Prepared by William F. Carne, PhD and Lynn Klanchar, RN, MS, Richmond PADRECC
Visual Misperceptions and Hallucinations: Attentional Control Dysfunction?
Noting that visual misperceptions and hallucinations occur in over 50% of Parkinson’s disease patients, the authors propose a theoretical framework for the pathogenesis of these phenomena that relates to the failure in competing yet complimentary neural networks that regulate attention and the accurate perception of visual stimuli. They postulate that perceptual errors are related to impaired signaling between a task-driven default mode network and a stimulus-driven ventral attentional network. Normally these errors are corrected by a goal-directed dorsal attentional network (DAN). However, the DAN correction does not occur because breakdowns in frontostriatal circuitry fail to activate a filtering mechanism and false images are reinforced. The authors note that the model is consistent with earlier models of misperception and hallucinations and lends itself to electrophysiological, pharmacological and functional imaging exploration and verification.
Shine, J. M., Halliday, G. M., Naismith, S. L. and Lewis, S. J. (2011), Visual misperceptions and hallucinations in Parkinson's disease: Dysfunction of attentional control networks?. Movement Disorders, 26: 2154–2159. doi: 10.1002/mds.23896
Wearing-Off Scales Critiqued
A majority of patients with Parkinson’s disease develop significant wearing off symptoms after a few years of dopaminergic therapy, and multiple clinical scales have been developed to assess the degree and severity of wearing-off. A Movement Disorder Society Task Force was commissioned to examine these scales and developed a hierarchical classification scheme of “Recommended”, “Suggested” or “Listed”. Three diagnostic screening scales (three versions of the Wearing-Off Quest (WOQ), with 32, 19, and 9 items respectively) and four severity scales (UPDRS-III, MDS-UPDRS-IV, Treatment Response Scales (TRS), and Motor Fluctuation Diaries / CAPSIT-PD Diary) were identified. Scales were evaluated according to descriptive properties, availability, content and clinimetric properties. Two diagnostic screening questionnaires met the “Recommended” criteria (WOQ-19 and WOQ-9) while the third (WOQ-39) was “Suggested”. Only the patient diaries were “Recommended “for severity, while the UPDRS-III and the MDS-UPDRS-IV were “Suggested”. The TRS only was “Listed”. The authors discuss the limitations of the current scales and the hope that technology will help to overcome these shortcomings in the future.
Antonini, A., Martinez-Martin, P., Chaudhuri, R. K., Merello, M., Hauser, R., Katzenschlager, R., Odin, P., Stacy, M., Stocchi, F., Poewe, W., Rascol, O., Sampaio, C., Schrag, A., Stebbins, G. T. and Goetz, C. G. (2011), Wearing-off scales in Parkinson's disease: Critique and recommendations. Movement Disorders, 26: 2169–2175. doi: 10.1002/mds.23875
Obesity, Diabetes and PD
This prospective study examined whether anthropometric factors (baseline and young adulthood BMI, weight change, waist circumference, location of any weight gain and history of diabetes) were associated with PD risk in > 147,000 American Cancer Society CPS II Nutrition Cohort patients. Patients were followed from 1992-2005 with 656 incident cases of PD noted. Neither body mass nor waist circumference predicted PD risk. Likewise a history of diabetes was not a risk factor for PD. Further analysis did not reveal any impact of body mass at age 18, change in body mass between age 18 and baseline or gender influence upon the incidence of PD. The authors note that this large scale study may be limited by the self-report nature of the information, but its findings are consistent with other United States large scale, longitudinal studies. Contrary findings in Finnish studies raise the possibility of genetic influences.
Palacios, N., Gao, X., McCullough, M. L., Jacobs, E. J., Patel, A. V., Mayo, T., Schwarzschild, M. A. and Ascherio, A. (2011), Obesity, diabetes, and risk of Parkinson's disease. Movement Disorders, 26: 2253–2259. doi: 10.1002/mds.23855
Correlates of care relationship mutuality among carers of people with Alzheimer’s and Parkinson’s disease
This study was a secondary analysis of longitudinal data from a 5-year prospective two-group randomized trial of informal carers of older adults with Alzheimer’s or PD. The authors examined whether mutuality differed by care recipient factors (level of physical and cognitive ability) or by care factors (age, gender, race, kin relation to care recipient, depressive symptoms, and years of care giving) over a 12-month period. Mutuality is concerned with the degree of caring, affection, intimacy, mutual concern and overall relationship satisfaction experienced by those involved. The carer’s perception of mutuality was measured by “The Mutuality Scale of the Family Care Inventory”. It includes items such as “How close do you feel to him or her?”, “To what extent to you see eye-to-eye?” Study results suggest that high mutuality between carers and their care recipients increases the likelihood of carers to continue care. Carers who report high mutuality are less likely to be depressed and more likely to provide care for longer periods. Mutuality was negatively affected by low care recipient functional ability and more carer depressive symptoms. Teaching relationship-focused skill training strategies, developing and testing nursing interventions that enhance care relationship quality are potential implications for practice. The authors acknowledge that future studies should also include the care recipient’s perception of the relationship whenever possible since mutuality is a concept that should be surveyed from all parties involved.
Shim, B., Landerman, L. R., and Davis, L.L. (2011), Correlates of care relationship mutuality among carers of people with Alzheimer’s and Parkinson’s disease. Journal of Advanced Nursing 67(8), 1729-1738. Doi: 10.1111/j.1365-2648.2011.05618.x