Ishraq Siddiqui

Pain in Parkinson's disease: Analysis and literature review

Pain is a common problem faced by Parkinsons disease (PD) patients. Despite its impact and disabling effects pain is still frequently overlooked. In this study we analyze a representative sample of peer reviewed literature for the prevalence and types of pain in PD, the impact and significance of pain in the quality of life of the PD patient and the challenges inherent in the diagnosis and management of pain in PD patients. We compared and analyzed the findings of articles indexed in the PubMed database which looked at symptoms reported by large cohorts of PD patients. These articles all reported the incidence, nature and quality of pain in these patients and described the effects of pain on quality of life and generally were cross-sectional, retrospective or case-control studies, though a major pharmacoepidemiological design study was also analyzed. Results of our analysis showed that the pain was prevalent in 59.77% of PD patients. Five different types of pain were reported by PD patients--dystonia, musculoskeletal pain, nerve/nerve root pain, primary/central pain and according to some, akathisia. Patients who reported pain symptoms were also significantly more likely to report associated depression and a decreased quality of life. Many PD patients also reported poor management of pain and lower analgesic use than would be expected. We further discuss some of the possible approaches toward the development of a treatment algorithm regarding the management of pain in PD. We conclude that pain in is an under-recognized and under treated symptom in PD patients. Effective management of pain in PD patients would significantly improve their quality of life. Our analysis is in line with current thinking that identifies PD is much more of a multisystem disease with non-motor symptoms than previously thought.

Motivated to do well: An examination of the relationships between motivation, effort, and cognitive performance in schizophrenia

The uncertain relationship between negative symptoms, and specifically motivational deficits, with cognitive dysfunction in schizophrenia is in need of further elucidation as it pertains to the interpretation of cognitive test results. Findings to date have suggested a possible mediating role of motivational deficits on cognitive test measures, although findings from formal examinations of effort using performance validity measures have been inconsistent. The aim of this study was to examine the relationships between motivation, effort exerted during cognitive testing, and cognitive performance in schizophrenia. Sixty-nine outpatients with schizophrenia or schizoaffective disorder were evaluated for psychopathology, severity of motivational deficits, effort exerted during cognitive testing, and cognitive performance. Motivation and degree of effort exerted during cognitive testing were significantly related to cognitive performance, specifically verbal fluency, verbal and working memory, attention and processing speed, and reasoning and problem solving. Further, effort accounted for 15% of the variance in cognitive performance, and partially mediated the relationship between motivation and cognitive performance. Examining cognitive performance profiles for individuals exerting normal or reduced effort revealed significant differences in global cognition, as well as attention/processing speed and reasoning and problem solving. These findings suggest that cognitive domains may be differentially affected by impairments in motivation and effort, and highlight the importance of understanding the interplay between motivation and cognitive performance deficits, which may guide the appropriate selection of symptom targets for promoting recovery in patients.

Dissecting negative symptoms in schizophrenia: Opportunities for translation into new treatments

Among the constellation of symptoms that characterize schizophrenia, negative symptoms have emerged as a critical feature linked to the functional impairment experienced by affected individuals. Despite advances in our understanding of the role of negative symptoms in the illness, effective treatments for these debilitating symptoms have remained elusive. In this review we explore the contemporary conceptualization of negative symptoms in schizophrenia, including the identification of two key subdomains of diminished expression and amotivation, and clarifications around hedonic capacity. We then explore strategies for clinical assessments of negative symptoms, followed by findings using objective paradigms for evaluating discrete aspects of these negative symptoms in clinical populations and animal models, both for symptoms of diminished expression and within the multifaceted motivation system. We conclude with a consideration of current strategies for drug development for these negative symptoms, the role of heterogeneity in the clinical presentation of symptoms in schizophrenia and opportunities for personalized assessment and treatment approaches, as well as a commentary on current clinical drug trial design and the role of environmental opportunities for novel treatments to effect change and improve outcomes for affected individuals.

Association of pain, Parkinson's disease, and restless legs syndrome

BACKGROUND Many patients with restless legs syndrome (RLS) and Parkinsons disease (PD) report having pain, however, the impact of the combination of PD and RLS on pain has not been analyzed extensively. The objective of this study was to explore the potential relationship between RLS and pain in individuals with and without PD, the prevalence of RLS in PD, the prevalence and severity of pain in PD and RLS, and how these measures are related to PD patients and controls. METHODS The study included 127 PD patients and an equal number of non-PD patients who were assessed for pain and RLS-like symptoms by using RLS diagnostic survey, RLS rating scale and Brief Pain Inventory. RESULTS The results showed that 21.3% of PD patients had RLS, compared to only 4.7% in the control group, representing a highly significant difference (p<0.005). The frequency of reporting pain was also significantly higher among PD patients with RLS (p<0.005), but not in control group. However, the mean difference in average pain severity was not significantly different between the PD with RLS and non-PD with RLS, nor was the pain level and severity significantly correlated with RLS severity for either group. CONCLUSION The presence of pain in PD patients may be exacerbated by RLS or in RLS patients, having PD may exacerbate pain.

Simulating real world functioning in schizophrenia using a naturalistic city environment and single-trial, goal-directed navigation

Objective: To develop a virtual reality platform that would serve as a functionally meaningful measure of cognition in schizophrenia and that would also complement standard batteries of cognitive tests during clinical trials for cognitive treatments in schizophrenia, be amenable to human neuroimaging research, yet lend itself to neurobiological comparison with rodent analogs. Method: Thirty-three patients with schizophrenia and 33 healthy controls matched for age, sex, video gaming experience, and education completed eight rapid, single-trial virtual navigation tasks within a naturalistic virtual city. Four trials tested their ability to find different targets seen during the passive viewing of a closed path that led them around different city blocks. Four subsequent trials tested their ability to return to four different starting points after viewing a path that took them several blocks away from the starting position. Results: Individuals with schizophrenia had difficulties in way-finding, measured as distance travelled to find targets previously encountered within the virtual city. They were also more likely not to notice the target during passive viewing, less likely to find novel shortcuts to targets, and more likely to become lost and fail completely in finding the target. Total travel distances across all eight trials strongly correlated (negatively) with neurocognitive measures and, for 49 participants who completed the Quality of Life Scale, psychosocial functioning. Conclusion: Single-trial, goal-directed navigation in a naturalistic virtual environment is a functionally meaningful measure of cognitive functioning in schizophrenia.

Challenges in diagnosis of young onset Parkinson's disease

Young onset Parkinsons disease patients, typically aged 21 to between 40 and 55, have symptomatology similar to regular onset patients. Despite this, we suspect that physicians take longer to diagnose young onset patients since Parkinsons disease is ruled out due to the younger age. The history prior to diagnosis of 14 young onset patients (within 21 to 45 years of age) was compared with an equivalent number of regular onset patients matched by gender, tremor presence, and Hoehn and Yahr stage. Indeed, a longer period of time was taken to diagnose younger patients with an average of additional 15 months (p<0.001). This trend of older patients being diagnosed sooner was present in the regular onset group analyzed in isolation, but not so for the younger group. The lack of age-dependent variation in time required for diagnosis suggests that Parkinsons disease is not considered at all in the diagnosis for an extended period, accounting for the large difference in prevalence of young onset group to the regular onset group. We also observed a significantly higher number of neurologist visits (p=0.002) and clinical investigations (p<0.001) prior to diagnosis of young-onset patients. Due to the impact of delayed diagnoses on young onset patients and clinical resources, we propose that Parkinsons disease be more actively considered in differential diagnoses of younger patients presenting associated symptoms.

Abbreviated quality of life scales for schizophrenia: Comparison and utility of two brief community functioning measures

BACKGROUND The Heinrichs-Carpenter Quality of Life Scale (QLS) is the most extensively used real-world community functioning scale in schizophrenia research. However, the extensive time required to administer it and the inclusion of items that overlap conceptually with negative symptoms limit its use across studies. The present study examined the validity and utility of two abbreviated QLS measures against the full QLS excluding negative symptom items. METHOD The sample included 1427 patients with schizophrenia who completed the baseline visit in the CATIE study. The validity of two abbreviated QLS measures (7-item and 4-item) were examined with the full QLS, excluding the intrapsychic foundations subscale, using correlation analysis. The utility of the abbreviated measures was explored by examining associations between the functioning scales and clinical variables and longitudinal change. RESULTS Both abbreviated QLS measures were highly predictive of the full QLS (both r=0.91, p<0.001), with no difference in predictive value between the abridged measures. Functional status was significantly associated with symptoms and cognition. Importantly, the strength of these associations was similar between the abbreviated and full QLS. Finally, multiple regression models examining the explanatory power of amotivation/apathy in predicting functioning scores after other symptoms and neurocognition had been accounted for were essentially identical irrespective of the QLS instrument used as the dependent measure. Longitudinal change was also similar across the three scales. CONCLUSIONS The 7-item abbreviated QLS is recommended as a brief measure of community functioning for individuals with schizophrenia, especially when assessment of functional outcome is not the focus.

The Effects of Video Games on Cognition and Brain Structure: Potential Implications for Neuropsychiatric Disorders

Video games are now a ubiquitous form of entertainment that has occasionally attracted negative attention. Video games have also been used to test cognitive function, as therapeutic interventions for neuropsychiatric disorders, and to explore mechanisms of experience-dependent structural brain changes. Here, we review current research on video games published from January 2011 to April 2014 with a focus on studies relating to mental health, cognition, and brain imaging. Overall, there is evidence that specific types of video games can alter brain structure or improve certain aspects of cognitive functioning. Video games can also be useful as neuropsychological assessment tools. While research in this area is still at a very early stage, there are interesting results that encourage further work in this field, and hold promise for utilizing this technology as a powerful therapeutic and experimental tool.

Examination of the validity of the Brief Neurocognitive Assessment (BNA) for schizophrenia

BACKGROUND Although many comprehensive batteries exist to evaluate the nature and degree of cognitive impairments in patients with schizophrenia, short batteries hold promise for rapidly screening and estimating deficits in global cognition. Recently, the Brief Neurocognitive Assessment (BNA) was established and has been shown to have similar validity and utility to a more comprehensive battery of cognitive tests in evaluating global cognitive impairments in patients with schizophrenia. The present study sought to further establish the validity of the BNA by comparing it with the MATRICS Consensus Cognitive Battery (MCCB). METHODS One-hundred seventy-six patients with schizophrenia and 300 healthy volunteers participated in the present study. Global cognition was evaluated using the MCCB composite score and estimated using the BNA. To examine practice effects and test-retest reliability, patients were re-assessed after 4weeks. RESULTS The BNA was highly correlated with global cognition as evaluated by the MCCB in both the schizophrenia (r=0.82) and healthy control samples (r=0.75). Both instruments were similarly sensitive to deficits in global cognition in patients with schizophrenia relative to healthy controls. The BNA also demonstrated high test-retest reliability in patients with schizophrenia (r=0.87), comparable to the level observed with the MCCB (r=0.91). In addition, both the BNA and MCCB showed a similar level of practice effects (both Cohens d=0.11), and both instruments demonstrated equivalent sensitivities to longitudinal change. Furthermore, scores from the BNA and MCCB were related to symptom severity and functional capacity to a similar degree. CONCLUSIONS The BNA provides clinicians and researchers with an efficient and reliable means by which to evaluate global neurocognitive impairments in patients with schizophrenia by allowing estimation of performance on a more comprehensive standardized battery.

Investigating consummatory and anticipatory pleasure across motivation deficits in schizophrenia and healthy controls

Anhedonia has traditionally been considered a characteristic feature of schizophrenia, but the true nature of this deficit remains elusive. This study sought to investigate consummatory and anticipatory pleasure as it relates to motivation deficits. Eighty-four outpatients with schizophrenia and 81 healthy controls were administered the Temporal Experience of Pleasure Scale (TEPS), as well as a battery of clinical and cognitive assessments. Multivariate analyses of variance were used to examine the experience of pleasure as a function of diagnosis, and across levels of motivation deficits (i.e. low vs. moderate. vs. high) in schizophrenia. Hierarchical regression analyses were also conducted to evaluate the predictive value of amotivation in relation to the TEPS. There were no significant differences between schizophrenia and healthy control groups for either consummatory or anticipatory pleasure. Within the schizophrenia patients, only those with high levels of amotivation were significantly impaired in consummatory and anticipatory pleasure compared to low and moderate groups, and compared to healthy controls. Further, our results revealed that amotivation significantly predicts both consummatory and anticipatory pleasure, with no independent contribution of group. Utilizing study samples with a wide range of motivation deficits and incorporating objective paradigms may provide a more comprehensive understanding of hedonic deficits.