Search

Background Several studies have reported an increased risk for patients with essential tremor to develop Parkinson's disease. In addition, hyperechogenicity in the area of the substantia nigra has been associated with a markedly increased risk for Parkinson's disease. The objective of this study was to evaluate the validity of substantia nigra hyperechogenicity in patients with essential tremor as a risk marker for Parkinson's disease. Methods Transcranial sonography was performed in 70 patients suffering from essential tremor. Fifty-four of these patients were available for follow-up after a mean of 6.16 ± 2.05 years and were assessed for the incidence of new-onset Parkinson's disease. Results The relative risk for developing Parkinson's disease in patients with essential tremor who had hyperechogenicity at baseline versus those without this hyperechogenicity was 7.00 (95% confidence interval, 1.62–30.34; sensitivity, 77.8%; specificity, 75.6%). Conclusions Substantia nigra hyperechogenicity is also associated with an increased risk for Parkinson's disease in patients with essential tremor. These findings further support the potential role of this echofeature as a risk marker for Parkinson's disease. © 2016 Movement Disorder Society

Background This study reports the baseline characteristics of diffusion tensor imaging data in Parkinson's disease (PD) patients and healthy control subjects from the Parkinson's Progression Markers Initiative. The main goals were to replicate previous findings of abnormal diffusion imaging values from the substantia nigra. in a large multicenter cohort and determine whether nigral diffusion alterations are associated with dopamine deficits. Methods Two hundred twenty subjects (PD = 153; control = 67) from 10 imaging sites were included. All subjects had a full neurological exam, a (123I)ioflupane dopamine transporter (DAT) single-photon emission computer tomography scan, and diffusion tensor imaging. Fractional anisotropy as well as radial and axial diffusivity was computed within multiple regions across the substantia nigra. Results A repeated-measures analysis of variance found a marginally nonsignificant interaction between regional fractional anisotropy of the substantia nigra and disease status (P = 0.08), conflicting with an earlier study. However, a linear mixed model that included control regions in addition to the nigral regions revealed a significant interaction between regions and disease status (P = 0.002), implying a characteristic distribution of reduced fractional anisotropy across the substantia nigra in PD. Reduced fractional anisotropy in PD was also associated with diminished DAT binding ratios. Both axial and radial diffusivity were also abnormal in PD. Conclusions Although routine nigral measurements of fractional anisotropy are clinically not helpful, the findings in this study suggest that more-sophisticated diffusion imaging protocols should be used when exploring the clinical utility of this imaging modality. © 2015 International Parkinson and Movement Disorder Society

Background A subgroup of patients initially diagnosed with Parkinson's disease (PD) turn out to have normal dopamine transporter single-photon emission computed tomography imaging and have been labeled as subjects without evidence of dopaminergic deficit (SWEDDs). In this study, we sought to further characterize these patients and have analyzed the frequency of nonmotor symptoms (NMS) in SWEDDs, PD patients, and healthy controls. Methods We analyzed the baseline clinical data of 412 PD patients, 184 controls, and 62 SWEDDs included in the Parkinson's Progression Marker Initiative study on a variety of different NMS questionnaires. Results Both PD patients and SWEDDs had greater frequency of NMS than healthy controls. Furthermore, some NMS, such as orthostatic hypotension as well as cardiovascular and thermoregulatory dysfunction were even more commonly reported in SWEDDs than in PD patients, whereas hyposmia was more common in PD, compared to SWEDDs. Conclusion NMS are more frequent in SWEDDs than in controls, and autonomic dysfunction and orthostatic hypotension were even more common than in PD patients. These findings support the notion that SWEDDS represent a group of patients with still poorly understood pathophysiology. © 2015 International Parkinson and Movement Disorder Society

The efficacy of deep brain stimulation (DBS) to treat medically intractable motor complications in advanced Parkinson’s disease (PD) has been established in multiple randomized controlled long-term trials of 6 months duration or longer. These have revealed consistent findings of markedly reduced motor complications and improved quality of life (QoL) as compared with best medical management in advanced PD patients with a mean duration of levodopa treatment usually above 10 years, such that current medical practice is to reserve DBS for those PD subjects with a prolonged history of intractable response oscillations and dyskinesias. 1,2 Recently, Schuepbach et al. 3 investigated the effect of DBS on QoL in PD patients with significantly shorter disease duration and a history of motor complications from Ldopa of 3 years. Their EARLYSTIM trial randomized 251 patients to either DBS plus medical therapy or medical therapy alone demonstrating significant improved QoL, motor disability, activities of daily living, and L-dopa‐induced motor complications in the DBS-treated patients versus those on best medical therapy alone after 2 years of follow-up. The authors suggested to consider earlier use of DBS than is currently reflected by clinical practice and to potentially opt for surgical treatment in patients within the first 3 years after the onset of motor complications. An accompanying editorial to this publication, however, cautioned that the investigated population in the EARLYSTIM trial might only represent a small fraction of PD patients, 4 possibly less than 10%. The authors themselves point out that their study population might not be 100% representative for the general PD population to explain the usually high rate of suicide and suicide attempts during the trial. We sought to better define the percentage of PD patients seen in a tertiary movement disorders center of the type recruited and participating in EARLYSTIM for whom the current trial results might prompt a change in the timing of DBS. For this purpose we retrospectively applied the main inclusion and exclusion criteria of EARLYSTIM to all PD patients seen at the movement disorders center at the Department of Neurology of the Medical University Inns