Metaiodobenzylguanidine Scintigraphy Research Articles

The relationship between lung MIBG uptake and clinical response to renal denervation

Abstract Background Renal denervation (RDN) reduces the sympathetic overdrive and can optimize blood pressure control in patients with difficult-to-treat hypertension (DTH). However, a substantial proportion of patients undergoing RDN do not show a clinical response to the procedure, making it critical to identify novel and more accurate predictors. The metaiodobenzylguanidine (MIBG) scintigraphy allows non-invasive assessment of sympathetic nerve activity. Yet, studies evaluating the heart and kidney MIBG uptake as predictors of clinical response to RDN provided conflicting results, and a comprehensive evaluation of the MIBG uptake in different organs of DTH patients undergoing RDN is lacking. Purpose To explore if a more comprehensive evaluation of MBG uptake in the kidneys, heart and lungs can predict the clinical response to RDN. Methods Eighteen patients with DTH underwent evaluation of their clinical and pharmacological history, office and ambulatory BP values and levels of cardiovascular risk factors. A rest echocardiography, carotid vascular ultrasound and MIBG scintigraphy were also performed before RDN. The patient’s pharmacological history and office and ambulatory BP values were re-evaluated after 3 months from RDN. We considered responders (R) those subjects with a significant reduction of the office BP values on stable BP-lowering treatment or a reduced burden of BP-lowering medications while maintaining optimal control of the office BP. Results Ten patients could be classified as R (1 woman, mean age 49±10 years), while 7 were non-responders (NR, 2 women, mean age 53±8 years). The reduction in office systolic and diastolic BP (baseline vs 3 months) was significantly larger in R vs NR (p=0.01 for both). The burden of BP-lowering medications after the procedure was reduced by 39% in R, compared to 2% in NR (p<0.01). Responders had a higher baseline HR and prevalence of carotid atherosclerosis than NR (p<0.05 for both). In early MIBG acquisitions, the lung/mediastinum ratio on both sides showed higher MIBG uptake in R vs NR (p<0.05). There was a higher MIBG uptake in the right vs. left lung in the whole population and in R vs NR. In late acquisitions, only the left side showed a significant difference between R and NR (p<0.05). The associations between the lung/mediastinum ratio MIBG uptake and response to RDN remained significant after adjusting for the baseline clinical predictors of the RDN response. All other MIBG scintigraphy parameters were similar between groups. Conclusions Our results suggest that RDN might be less effective in patients with an advanced burden of hypertension-mediated target organ damage and confirm a higher HR as a reliable predictor of the clinical response to the procedure. We also document a novel association between the lung/mediastinum ratio MIBG uptake and response to RDN that, if confirmed in future studies, might provide a novel marker to improve the selection of patients undergoing RDN.

Impairment of Cognitive Function Increases Mortality Risk in Relation to Cardiac Sympathetic Denervation and Renal Dysfunction in Patients With Systolic Heart Failure.

In contrast to the well-known prognostic values of the cardiorenal linkage, it remains unclear whether impaired cognitive function affects cardiac prognosis in relation to cardiac sympathetic innervation and renal function in patients with heart failure (HF). A total of 433 consecutive HF patients with left ventricular ejection fraction (LVEF) <50% underwent the Mini-Mental State Examination (MMSE) and a neuropsychological test for screening of cognition impairment or subclinical dementia. Following metaiodobenzylguanidine (MIBG) scintigraphy, patient outcomes with a primary endpoint of lethal cardiac events (CEs) were evaluated for a mean period of 14.8 months. CEs were documented in 84 HF patients during follow-up. MMSE score, estimated glomerular filtration rate (eGFR) and standardized heart-to-mediastinum ratio of MIBG activity (sHMR) were significantly reduced in patients with CEs compared with patients without CEs. Furthermore, overall multivariate analysis revealed that these parameters were significant independent determinants of CEs. The cutoff values of MMSE score (<26), sHMR (<1.80) and eGFR (<47.0 mL/min/1.73 m2) determined by receiver operating characteristic (ROC) analysis successfully differentiated HF patients at more increased risk for CEs from other HF patients. Impairment of cognitive function is not only independently related to but also synergistically increases cardiac mortality risk in association with cardiac sympathetic function and renal function in patients with HF.

Plasma biomarkers of neurodegeneration in patients and high risk subjects with Lewy body disease

Comorbid Alzheimer’s disease (AD) neuropathology is common in Lewy body disease (LBD); however, AD comorbidity in the prodromal phase of LBD remains unclear. This study investigated AD comorbidity in the prodromal and symptomatic phases of LBD by analyzing plasma biomarkers in patients with Parkinson’s disease (PD) and dementia with Lewy bodies (DLB) and individuals at risk of LBD (NaT-PROBE cohort). Patients with PD (PD group, n = 84) and DLB (DLB group, n = 16) and individuals with LBD with ≥ 2 (high-risk group, n = 82) and without (low-risk group, n = 37) prodromal symptoms were enrolled. Plasma amyloid-beta (Aβ) composite was measured using immunoprecipitation-mass spectrometry assays. Plasma phosphorylated tau 181 (p-tau181), neurofilament light chain (NfL), and alpha-synuclein (aSyn) were measured using a single-molecule array. Plasma p-tau181 levels were higher in the PD and DLB groups than in the low-risk group. Aβ composite level was higher in the DLB group than in the high-risk group. AD-related biomarker levels were not elevated in the high-risk group. NfL levels were higher in the high-risk, PD, and DLB groups than in the low-risk group. In the PD group, Aβ composite was associated with cognitive function, p-tau181 with motor function and non-motor symptoms, and NfL with cognitive and motor functions and non-motor symptoms. In the high-risk group, NfL was associated with metaiodobenzylguanidine scintigraphy abnormalities. The PD and DLB groups exhibited comorbid AD neuropathology, though not in the prodromal phase. Elevated plasma NfL levels, even without elevated AD-related plasma biomarker levels, may indicate aSyn-induced neurodegeneration in the LBD prodromal phase.

Clinical presentations and diagnostic application of proposed biomarkers in psychiatric-onset prodromal dementia with Lewy bodies.

Research criteria for the diagnosis of prodromal dementia with Lewy bodies (DLB) include three clinical subtypes: mild cognitive impairment with Lewy bodies (MCI-LB), delirium-onset prodromal DLB, and psychiatric-onset prodromal DLB. Late-onset psychiatric manifestations are at a higher risk of developing dementia, but its relation to prodromal DLB remains unclear. In addition to the risk of severe antipsychotic hypersensitivity reactions, accurate discrimination from non-DLB cases is important due to the potential differences in management and prognosis. This article aims to review a rapidly evolving psychiatric topic and outline clinical pictures of psychiatric-onset prodromal DLB, including the proposed biomarker findings of MCI-LB: polysomnography-confirmed rapid eye movement sleep behaviour disorder, cardiac [123I]metaiodobenzylguanidine scintigraphy, and striatal dopamine transporter imaging. We first reviewed clinical pictures of patients with autopsy-confirmed DLB. Regarding clinical reports, we focused on the patients who predominantly presented with psychiatric manifestations and subsequently developed DLB. Thereafter, we reviewed clinical studies regarding the diagnostic applications of the proposed biomarkers to patients with late-onset psychiatric disorders. Clinical presentations were mainly late-onset depression and psychosis; however, other clinical manifestations were also reported. Psychotropic medications before a DLB diagnosis may cause extrapyramidal signs, and potentially influences the proposed biomarker findings. These risks complicate clinical manifestation interpretation during the management of psychiatric symptoms. Longitudinal follow-up studies with standardised evaluations until conversion to DLB are needed to investigate the temporal trajectories of core features and proposed biomarker findings. In patients with late-onset psychiatric disorders, identification of patients with psychiatric-onset prodromal DLB provides the opportunity to better understanding the distinct prognostic subgroup that is at great risk of incident dementia. Advances in the establishment of direct biomarkers for the detection of pathological α-synuclein may encourage reorganising the phenotypic variability of prodromal DLB.

Evaluation of pharmacokinetics, safety, and efficacy of [211At] meta-astatobenzylguanidine ([211At] MABG) in patients with pheochromocytoma or paraganglioma (PPGL): A study protocol.

Pheochromocytoma, or paraganglioma (PPGL), is a tumor that arises from catecholamine-producing chromaffin cells of the adrenal medulla or paraganglion. Systemic therapy, such as the combination of cyclophosphamide, vincristine, and dacarbazine or therapeutic radiopharmaceuticals such as [131I] meta-iodobenzylguanidine (MIBG), may be administered in cases of locally advanced tumors or distant metastases. However, the current therapies are limited in terms of efficacy and implementation. [211At] meta-astatobenzylguanidine (MABG) is an alpha-emitting radionuclide-labeled ligand that has demonstrated remarkable tumor-reducing effects in preclinical studies, and is expected to have a high therapeutic effect on pheochromocytoma cells. We are currently conducting an investigator-initiated first-in-human clinical trial to evaluate the pharmacokinetics, safety, and efficacy of [211At] MABG. Patients with locally unresectable or metastatic PPGL refractory to standard therapy and scintigraphically positive [123I] MIBG aggregation are being recruited, and a 3 + 3 dose escalation design was adopted. The initial dose of [211At] MABG is 0.65 MBq/kg, with a dose escalation in a 1:2:4 ratio in each cohort. Dose-limiting toxicity is observed for 6 weeks after a single bolus dose of [211At] MABG, and the patients are observed for 3 months to explore safety and efficacy profiles. The primary endpoint is dose-limiting toxicity to determine both maximum tolerated and recommended doses. The secondary endpoints include radiopharmacokinetics, urinary radioactive excretion rate, urinary catecholamine response rate, objective response rate, progression free survival, [123I] MIBG scintigraphy on reducing tumor accumulation, and quality of life. jRCT2021220012 registered on 17 June 2022.

Decreased heart rate variability in sympathetic dominant states in Parkinson's disease and isolated REM sleep behavior disorder

IntroductionParkinson's disease (PD) presents with decreased heart rate variability (HRV) from its early stages. However, most of its evidence originates from HRV measurements in parasympathetic dominant states. In this study, we aimed to examine whether HRV in sympathetic dominant states during the head-up tilt table test (HUT) serves as a marker of autonomic dysfunction in PD and isolated REM sleep behavior disorder (iRBD). MethodsWe retrospectively assessed 102 patients with PD, 10 patients with iRBD, and 43 healthy controls. We then measured the coefficient of variation of RR intervals as an HRV parameter in sympathetic dominant states (CVRR-S) and parasympathetic dominant states (CVRR-P). Furthermore, we evaluated parameters of cardiac autonomic function, including HUT and the heart-to-mediastinum (H/M) ratio of cardiac metaiodobenzylguanidine scintigraphy. ResultsPatients with iRBD and PD at Hoehn and Yahr stage I exhibited a significantly decreased CVRR-S compared to healthy controls (controls vs. iRBD vs. PD; 1.82 ± 0.64 % vs. 1.13 ± 0.41 % vs. 1.15 ± 0.51 %, p < 0.001), although no further deterioration was observed in PD at more severe Hoehn and Yahr stages. CVRR-S showed a significant correlation with the H/M ratio in PD (r = 0.51, p < 0.001). Additionally, receiver operating characteristic (ROC) analysis revealed a larger area under the ROC curve in CVRR-S compared to that in CVRR-P for discriminating PD or iRBD from healthy controls. ConclusionHRV in sympathetic dominant states shows the potential to be a marker of autonomic dysfunction in iRBD and early-stage PD, aiding in early diagnosis and patient stratification.

Comparison between whole-body magnetic resonance imaging and whole-body metaiodobenzylguanidine scintigraphy in the evaluation of primary tumor and metastases in neuroblastoma.

Whole-body metaiodobenzylguanidine (131 I-MIBG) scintigraphy is the gold standard method to detect neuroblastoma; however, it depends on radioactive material and is expensive. In contrast, whole-body magnetic resonance imaging (WB-MRI) is affordable in developing countries and has been shown to be effective in the evaluation of solid tumors. This study aimed to compare the sensitivity and specificity of WB-MRI with MIBG in the detection of primary tumors and neuroblastoma metastases. This retrospective study enrolled patients with neuroblastoma between 2013 and 2020. All patients underwent WB-MRI and MIBG at intervals of up to 15days. The results were marked in a table that discriminated anatomical regions for each patient. Two experts evaluated, independently and in anonymity, the WB-MRI images, and two others evaluated MIBG. The results were compared in terms of sensitivity and specificity, for each patient, considering MIBG as the gold standard. This study was approved by the UNIFESP Ethics Committee. Thirty patients with neuroblastoma were enrolled in this study. The age ranged from 1 to 15years, with a mean of 5.7years. The interval between exams (WB-MRI and MIBG) ranged from 1 to 13days, with an average of 6.67days. Compared to MIBG, WB-MRI presented a sensitivity and specificity greater than or equal to 90% for the detection of primary neuroblastoma in bones and lymph nodes. When we consider the patient without individualizing the anatomical regions, WB-MRI presented sensitivity of 90% and specificity of 73.33%. In conclusion, WB-MRI is a sensitive and specific method to detect neuroblastoma in bone and lymph nodes and highly sensible to primary tumor diagnosis, suggesting that this test is a viable alternative in places where MIBG is difficult to access. Studies with a larger number of cases are necessary for definitive conclusions.

Diagnostic problems in pediatrics on the example of a clinical case of neuroblastoma

Neuroblastoma (NB) is a malignant extracranial solid tumor of childhood. The peak incidence occurs in the first year of life. In 50% of cases, the disease already has signs of metastasis at the time of diagnosis. The clinical picture in neuroblastoma is varied; the symptoms are not specific and depend on the localization. The diagnosis is confirmed by histological examination of the biopsy of the primary tumor and metastasis. A specific method for the topical diagnosis of neuroblastoma is 123I-labeled metaiodobenzylguanidine scintigraphy, which makes it possible to detect the primary tumor, the presence of regional and distant metastases. Combinations of high-dose chemotherapy and transplantation of autologous stem cells and differentiating agents, as well as immunotherapy with anti-GD2 monoclonal antibodies, can increase the life expectancy of patients.

Impact of diabetes and glycated hemoglobin level on the clinical manifestations of Parkinson's disease

BackgroundThe coexistence of diabetes mellitus (DM) has been suggested to accelerate the progression of Parkinson's disease (PD) and make the phenotype more severe. In this study, we investigated whether DM or glycated hemoglobin (HbA1c) levels affect the differences in motor and nonmotor symptoms. MethodsWe conducted a cross-sectional study including 140 consecutive Japanese patients with PD for whom medical history and serum HbA1c records were available. The PD patients with a DM diagnosis were classified into the diabetes-complicated group (PD-DM) and the nondiabetes-complicated group (PD-no DM). Next, patients were classified based on a median HbA1c value of 5.7, and clinical parameters were compared. The correlations between HbA1c levels and other clinical variables were analyzed. ResultsOf 140 patients, 23 patients (16%) had DM. Compared to PD-no DM patients, PD-DM patients showed lower MMSE scores. Compared to the lower HbA1c group, the higher HbA1c group showed a higher MDS-UPDRS part III score and a lower metaiodobenzylguanidine (MIBG) scintigraphy heart-to-mediastinum (H/M) ratio. HbA1c levels were positively correlated with age and the MDS-UPDRS part III score and negatively correlated with the MMSE score and H/M ratio on cardiac MIBG scintigraphy. Binary logistic regression analysis, which included age, sex, disease duration, and MMSE and MDS-UPDRS part III scores as independent variables, revealed that a lower MMSE score was an independent contributor to PD-DM and PD with high HbA1c levels. ConclusionsDM complications and high HbA1c levels may affect cognitive function in patients with PD.

Exploring the prevalence of undetected bradyarrhythmia in dementia with Lewy bodies

PurposeTo explore the prevalence of undetected bradyarrhythmia in a cohort of people with dementia with Lewy bodies.MethodsThirty participants diagnosed with dementia with Lewy bodies were enrolled from three memory clinics in southern Sweden between May 2021 and November 2022. None had a history of high-grade atrioventricular block or sick sinus syndrome. Each participant underwent orthostatic testing, cardiac [123I]metaiodobenzylguanidine scintigraphy and 24-h ambulatory electrocardiographic monitoring. Concluding bradyarrhythmia diagnosis was obtained until the end of December 2022.ResultsThirteen participants (46.4%) had bradycardia at rest during orthostatic testing and four had an average heart rate < 60 beats per minute during ambulatory electrocardiographic monitoring. Three participants (10.7%) received a diagnosis of sick sinus syndrome, of whom two received pacemaker implants to manage associated symptoms. None received a diagnosis of second- or third-degree atrioventricular block.ConclusionThis report showed a high prevalence of sick sinus syndrome in a clinical cohort of people with dementia with Lewy bodies. Further research on the causes and consequences of sick sinus syndrome in dementia with Lewy bodies is thus warranted.

The role of MIBG scan in the diagnosis of pheochromocytoma.

e15064 Background: Pheochromocytoma is an uncommon adrenal medulla tumor. Metaiodobenzylguanidine (MIBG) scintigraphy is the current gold standard functional imaging method for evaluating pheochromocytoma, due to its excellent 100% specificity, 80% sensitivity, and general availability. In addition to establishing an extension evaluation and monitoring medication efficacy, MIBG scintigraphy is essential to confirm the diagnosis of suspected pheochromocytoma, especially when there is a tumor-like adrenal mass whose etiology is to be determined and biopsy is contraindicated given the risk of catecholamine discharge with hypertensive flare and the risk of bleeding. Our aims are to determine the efficacy of scintigraphy in the diagnosis of pheochromocytoma by examining the epidemiological characteristic and uptake patterns of the disease. Methods: In a retrospective analysis from January 2010 to December 2020, we examined pheochromocytoma patients medical records who had been referred for MIBG scintigraphy to the regional western Algerian Nuclear Medicine department at the University Hospital Center of Tlemcen. Prior to a progressive intravenous injection of 40–80 MBq of l-MIBG, patients underwent preparation (discontinuation of interfering drugs with I-MIBG especially antihypertensive treatment, thyroid blocking, and hydration). Imaging acquisition was carried out 48 and 72 hours later. Results: Fifty patients with probable pheochromocytoma (sex ratio = 0,78; mean age = 43 [17-74] years) completed I-MIBG scintigraphy prior to adrenalectomy. The MIBG scan has a high specificity and positive predictive value (100%). It confirms the presence of pheochromocytoma in 21 cases (42%), even if the metanephrine is normal in a patient with a non-secreting pheochromocytoma. In 18 cases, the main pattern is a single, homogenous, and intense intra-abdominal uptake. For the three remaining patients, a voluminous and heterogeneous uptake with a photopenic center that was associated to a necrotic adrenal mass larger than 10 cm in size, seen on abdominal Computerized Tomography (CT). In this retrospective analysis, no cases of metastatic or multiple diseases were documented. The sensitivity and negative predictive value are 84% and 86%, respectively. In 29 patients (58%), the scan reveals no abnormalities in uptake. This is attributed, in part, to 30% false positive biology (sampling conditions of urinary and/or plasmatic metanephrines and/or normetanephrines), 20% false positive CT imaging (differential diagnosis of adrenal mass: benign or malignant adrenal nodule), and 8% false negative MIBG scintigraphy (subcentimetric, cystic and necrotic lesion). Conclusions: Due to its exceptional specificity, robust sensitivity, and whole-body staging, MIBG scintigraphy—along with biology and morphology imaging—is a crucial noninvasive diagnostic method for the management of pheochromocytoma prior to adrenalectomy.

Clinico-imaging features of subjects at risk of Lewy body disease in NaT-PROBE baseline analysis

Individuals with prodromal symptoms of Lewy body disease (LBD), such as rapid eye movement sleep behavior disorder (RBD), often showed imaging defects similar to patients with Parkinson’s disease and dementia with Lewy bodies. We examined dopamine transporter (DaT) single-photon-emission computed tomography (SPECT) and metaiodobenzylguanidine (MIBG) scintigraphy in 69 high-risk subjects with ≥2 prodromal symptoms (dysautonomia, hyposmia, and probable RBD) and 32 low-risk subjects without prodromal symptoms, whom were identified through a questionnaire survey of health checkup examinees. The high-risk subjects had significantly worse scores on Stroop test, line orientation test, and the Odor Stick Identification Test for Japanese than the low-risk subjects. The prevalence of abnormalities on DaT-SPECT was higher in the high-risk group than in the low-risk group (24.6% vs. 6.3%, p = 0.030). A decreased uptake on DaT-SPECT was associated with motor impairment, and MIBG scintigraphy defects were associated with hyposmia. The simultaneous evaluation of DaT-SPECT and MIBG scintigraphy may capture a wide range of individuals with prodromal LBD.

Research diagnostic criteria for mild cognitive impairment with Lewy bodies: A systematic review and meta-analysis.

Operationalized research criteria for mild cognitive impairment with Lewy bodies (MCI-LB) were published in 2020. The aim of this systematic review and meta-analysis was to review the evidence for the diagnostic clinical features and biomarkers in MCI-LB set out in the criteria. MEDLINE, PubMed, and Embase were searched on 9/28/22 for relevant articles. Articles were included if they presented original data reporting the rates of diagnostic features in MCI-LB. Fifty-seven articles were included. The meta-analysis supported the inclusion of the current clinical features in the diagnostic criteria. Evidence for striatal dopaminergic imaging and meta-iodobenzylguanidine cardiac scintigraphy, though limited, supports their inclusion. Quantitative electroencephalogram (EEG) and fluorodeoxyglucose positron emission tomography (PET) show promise as diagnostic biomarkers. The available evidence largely supports the current diagnostic criteria for MCI-LB. Further evidence will help refine the diagnostic criteria and understand how best to apply them in clinical practice and research. A meta-analysis of the diagnostic features of MCI-LB was carried out. The four core clinical features were more common in MCI-LB than MCI-AD/stable MCI. Neuropsychiatric and autonomic features were also more common in MCI-LB. More evidence is needed for the proposed biomarkers. FDG-PET and quantitative EEG show promise as diagnostic biomarkers in MCI-LB.

Pitfalls in the diagnosis and treatment of a hypertensive patient with unilateral primary aldosteronism and contralateral pheochromocytoma: a case report

BackgroundPrimary aldosteronism (PA) is a common cause of secondary hypertension, whereas pheochromocytoma is a rare cause of it. Thus, concomitant PA and pheochromocytoma is a very rare condition.Case presentationA 52-year-old woman was admitted to our hospital with suspected PA based on the presence of hypertension, spontaneous hypokalemia, and a high aldosterone-to-renin ratio. She had no catecholamine excess symptoms other than hypertension. Abdominal computed tomography (CT) showed a right lipid-rich adrenal mass and a left lipid-poor adrenal mass. PA was diagnosed by the captopril challenge test. The 24-h urinary fractionated metanephrines were slightly elevated. Adrenal vein sampling (AVS) confirmed that the right adrenal gland was responsible for aldosterone hypersecretion. Medical therapy with eplerenone was started because the patient refused surgery. Five years later, she requested surgery for PA. The second AVS confirmed right unilateral hyperaldosteronism, as expected. Repeated abdominal CT showed the enlargement of the left adrenal mass. The 24-h urinary fractionated metanephrines had risen to the diagnostic level. 123I- metaiodobenzylguanidine (MIBG) scintigraphy showed a marked tracer uptake in the left adrenal mass with no metastatic lesion. After preoperative management with α-blockade, laparoscopic left partial adrenalectomy was performed. Immunohistochemical examination of the tumor showed chromogranin A positivity leading to the diagnosis of left pheochromocytoma.ConclusionsWe report an extremely rare case of concomitant unilateral PA and contralateral pheochromocytoma. When diagnosing unilateral PA by AVS, especially in cases with a lipid-poor adrenal mass, clinicians should rule out the possibility of the presence of pheochromocytoma before proceeding to undergo unilateral adrenalectomy. Although there is no standard treatment for this rare condition, it is essential to select personalized treatment from the perspective of conserving the adrenal gland.

Early Effect of Transcatheter Mitral Valve Repair on Cardiac Sympathetic Nerve Activity

BackgroundCardiac sympathetic nerve activity (SNA) is overactivated in heart failure patients and associated with clinical outcomes. The aim of this study is to investigate the early effect of MitraClip repair on cardiac SNA. MethodsWe evaluated the change of cardiac SNA by 123I- meta-iodobenzylguanidine (MIBG) scintigraphy in patients who underwent MitraClip repair from March 2019 to June 2020 in our hospital. Patients without acute procedural success were excluded, including patients who died or underwent mitral valve surgery before discharge. MIBG scintigraphy was performed at baseline and 1 ​month after MitraClip repair. ResultsWe analyzed 48 patients (mean age 78.6 ± 10 years; 52.1% male; 37 secondary mitral regurgitation [SMR]/11 primary mitral regurgitation [PMR]). MR severity and New York Heart Association functional class significantly improved from baseline to 1 ​month after MitraClip repair (both p < 0.001). Overall, delay heart-mediastinum ratio (H/M) had no significant change, and washout rate (WR) showed a decreasing trend (delay H/M; pre 2.07 ± 0.46, post 2.05 ± 0.49, paired p = 0.348, WR; pre 36.1 ± 11.6%, post 33.6 ± 11.7%, paired p = 0.061). In PMR patients, WR was significantly decreased, however, delay H/M was not (delay H/M; pre 2.15 ± 0.50, post 2.10 ± 0.57, paired p = 0.019, WR; pre 34.6 ± 10.5%, post 26.7 ± 13.8%, paired p = 0.568). In contrast, in SMR patients, neither delay H/M nor WR were significantly changed (delay H/M; pre 2.05 ± 0.45, post 2.03 ± 0.47, paired p = 0.474, WR; pre 36.6 ± 11.9%, post 35.7 ± 10.4%, paired p = 0.523). ConclusionsOur study demonstrates that MitraClip repair could significantly decrease cardiac SNA of WR in PMR patients during 1-month follow-up, however, in SMR patients, the significant change of MIBG parameters was not observed.

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

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. 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). 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. 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. 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.

False-positive 123I-metaiodobenzylguanidine scintigraphy in a patient with a gastrointestinal stromal tumor presenting as a left adrenal incidentaloma.

A 47-year-old man was diagnosed with a left adrenal incidentaloma at 40 years of age. The tumor had irregular margins and grew from 18 mm to 30 mm in maximum diameter over 7 years. On computed tomography scan, the mass appeared to localize within the tip of the lateral limb of the left adrenal gland, and between the left adrenal gland and the posterior wall of the stomach. The plasma corticotropin and cortisol concentrations and the 24-h urine fractionated metanephrine levels were normal. 123I-metaiodobenzylguanidine scintigraphy showed tumor avidity consistent with a hormonally inactive pheochromocytoma. A laparoscopic left adrenalectomy was performed; however, no tumor was present in the resected specimen. Abdominal computed tomography postoperatively showed that the tumor remained intact and appeared to connect to the posterior wall of the stomach. A laparotomy was performed and the tumor was removed. The tumor was localized to the intraperitoneal space and isolated from the posterior wall of the stomach. The pathological diagnosis was a gastrointestinal stromal tumor. Clinicians need to be aware of the limitations of diagnostic imaging studies in diagnosing non-functioning adrenal incidentalomas, which require a pathological analysis for the final diagnosis. Moreover, clinicians need to provide patients with sufficient informed consent when deciding on treatment strategies. Anatomic structures and tumors that develop in neighboring tissues to the adrenal glands may be confused with primary adrenal tumors. 123I- metaiodobenzylguanidine (MIBG) scintigraphy is specific for diagnosing pheochromocytomas and paragangliomas; however, it has been reported that 123I-MIBG may accumulate in neuroendocrine tumors as well as other tumors. Clinicians should recognize the limitations of imaging studies and the uncertainty of an imaging-based preoperative diagnosis.

Carotid Artery Revascularization Improves Cardiac Sympathetic Nerve Activity in Patients With Carotid Artery Stenosis.

The carotid sinus baroreceptor reflex controls the neural regulation of blood pressure. Baroreceptor disorders due to carotid sinus atherosclerosis have detrimental cardiovascular effects. This study investigated the medium-term effects of carotid artery revascularization (CAR) on sympathetic and cardiac function and systemic blood pressure variability in patients with carotid artery stenosis. This study included 21 consecutive patients (median age 70 years, 18 men) with carotid artery stenosis scheduled for CAR. 123I metaiodobenzylguanidine (MIBG) scintigraphy, echocardiography, brain natriuretic peptide levels, 24-h Holter electrocardiography (ECG), and ambulatory blood pressure monitoring assessed approximately 3 months postoperatively were compared to preoperative data. All 21 enrolled patients underwent CAR. Carotid artery stenting was done in three patients with cardiovascular risk or anatomical difficult for carotid endarterectomy. The mean common carotid artery end-diastolic velocity improved significantly (P < 0.01) by 1.6-fold, from 10.8 ± 3.2 to 16.1 ± 7.1 cm/s. In 123I-MIBG scintigraphy, the heart-to-mediastinum (H/M) count ratio was significantly higher than preoperatively (from 2.66 ± 0.48 to 2.86 ± 0.56, P = 0.03). Holter ECG analysis revealed a significant decrease in the low-frequency/high-frequency (LF/HF) ratio compared to preoperatively (from 2.17 ± 1.20 to 1.62 ± 0.68, P = 0.04). These findings suggest decreased myocardial sympathetic activation. In echocardiography, the tissue Doppler-derived e' increased, and E/e' decreased significantly (P < 0.05) from 11.7 ± 5.1 to 10.1 ± 4.0, suggesting an improved left ventricular diastolic capacity. The mean 24-h and nighttime blood pressures were unchanged. CAR in patients with carotid stenosis may provide medium-term improvement in cardiac sympathetic nerve activity and left ventricular diastolic dysfunction.

When a Multidisciplinary Approach Is Life-Saving: A Case Report of Cardiogenic Shock Induced by a Large Pheochromocytoma.

Background: Pheochromocytoma is known for its instantaneous presentation, especially in the younger population. Hemodynamic instability may be the cause of severe complications and impede patients’ ability to undergo surgical treatment. These tumours are surgically difficult to treat due to the risk of catecholamine release during their manipulations, and when they are large, the tumour size represents an additional challenge. In our report, cardiogenic shock developed due to increases in systemic vascular resistance, and the lesion’s size induced surgeons to perform open surgery. Case presentation: A 46-year-old female patient was admitted to our intensive care unit with hypertension and later cardiogenic shock. Systolic dysfunction was noted, along with severely increased systemic vascular resistance. A CT scan showed a left-sided 8.5 cm adrenal mass, which was confirmed as pheochromocytoma using meta-iodobenzylguanidine scintigraphy. Anaesthesiologists and the surgical team planned an effective strategy of treatment. Given the lesion’s size and its apparent invasion of the neighbouring organs, open adrenalectomy (after prolonged hemodynamic stabilisation) was considered safer. The surgery was successful, and the patient remains free from disease two years after the initial event. Conclusions: Large pheochromocytoma can be safely and effectively treated with open surgery by experienced hands but only by seeking to reach hemodynamic stabilisation and minimising the release of catecholamine before and during surgery.

Sleep and Autonomic Manifestations in Parkinson's Disease Complicated With Probable Rapid Eye Movement Sleep Behavior Disorder.

Patients with Parkinson’s disease (PD) complicated with rapid eye movement sleep behavior disorder (RBD) present with distinct clinical features. The purpose of this study was to determine the clinical features of sleep and autonomic symptoms in PD patients with probable RBD (pRBD). The study included 126 patients with PD. pRBD was defined as having a history of dream-enacting behavior with a total score of 5 or greater on the Japanese version of the RBD Screening Questionnaire (RBDSQ-J). The Parkinson’s Disease Sleep Scale-2 (PDSS-2) was used to evaluate sleep disturbances. Scales for Outcomes in Parkinson’s Disease-Autonomic dysfunction (SCOPA-AUT) were used to evaluate autonomic symptoms. Clinical assessments included disease severity, motor symptoms, olfaction, depression, cognitive function, levodopa equivalent dose (LED), and cardiac metaiodobenzylguanidine (MIBG) scintigraphy. Correlations between RBDSQ-J total scores and clinical variables were analyzed. Compared to PD patients without pRBD, PD patients with pRBD showed severe hyposmia, severe sleep-related symptoms, severe dysautonomia, and more reduced cardiac MIBG scintigraphy. Within the PDSS-2, the “PD symptoms at night” domain was significantly more severe in PD patients with pRBD. Within the SCOPA-AUT, the “urinary” and “cardiovascular” domains were significantly higher in PD patients with pRBD. In correlation analyses, RBDSQ-J total scores were positively correlated with PDSS-2 total scores, “PD symptoms at night” and “disturbed sleep” domains, Epworth Sleepiness Scale scores, SCOPA-AUT total scores, “urinary,” “cardiovascular,” and “thermo” domain scores, and LED. RBDSQ-J total scores were negatively correlated with cardiac MIBG scintigraphy uptake. Binary logistic regression analysis showed that PDSS-2 subitem 7 (distressing hallucinations) and SCOPA-AUT subitem 11 (weak stream of urine) were significant determinants for pRBD. Our study showed that PD patients with pRBD had characteristic sleep and autonomic symptoms.