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Dopamine receptors are abundant along the central nigrostriatal tract and are expressed as 5 subtypes in two receptor families. In PD, compensatory changes in dopamine receptors emerge as a consequence of the loss of dopamine nerve terminals or dopaminergic pharmacotherapy. We performed a systematic review and meta‐analysis of the available PET and single‐photon emission computed tomography studies that have investigated dopamine receptors in PD, PSP and MSA. The inclusion criteria were studies including human PET or single‐photon emission computed tomography imaging; dopamine receptor tracers (D1‐like or D2‐like) and idiopathic PD, PSP, or MSA patients compared with healthy controls. The 67 included D2‐like studies had 1925 patients. Data were insufficient for an analysis of D1‐like studies. PD patients had higher striatal binding early in the disease, but after a disease duration of 4.36 years, PD patients had lower binding values than healthy controls. Striatal D2R binding was highest in unmedicated early PD patients and in the striatum contralateral to the predominant motor symptoms. PSP and MSA‐P patients had lower striatal D2R binding than PD patients (14.2% and 21.8%, respectively). There is initial upregulation of striatal D2Rs in PD, which downregulate on average 4 years after motor symptom onset, possibly because of agonist‐induced effects. The consistent upregulation of D2Rs in the PD striatum contralateral to the predominant motor symptoms indicates that receptor changes are driven by neurodegeneration and loss of striatal neuropil. Both PSP and MSA patients have clearly lower striatal D2R binding values than PD patients, which offers an opportunity for differential diagnostics. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society [ABSTRACT FROM AUTHOR]

Spinal cord stimulation has been used for the treatment of chronic pain for decades. In 2009, our laboratory proposed, based on studies in rodents, that electrical stimulation of the dorsal columns of the spinal cord could become an effective treatment for motor symptoms associated with Parkinson's disease (PD). Since our initial report in rodents and a more recent study in primates, several clinical studies have now described beneficial effects of dorsal column stimulation in parkinsonian patients. In primates, we have shown that dorsal column stimulation activates multiple structures along the somatosensory pathway and desynchronizes the pathological cortico-striatal oscillations responsible for the manifestation of PD symptoms. Based on recent evidence, we argue that neurological disorders such as PD can be broadly classified as diseases emerging from abnormal neuronal timing, leading to pathological brain states, and that the spinal cord could be used as a "channel" to transmit therapeutic electrical signals to disrupt these abnormalities. © 2017 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

People with Parkinson's disease (PD) often have a posture characterized by lateral trunk flexion poorly responsive to antiparkinsonian drugs. To examine the effects of a rehabilitation programme (daily individual 90-minute-sessions, 5-days-a-week for 4-consecutive weeks) on lateral trunk flexion and mobility, 22 PD patients with mild to severe lateral trunk flexion, and 22 PD patients without trunk flexion were studied. Patients were evaluated using the Unified Parkinson's Disease Rating Scale motor subscale (UPDRS-III) score, and the kinematic behavior of the trunk was recorded by means of an optoelectronic system to determine: a) trunk flexion, inclination and rotation values in the erect standing posture; b) ranges of trunk flexion and inclination during trunk movements. After the treatment, significant decreases in trunk flexion [24°(4) vs. 14°(3), P < 0.001] and inclination in the static condition [23°(5) vs. 12°(4), P < 0.001)] were observed, both of which were maintained at the 6-month follow up. During the trunk flexion task, a significantly increased range of trunk flexion [64°(15) vs. 83°(15), P < 0.001] was observed; similarly, during the lateral bending task, the range of trunk inclination was found to be significantly increased, both toward the side of the trunk deviation [29°(8) vs. 42°(13), P < 0.01] and toward the contralateral side [14°(6) vs 29°(11), P < 0.01]. No further significant changes were observed at the 6-month follow-up. Trunk flexion and inclination values in the upright standing posture correlated slightly with the UPDRS-III score. Our findings show that significant improvements in axial posture and trunk mobility can be obtained through the 4-week rehabilitation programme described, with a parallel improvement in clinical status. © 2010 Movement Disorder Society [ABSTRACT FROM AUTHOR]

In this article, we review the state of the art knowledge concerning structural and functional imaging in multiple system atrophy (MSA). The relative value of imaging modalities in the differential diagnosis of MSA from other parkinsonian syndromes is debated. It is concluded that, although neuroimaging biomarkers provide valuable supportive data alongside clinical assessments, it is not possible to use them as surrogate markers. © 2009 Movement Disorder Society [ABSTRACT FROM AUTHOR]

Progressive Supranuclear Palsy (PSP) is a progressive neurodegenerative disorder. In contrast to Parkinson's disease (PD) and dementia with Lewy bodies (DLB), replacement therapy with dopaminergic and cholinergic agents in PSP has been disappointing. The neurochemical basis for this is unclear. Our objective was to measure dopaminergic and cholinergic receptors in the basal ganglia of PSP and control brains. We measured, autoradiographically, dopaminergic (dopamine transporter, 125I PE2I and dopamine D2 receptors, 125I epidepride) and cholinergic (nicotinic alpha4beta2 receptors, 125I 5IA85380 and muscarinic M1 receptors, 3H pirenzepine) parameters in the striatum and pallidum of pathologically confirmed PSP cases (n=15) and controls (n=32). In PSP, there was a marked loss of dopamine transporter and nicotinic alpha4beta2 binding in the striatum and pallidum, consistent with loss of nigrostriatal neurones. Striatal D2 receptors were increased in the caudate and muscarinic M1 receptors were unchanged compared with controls. These results do not account for the poor response to dopaminergic and cholinergic replacement therapies in PSP, and suggest relative preservation of postsynaptic striatal projection neurones bearing D2/M1 receptors. [ABSTRACT FROM AUTHOR]

Alterations in presynaptic and postsynaptic dopaminergic system and cerebral glucose metabolism in corticobasal degeneration (CBD) were assessed to evaluate the potential usefulness of different imaging methods for CBD. 123I-FP-CIT/123I-β-CIT SPECT and 123I-IBZM SPECT as well as 18F-FDG PET were performed in eight CBD patients. Decreased presynaptic dopamine transporter binding was found in all CBD patients while D2 receptor binding was reduced in only one patient. 18F-FDG PET displayed a contralateral hypometabolism in cortical and subcortical areas in seven out of eight patients. Our results demonstrate that glucose metabolism and DAT are reduced, while D2 receptors may be frequently preserved in CBD. © 2006 Movement Disorder Society [ABSTRACT FROM AUTHOR]

The diagnosis of corticobasal degeneration (CBD) is difficult despite the existence of some typical clinical features. Single photon emission computerized tomography (SPECT) in CBD presents an original pattern (with asymmetric hypoperfusion in pre- and retrorolandic regions) that could facilitate the differential diagnosis of CBD relative to the other degenerative parkinsonian syndromes. The objective of our study was to compare the regional cerebral blood flow measurements studied by SPECT in both CBD and Parkinson's disease (PD) using a multivariate procedure. Twenty-one patients with probable CBD and 20 patients with probable PD underwent brain (99m)Tc HmPaO SPECT. We used factorial discriminant analysis (FDA) to study the relative fixation of 26 regions of interest (ROIs) drawn on two transverse slices, together with the asymmetry indexes of 13 pairs of ROIs. FDA performed using the full set of parameters classified all the patients correctly. In order to classify the patients more easily, a predictive score using a selection of parameters was established. The most discriminating ROIs were the temporoinsular, temporoparietal, and frontal medial regions. We believe that this semiautomatic classification may be a precious tool for reinforcing the current clinical differential diagnosis of CBD and PD. [ABSTRACT FROM AUTHOR]

The effects of a self-supervised home exercise program and a physiotherapist-supervised exercise program on motor symptoms in Parkinson's disease (PD) patients were compared in a prospective single-blinded clinical trial. Nineteen subjects (6 women, 13 men; mean age, 65 ± 8 years) with Hoehn and Yahr Stages 2 to 3 were recruited. Subjects were self-selected into an 8-week exercise program that was self-supervised (HOME group) or physiotherapist-supervised (PT group). The primary outcome measurement was the Unified Parkinson's Disease Rating Scale (UPDRS) Motor subsection score (UPDRSm). The secondary outcome measurements were the Berg Balance Scale, Timed Up and Go Test, UPDRS Total score, and the Activities-specific Balance Confidence Scale. All outcomes were assessed at baseline and at 8 and 16 weeks after the start of the study. The investigators were blinded to the subject treatment group. Bonferroni-corrected paired Student's t test was used to evaluate the change in the UPDRSm from baseline to 8 weeks. Ninety-five percent confidence intervals (CI) were calculated for the change in the secondary outcome measurements from baseline to 8 weeks. There was statistically significant and equal decrease in the UPDRSm from baseline to 8 weeks in both treatment groups. There was no difference in the 95% CI in the change of the secondary outcome measurements. A self-supervised exercise program was found to have similar effectiveness as a physiotherapist-supervised exercise program in improving motor symptoms in PD patients. This finding is important in the counseling of PD patients regarding adjunctive treatment of motor symptoms of PD with exercise. © 2005 Movement Disorder Society [ABSTRACT FROM AUTHOR]

Reports of parkinsonism in phenylketonuria are exceedingly rare. We report on a patient who had received a delayed diagnosis of phenylketonuria as an infant and subsequently developed levodopa-responsive parkinsonism at the age of 33. Single-photon emission computed tomography (SPECT) using 123I-FP-CIT ([123)I]-2 beta-carbomethoxy-3beta-(-4-iodophenyl)-N-(3-fluoropropyl)-nortropane) used to measure dopamine transporter levels on two occasions, 7 and 9 years after the onset of neurological symptoms, were normal. Iodine-123-iodo-lisuride SPECT (IBZM) imaging, however, showed reduced caudate over putamen binding. This combination of imaging findings indicates a possible upregulation of postsynaptic D2 receptors in the context of intact presynaptic dopamine nerve terminal density. © 2004 Movement Disorder Society [ABSTRACT FROM AUTHOR]

Tropane-related tracers for SPECT and PET scanning have shown their value in assessing the in vivo striatal presynaptic status of the dopaminergic neurotransmitter system in man. Previously, there were a few other tracers suggested to be useful in the study of in vivo brain biochemistry in humans, particularly in patients afflicted with Parkinson's disease (PD) or parkinsonian syndromes. We summarize the work concerning the two main tracers applied in that context using single photon emission tomography (SPECT) scanning in patients with PD: IBZM and HMPAO. IBZM binds specifically to striatal dopamine D2 receptors and HMPAO uptake is a measure of cerebral tissue perfusion. © 2003 Movement Disorder Society [ABSTRACT FROM AUTHOR]

Neuropsychiatric symptoms, including dementia, frequently coexist with parkinsonian disorders and may cause diagnostic confusion as well as management problems. Functional imaging studies include single photon emission computerised tomography (SPECT), positron emission tomography (PET), proton magnetic resonance spectroscopy, diffusion tensor imaging, and functional magnetic resonance imaging. This review addresses the utility of these techniques, from the clinician's perspective, focusing on the most common causes of parkinsonism and cognitive impairment, Parkinson's disease with dementia, dementia with Lewy bodies, and Alzheimer's disease. The potential and limitations of these techniques for accurate and early diagnosis, monitoring disease progression, and establishing the pathophysiological basis underlying key clinical features are considered. The development of new probes for SPECT and PET cameras capable of labeling protein aggregates (e.g., β-amyloid) will offer exciting new insights into the spatial and temporal pattern of pathophysiological processes. Longitudinal studies with clinicopathological correlation represent the 'gold standard' for fully evaluating functional imaging techniques. © 2003 Movement Disorder Society [ABSTRACT FROM AUTHOR]