Functional neuroimaging of the interference between working memory and the control of periodic ankle movement timing

Background

Limited information processing capacity in the brain necessitates task prioritisation and subsequent adaptive behavioural strategies for the dual-task coordination of locomotion with severe concurrent cognitive loading. Commonly observed strategies include prioritisation of gait at the cost of reduced performance in the cognitive task. Alternatively alterations of gait parameters such as gait velocity have been reported presumably to free processing capacity for the benefit of performance in the cognitive task. The aim of this study was to describe the neuroanatomical correlates of adaptive behavioural strategies in cognitive-motor dual-tasking when the competition for information processing capacity is severe and may exceed individuals’ capacity limitations.

Methods

During an fMRI experiment, 12 young adults performed slow continuous, auditorily paced bilateral anti-phase ankle dorsi-plantarflexion movements as an element of normal gait at .5 Hz in single and dual task modes. The secondary task involved a visual, alphabetic N-back task with presentation rate jittered around .7 Hz. The N-back task, which randomly occurred in 0-back or 2-back form, was modified into a silent counting task to avoid confounding motor responses at the cost of slightly increasing the task′s general coordinative complexity. Participants’ ankle movements were recorded using an optoelectronic motion capture system to derive kinematic parameters representing the stability of the movement timing and synchronization. Participants were instructed to perform both tasks as accurately as possible.

Results

Increased processing complexity in the dual-task 2-back condition led to significant changes in movement parameters such as the average inter-response interval, the coefficient of variation of absolute asynchrony and the standard deviation of peak angular velocity. A regions-of-interest analysis indicated correlations between these parameters and local activations within the left inferior frontal gyrus (IFG) such that lower IFG activations coincided with performance decrements.

Conclusions

Dual-task interference effects show that the production of periodically timed ankle movements, taken as modelling elements of the normal gait cycle, draws on higher-level cognitive resources involved in working memory. The interference effect predominantly concerns the timing accuracy of the ankle movements. Reduced activations within regions of the left IFG, and in some respect also within the superior parietal lobule, were identified as one factor affecting the timing of periodic ankle movements resulting in involuntary ‘hastening’ during severe dual-task working memory load. This ‘hastening’ phenomenon may be an expression of re-automated locomotor control when higher-order cognitive processing capacity can no longer be allocated to the movements due to the demands of the cognitive task. The results of our study also propose the left IFG as a target region to improve performance during dual-task walking by techniques for non-invasive brain stimulation.     

Patient attitudes and expectations of dental implant treatment--a questionnaire study

The aim of the present study was to evaluate patient attitudes and expectations relative to dental implant treatment. A questionnaire was mailed to all 400 patients that had received dental implant treatment at a large multi-specialist clinic during 2008. The questionnaire included questions relative to the reasons for dental implant treatment, if the patient earlier had considered dental implants, expectations of the treatment, discomfort during and after surgery, and how the patient perceived the esthetic outcome. The response rate was 61% (114 men/130 women). The stated reason for tooth loss was in 50% of the patients periodontitis,19% caries, 8% accidents,13% other reasons, and 10% no stated reason. Almost all patients (96%) were satisfied with the esthetic appearance and also regarding the information of the treatment (94%). Regarding the time between surgery and completion of prosthetic work, 79% (n = 192) found it to be reasonable. 71% (n = 170) thought the cost was what they had expected. 47% of the patients experienced the implant surgery better than expected and 48% as expected. In conclusion, the present study revealed that almost all patients were satisfied with the function and esthetics of the dental implant reconstruction and most patients were also satisfied regarding the costs and treatment duration.     

Arthroscopy in the diagnosis of acute injuries to the knee joint

Summary This study evaluates the role of arthroscopy in the diagnosis of acute injuries to the knee. One hundred and fifty four patients with a suspected ligament injury or effusion of the knee joint underwent arthroscopy. A haemarthrosis was present in 82% and a bloodless effusion in 10%. Meniscal tears were found in 19% of the knees. Fresh ligament ruptures were present in 71% and an associated haemarthrosis in 95% of these; 65% were partial tears. The commonest isolated lesion was a complete or partial tear of the anterior cruciate, which occurred in 15% of cases. More than one ligament injury occurred in 56%, the commonest combination being tears of the anterior cruciate and medial collateral ligaments. In a high percentage of cases, arthroscopy revealed unsuspected injuries of significance in management. In 39%, an open or closed procedure followed arthroscopy. There were no complications from the diagnostic arthroscopy. We conclude that arthroscopy provides a more accurate diagnosis than clinical examination alone, and is especially valuable for assessing the patient with a haemarthrosis of the knee.

---

Résumé Le but cette étude est d'évaleur le rôle de l'arthroscopie dans le diagnostic des lésions traumatiques récentes du genou. Cent cinquante et un sujets chez lesquels on pouvait soupçonner une lésion ligamentaire ou un épanchement du genou ont subi une arthroscopie. Il existait une hémarthrose dans 82% des cas et une hydarthrose dans 10%. On a découvert une déchirure d'un ménisque dans 19% des genoux. Il y avait une rupture ligamentaire récente dans 71% des cas, et chez 95% d'entre eux une hémarthrose y était associée. La lésion isolée la plus fréquente était la rupture, partielle ou complète du ligament croisé antérieur, qui existait dans 15% des cas. On notait l'atteinte de plus d'un seul ligament dans 56% des cas, l'association la plus habituelle étant la déchirure des ligaments croisé et latéral interne. Dans une importante proportion de cas l'arthrose a mis en évidence des lésions inattendues, nécessitant des mesures thérapeutiques particulières. Chez 39% des patients l'arthroscopie a ét suivie d'un traitement chirurgical, à ciel ouvert ou non. L'arthroscopie à visée diagnostique n'a entraîné aucune complication. Les auteurs concluent que l'arthroscopie permet un diagnostic lésionnel plus précis que le simple examen clinique et qu'elle est particuliérement utile chez les sujets qui présentent une hémarthrose du genou.

     

Cytokine-based and targeted therapy of metastatic renal cell carcinoma--a current analysis

The systemic treatment of renal cell cancer represents a challenge for uro-oncologists. Although no internationally recognised treatment regime has been defined, cytokine therapy has been the standard of care for metastatic disease. The growing understanding of the relevant mechanisms in the molecular biology of renal cell carcinoma has led to the development of targeted therapies. Novel tyrosine kinase and angiogenesis inhibitors have had a beneficial effect on progression-free and overall survival in patients with advanced renal cell cancer and represented a significant progress. Even though several important aspects regarding treatments and combinations of these drugs with each other as well as with cytokines still remain unclear, cytokine therapy will probably become less important as a first-line treatment. With increasing therapeutic options becoming available as potential new standards and with the old standards being poorly defined, a critical analysis of the role of different systemic therapies for renal cell carcinoma is warranted. A better knowledge of molecular markers and their prognostic relevance could allow the rational use of different targeted therapies in individual patients in the future. Until such therapies become available, the systemic treatment options should be selected carefully in individual patients.     

Percent of plaque on individual tooth surfaces and differences in plaque area between adjacent teeth in healthy adults

Abstract Objectives: To apply a planimetric method to determine the percentage of the tooth area covered by plaque on individual tooth surfaces and to compare the percentage of plaque between adjacent tooth surfaces. Methods: Forty‐three adults, mean age 43.0 years, with no signs of periodontal disease, participated. The subjects underwent comprehensive professional cleaning of all teeth. The subjects were then instructed to maintain their ordinary oral hygiene habits. Plaque was registered after 1 month, on each individual tooth surface by use of P%I. Results: The pattern of plaque accumulation was in large symmetrical, with differences in mean P%I between several adjacent tooth surfaces, e.g. for the maxillary buccal and lingual tooth surfaces between the first and second molars (P < 0.001) and for the lingual tooth surfaces between the canines and the first premolars (P < 0.01). Conclusion: In the present study, it was possible to identify and describe adjacent tooth surfaces with the most pronounced plaque accumulation, to make further improvements of oral hygiene possible.     

Sexual Function and Quality of Life for Women with Mild‐to‐Moderate Stress Urinary Incontinence

Introduction: Sexual function is affected by stress urinary incontinence with or without pelvic organ prolapse. The aim of the study was to describe the sexual function of women with mild‐to‐moderate stress urinary incontinence, with or without pelvic organ prolapse (up to stage 2) and examine correlations with symptoms and quality of life. This investigation was part of a large, randomized, clinical trial of women with stress urinary incontinence who participated in an exercise intervention. Methods: Women included in the study suffered from stress urinary incontinence as measured by a pad test and were interested in an exercise intervention. All participants underwent assessment for prolapse staging. Instruments included: the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ‐12), Incontinence Quality of Life Questionnaire (I‐QOL), and a health and urinary leakage questionnaire. Results: One hundred and eighty‐seven ambulatory women, aged 20 to 65 years, had a mean sexual function score of 36.9 (standard deviation [SD] 5.9). No significant correlation was found between the sexual function scores and quantity of urinary leakage. A significant correlation existed between the sexual function and I‐QOL scores (P < .001). An additional finding was that women with urgency symptoms were older (P= .04) and had significantly lower sexual function scores (mean 35.7; SD 6.4) than those who did not report urgency (mean 38.7; SD 4.6; P < .001). Discussion: Women with mild‐to‐moderate stress urinary incontinence, without or with lower stages of pelvic organ prolapse, demonstrated good sexual function, which correlated with physical and psychosocial factors. Health professionals need to perform multifaceted intake assessments on women with urinary leakage to customize their health promotion regimen.