Detecting subtle fingertip sensory and motor dysfunction in adults with type II diabetes

Although evidence has emerged regarding functional neural impairment of all four limbs with a diagnosis of type II diabetes (T2D), there is conflicting evidence regarding impairment in manual function with the disease. The purpose of the current study was to evaluate hand/fingertip function in T2D as compared to healthy age- and gender-matched controls. Ten adults with T2D and ten healthy age- and gender-matched control subjects underwent a battery of clinically validated and laboratory-based evaluations of sensory function, motor function, and quality of life evaluation. The T2D group exhibited sensory dysfunction and altered kinetic output and inconsistent differences in clinically-validated timed performance tasks as compared to age-matched controls. No difference in quality of life was found between the two groups. Sensory dysfunction and some timed evaluations correlated with disease severity. Linear kinetic features did not covary with diminished sensation; however, nonlinear measures did covary with sensation changes. None of the recorded measures were related to clinical diagnosis of peripheral neuropathy. The relationship among exhibited behavioral changes is discussed in terms of small fiber neuropathy, micro-vascular adaptations, and endothelial dysfunction co-occurring with T2D.     

Tooth and periodontal clinical attachment loss are associated with hyperglycemia in patients with diabetes

Background: Periodontal disease has been associated with diabetes, but there is still controversy on the relationship between periodontal clinical parameters and glycemic control. The purpose of this study is to assess the relationship between blood glucose levels and clinical parameters of periodontal disease in individuals with diabetes. Methods: A total of 65 individuals with diabetes and 81 individuals without diabetes were included in the study. A full-mouth periodontal examination and preprandial fasting glycemia values were recorded for each individual. Glycosylated hemoglobin was only measured in patients with diabetes. A comparative analysis between groups (Mann-Whitney U test) and a correlation analysis between glycemia and periodontal parameters were performed (Spearman test). Results: Patients without diabetes presented more teeth than individuals with diabetes (P <0.05). Patients with diabetes with periodontitis displayed loss of periodontal clinical attachment compared to patients without diabetes, but the highest value was observed in patients with periodontitis that reported a smoking habit. Furthermore, patients with diabetes with periodontitis presented higher glycemia and glycated hemoglobin values in contrast to patients with gingivitis. Patients with diabetes with hyperglycemia had a higher risk to develop periodontitis (odds ratio = 2.24; 95% confidence interval = 1.02 to 4.93). A positive correlation was observed between glycemia and clinical attachment loss (AL), whereas a negative correlation between glycemia and the number of teeth present was found (P <0.05). Conclusions: Tooth and periodontal AL were increased by hyperglycemia in individuals with diabetes. This study contributes additional evidence that diabetes could aggravate periodontal disease and affect the systemic health of individuals.     

Abnormal functioning of the semantic network in schizophrenia patients with thought disorganization. An exemplar production task

Numerous studies have indicated that thought disorganization in schizophrenia is associated with an enhanced semantic priming effect. This suggests abnormal functioning of the semantic network in these patients, with disinhibited spreading of semantic activation. We investigated whether thought disorganization is also associated with atypical responses in the production of semantic category exemplars. An exemplar production task was administered to 43 patients with schizophrenia and 24 healthy controls. The names of 16 semantic categories were provided, and the participants were requested to produce an exemplar for each category. The typicality of the response was rated according to norms. Higher ratings of thought disorganization were associated with the production of more atypical exemplars. In addition, the patients with high thought disorganization scores were significantly more atypical in their responses than were the healthy controls. In contrast, the patients with low thought disorganization scores were equivalent to the healthy controls. Higher ratings of affective flattening were associated with the production of less atypical exemplars. The results corroborate, within a different paradigm than semantic priming, the theory that thought disorganization is associated with faster and more distant connections within the semantic network. This effect is counteracted by affective flattening.     

Disruption of visual and motor connectivity in spinocerebellar ataxia type 7

Spinocerebellar ataxia type 7 (SCA7) is an autosomal‐dominant neurodegenerative disorder characterized by progressive ataxia and retinal dystrophy. It is caused by a CAG trinucleotide expansion in the ataxin7 gene. Anatomical studies have shown severe cerebellar degeneration and region‐specific neocortical atrophy in SCA7 patients. However, the impact of the neurodegeneration on the functional integration of the remaining tissue is still unknown. The aim of this study was to examine functional connectivity abnormalities in areas with significant gray matter atrophy in SCA7 patients and their relationship with number of CAG repeats. Using a combination of voxel‐based morphometry and resting‐state fMRI, we studied 26 genetically confirmed SCA7 patients and aged‐matched healthy controls. In SCA7 patients we found reduced functional interaction between the cerebellum and the middle and superior frontal gyri, disrupted functional connectivity between the visual and motor cortices, and increased functional coordination between atrophied areas of the cerebellum and a range of visual cortical areas compared with healthy controls. The degree of mutation expansion showed a negative effect on both the functional interaction between the right anterior cerebellum and the left superior frontal gyrus and the connectivity between the right anterior cerebellum and left parahippocampal gyrus. We found abnormal functional connectivity patterns, including both hypo‐ and hyperconnectivity, compared with controls. These abnormal patterns show reasonable association with the severity of gene mutation. Our findings suggest that aberrant changes are prevalent in both motor and visual systems, adding significantly to our understanding of the pathophysiology of SCA7. © 2013 International Parkinson and Movement Disorder Society     

Effects of raloxifene therapy on circulating osteoprotegerin and RANK ligand levels in post-menopausal osteoporosis

Previous in vitro studies suggest that the anti-resorptive effect of raloxifene might be mediated by changes in several cytokines involved in the bone remodeling process. In this context, the osteoprotegerin (OPG)- receptor activator of NF kappa B ligand (RANKL) system is considered a key component in the osteoclastogenesis regulation. The aim of this study was to determine the effects of raloxifene treatment on serum concentrations of OPG, receptor RANKL and its relationship with biochemical markers of bone turnover and bone mineral density (BMD) in previously untreated women with post-menopausal osteoporosis. We selected 47 post-menopausal women (mean age 63+/-7 yr) with densitometric criteria of osteoporosis. We determined at baseline, 3, 6, and 12 months anthropometric parameters, biochemical markers of bone turnover, serum levels of 25(OH) D, serum levels of OPG and RANKL. BMD (dual-energy x-ray absorptiometry) in lumbar spine (LS) femoral neck and total hip was measured at baseline and 12 months after raloxifene (60 mg/day) treatment. Serum levels of OPG decreased in the 3rd and 6th month of treatment (p<0.001) and returned to basal levels in the 12th month. There was a significant decrease of RANKL levels and OPG/RANKL ratio after 1 yr of raloxifene treatment. In addition, BMD in LS increased significantly (2.5%) in the 12th month of treatment (p=0.031). Finally, the biochemical markers of bone turnover (total alkaline phosphatase, bone alkaline phosphatase, osteocalcin, tartrate-resistant acid phosphatase, urine cross-linked carboxi-terminal telopeptide of type I collagen) decreased significantly from the 3rd month of treatment. In conclusion, our results support the hypothesis that raloxifene may inhibit osteoclast activity, at least partly modulating the OPG-RANKL system.