The effect of handedness on mental rotation of hands: a systematic review and meta-analysis.

Body-specific mental rotation is thought to rely upon internal representations of motor actions. Handedness is a source of distinctly different motor experience that shapes the development of such internal representations. Yet, the influence of handedness upon hand mental rotation has never been systematically evaluated. Five databases were searched for studies evaluating hand left/right judgement tasks in adults. Two independent reviewers performed screening, data extraction, and critical appraisal. Eighty-seven datasets were included, with 72 datasets pooled; all had unclear/high risk of bias. Meta-analyses showed that right-handers were faster, but not more accurate, than left-handers at hand mental rotation. A unique effect of handedness was found on performance facilitation for images corresponding to the dominant hand. Meta-analyses showed that right-handers were quicker at identifying images of right hands than left hands-a dominance advantage not evident in left-handers. Differing hand representations (more lateralised hand dominance in right-handers) likely underpin these findings. Given potential differences between hand preference and motor performance, future research exploring their distinct contributions to mental rotation is warranted.

Personalized treatment planning in eye brachytherapy for ocular melanoma: Dosimetric analysis on ophthalmic structure at risk.

PURPOSE: To evaluate the impact on dose distribution to eye organs-at-risk (eOARs) of a computed tomography (CT)-based treatment planning in eye plaque brachytherapy (EPB) treatment. METHODS: We analyzed 19 ocular melanoma patients treated with ruthenium-106 plaques to a total dose of 100 Gy to tumor apex using conventional central-axis-point dose calculation. Treatments were re-planned using the Plaque Simulator (PS) software implementing two different strategies: a personalized CT-eye-model (CT-PS) and a standard-eye-model (SEM-PS) defined by Collaborative Ocular Melanoma Study. Dice coefficient and Hausdorff distance evaluated the concordance between eye-bulb-models. Mean doses (Dmean) to tumor and eOARs were extracted from Dose-Volume-Histograms and Retinal-Dose-Area-Histogram. Differences between planning approaches were tested by Wilcoxon signed-rank test. RESULTS: In the analyzed cohort, 8 patients (42%) had posterior tumor location, 8 (42%) anterior, and 3 (16%) equatorial. The SEM did not accurately described the real CT eye-bulb geometry (median Hausdorff distance 0.8 mm, range: (0.4-1.3) mm). Significant differences in fovea and macula Dmean values were found (p = 0.04) between CT-PS and SEM-PS schemes. No significant dosimetric differences were found for tumor and other eOARs. The planning scheme particularly affects the OARs closest to the tumor with a general tendency of SEM-PS to overestimate the doses to the OARs closest to the tumor. CONCLUSION: The dosimetric accuracy achievable with CT-PS EPB treatment planning may help to identify ocular melanoma patients who could benefit the most from a personalized eye dosimetry for an optimal outcome in terms of tumor coverage and eOARs sparing. Further research and larger studies are underway.

Radiation-induced acute dysphagia : Prospective observational study on 42 head and neck cancer patients.

PURPOSE: Acute toxicity in head and neck (H&N) cancer patients treated with definitive radiotherapy (RT) has a crucial role in compliance to treatments. The aim of this study was to correlate doses to swallowing-associated structures and acute dysphagia. METHODS: We prospectively analyzed 42 H&N cancer patients treated with RT. Dysphagia (grade ≥ 3) and indication for percutaneous endoscopic gastrostomy (PEG) insertion were classified as acute toxicity. Ten swallowing-related structures were considered for the dosimetric analysis. The correlation between clinical information and the dose absorbed by the contoured structures was analyzed. Multivariate logistic regression method using resampling methods (bootstrapping) was applied to select model order and parameters for normal tissue complication probability (NTCP) modelling. RESULTS: A strong multiple correlation between dosimetric parameters was found. A two-variable model was suggested as the optimal order by bootstrap method. The optimal model (Rs = 0.452, p < 0.001) includes V45 of the cervical esophagus (odds ratio [OR] = 1.016) and Dmean of the cricopharyngeal muscle (OR = 1.057). The model area under the curve was 0.82 (95% confidence interval 0.69-0.95). CONCLUSION: Our results suggested that the absorbed dose to the cricopharyngeal muscle and cervical esophagus might play a relevant role in the development of acute RT-related dysphagia.

Predictors of Asymptomatic Radiation-induced Abdominal Atherosclerosis.

AIMS: To identify predictors of asymptomatic radiation-induced abdominal atherosclerosis in patients treated with radiotherapy and evaluated by abdominal vascular ultrasonography. MATERIALS AND METHODS: Forty-two testicular classic seminoma patients (median age 34 years, range 16-56) undergoing radical inguinal orchiectomy were analysed. Twenty-six patients underwent post-surgery radiotherapy (median total dose 25 Gy, range 25-43), two of them also received chemotherapy (CHT) and 16 patients were treated with surgery alone or by surgery followed by CHT (control group). The presence of stenosis in an abdominal vessel and renal resistive index (RRI), evaluated by echo-colour Doppler (ECD), were considered as indicators of late vascular damage. Chi-square and Mann-Whitney tests were used to compare groups. For the radiotherapy group, near maximum (D2%) and mean dose (Dmean) metrics of critical structures (abdominal arteries and renal hila) were extracted from retrievable dose maps (18 of 26 radiotherapy patients). To evaluate clinical and dosimetric factors associated with vascular damage, univariate and multivariate analyses were carried out. The impact of dose to arteries, evaluated as separate subvolumes, was analysed comparing the stenotic arteries with normal ones by logistic regression. The area under the receiver operator characteristic curve (AUC) was used to evaluate the test accuracy. RESULTS: In the radiotherapy group there was a significantly different incidence of stenosis (31% versus 0%, P = 0.016) and a higher median average RRI (0.63 versus 0.60, P = 0.032) compared with the control group. The median time intervals between treatment and ECD were 64 months (range 12-120) and 48 months (range 12-168) in the radiotherapy and control groups (P = 0.399), respectively. A younger age at radiotherapy was the only clinical risk factor for stenosis (P = 0.006). Artery Dmean was significantly associated with stenosis (P = 0.008), with an odds ratio of 1.13 (95% confidence interval 1.01-1.26) and an AUC of 0.85 (95% confidence interval 0.77-0.91). Renal hilum D2% was correlated with RRI (Rs = 0.406, P = 0.02). CONCLUSIONS: Late vascular damage represents a potential effect of abdominal radiotherapy, even at a moderate dose. Younger age at irradiation, artery and renal hila dose metrics are associated with increased risk. Ultrasound-based follow-up may allow for non-invasive early detection of asymptomatic radiation-induced damage, helping to prevent severe vascular events.

Developmental changes in cognitive and behavioural functioning of adolescents with fragile-X syndrome.

BACKGROUND: Individuals with fragile-X syndrome exhibit developmental delay, hyperexcitation and social anxiety; they also show lack of attention and hyperactivity. Few studies have investigated whether levels of functioning change with increasing age. Here, we explored developmental changes across adolescence in the cognitive and behavioural profile of individuals with fragile-X syndrome. To this scope, we assessed intellectual functioning, adaptive behaviour, autistic symptomatology, behavioural problems (e.g. hyperactivity/lack of attention) and strengths (prosocial behaviours). METHOD: Thirty-six participants underwent standardised outcome measures (i.e. the Wechsler Intelligence Scales-Revised, the Childhood Autism Rating Scale, the Vineland Adaptive Behavior Scales, and the Strengths and Difficulty Questionnaire) in three time points (Time 1: 9-11; Time 2: 11-13, and Time 3: 13-15 years). RESULTS: Verbal IQ improved across time, whereas Nonverbal IQ declined and Full Scale IQ was quite unchanged. Autism ratings decreased; communication and social aspects of adaptive behaviour also enhanced. Finally, elevated levels of hyperactivity/lack of attention at Time 1 significantly improved across the three time points, whereas emotional symptoms, behavioural difficulties, problems with peers and prosocial behaviours remained stable over time. CONCLUSION: These findings revealed specific developmental changes in cognitive and behavioural functioning of individuals with fragile-X syndrome, likely related to a progressive maturation of brain systems devoted to attentional control.

Unawareness of "illnesses": a case of right-sided hemiballism.

The Authors describe a non-demented patient who, after a left subthalamic haemorrhage causing hemiballism, was completely unaware of both neurological (i.e., dyskinesias) and non-neurological (i.e., cough) symptoms occurring after the stroke. In contrast, he was perfectly able to acknowledge pathological conditions affecting him before the brain damage. Neuropsychological assessment showed no cognitive defects, but revealed the presence of frontal behaviours (e.g., perseverations and utilization behaviours). This unusual clinical picture was ascribed to damage of frontal-subcortical circuits involved in conscious representation of current bodily states.

Movement velocity effects on kinaesthetic localisation of spatial positions.

In the present study, we examined how subjects locate spatial positions and code them in short-term memory. In the first experiment, blindfolded subjects were asked to perform movements in the near or far peripersonal space (criterion movement, CM). Then, subjects had to reach the end-point of CM (reproduction movement, RM). Movements could be performed either slowly or rapidly. Also, CM and RM could be performed with the same (congruent conditions) or different velocity (incongruent conditions). The results showed that performance was accurate in the two congruent conditions. Conversely, in the incongruent conditions, subjects made undershoot errors when the CM was fast and overshoot errors when it was slow. In the second experiment, blindfolded subjects also performed CM and RM in congruent or incongruent conditions. However, the CM and RM could start from the same or different position. We found again undershoot errors when the CM was fast and RM was slow and overshoot errors in the reverse condition. The results of both experiments suggest that the information about movement velocity contributes to the kinaesthetic coding in memory of a spatial location to be reached with arm movement.