131I-MIBG myocardial scintigraphy for differentiation of Parkinson's disease from multiple system atrophy or essential tremor in Chinese population

Distinguishing essential tremor from Parkinson's disease: clinical and experimental tools

INTRODUCTION

Essential tremor (ET) and Parkinson's disease (PD) are the most common causes of tremor and the most prevalent movement disorders, with overlapping clinical features that can lead to diagnostic challenges, especially in the early stages.

AREAS COVERED

In the present paper, the authors review the clinical and experimental studies and emphasized the major aspects to differentiate between ET and PD, with particular attention to cardinal phenomenological features of these two conditions. Ancillary and experimental techniques, including neurophysiology, neuroimaging, fluid biomarker evaluation, and innovative methods, are also discussed for their role in differential diagnosis between ET and PD. Special attention is given to investigations and tools applicable in the early stages of the diseases, when the differential diagnosis between the two conditions is more challenging. Furthermore, the authors discuss knowledge gaps and unsolved issues in the field.

EXPERT OPINION

Distinguishing ET and PD is crucial for prognostic purposes and appropriate treatment. Additionally, accurate diagnosis is critical for optimizing clinical and experimental research on pathophysiology and innovative therapies. In a few years, integrated technologies could enable accurate, reliable diagnosis from early disease stages or prodromal stages in at-risk populations, but further research combining different techniques is needed.

Comprehensive blood metabolomics profiling of Parkinson's disease reveals coordinated alterations in xanthine metabolism

Parkinson's disease (PD) is a highly heterogeneous disorder influenced by several environmental and genetic factors. Effective disease-modifying therapies and robust early-stage biomarkers are still lacking, and an improved understanding of the molecular changes in PD could help to reveal new diagnostic markers and pharmaceutical targets. Here, we report results from a cohort-wide blood plasma metabolic profiling of PD patients and controls in the Luxembourg Parkinson's Study to detect disease-associated alterations at the level of systemic cellular process and network alterations. We identified statistically significant changes in both individual metabolite levels and global pathway activities in PD vs. controls and significant correlations with motor impairment scores. As a primary observation when investigating shared molecular sub-network alterations, we detect pronounced and coordinated increased metabolite abundances in xanthine metabolism in de novo patients, which are consistent with previous PD case/control transcriptomics data from an independent cohort in terms of known enzyme-metabolite network relationships. From the integrated metabolomics and transcriptomics network analysis, the enzyme hypoxanthine phosphoribosyltransferase 1 (HPRT1) is determined as a potential key regulator controlling the shared changes in xanthine metabolism and linking them to a mechanism that may contribute to pathological loss of cellular adenosine triphosphate (ATP) in PD. Overall, the investigations revealed significant PD-associated metabolome alterations, including pronounced changes in xanthine metabolism that are mechanistically congruent with alterations observed in independent transcriptomics data. The enzyme HPRT1 may merit further investigation as a main regulator of these network alterations and as a potential therapeutic target to address downstream molecular pathology in PD.

Cardiac 123I-Metaiodobenzylguanidine (MIBG) Scintigraphy in Parkinson's Disease: A Comprehensive Review

Cardiac sympathetic denervation, as documented on 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, is relatively sensitive and specific for distinguishing Parkinson's disease (PD) from other neurodegenerative causes of parkinsonism. The present study aims to comprehensively review the literature regarding the use of cardiac MIBG in PD. MIBG is an analog to norepinephrine. They share the same uptake, storage, and release mechanisms. An abnormal result in the cardiac MIBG uptake in individuals with parkinsonism can be an additional criterion for diagnosing PD. However, a normal result of cardiac MIBG in individuals with suspicious parkinsonian syndrome does not exclude the diagnosis of PD. The findings of cardiac MIBG studies contributed to elucidating the pathophysiology of PD. We investigated the sensitivity and specificity of cardiac MIBG scintigraphy in PD. A total of 54 studies with 3114 individuals diagnosed with PD were included. The data were described as means with a Hoehn and Yahr stage of 2.5 and early and delayed registration H/M ratios of 1.70 and 1.51, respectively. The mean cutoff for the early and delayed phases were 1.89 and 1.86. The sensitivity for the early and delayed phases was 0.81 and 0.83, respectively. The specificity for the early and delayed phases were 0.86 and 0.80, respectively.

High clinical diagnostic accuracy of combined salivary gland and myocardial metaiodobenzylguanidine scintigraphy in the diagnosis of Parkinson's disease

Background

Decreased myocardial uptake of ¹³¹I-metaiodobenzylguanidine (MIBG) is known to be an important feature to diagnose Parkinson's disease (PD). However, the diagnosis accuracy of myocardial MIBG scintigraphy alone is often unsatisfying. Recent studies have found that the MIBG uptake of the major salivary glands was reduced in PD patients as well.

Purpose

To evaluate the diagnostic value of major salivary gland MIBG scintigraphy in PD, and explore the potential role of myocardial MIBG scintigraphy combined with salivary gland MIBG scintigraphy in distinguishing PD from non-PD (NPD).

Methods

Thirty-seven subjects were performed with ¹³¹I-MIBG scintigraphy. They were classified into the PD group (N = 18) and the NPD group (N = 19), based on clinical diagnostic criteria, DAT PET and ¹⁸F-FDG PET imaging findings. Images of salivary glands and myocardium were outlined to calculated the MIBG uptake ratios.

Results

The combination of left parotid and left submandibular gland early images had a good performance in distinguishing PD from NPD, with sensitivity, specificity, and accuracy of 50.00, 94.74, and 72.37%, respectively. Combining the major salivary gland and myocardial scintigraphy results in the early period showed a good diagnostic value with AUC, sensitivity and specificity of 0.877, 77.78, and 94.74%, respectively. Meanwhile, in the delayed period yield an excellent diagnostic value with AUC, sensitivity and specificity of 0.904, 88.89, and 84.21%, respectively.

Conclusion

¹³¹I-MIBG salivary gland scintigraphy assisted in the diagnosis and differential diagnosis of PD. The combination of major salivary gland and myocardial ¹³¹I-MIBG scintigraphy further increased the accuracy of PD diagnosis.

Do statins reduce the rate of revision surgery after chronic subdural hematoma drain?

BACKGROUND

With chronic subdural hematoma (CSDH), surgery is the therapeutic mainstay for large or symptomatic cases. Statins are reported to be effective as the primary therapy of CSDH to obviate the need for surgery. However, the effect of statins on the postoperative course of CSDH is largely unclear. We therefore sought to determine whether statins reduce the rate of repeat surgery after CSDH drain.

METHODS

We performed an analysis of all patients who underwent surgery for CSDH at our institution between 2012 and 2018. The patients were separated into those who received statins as part of their previous medication (statin group) and those who did not (control group). The medical records were reviewed for repeat surgeries and complications. Additionally, patients or their relatives were contacted via phone to obtain missing data and inquire about possible repeat surgeries at other institutions.

RESULTS

We identified 407 patients who received CSDH evacuation via burr hole craniotomy. In total, 123 patients were treated with statins as part of their daily medication. Repeat surgery was performed in 26 patients in the statin group (21.1%) and 57 patients in the non-statin group (20.1%, p = 0.81). Upon multivariate logistic regression analysis, neither of the variables statins, age, antithrombotic medication, Charlson comorbidity index, or Markwalder grading score yielded a statistically significant effect upon the revision rate.

CONCLUSIONS

We found no evidence for the protective effect of statins in patients who underwent surgery for CSDH. We thus conclude that statin therapy is not warranted for CSDH perioperatively.

123I-Metaiodobenzylguanidine Myocardial Scintigraphy in Discriminating Degenerative Parkinsonisms

Background

¹²³I-Metaiodobenzylguanidine (¹²³I-MIBG) myocardial scintigraphy is a useful technique to differentiate Parkinson's disease (PD) from atypical parkinsonisms, since it is generally abnormal in PD and normal in the latter. Reduction of myocardial MIBG uptake is a supportive feature in the latest PD diagnostic criteria.

Objectives

To explore the clinical contribution of myocardial scintigraphy in discriminating different forms of parkinsonisms, especially when atypical features are present.

Methods

Forty-one patients with parkinsonism underwent a ¹²³I-MIBG myocardial scintigraphy in our Movement Disorders Center. Disease evolution was reviewed by applying the latest disease criteria for PD, multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS), as appropriate. Three diagnostic times were defined: T1 (before scintigraphy execution), T2 (immediately after the exam) and T3 (two years later). Early and delayed heart/mediastinum (H/M) ratios and washout rate (WR) were analyzed.

Results

Myocardial scintigraphy showed impaired MIBG uptake in 12 out of 15 patients with a definite PD diagnosis, while normal uptake was found in 20 of 26 patients with no-PD. Early and delayed H/M ratios were significantly lower in PD compared to overall no-PD patients and MSA patients. ¹²³I-MIBG myocardial scintigraphy was abnormal in all PD patients with dysautonomia. After ¹²³I-MIBG myocardial scintigraphy (T2), in 9 patients (22%) an improvement of diagnostic accuracy was reached.

Conclusions

Diagnostic accuracy of myocardial scintigraphy in distinguishing PD from atypical parkinsonism was suboptimal. Nevertheless, this study confirmed the relevance of ¹²³I-MIBG myocardial scintigraphy for the discrimination of PD from atypical parkinsonism, especially when dysautonomic symptoms are present.

Changes in clinical features of multiple system atrophy in Japan

Introduction

Methods

Results

Conclusion

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We investigated the clinical features of 80 probable MSA patients.

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We compared two groups of probable MSA patients according to the period of diagnosis.

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MSA with predominant cerebellar ataxia (MSA-C) was predominant in both groups.

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MSA with predominant parkinsonism (MSA-P) increased in the recent diagnosis group.

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Aging and development of examination tools may have influenced these results.

Clinical neurophysiology of multiple system atrophy

Multiple system atrophy (MSA) is an adult-onset, rapidly progressive neurodegenerative syndrome. The diagnosis of MSA is primarily clinical. Neurophysiologic studies can provide important clues to the diagnosis of MSA and differentiate it from other neurodegenerative diseases especially when the clinical picture is unclear. This chapter reviews common and less common neurophysiological studies useful in the diagnosis of MSA.

Roles of cardiac sympathetic neuroimaging in autonomic medicine

Sympathetic neuroimaging is based on the injection of compounds that either radiolabel sites of the cell membrane norepinephrine transporter (NET) or that are taken up into sympathetic nerves via the NET and radiolabel intra-neuronal catecholamine storage sites. Detection of the radioactivity is by planar or tomographic radionuclide imaging. The heart stands out among body organs in terms of the intensity of radiolabeling of sympathetic nerves, and virtually all of sympathetic neuroimaging focuses on the left ventricular myocardium. The most common cardiac sympathetic neuroimaging method worldwide is ¹²³I-metaiodobenzylguanidine (¹²³I-MIBG) scanning. ¹²³I-MIBG scanning is used routinely in Europe and East Asia in the diagnostic evaluation of neurogenic orthostatic hypotension (nOH), to distinguish Lewy body diseases (e.g., Parkinson disease with orthostatic hypotension (OH), pure autonomic failure) from non-Lewy body diseases (e.g., multiple system atrophy) and to distinguish dementia with Lewy bodies from Alzheimer's disease. In the USA, ¹²³I-MIBG scanning has been approved by the Food and Drug Administration for the evaluation of pheochromocytoma and some forms of heart failure-but not for the above-mentioned differential diagnoses. Positron emission tomographic methods based on imaging agents such as ¹⁸F-dopamine are categorized as research tools, despite more than a quarter century of clinical experience with these modalities. Considering that ¹²³I-MIBG scanning is available at most academic medical centers in the USA, cardiac sympathetic neuroimaging by this methodology merits consideration as an autonomic test, especially in patients with nOH.