¹²³I‐Metaiodobenzylguanidine Myocardial Scintigraphy in Discriminating Degenerative Parkinsonisms

Abstract

BackgroundBackground: 123 I-Metaiodobenzylguanidine ( 123 I-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 Objectives: To explore the clinical contribution of myocardial scintigraphy in discriminating different forms of parkinsonisms, especially when atypical features are present. Methods Methods: Forty-one patients with parkinsonism underwent a 123 I-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 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. 123 I-MIBG myocardial scintigraphy was abnormal in all PD patients with dysautonomia. After 123 I-MIBG myocardial scintigraphy (T2), in 9 patients (22%) an improvement of diagnostic accuracy was reached. Conclusions Conclusions: Diagnostic accuracy of myocardial scintigraphy in distinguishing PD from atypical parkinsonism was suboptimal. Nevertheless, this study confirmed the relevance of 123 I-MIBG myocardial scintigraphy for the discrimination of PD from atypical parkinsonism, especially when dysautonomic symptoms are present.Parkinson's disease (PD) is a chronic progressive neurodegenerative disorder clinically characterized by bradykinesia, rigidity, tremor at rest, and postural abnormalities with gait impairment. 1 Atypical parkinsonisms belong to a group of rare degenerative disorders, presenting with a relatively rapidly progressive parkinsonian syndrome, poor response to dopaminergic treatment, and additional clinical signs. Specifically, Multiple system atrophy (MSA) is characterized by a combination of autonomic failure, parkinsonism, and cerebellar signs. Cardinal features of progressive supranuclear palsy (PSP) include postural instability, early falls, and vertical gaze palsy. Finally, corticobasal syndrome (CBS) presents with an asymmetrical parkinsonism typically associated with limb dystonia, myoclonus, apraxia and alien limb phenomena. 2 Despite their distinct clinical features, the differential diagnosis between PD and atypical parkinsonisms is a recurrent clinical challenge, even among skilled neurologists and

Comparative Study between the Diagnostic Effectiveness of Brain SPECT with [123I]Ioflupane and [123I]MIBG Scintigraphy in Multiple System Atrophy

“…As a first, we have shown that there is a direct relationship between the delayed HMR and the risk of MSA (for each unit increase in delayed HMR, the risk of suspected MSA increases by 1.58) (OR = 1.58, p < 0.05). In addition, we propose that the cut-off of this index could be set at 1.43 (S = 85.3, E = 100%), a value close to previous studies [46][47][48]. In addition, other neurodegenerative diseases such as PD show lower values with respect to this cut-off point, allowing us to differentiate between them [49,50].…”

Longitudinal immunophenotyping to track motor progression in Parkinson’s Associated with a TH mutation

“…Many of the symptoms and some of the progression patterns in PD are similar, whether idiopathic or genetic 6,7 . Currently, tracking the progression of PD or its response to symptomatic treatments, such as levodopa, has been attempted using imaging modalities such as DAT and MRI, as well as skin biopsy and MIBG cardiac testing 8–13,14 . While recent research has highlighted several promising disease progression markers 15–17 , their longitudinal applicability in monitoring progression for individual PD patients has not been clearly demonstrated.…”

Immunophenotyping Tracks Motor Progression in Parkinson’s Disease Associated with a TH Mutation

“…Many of the symptoms and some of the progression patterns in PD are similar, whether idiopathic or genetic [6,7]. Currently, tracking the progression of PD or its response to symptomatic treatments, such as levodopa, has been attempted using imaging modalities such as DAT and MRI, as well as skin biopsy and MIBG cardiac testing [8][9][10][11][12][13][14]. While recent research has highlighted several promising disease progression markers [15][16][17], their longitudinal applicability in monitoring progression for individual PD patients has not been clearly demonstrated.…”