Recent research suggests 2 principal processes are assessed in many neuropsychological tests of prefrontal functioning: the ability to keep transient information on-line (working memory) and the ability to inhibit prepotent, but incorrect, responses. The current studies examined the hypothesis that taxing working memory beyond some threshold can result in decreased inhibition, resembling the errors committed by patients with prefrontal dysfunctions. Across 3 studies, 70 nonpatient subjects were tested on the antisaccade (AS) task (D. Guitton, H. A. Buchtel, & R. M. Douglas, 1985)-a task sensitive to inhibitory deficits. Subjects were required to look in the opposite direction of a flashed cue, inhibiting the reflexive tendency to saccade to the cue. Subjects performed concurrent tasks that varied working-memory load. The results indicated that conditions with the highest working-memory load produced inhibitory errors comparable to patients with prefrontal dysfunctions. The findings are discussed in terms of the interaction between working memory and the inhibition of prepotent responses.

The aims of this study are to ascertain the prevalence of anxiety and depressive disorders in an outpatient population with osteoarthritis (OA), examine the interrelationships between severity of OA, pain, disability, and depression, and evaluate the Hospital Anxiety and Depression Scale (HADS) as a screening tool for this population. Patients with lower limb OA were evaluated with the Short Form McGill Pain and Present Pain Index Questionnaires, and a visual analogue scale, WOMAC Osteoarthritis Index-section C, and the HADS. Participants underwent a structured clinical interview by a liaison psychiatrist (AB). X-rays of affected joints were rated for disease severity. Fifty-four patients (42 females; mean age 63.3) were investigated. The prevalence of clinically significant anxiety and/or depression was 40.7% (95% confidence interval (CI), 27.6-55.0%). HADS was a good predictor of anxiety and depression with a sensitivity and specificity of 88% (95%CI, 64% to 99%) and 81% (95%CI, 65% to 92%), respectively. Pain correlated with HADS anxiety and depression scores (e.g. Rank correlation coefficients (Kendall's tau-b) between total HADS scores and Pain VAS scores 0.29; p=0.003). Disability was greater in patients with depression and/or anxiety (e.g. total HADS score; Kendall's rank correlation coefficient tau-b=0.26, p=0.007) OA severity as determined by radiological score was not a good predictor for anxiety nor depression and only weakly associated with disability. Anxiety and depression are very common in OA patients. HADS anxiety was a better predictor of diagnosed anxiety than HADS depression was of diagnosed depression. HADS is a valid and reliable screening instrument for detecting mood disorder, but not a diagnostic tool or a substitute for asking about symptoms of depression. The interrelationship between mental health, pain and disability is strong. We should therefore adopt a multidisciplinary approach to the management of OA.

ObjectiveBone marrow lesions (BMLs) are well described in osteoarthritis (OA) using MRI and are associated with pain, but little is known about their pathological characteristics and gene expression. We evaluated BMLs using novel tissue analysis tools to gain a deeper understanding of their cellular and molecular expression.MethodsWe recruited 98 participants, 72 with advanced OA requiring total knee replacement (TKR), 12 with mild OA and 14 non-OA controls. Participants were assessed for pain (using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)) and with a knee MRI (using MOAKS). Tissue was then harvested at TKR for BML analysis using histology and tissue microarray.ResultsThe mean (SD) WOMAC pain scores were significantly increased in advanced OA 59.4 (21.3) and mild OA 30.9 (20.3) compared with controls 0.5 (1.28) (p<0.0001). MOAKS showed all TKR tissue analysed had BMLs, and within these lesions, bone marrow volume was starkly reduced being replaced by dense fibrous connective tissue, new blood vessels, hyaline cartilage and fibrocartilage. Microarray comparing OA BML and normal bone found a significant difference in expression of 218 genes (p<0.05). The most upregulated genes included stathmin 2, thrombospondin 4, matrix metalloproteinase 13 and Wnt/Notch/catenin/chemokine signalling molecules that are known to constitute neuronal, osteogenic and chondrogenic pathways.ConclusionOur study is the first to employ detailed histological analysis and microarray techniques to investigate knee OA BMLs. BMLs demonstrated areas of high metabolic activity expressing pain sensitisation, neuronal, extracellular matrix and proinflammatory signalling genes that may explain their strong association with pain.

To compare the findings on magnetic resonance (MR) images of the knee obtained with a three-dimensional gradient-echo (GRE) sequence with findings at arthroscopy, the menisci, cruciate ligaments, and hyaline cartilage were assessed in 100 patients. At MR imaging (performed by means of fast imaging with steady-state precession) and arthroscopy, the menisci (n = 200) and areas of hyaline cartilage (n = 500) were assigned grades of zero (normal) to three (greatest abnormality). The cruciate ligaments were considered intact, partially torn, or completely torn. The sensitivity of MR imaging in diagnosis of meniscal tears seen at arthroscopy was 97% and the specificity, 94%. For complete tears of the anterior cruciate ligament, the sensitivity was 92% and specificity, 96%. In the posterior cruciate ligament, both the sensitivity and specificity were 100%. Good correlation existed between findings at MR imaging and those at arthroscopy in assessment of focal thinning and full-thickness loss of hyaline cartilage, but arthroscopy enabled superior visualization of minor fissuring. Three-dimensional GRE MR imaging enables accurate assessment of the articular cartilage of the knee. The evaluation of meniscal tears and the cruciate ligaments has a high negative predictive value.

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