161 research outputs found
Prevention of stone migration with the Accordion during endoscopic ureteral lithotripsy.
BACKGROUND AND PURPOSE: Endoscopic lithotripsy is often prolonged secondary to the retrograde migration of calculous fragments. Various balloons, baskets, and other devices have been used to prevent this migration. Our purpose is to analyze the effect of the Accordion(®) on stone migration and overall efficiency during lithotripsy.
PATIENTS AND METHODS: We prospectively evaluated 21 patients with a total of 23 distal ureteral stones. Patients underwent lithotripsy using an endoscopic impact lithotriptor. The Accordion was randomly used in 11 of these 21 patients. Data were collected regarding stone migration, stone size, stone ablation, ureteral clearing, and lengths of time for various stages of each procedure.
RESULTS: Patients who were treated with the Accordion device experienced significantly less retrograde migration during fragmentation (P=0.0064). When stone volume was taken into account (but not on a per stone basis), ablation and ureteral clearing were also expedited, and fewer lithotripter hits and basket sweeps were needed.
CONCLUSION: The Accordion device is effective in preventing the migration of stone fragments during endoscopic ureteral lithotripsy. Our data suggest that this device may also increase efficiency of the fragmentation and clearance of ureteral calculi
Increasing human motor skill acquisition by driving theta-gamma coupling
Skill learning is a fundamental adaptive process, but the mechanisms remain poorly understood. Some learning paradigms, particularly in the memory domain, are closely associated with gamma activity that is amplitude-modulated by the phase of underlying theta activity, but whether such nested activity patterns also underpin skill learning is unknown. Here we addressed this question by using transcranial alternating current stimulation (tACS) over sensorimotor cortex to modulate theta-gamma activity during motor skill acquisition, as an exemplar of a non-hippocampal-dependent task. We demonstrated, and then replicated, a significant improvement in skill acquisition with theta-gamma tACS, which outlasted the stimulation by an hour. Our results suggest that theta-gamma activity may be a common mechanism for learning across the brain and provides a putative novel intervention for optimising functional improvements in response to training or therapy
No association between polymorphisms in the BDNF gene and age at onset in Huntington disease
BACKGROUND: Recent evidence suggests that brain-derived neurotrophic factor (BDNF) is an attractive candidate for modifying age at onset (AO) in Huntington disease (HD). In particular, the functional Val66Met polymorphism appeared to exert a significant effect. Here we evaluate BDNF variability with respect to AO of HD using markers that represent the entire locus. METHODS: Five selected tagging polymorphisms were genotyped across a 65 kb region comprising the BDNF gene in a well established cohort of 250 unrelated German HD patients. RESULTS: Addition of BDNF genotype variations or one of the marker haplotypes to the effect of CAG repeat lengths did not affect the variance of the AO. CONCLUSION: We were unable to verify a recently reported association between the functional Val66Met polymorphism in the BDNF gene and AO in HD. From our findings, we conclude that neither sequence variations in nor near the gene contribute significantly to the variance of AO
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Lesion site and therapy time predict responses to a therapy for anomia after stroke: a prognostic model development study
Stroke is a leading cause of disability, and language impairments (aphasia) after stroke are both common and particularly feared. Most stroke survivors with aphasia exhibit anomia (difficulties with naming common objects), but while many therapeutic interventions for anomia have been proposed, treatment effects are typically much larger in some patients than others. Here, we asked whether that variation might be more systematic, and even predictable, than previously thought. 18 patients, each at least 6 months after left hemisphere stroke, engaged in a computerised treatment for their anomia over a 6-week period. Using only: (a) the patients' initial accuracy when naming (to-be) trained items; (b) the hours of therapy that they devoted to the therapy; and (c) whole-brain lesion location data, derived from structural MRI; we developed Partial Least Squares regression models to predict the patients' improvements on treated items, and tested them in cross-validation. Somewhat surprisingly, the best model included only lesion location data and the hours of therapy undertaken. In cross-validation, this model significantly out-performed the null model, in which the prediction for each patient was simply the mean treatment effect of the group. This model also made promisingly accurate predictions in absolute terms: the correlation between empirical and predicted treatment response was 0.62 (95% CI 0.27, 0.95). Our results indicate that individuals' variation in response to anomia treatment are, at least somewhat, systematic and predictable, from the interaction between where and how much lesion damage they have suffered, and the time they devoted to the therapy
Assessment of Sleep Pattern in Egyptian Elderly Subjects with Vascular Dementia: An Egyptian Study on Elderly Population
Background: Sleep is considered to be very important for cognitive function and also cognitive deficits and sleep disorders are influenced by one another. Currently, growing evidence suggests that sleep disturbances is common in vascular dementia (VaD).
Study Objectives: The goal of the current study was to assess the disturbance in sleep pattern in patients with vascular dementia(VaD) and compare it to healthy normally cognitive elderly individuals. The study further investigated whether meaningful differences in the Subjective sleep assessment (ESS and PSQI) and sleep measurements (PSG) in VaD patients.
Study Design/Method: Overnight PSG recordings and self-reported sleep measures were obtained from 20 healthy elderly subjects and 20 VaD patients at the sleep laboratory.
Results: This study showed abnormal subjective sleep quality in all patients and revealed that the most common sleep complaintsamong VaD patients were excessive daytime sleepiness (EDS), sleep disordered breathing (SDB), insomnia and RLS and PLMS and REM behavioral disordered, respectively. Moreover, patients spent more time in stage I sleep, but less time in SWS and REM sleep compared to control populations, with delayed REML and less 1st REML. In addition, increased sleep fragmentation (WASO and SFI) and increased AI and PLMS index were detected in VaD patients. Finally, VaD patients had significantly (p < 0.05) high apnea, hypopnea and RDI score with high average SpO2 desaturation.
Conclusions: It is conclude that sleep is significantly (p < 0.05) impaired in patients with VaD at both the objective and subjective levels which may be used as a diagnostic marker of VaD. SBD is a common feature of VaD leading to fragmented sleep, increased nocturnal confusion and excessive daytime sleepiness. Subjective sleep assessment questionnaire by (ESS and PSQI) can be used in VaD patients when objective sleep assessment by PSG recordings is difficult to be done. The PSG study of sleep continuity, sleep architecture and REM sleep may help in the prevention of progression of VaD
Predicting online behavioural responses to transcranial direct current stimulation in stroke patients with anomia
Anomia, or difficulty naming common objects, is the most common, acquired impairment of language. Effective therapeutic interventions for anomia typically involve massed practice at high doses. This requires significant investment from patients and therapists. Aphasia researchers have increasingly looked to neurostimulation to accelerate these treatment effects, but the evidence behind this intervention is sparse and inconsistent. Here, we hypothesised that group-level neurostimulation effects might belie a more systematic structure at the individual level. We sought to test the hypothesis by attempting to predict the immediate (online), individual-level behavioural effects of anodal and sham neurostimulation in 36 chronic patients with anomia, performing naming and size judgement tasks. Using clinical, (pre-stimulation) behavioural and MRI data, as well as Partial Least Squares regression, we attempted to predict neurostimulation effects on accuracies and reaction times of both tasks. Model performance was assessed via cross-validation. Predictive performances were compared to that of a null model, which predicted the mean neurostimulation effects for all patients. Models derived from pre-stimulation data consistently outperformed the null model when predicting neurostimulation effects on both tasks’ performance. Notably, we could predict behavioural declines just as well as improvements. In conclusion, inter-patient variation in online responses to neurostimulation is, to some extent, systematic and predictable. Since declines in performance were just as predictable as improvements, the behavioural effects of neurostimulation in patients with anomia are unlikely to be driven by placebo effects. However, the online effect of the intervention appears to be as likely to interfere with task performance as to improve it
Securing recruitment and obtaining informed consent in minority ethnic groups in the UK
Background: Previous health research has often explicitly excluded individuals from minority
ethnic backgrounds due to perceived cultural and communication difficulties, including studies
where there might be language/literacy problems in obtaining informed consent. This study
addressed these difficulties by developing audio-recorded methods of obtaining informed consent
and recording data. This report outlines 1) our experiences with securing recruitment to a
qualitative study investigating alternative methods of data collection, and 2) the development of a
standardised process for obtaining informed consent from individuals from minority ethnic
backgrounds whose main language does not have an agreed written form.
Methods: Two researchers from South Asian backgrounds recruited adults with Type 2 diabetes
whose main language was spoken and not written, to attend a series of focus groups. A screening
tool was used at recruitment in order to assess literacy skills in potential participants. Informed
consent was obtained using audio-recordings of the patient information and recording patients'
verbal consent. Participants' perceptions of this method of obtaining consent were recorded.
Results: Recruitment rates were improved by using telephone compared to face-to-face methods.
The screening tool was found to be acceptable by all potential participants. Audio-recorded
methods of obtaining informed consent were easy to implement and accepted by all participants.
Attrition rates differed according to ethnic group. Snowballing techniques only partly improved
participation rates.
Conclusion: Audio-recorded methods of obtaining informed consent are an acceptable
alternative to written consent in study populations where literacy skills are variable. Further
exploration of issues relating to attrition is required, and a range of methods may be necessary in
order to maximise response and participation
Interepidemic Rift Valley Fever Virus Seropositivity, Northeastern Kenya
Exposure is associated with long-term retinal disease and is most common in rural settings among older men who have contact with aborting animals
Neonatal Myocardial Infarction or Myocarditis?
We report a 29 week-gestation preterm infant who presented during his second week of life with cardiogenic shock. Clinical presentation and first diagnostics suggested myocardial infarction, but echocardiographic features during follow-up pointed to a diagnosis of enteroviral myocarditis. The child died of chronic heart failure at 9 months of age. Autopsy showed passed myocardial infarction. No signs for active myocarditis were found. We discuss the difficulties in differentiating between neonatal myocardial infarction and myocarditis. Recognizing enteroviral myocarditis as cause for cardiogenic shock is of importance because of the therapeutic options
Postepidemic Analysis of Rift Valley Fever Virus Transmission in Northeastern Kenya: A Village Cohort Study
RVFV infection causes significant disease in both human and animal populations, resulting in significant agricultural, economic and public health consequences. We conducted a cohort study on residents of a high-risk area to measure human anti-RVFV seroprevalence, to identify risk factors, and to estimate the durability of prior RVFV immunity. One hundred two individuals tested for RVFV exposure before the 2006–2007 RVF outbreak were restudied to determine interval anti-RVFV seroconversion and persistence of humoral immunity since 2006. Ninety-two additional subjects were enrolled from randomly selected households to help identify risk factors for current seropositivity. Seroprevalence in the region was high (23%). 1/85 at-risk individuals restudied in the follow-up cohort had seroconverted since early 2006. 29% of newly tested individuals were seropositive. After adjustment in multivariable logistic models, age, village, and drinking raw milk were significantly associated with RVFV seropositivity. Visual impairment (defined as ≤20/80) was much more likely in the RVFV-seropositive group. Among those with previous exposure, RVFV titers remained at protective levels (>1∶40) for more than 3 years. This study highlights the high seroprevalence among Northeastern Kenyans and the ongoing surge in seroprevalence with each RVF outbreak
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