123I-metaiodobenzylguanidine Scintigraphy Research Articles

Autonomic disorders and myocardial 123I-metaiodobenzylguanidine scintigraphy in Huntington’s disease

BackgroundHuntington’s disease (HD) patients often present with abnormal modulation of blood pressure and heart rate. We investigated whether cardiac autonomic innervation assessed by 123I-metaiodobenzylguanidine (MIBG) imaging is impaired in HD patients, in comparison with controls (Ctrl). MethodsFifteen patients (6 F and 9 M) were assessed by the motor section of the Unified HD Rating Scale, the Total Function Capacity, and the scale for outcomes in Parkinson’s disease-autonomic (SCOPA-AUT) questionnaire. All patients and 10 Ctrl (5 F and 5 M) underwent 123I-MIBG imaging. From planar images, the early and late heart-to-mediastinum (H/M) ratios and myocardial washout rates (WR) were calculated. ResultsWe did not find significant differences in early and late H/M ratios and WR between the two groups. At individual level, three patients showed reduced early and/or late H/M ratios. The most common autonomic complaints were gastrointestinal and genitourinary disorders. SCOPA-AUT questionnaire score results positively correlated with the disease duration and WR. ConclusionsOur study indicates that myocardial postganglionic sympathetic innervation is essentially preserved or only minimally involved in HD. These findings suggest that the cardiovascular dysfunction might be mainly due to the impairment of brain areas associated with the regulation and modulation of the heart function.

The value of single-photon emission computed tomography combined with computed tomography imaging in ¹²³I-Metaiodobenzylguanidine scintigraphy in children with neuroblastoma

The value of single-photon emission computed tomography combined with computed tomography imaging in ¹²³I-Metaiodobenzylguanidine scintigraphy in children with neuroblastomaWhole body scintigraphy with ¹²³I-Metaiodobenzylguanidine (¹²³I-MIBG) is an important imaging modality for evaluation of patients with neuroblastoma (NB). As the intrinsic nuclear scintigraphic characteristics, the assessment of conventional planar ¹²³I-MIBG images presents some difficulties. The limited resolution of planar images can induce false-negative results for small lesions, whereas the presence of physiologic MIBG uptake is not always easily differentiable from pathologic uptake and can induce false-positive results. Single-photon emission computed tomography combined with computed tomography (SPECT/ CT) hybrid imaging technique, allowing the direct fusion of morphologic and functional information, has been suggested to be more accurate. However, SPECT/CT imaging renders slightly more radiation to patients from CT portion of the study and is time consuming. The aim of our study was to investigate how much SPECT/CT can have additional diagnostic value over planar imaging in NB patients at initial staging. The study was approved by the Independent Ethics Committee and the Scientific Council of the D. Rogachev NMRCPHOI. A total of 251 SPECT/CT scans following by planar ¹²³I-MIBG imaging scans performed in 251 patients with NB were retrospectively analyzed. In 72.1% of the studies, the whole-body planar images and SPECT/CT images showed the same result. In 27.9% of studies, however, SPECT/CT images provided additional very important information. In our study, the diagnosis reached by planar imaging was revised or specified by SPECT/CT in 70 of the 251 patients and was clinically significant.

Usefulness of semi-quantitative analysis in 123I metaiodobenzylguanidine SPECT/CT for the differentiation of pheochromocytoma and cortical adenoma.

123I metaiodobenzylguanidine (MIBG) scintigraphy is a useful tool for the diagnosis of pheochromocytomas (PHEOs), but some PHEOs are difficult to differentiate from cortical adenoma (CA) or normal adrenal uptake by visual evaluation alone. A new semi-quantitative analysis using 123I MIBG SPECT/CT is thus expected. Herein, we introduce the tumor-to-liver count ratio (T/L) and the tumor-to-muscle count ratio (T/M). We examined the cases of 21 patients with PHEOs (10 males, 11 females; age 24-80, median 61 years) and 23 patients with CA (15 males and 8 females, age 30-78, median 58 years). The visual scoring based on 123I MIBG planar images (planar score) and SPECT images (SPECT score) was used as the conventional evaluation. Using 123I MIBG SPECT/CT findings, we calculated the semi-quantitative values of the count ratio using the maximum or mean count of the tumor and the liver or muscle as the reference organ (T/Lmax, T/Lmean, T/Mmax and T/Mmean). Each evaluation of the PHEOs and CAs was compared, and the diagnosing performance was evaluated based on an ROC analysis. The area under curve (AUC) values were as follows: the planar score, 0.833; SPECT score, 0.813; T/Lmax, 0.986; T/Lmean, 0.975; T/Mmax, 0.955; and T/Mmean, 0.933. The AUC for T/Mmax was significantly higher than those of the planar score, and SPECT score by ROC analysis (p < 0.01 each). The semi-quantitative value of 123I MIBG SPECT/CT is more useful than the conventional visual evaluation for differentiating PHEOs from CAs.

Influence of characteristics of epicardial adipose tissue and myocardial sympathetic innervation on the development of late recurrence of atrial fibrillation after radiofrequency ablation

Aim. To investigate the relationship between radiological characteristics of epicardial adipose tissue (EAT) and myocardial sympathetic activity, as well as to study their association with late recurrence of atrial fibrillation (AF) after radiofrequency ablation (RFA).Material and methods. This prospective study included 26 people with persistent and long-standing persistent AF scheduled for interventional AF treatment. Before the RFA procedure, all patients underwent cardiac 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy to assess the myocardial sympathetic innervation and contrast-enhanced cardiac multislice computed tomography to assess pulmonary vein anatomy, left atrial volume, and EAT volume. Clinical follow-up, including 12-lead electrocardiography (ECG) and 24-hour ECG monitoring, was carried out 3, 6 and 12 months after RFA.Results. After the end of follow-up, the patients were divided into two groups: with AF recurrence (group 1, n=8) and without AF recurrence (group 2, n=18). Multivariate logistic analysis found that only the 123I-MIBG washout rate (odds ratio, 1,0943; 95% confidence interval, 1,0138-1,1812) proved to be an independent predictor of late AF recurrence after RFA. ROC analysis revealed that a 123I-MIBG washout rate &gt;21% with a sensitivity of 75% and a specificity of 83,3% (AUC=0,844; p&lt;0,001) predicts late AF recurrence after RFA.Conclusion. Parameters of myocardial sympathetic activity, assessed by 123I-MIBG myocardial scintigraphy, are associated with late AF recurrence after RFA in patients with persistent and long-standing persistent AF. There were no reliable data confirming associations between myocardial sympathetic innervation and radiological EAT indicators, as well as the effect of the latter on the risk of AF recurrence after RFA.

Abstract 9177: Prognostic Value of Chronic Kidney Disease and Cardiac Sympathetic Dysfunction Assessed by 123 I-metaiodobenzylguanidine Scintigraphy for Lethal Arrhythmic Events in Chronic Heart Failure

Introduction: Clinical implication of chronic kidney disease (CKD) and cardiac sympathetic nerve activity (CSNA) for lethal arrhythmic events has not been fully elucidated in patients with chronic heart failure (CHF). Hypothesis: The combination of CKD and abnormal CSNA, assessed by 123 I-metaiodobenzylguanidine ( 123 I-MIBG) scintigraphy, may provide useful prognostic information for the incidence of lethal arrhythmic events. Methods: We studied 165 consecutive hospitalized CHF patients without dialysis. In a clinically stable condition, cardiac 123 I-MIBG scintigraphy was performed. CKD was defined as estimated glomerular filtration rate (eGFR) &lt;60 ml/min/1.73m 2 , and abnormal CSNA was defined as late heart to mediastinum ratio &lt;1.6. We then investigated the incidence of lethal arrhythmic events (sustained ventricular arrhythmia, appropriate implantable cardioverter-defibrillator therapy, or sudden cardiac death). Results: During a median follow-up of 5.3 years, lethal arrhythmic events were observed in 40 patients (24.2%). The patients were divided into 4 groups according to the presence of CKD and CSNA abnormality: non-CKD/ normal CSNA ( n = 52), CKD/ normal CSNA ( n = 39), non-CKD/ abnormal CSNA ( n = 33), and CKD/ abnormal CSNA ( n = 41).The Kaplan-Meier analysis showed that CKD/ abnormal CSNA had the highest event rate (log-rank p = 0.004). In addition, the multivariable Cox proportional hazard analysis after the adjustment of multiple confounders showed that CKD/ abnormal CSNA was an independent predictor for lethal arrhythmic events compared to non-CKD/ normal CSNA (HR, 4.667, p = 0.006). However, the other two groups did not show significant differences compared to non-CKD/ normal CSNA. Conclusions: The combination of CKD and abnormal CSNA, assessed by cardiac 123 I-MIBG scintigraphy, had a significant prognostic value for the incidence of lethal arrhythmic events in patients with CHF.

Factors Influencing Cardiac Sympathetic Nervous Function in Patients With Severe Aortic Stenosis: Assessment by 123I-Metaiodobenzylguanidine Myocardial Scintigraphy

Numerous studies have shown that 123I-metaiodobenzylguanidine (MIBG) scintigraphy, an index of cardiac sympathetic nervous (CSN) activity, is useful for predicting prognosis in patients with heart failure. However, the factors influencing the CSN activity of patients with severe aortic stenosis (AS) remain unclear. We enrolled 91 patients with severe AS who underwent 123I-MIBG scintigraphy, coronary computed tomography (CCT), and transthoracic echocardiography. When CCT angiography (CCTA) showed an obstructive epicardial artery, invasive coronary angiography was performed within 1 week of CCTA. There were 21 male and 70 female patients with a mean age of 84±5 years. Eighty-five (85) patients (93%) had hypertension and 13 patients (14%) had diabetes. Two (2) patients (2%) had previous myocardial infarction and eight (9%) had a previous coronary intervention. All patients had severe AS: aortic valve area was 0.63±0.18 cm2 and the mean pressure gradient was 56±19 mmHg. Regarding 123I-MIBG parameters, early heart-to-mediastinum (H/M) ratio was 3.1±0.5, delayed H/M ratio was 2.8±0.6, and the washout rate (WR) was 35%±13%. Multivariable linear regression analysis showed that coronary artery disease (β=-0.30, p=0.002) was an independent predictor of delayed H/M ratio, and that aortic valve area (β=-0.20, p=0.048) was an independent predictor of WR. Our findings suggest that coronary artery disease is an independent predictor of delayed H/M ratio, and aortic valve area is an independent predictor of WR in patients with severe AS.

Dopamine-Secreting Pheochromocytoma and Paraganglioma.

Predominantly or exclusively dopamine-secreting pheochromocytoma and paraganglioma are very rare. We report a 64-year-old woman with an adrenal incidentaloma. She was normotensive and had no symptoms of catecholamine excess. The 24-hour urine catecholamine level showed normal norepinephrine (122.9 μg/day), normal epinephrine (24.3 μg/day), and markedly elevated dopamine (148 212.4 μg/day). 123I-metaiodobenzylguanidine (MIBG) scintigraphy revealed tumor uptake. After α-blockade as preoperative management, she successfully underwent laparoscopic left adrenalectomy and was finally diagnosed with an exclusively dopamine-secreting pheochromocytoma. The tumor was histologically comprised of small polygonal cells with high cellularity and was immunohistochemically positive for all 3 catecholamine-synthesizing enzymes: tyrosine hydroxylase (very weak), dopamine β-hydroxylase (heterogeneous), and phenylethanolamine N-methyltransferase (very weak). Electron microscopy revealed very few catecholamine-containing small vesicles with a few organelles, which reflected immature cells. No biochemical or imaging evidence of recurrence or metastasis were evident 1 year after the surgery. We conducted a literature search in the PubMed database. A total of 33 cases were collected. Our case had the second-highest 24-hour urinary dopamine excretion and was the first in which immunostaining for catecholamine synthase and electron microscopy were performed together. Histological findings in our case give a possible hypothesis that the mechanism underlying a dopamine-secreting pheochromocytoma is associated with immature catecholamine vesicles in which dopamine β-hydroxylase is localized, thus resulting in inhibited conversion from dopamine to norepinephrine. We also discuss the reasons for the lack of catecholamine excess symptoms, whether preoperative management of α-blockade is needed, and the association between the prognosis and genetic mutation, with an extensive literature review.

Predictive impacts of chronic kidney disease and cardiac sympathetic nervous activity on lethal arrhythmic events in chronic heart failure.

BackgroundThe clinical implications of chronic kidney disease (CKD) and cardiac sympathetic nervous activity (CSNA) regarding lethal arrhythmic events have not yet been fully elucidated in patients with chronic heart failure (CHF). We hypothesized that the combination of CKD and abnormal CSNA, assessed by 123I‐metaiodobenzylguanidine (123I‐MIBG) scintigraphy, may provide useful prognostic information for lethal arrhythmic events.MethodsWe studied 165 consecutive hospitalized CHF patients without dialysis. Cardiac 123I‐MIBG scintigraphy was performed in a clinically stable condition, and abnormal CSNA was defined as a late heart‐to‐mediastinum ratio of <1.6. CKD was defined as an estimated glomerular filtration rate of <60 ml/min/1.73 m2. We then investigated the incidence of lethal arrhythmic events (sustained ventricular tachyarrhythmia, appropriate implantable cardioverter‐defibrillator therapy, or sudden cardiac death).ResultsDuring a median follow‐up of 5.3 years, lethal arrhythmic events were observed in 40 patients (24.2%). The patients were divided into four groups according to the presence of CKD and CSNA abnormality: non‐CKD/normal CSNA (n = 52), CKD/normal CSNA (n = 39), non‐CKD/abnormal CSNA (n = 33), and CKD/abnormal CSNA (n = 41). Kaplan–Meier analysis showed that CKD/abnormal CSNA had the highest event rate (log‐rank p = .004). Additionally, the Cox proportional hazard analysis revealed that CKD/abnormal CSNA was a predictor for lethal arrhythmic events compared with non‐CKD/normal CSNA (hazard ratio, 5.368, p = .001). However, the other two groups did not show significant differences compared with the non‐CKD/normal CSNA group.ConclusionsThe combination of CKD and abnormal CSNA, assessed by 123I‐MIBG scintigraphy, had a high predictive value for lethal arrhythmic events in patients with CHF.

Aceruloplasminemia: a multimodal imaging study in an Italian family with a novel mutation.

Structural abnormalities in thalami and basal ganglia, in particular the globus pallidus (GP), are a neuroimaging hallmark of hereditary aceruloplasminemia (HA), yet few functional imaging data exit in HA carriers. This study investigated the iron-related structural and functional abnormalities in an Italian HA family. Multimodal imaging was used including structural 3T MRI, functional imaging (SPECT imaging with 123I-ioflupane (DAT-SPECT), cardiac 123I metaiodobenzylguanidine (123I-MIBG) scintigraphy, and 18F-fluorodeoxyglucose (18F-FDG)-PET imaging). In the proband, MRI and scintigraphic evaluations were performed at baseline, 2 and 4years (structural imaging), and 2years of follow-up period (functional imaging). We investigated two cousins carrying a novel splicing homozygous mutation in intron 6 (IVS6 + 1 G > A) of CP gene. Interestingly, MRI features in both subjects were characterized by marked iron accumulation in the thalami and basal ganglia nuclei, while GP was not affected. MRI performed in the proband at 2 and 4years of follow-up confirmed progressive neurodegeneration of the thalami and basal ganglia without the involvement of GP. Functional imaging showed reduced putaminal DAT uptake in both cousins, whereas cardiac MIBG and FDG uptakes performed in the proband were normal. Longitudinal scintigraphic investigations did not show significant changes over the time. For HA carriers, our findings demonstrate that GP was spared by iron accumulation over the time. The nigrostriatal presynaptic dopaminergic system was damaged while the cardiac sympathetic system remained longitudinally preserved, thus expanding the imaging features of this rare inherited disorder.

Assessment of therapeutic effects of statin on cardiac sympathetic nerve activity after reperfusion therapy in patients with first ST-segment elevation myocardial infarction and normal low-density lipoprotein cholesterol

BackgroundStatin treatment reduces enhanced cardiac sympathetic nerve activity (CSNA) in patients with heart disease, and reduces adverse cardiac events in patients with coronary artery disease. MethodsWe retrospectively evaluated the first ST-segment elevation myocardial infarction (STEMI) patients and low-density lipoprotein cholesterol < 120 mg/dL in our database who underwent 123I-metaiodobenzylguanidine (MIBG) scintigraphy 3 weeks after admission. Sixty STEMI patients after primary coronary angioplasty were selected, and used propensity score matching to compare patients treated with strong statin (n = 30), and those who did not (n = 30). Moreover, echocardiographic left ventricular (LV) parameters were determined, and plasma procollagen type III amino terminal peptide (PIIINP) was also measured before and 3 weeks after treatment. ResultsFollowing primary angioplasty, age, gender, risk factors, culprit coronary artery, peak serum creatine phosphokinase concentration, and recanalization time were similar in the two groups. However, the statin group showed significantly lower delayed total defect score and washout rate evaluated by 123I-MIBG scintigraphy (22.4 ± 8.1 vs. 29.6 ± 10.5; P < 0.01, and 30.4 ± 8.9% vs. 40.1 ± 11.4%; P < 0.005, respectively) and higher delayed heart/mediastinum count ratio (2.17 ± 0.38 vs. 1.96 ± 0.30, P < 0.05) compared with the non-statin group. Moreover, the degree of change in LV parameters and PIIINP was more favorable in the statin group than in the non-statin group. ConclusionsAdministration of statin improves CSNA after reperfusion therapy in patients with first STEMI.

Inhibitor of Tyrosine Hydroxylase and Catecholamine-induced Cardiomyopathy in Pheochromocytoma

Usual clinical presentation of secreting pheochromocytoma is headache, palpitations, sweating and paroxysmal hypertension but emergency situations are also described. We herein reported a case of pheochromocytoma revealed by cardiogenic shock on dilated cardiomyopathy with improvement of left ventricular ejection fraction (LVEF) after the introduction of an inhibitor of tyrosine hydroxylase. A 41-year-old patient was admitted in the ICU for cardiogenic shock with initially hypertension emergency and tachycardia. Transthoracic echocardiography revealed a dilated cardiomyopathy with estimated 2-dimensional LVEF at 15 %. A computed tomography angiography was performed to rule out a pulmonary embolism and led to discover bilateral adrenal tumors measured at 3 cm and 2 cm respectively on the left and right sides. Plasmatic noradrenaline was increased 5.5 μg/L ( N < 0.60). 123I-metaiodobenzylguanidine scintigraphy, 18F-fluorodeoxyglucose and FDOPA positron emission tomography showed uptake of the 2 lesions. Despite an optimized heart failure treatment including an angiotensin-converting-enzyme inhibitor, a diuretic, an inhibitor of aldosterone and increasing doses of beta-blocker in addition to a calcic-blocker and alpha-blocker for hypertension, a stagnation of LVEF around 20 % was still observed ten weeks after diagnosis, contraindicating the patient for adrenal surgery. The addition of an inhibitor of tyrosine hydroxylase (metyrosine, 1500 mg/day) led to a dramatic decrease of blood metanephrines (0.21 versus 1.42 μg/L before the introduction), even if results must be interpreted with caution regarding possible interference with this different medicine. Moreover, LVEF improved up to 40 % within 22 weeks allowing the bilateral adrenelactomy. Pathology results confirmed the diagnosis of benign bilateral pheochromocytomas. Genetic analysis showed a MAX mutation (c.145T > C, p.S49P). Congestive heart failure has a poor prognosis unless a correctable cause is identified. For the treatment of pheochromocytoma, surgical removal of tumor is the first choice but in particular cases, using an inhibitor of tyrosine hydroxylase could be a short-term alternative in preparation to surgery.

Looking Beyond Diabetes: A Case of Worsening Hyperglycemia as a Manifestation of Ectopic Cushing’s Syndrome Secondary to an Adrenocorticotropic Hormone-Producing Pheochromocytoma

A 76-year-old woman presented with worsening fasting hyperglycemia on routine blood sugar measurement, previously well-controlled on Metformin, requiring initiation of insulin. Her medical history included type 2 diabetes mellitus, hypertension, and aortic stenosis. Over the next few weeks, she developed bilateral upper and lower extremity proximal muscle weakness, episodes of confusion, rapid weight loss and increasing lower extremity edema. She did not have typical Cushingoid features of moon facies, easy bruising, centripetal obesity, abdominal striae, dorsocervical fat padding, or hyperpigmentation. Laboratory data revealed severe hypokalemia, elevated cortisol of 138 (3.7–19.4 ug/dL) and ACTH of 368 (6–50 pg/mL) consistent with ACTH-dependent Cushing’s syndrome. She was hospitalized for emergent therapy with etomidate infusion, potassium supplementation, and started on spironolactone. 24-hour urinary analysis demonstrated elevated catecholamines and metanephrines: epinephrine 552 (2–16 mcg/g cr), norepinephrine 1881 (7-5 mcg/g cr), metanephrine 4095 (21–153 mcg/g cr), normetanephrine 3920 (108–524 mcg/g cr).CT abdomen showed 3.8 cm mass in the left adrenal gland with enhancing walls and central hypoattenuation and a normal contralateral adrenal gland. MR brain showed a partial empty sella without any mass. 123I-metaiodobenzylguanidine scintigraphy showed uptake in the left adrenal mass. Once cortisol was reduced to <25 ug/dL, she was transitioned from etomidate to metyrapone; alpha-methyltyrosine and prazosin was also begun. Following left laparoscopic adrenalectomy, ACTH decreased to <5 pg/mL confirming that the pheochromocytoma was the source of ectopic Cushing’s. Gross examination of the mass was notable for a spongy, tan, roughly spherical medullary neoplasm (3 cm in diameter) with a rim of brown and focally yellow adrenal cortex up to 4 mm thick. Marked diffuse adrenal cortical hyperplasia was noted. The tumor showed varied growth patterns, including solid areas and spongy, angioma-like areas with prominent small blood vessels. Immunohistochemical staining was positive for somatostatin receptor 2A, tyrosine hydroxylase and ACTH in tumor cells and negative for T-PIT. She was discharged on replacement hydrocortisone therapy, minimal insulin for diabetes and has shown substantial clinical improvement.Cushing’s syndrome due to ectopic ACTH-producing pheochromocytoma is rare. Worsening hyperglycemia in the presence of hypertension, even without typical clinical findings of Cushing’s, should prompt further hormonal work up. The absence of the transcription factor TPIT, which is a lineage determinant for pituitary corticotrophs, suggests that novel pathways are involved in differentiation of cells that produce ectopic ACTH.

Interobserver Agreement in the Diagnosis of Parkinson Disease with Cardiac 123I-Metaiodobenzylguanidine Scintigraphy.

The aim of this study was to analyze the interobserver agreement of visual and quantitative assessment of cardiac 123I-metaiodobenzylguanidine scintigraphy. Methods: Planar images were acquired using a low-energy collimator. The heart-to-mediastinum (HM) ratio was adjusted for the use of a low-energy collimator, using a published formula. Interpretation was undertaken both visually and after the addition of adjusted HM ratios. Image findings were classified as normal, abnormal, or borderline. Results: The cohort consisted of 10 patients. On visual interpretation only, there was strong agreement on the interpretation of the scan (κ = 0.82, P < 0.01). Adjusted HM ratios led to a significant increase in mean ratios (1.79 vs. 1.36, P = 0.02) and, when utilized in reporting, resulted in perfect agreement (κ = 1.0, P < 0.01). Conclusion: The use of quantified HM ratios adjusted for low-energy collimator use improves on visual assessment alone and allowed for excellent interobserver agreement.

Clinical manifestations of Parkinson's disease harboring VPS35 retromer complex component p.D620N with long-term follow-up

IntroductionTo identify and investigate patients with Parkinson's disease (PD) harboring VPS35 variants in Japan. MethodsUsing targeted gene panel screening, we analyzed 393 familial, 294 young-onset, and 52 late-onset sporadic PD patients derived from the Juntendo PD DNA bank, and obtained clinical information from the medical records on each patient in whom we found VPS35 p.D620N variants. ResultsWe identified VPS35 p.D620N in three new patients: two patients with familial PD and one patient with sporadic PD. Additionally, we newly confirmed p.D620 from a patient of a family reported previously. The prevalence of familial PD was 0.7% (2/307), young-onset sporadic PD was 0.3% (1/294), and late-onset sporadic PD was 0% (0/52) in our cohort. Combining four patients with p.D620N from our previous reports, haplotype analysis indicated at least two founders in our cohort. Patients commonly showed a slow progression of parkinsonism with onset in middle or late age and mild parkinsonism with good response to levodopa and little cognitive decline even for more than 10 years of disease duration. Psychosis was occurred in two patients. One-half of patients required device-aided therapies such as deep brain stimulation or levodopa-carbidopa intestinal gel. Brain magnetic resonance imaging mostly showed normal findings, even at more than 10 years after onset. 123I-metaiodobenzylguanidine myocardial scintigraphy indicated normal heart-to-mediastinum ratio values among three of four patients. Conclusions: Patients with VPS35 p.D620N showed distinctive symptoms and neuroimaging. Our findings expand the clinical findings of patients with VPS35 variants.

A diagnostic strategy for Parkinsonian syndromes using quantitative indices of DAT SPECT and MIBG scintigraphy: an investigation using the classification and regression tree analysis

PurposeWe aimed to evaluate the diagnostic performances of quantitative indices obtained from dopamine transporter (DAT) single-photon emission computed tomography (SPECT) and 123I-metaiodobenzylguanidine (MIBG) scintigraphy for Parkinsonian syndromes (PS) using the classification and regression tree (CART) analysis.MethodsWe retrospectively enrolled 216 patients with or without PS, including 80 without PS (NPS) and 136 with PS [90 Parkinson’s disease (PD), 21 dementia with Lewy bodies (DLB), 16 progressive supranuclear palsy (PSP), and 9 multiple system atrophy (MSA). The striatal binding ratio (SBR), putamen-to-caudate ratio (PCR), and asymmetry index (AI) were calculated using DAT SPECT. The heart-to-mediastinum uptake ratio (H/M) based on the early (H/M [Early]) and delayed (H/M [Delay]) images and cardiac washout rate (WR) were calculated from MIBG scintigraphy. The CART analysis was used to establish a diagnostic decision tree model for differentiating PS based on these quantitative indices.ResultsThe sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 87.5, 96.3, 93.3, 92.9, and 93.1 for NPS; 91.1, 78.6, 75.2, 92.5, and 83.8 for PD; 57.1, 95.9, 60.0, 95.4, and 92.1 for DLB; and 50.0, 98.0, 66.7, 96.1, and 94.4 for PSP, respectively. The PCR, WR, H/M (Delay), and SBR indices played important roles in the optimal decision tree model, and their feature importance was 0.61, 0.22, 0.11, and 0.05, respectively.ConclusionThe quantitative indices showed high diagnostic performances in differentiating NPS, PD, DLB, and PSP, but not MSA. Our findings provide useful guidance on how to apply these quantitative indices in clinical practice.

Analysis of heart rate response to obstructive apnea/hypopnea events in patients with Parkinson's disease with relatively severe sleep apnea syndrome

Detection of non-motor symptoms specific to patients with Parkinson's disease (PD) is an important area for investigation because it may lead to early PD diagnosis. The aim of this study is to (i) verify whether there were differences between patients with PD and concurrent relatively severe sleep apnea syndrome (SAS) and non-PD patients with relatively severe SAS in terms of heart rate response to obstructive apnea/hypopnea events during sleep and (ii) to clarify the correlation between the extent of the heart rate response and the level of cardiac sympathetic denervation measured by 123 I-metaiodobenzylguanidine (MIBG) scintigraphy. We analyzed the heart rate response to obstructive apnea/hypopnea events during sleep in 23 patients with PD and concomitant relatively severe SAS as well as in 36 non-PD patients with relatively severe SAS. The amplitude of increase in the heart rate in response to apnea/hypopnea events was significantly lower for patients in the PD group with SAS than for those in the non-PD group with SAS. A relatively strong positive correlation was found between the amplitude of heart rate increase in response to apnea/hypopnea events and the H/M ratio on 123 I-MIBG scintigraphy in the PD group with SAS. Our results suggest that the amplitude of heart rate increase in response to obstructive apnea/hypopnea events reflects cardiac sympathetic nerve activity, and that in patients with relatively severe SAS concomitant with PD, the reactive increase in heart rate is suppressed due to degeneration of the cardiac sympathetic nervous system.

Clinical relevance of 18F-FDG PET/CT in the postoperative follow-up of patients with history of medullary thyroid cancer.

BackgroundThe aim of the study was evaluation of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography with computed tomography (PET/CT) in the detection of active disease in the patients with suspected recurrence of the medullary thyroid carcinoma (MTC).Patients and methods18F-FDG PET/CT investigation was performed in 67 patients, investigated from 2010 to 2019. _ Follow up was performed from 6 to 116 months after surgery (median 16.5 months, x± SD = 29±28.9 months). Twenty five of 67 patients underwent 99mTc-dimercaptosuccinic acid (99mTc-DMSA) scintigraphy, 11 underwent somatostatin receptor scintigraphy (SRS) with 99mTc-HYNIC TOC while 11 123I-metaiodobenzylguanidine (MIBG) scintigraphy.ResultsFrom 67 patients, 35 (52.2%) had true positive 18F-FDG PET/CT findings (TP). Average maximal standardized uptake value (SUVmax) for all TP lesions was 5.01+3.6. In 25 (37.3%) patients findings were true negative (TN). Four (6%) patients had false positive (FP) findings while three (4.5%) were false negative (FN). Thus, sensitivity of the 18F-FDG PET/ CT was 92.11%, specificity 86.21%, positive predictive value 89.74%, negative predictive value 89.29% and accuracy 89.55%. In 27 patients (40%) 18F-FDG PET/CT finding influenced further management of the patient.Conclusions18F-FDG PET/CT has high accuracy in the detection of metastases/recurrences of MTC in patients after thyroidectomy as well as in evaluation and the appropriate choice of the therapy.

A patient with subjective cognitive decline and recurrent dream-enactment behaviours in a memory clinic: potential diagnostic utility of cardiac 123 I-metaiodobenzylguanidine scintigraphy.

A patient with subjective cognitive decline and recurrent dream-enactment behaviours in a memory clinic: potential diagnostic utility of cardiac 123 I-metaiodobenzylguanidine scintigraphy.

Actualización sobre el manejo diagnóstico y terapéutico del feocromocitoma y el paraganglioma

Pheochromocytomas and paragangliomas are catecholamine-producing tumours originating from chromaffin cells of the sympathetic nervous system of the adrenal medulla or extra-adrenal chromaffin tissue, respectively. They can be sporadic or be associated with genetic diseases in up to 30% of cases. Biochemical confirmation of the elevation of plasma and/or urinary metanephrines will establish the diagnosis of pheochromocytoma, whereas computed tomography or magnetic resonance imaging is used for the initial location diagnosis. In metastatic pheochromocytoma, 123I-metaiodobenzylguanidine (MIBG) scintigraphy and 18F-FDG or 68Ga-DOTATATE positron emission tomography may be helpful. Surgical resection, the only curative option in these patients, is the treatment of choice for pheochromocytomas and paragangliomas being correct preoperative preparation essential to reduce morbidity and mortality. Malignant pheochromocytoma is a rare entity that can only be diagnosed when metastases are present. There is no effective curative treatment; genetic predisposition, tumor development, disease progression and location of metastases will determine its prognosis.

Comparisons of cardiovascular dysautonomia and cognitive impairment between de novo Parkinson\u2019s disease and de novo dementia with Lewy bodies

BackgroundCognitive impairment may be correlated with cardiovascular dysautonomia, including blood pressure (BP) dysregulation, in Parkinson’s disease (PD), but the association between these factors in dementia with Lewy bodies (DLB) is uncertain. This study aimed to clarify whether cardiovascular dysautonomia had an influence on cognitive function in Lewy body disease or not.MethodsNinty-nine patients with de novo PD (n = 75) and DLB (n = 24) were evaluated using the Mini-Mental State Examination (MMSE) and Frontal Assessment Battery (FAB). Cardiac 123I-metaiodobenzylguanidine (MIBG) scintigraphy, orthostatic hypotension (OH), supine hypertension (SH), postprandial hypotension (PPH), nocturnal BP fall in 24-h ambulatory blood pressure monitoring (ABPM) and constipation were estimated. Associations of these factors with cognitive and executive dysfunction were examined.ResultsIn DLB, MIBG uptake was reduced and OH, PPH and SH were severely disturbed, compared to PD. The nocturnal BP fall in ABPM was lower in DLB, and the failure of nocturnal BP fall in PD was associated with MMSE, after adjustment for other clinical features. FAB was significantly associated nocturnal BP fall, age and SH in PD, but no significant correlations among factors were found for DLB.ConclusionThe significant association between nocturnal BP dysregulation and cognitive or executive decline in PD might be due to impaired microvascular circulation or invasion of α-synuclein in the CNS. The lack of a correlation of BP insufficiency with cognitive impairment in DLB suggests initial involvement of Lewy body pathology in the neocortex, regardless of Lewy body invasion of the autonomic nervous system.