production (MitoSox), which was also abolished by Trolox. A low concentration of rotenone (5 nm) that, by itself, did not evoke a [Ca2+]i rise resulted in a large (46.6 ± 25.3 nm) Ca2+ response when baseline [Ca2+]i was increased by a ‘priming’ protocol that activated voltage-gated Ca2+ channels. There was also a positive correlation between ‘naturally’ occurring variations in baseline [Ca2+]i and the rotenone-induced [Ca2+]i rise. This correlation was not seen in non-dopaminergic neurons of the substantia nigra pars reticulata (SNr). Our results show that mitochondrial ROS production is a key element in the effect of rotenone on ATP-gated K+ channels and TRPM2-like channels in SNc neurons, and demonstrate, in these neurons (but not in the SNr), a large potentiation of rotenone-induced [Ca2+]i rise by a small increase in baseline [Ca2+]i

Effectiveness of robot-assisted gait training on motor impairments in people with Parkinson's disease: A systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to evaluate the effectiveness of robot-assisted gait training (RAGT) on motor impairments in people with Parkinson's disease (PD). A computer-based systematic literature search was performed in six databases according to PRISMA guidelines. Randomized controlled trials (RCTs) that assessed the effects of RAGT on motor impairments in people with PD were included. GRADE approach and PEDro scale were used to determine the studies' quality of evidence. Meta-analyses were performed by calculating the weighted mean difference (WMD) at 95% confidence interval. Seven RCTs (PEDro: 5-8) met the inclusion criteria for systematic review and meta-analyses. The meta-analysis showed significant improvement on Unified Parkinson Disease Rating Scale Part III after intervention [WMD=3.292; 95% confidence interval (CI)=1.378-5.207; P=0.000], and after 1-month follow-up (WMD=5.512; 95% CI=2.396-8.629; P=0.001). Stride length (WMD=9.283; 95% CI=7.153-11.414; P=0.00) and gait speed (WMD=0.166; 95% CI=-0.090 to 0.243; P=0.000) showed significant improvements after RAGT. Balance as measured by Berg Balance Scale was improved significantly after intervention (WMD=3.87; 95% CI=0.374-6.735; P=0.029) and at 1-month follow-up (WMD=3.87; 95% CI=1.324-6.413; P=0.002). The pooled analysis did not detect any significant changes regarding stride time, cadence and functional balance scales. GRADE level of evidence ranged between high and low. The RAGT showed better outcomes than conventional interventions on some motor aspects in PD. However, RAGT did not seem superior to control interventions. Further RCTs that examine the effect of RAGT on more specific outcomes and at different medication statuses are required