Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

Interpretation of clinical trials comparing different drug regimens for Parkinson's disease (PD) is complicated by the different dose intensities used: higher doses of levodopa and, possibly, other drugs produce better symptomatic control but more late complications. To address this problem, conversion factors have been calculated for antiparkinsonian drugs that yield a total daily levodopa equivalent dose (LED). LED estimates vary, so we undertook a systematic review of studies reporting LEDs to provide standardized formulae. Electronic database and hand searching of references identified 56 primary reports of LED estimates. Data were extracted and the mean and modal LEDs calculated. This yielded a standardized LED for each drug, providing a useful tool to express dose intensity of different antiparkinsonian drug regimens on a single scale. Using these conversion formulae to report LEDs would improve the consistency of reporting and assist the interpretation of clinical trials comparing different PD medications.

Systematic review of levodopa dose equivalency reporting in Parkinson's disease

This article reviews and summarizes 200 years of Parkinson's disease. It comprises a relevant history of Dr. James Parkinson's himself and what he described accurately and what he missed from today's perspective. Parkinson's disease today is understood as a multietiological condition with uncertain etiopathogenesis. Many advances have occurred regarding pathophysiology and symptomatic treatments, but critically important issues are still pending resolution. Among the latter, the need to modify disease progression is undoubtedly a priority. In sum, this multiple-author article, prepared to commemorate the bicentenary of the shaking palsy, provides a historical state-of-the-art account of what has been achieved, the current situation, and how to progress toward resolving Parkinson's disease. © 2017 International Parkinson and Movement Disorder Society.

Past, present, and future of Parkinson's disease: A special essay on the 200th Anniversary of the Shaking Palsy

Depression occurs in around 35% of patients with Parkinson disease (PD) and is often persistent. Symptoms of depression can be evident in individuals at the time of diagnosis and might develop in the premotor stage of the disease. The underlying mechanisms of depression in PD are not known in detail, but changes in brain structure, signaling by neurotransmitters, and levels of inflammatory and neurotrophic factors are all suggested to contribute to its development. Psychosocial factors and pain could also have roles in depression. Changes in dopaminergic, noradrenergic and serotonergic systems in patients with PD might help to explain the incidence of depression in these individuals. Antidepressants that have dual serotonergic and noradrenergic effects are the drugs of choice for treating depression in PD. However, antiparkinsonian drugs might have beneficial effects not only on the motor symptoms of disease, but also on a patient's mood. Deep brain stimulation can worsen depression in some patients, but a preliminary study has suggested that transcranial magnetic stimulation could improve symptoms of depression. This Review describes the frequency and course of depression in patients with PD. The mechanisms that underlie depression in this disease are also discussed, and the management strategies for these patients are highlighted.

Depression in Parkinson disease—epidemiology, mechanisms and management

Diffusion Tensor Imaging of Cerebral White Matter Integrity in Cognitive Aging

The pathophysiology of depression and anxiety in Parkinson’s disease remains obscure. We aimed to compare the fractional anisotropy (FA) values of Parkinson’s disease (PD) patients with and without depression to investigate the nature of depression in PD. Twenty-eight patients were divided into two groups: those with depression and those without. Diagnosis of depression was made using the DSM-IV criteria. Patients in the two groups were matched for Hoehn Yahr stage. There were significant reductions in FA values in the bilateral frontal ROIs possibly representing anterior cingulate bundles. The anterior cingulate bundles play an important role in depression in PD, and some aspects of depression in PD have pathological processes in common with de novo depression.

Depression in Parkinson's disease. Diffusion tensor imaging study.

Little is known about the developing mechanisms of visual hallucinations in Parkinson's disease. This study aimed to investigate perfusion changes in parkinsonian patients with visual hallucinations using n-isopropyl-p-[123I]iodoamphetamine ([123I]IMP) single photon emission computed tomography imaging. A total of 70 consecutive patients, including 31 patients with visual hallucinations, and 39 patients without hallucinations, participated in this study. Patients with severe cognitive impairment (Mini-Mental State Examination score < 20), nonvisual hallucinations, or confusion were excluded. We compared brain perfusion changes between the two groups. We found that hallucinatory patients had significant perfusion reductions in the bilateral inferior parietal lobule, inferior temporal gyrus, precuneus gyrus, and occipital cortex compared to nonhallucinatory patients. These results suggested that hypoperfusion of the visual pathway was closely related to visual hallucinations in Parkinson's disease. © 2006 Movement Disorder Society

Hypoperfusion of the visual pathway in parkinsonian patients with visual hallucinations.

Does cardiac metaiodobenzylguanidine (MIBG) uptake in Parkinson's disease correlate with major autonomic symptoms?

Introduction – It is generally assumed that executive dysfunctions in Parkinson's disease (PD) are caused by degeneration of the basal ganglia or frontal cortex or both. However, there have been few studies investigating the relationship between executive dysfunctions and cerebral pathological change. The objective of this study was to evaluate various cognitive functions in non-demented patients with PD, and to compare the fractional anisotropy (FA) values of PD patients with and without executive dysfunction.



Materials and Methods –  Twenty-one consecutive non-demented patients with PD were enrolled in this study. Patients were divided into two groups on the basis of their Wisconsin Card Sorting Test score.



Results –  There was significant FA reduction in the left parietal white matter in the group in which the number of categories achieved was ≤2 relative to the group that achieved >2.



Conclusion –  Accumulating evidence suggests that conventional ‘frontal’ tasks correlate with both frontal lobe and parietal lobe function, and we suggest that pathological changes in the left parietal lobe may cause, in part, disturbances in executive tasks in PD.

Wisconsin Card Sorting Test in Parkinson's disease: diffusion tensor imaging.

Depression is common in individuals with Parkinson's disease. However, the pathophysiology of depression in Parkinson's disease remains obscure. Here we compared brain perfusion images of Parkinson's disease patients with and without depression to investigate correlations between depression and brain perfusion images in Parkinson's disease. We divided 40 consecutive patients with Parkinson's disease into two groups: patients with minor depression (n = 22) and patients without depression (n = 18). We then compared brain perfusion images between the two groups. As a result, hypoperfusion of the left superior and inferior frontal gyrus was demonstrated in depressed patients. These results were partially in agreement with previous studies on de novo and parkinsonian major depression. We could not conclude on whether pathophysiological mechanisms differed between de novo depression and depression with Parkinson's disease, and between major and minor depressions.

Kenichi Komatsu

Papers

Depression in Parkinson's disease. Diffusion tensor imaging study.

Hypoperfusion of the visual pathway in parkinsonian patients with visual hallucinations.

Does cardiac metaiodobenzylguanidine (MIBG) uptake in Parkinson's disease correlate with major autonomic symptoms?

Wisconsin Card Sorting Test in Parkinson's disease: diffusion tensor imaging.

Minor depression and brain perfusion images in Parkinson's disease.