Clinical determinants of primary and secondary fatigue in patients with Parkinson’s disease

Clinical and psychosocial factors associated separately with primary and secondary fatigue in Parkinson’s disease (PD) patients have not been thoroughly studied before. The aim of our study was to assess factors associated with different fatigue domains in groups with primary and secondary fatigue in PD separately. We divided 165 non-demented PD patients according to the absence/presence of depression, anxiety and excessive somnolence into groups with primary fatigue (N = 63) and with secondary fatigue (N = 102). Fatigue domains examined using the multidimensional fatigue inventory were associated through multiple linear regression analyses for each group separately with sociodemographic data, disease duration, functional status as assessed by the Unified Parkinson’s Disease Rating Scale, treatment, depression, anxiety, excessive somnolence and sleep quality. Out of the assessed non-motor symptoms, fatigue was the most frequent (77.6 %). The prevalence of fatigue in the secondary fatigue group was significantly higher than in the primary fatigue group. Both fatigue groups differed significantly in factors associated with different fatigue domains. Functional status or other disease-related factors were not associated with primary fatigue. In the secondary fatigue group, we found associations between some fatigue domains and functional status, older age, male gender and higher anxiety scores. To our knowledge, this is the first study to separately describe clinical determinants and psychosocial factors associated with different fatigue domains in primary and secondary fatigue in PD, underlining the importance of distinguishing primary and secondary fatigue in future PD studies and clinical practice.     

Enhancement of erythrocyte superoxide dismutase activity: effects on cellular oxidant defense

To delineate further the role of superoxide dismutase (SOD) in red blood cell (RBC) oxidant defense, normal human erythrocytes were osmotically lysed and resealed in the presence of varying concentrations of exogenous SOD. This resulted in a dose-dependent increase in SOD activity in the resealed erythrocytes while maintaining nearly normal RBC hemoglobin concentration (less than 10% decrease from the control value), cell volume, and cellular deformability. Surprisingly, a five- or ninefold increase in SOD activity yielded no additional protection against superoxide-generating drugs (phenazine methosulfate or menadione sodium bisulfite). No significant differences were observed between the control and SOD-loaded RBCs in O2-driven methemoglobin formation or generation of thiobarbituric acid-reactive substances. In contrast, RBCs with elevated SOD activity pretreated with sodium azide (to block catalase activity) or 1-chloro-2,4- dinitrobenzene (to deplete reduced glutathione, GSH) showed significantly enhanced methemoglobin generation in response to superoxide generating drugs. No differential response was noted between the control, control-resealed, and SOD-loaded RBCs to oxidants other than superoxide. Based on our results and other data, we conclude that elevated SOD activity may imbalance cellular oxidant defense, resulting in enhanced oxidation due to the accelerated generation of H2O2, the product of O2- dismutation. This effect is significantly exacerbated under conditions in which H2O2 catabolism is altered.     

Perceived health status as measured by the SF-36 in patients with multiple sclerosis: a review

This review of literature gives an overview of recent studies about perceived health status as measured by the Short-Form-36 (SF-36) Health Survey in patients with multiple sclerosis (MS). The SF-36 is one of the tools measuring health status in patients used in international research and clinical practice. It measures two main health concepts – physical and mental. The SF-36 represents a valid instrument able to detect differences in perceived health status in patients. A computer-aided search in Medline and PsycINFO resulted in 504 articles in English published from 1996 to August 2006. After the screening process on the basis of abstracts, eight articles consisting of empirical studies remained in which perceived health status was evaluated using the SF-36 Health Survey. Seven studies focused on disability and perceived health status in the SF-36. Two studies focused on the relationship between depression and perceived health status. These studies showed that MS patients with low disability and minor depression scored significantly better than patients with high disability and major depression in the SF-36 health dimensions. Gender seems to have no influence on perceived health status in MS patients. The longer the disease duration and the more severe the disease, the lower the patients scored in perceived health status. The more disabled, the more depressive and the older the patients, the poorer their perceived health status was. Health providers supporting appropriate treatment might pay more attention to more disabled and more depressive patients, with longer disease duration. Perceived health status can be a predictor of prognosis and intervention outcomes. The study shows the importance of measuring perceived health status in MS patients with implications for their quality of life and provision of care.     

Six-minute walking test in children with ESRD: discrimination validity and construct validity

The six-minute walking test (6MWT) may be a practical test for the evaluation functional exercise capacity in children with end-stage renal disease (ESRD). The aim of this study was to investigate the 6MWT performance in children with ESRD compared to reference values obtained in healthy children and, secondly, to study the relationship between 6MWT performance with anthropometric variables, clinical parameters, aerobic capacity and muscle strength. Twenty patients (13 boys and seven girls; mean age 14.1 ± 3.4 years) on dialysis participated in this study. Anthropometrics were taken in a standardized manner. The 6MWT was performed in a 20-m-long track in a straight hallway. Aerobic fitness was measured using a cycle ergometer test to determine peak oxygen uptake ( textV^· textO_text2peak ) left( {mathop {text{V}}limits^cdot {{text{O}}_{text{2peak}}}} right) , peak rate (W_peak) and ventilatory threshold (VT). Muscle strength was measured using hand-held myometry. Children with ESRD showed a reduced 6MWT performance (83% of predicted, p < 0.0001), irrespective of the reference values used. The strongest predictors of 6MWT performance were haematocrit and height. Regression models explained 59% (haematocrit and height) to 60% (haematocrit) of the variance in 6MWT performance. 6MWT performance was not associated with textV^· textO_text2peak {mathop {text{V}}limits^cdot {{text{O}}_{text{2peak}}}} , strength, or other anthropometric variables, but it was significantly associated with haematocrit and height. Children with ESRD scored lower on the 6MWT than healthy children. Based on these results, the 6MWT may be a useful instrument for monitoring clinical status in children with ESRD, however it cannot substitute for other fitness tests, such as a progressive exercise test to measure textV^· textO_text2peak {mathop {text{V}}limits^cdot {{text{O}}_{text{2peak}}}} or muscle strength tests.     

Assessment of a daily online implanted fiducial marker‐guided prostate radiotherapy process

The aims of this study were to investigate whether intrafraction prostate motion can affect the accuracy of online prostate positioning using implanted fiducial markers and to determine the effect of prostate rotations on the accuracy of the software‐predicted set‐up correction shifts. Eleven patients were treated with implanted prostate fiducial markers and online set‐up corrections. Orthogonal electronic portal images were acquired to determine couch shifts before treatment. Verification images were also acquired during treatment to assess whether intrafraction motion had occurred. A limitation of the online image registration software is that it does not allow for in‐plane prostate rotations (evident on lateral portal images) when aligning marker positions. The accuracy of couch shifts was assessed by repeating the registration measurements with separate software that incorporates full in‐plane prostate rotations. Additional treatment time required for online positioning was also measured. For the patient group, the overall postalignment systematic prostate errors were less than 1.5 mm (1 standard deviation) in all directions (range 0.2–3.9 mm). The random prostate errors ranged from 0.8 to 3.3 mm (1 standard deviation). One patient exhibited intrafraction prostate motion, resulting in a postalignment prostate set‐up error of more than 10 mm for one fraction. In 14 of 35 fractions, the postalignment prostate set‐up error was greater than 5 mm in the anterior–posterior direction for this patient. Maximum prostate rotations measured from the lateral images varied from 2° to 20° for the patients. The differences between set‐up shifts determined by the online software without in‐plane rotations to align markers, and with rotations applied, was less than 1 mm (root mean square), with a maximum difference of 4.1 mm. Intrafraction prostate motion was found to reduce the effectiveness of the online set‐up for one of the patients. A larger study is required to determine the magnitude of this problem for the patient population. The inability in the current software to incorporate in‐plane prostate rotations is a limitation that should not introduce large errors, provided that the treatment isocentre is positioned near the centre of the prostate.     

Increased arterial stiffness in young adults with end-stage renal disease since childhood

Increased arterial stiffness is a risk factor for mortality in adults over 40 yr of age with end-stage renal disease (ESRD). As no data exist on vascular changes in young adults with ESRD since childhood, a long-term outcome study was performed. All living Dutch adult patients with onset of ESRD between 1972 and 1992 at age 0 to 14 yr were invited for carotid artery and cardiac ultrasound and BP measurements. Data on clinical characteristics were collected by review of all medical charts. Carotid ultrasound data were compared with those of 48 age-matched and gender-matched healthy controls. Carotid artery and cardiac ultrasound was performed in 130 out of 187 eligible patients. Mean age was 29.0 (20.7 to 40.6) yr. Compared with controls, patients had a similar intima media thickness but a reduced mean arterial wall distensibility DC (40.0 versus 45.0 kPa(-1). 10(-3); 95% CI, -9.1 to -0.8; P < 0.001), an increased stiffness parameter beta (4.2 versus 3.8; 95% CI, 0.05 to 0.68; P = 0.02), an increased elastic incremental modulus E(inc) (0.35 versus 0.27 kPa. 10(3); 95% CI, 0.02 to 0.12; P < 0.001). Multiple regression analyses in all subjects revealed that ESRD was associated with an increase in beta and E(inc). Arterial wall properties of patients currently on dialysis and transplanted patients were comparable. In all patients, current systolic hypertension was associated with increased E(inc) and decreased DC. In conclusion, carotid arterial wall stiffness is increased in young adult patients with pediatric ESRD. Hypertension is a main determinant and might be a target for treatment of these potentially lethal arterial wall changes.     

Metabolic effects of growth hormone treatment: an early predictor of growth response?

Fourteen children receiving one year of recombinant human growth hormone (rhGH) treatment underwent measurement of serial changes in body composition (measured by skinfold thickness, bioelectrical impedance, and H2(18)O dilution), resting energy expenditure (REE, estimated by ventilated hood indirect calorimetry), and total free living daily energy expenditure (TEE, measured by the doubly labelled water technique). Mean height velocity increased from 4.9 to 8.6 cm/year after six months of treatment. Fat free mass (FFM) increased more during the first six weeks (24.4 g/day) than from six to 26 weeks of treatment (6.8 g/day); fat mass decreased by 7.2 g/day and 1.1 g/day respectively. The six week increase in REE (kJ/day) was maintained after six months of treatment, though expressed per kilogram FFM (kJ/kgFFM/day), returned to pretreatment values by three months. Height velocity increases at six months correlated with six week changes in fat mass measured by skinfold thickness and REE, though use of this relationship to predict growth response in individuals is limited by the wide 95% prediction intervals. No significant changes in growth, body composition, or energy expenditure were observed between six and 12 months of treatment, in either patients who had initially responded well to treatment or those who were poor initial responders to treatment and who had their dose of rhGH doubled after six months.