Drug-induced Parkinsonism versus Idiopathic Parkinson Disease: Utility of Nigrosome 1 with 3-T Imaging

Abstract

Purpose To explore the utility of nigrosome 1 with 3-T magnetic resonance (MR) imaging to differentiate idiopathic Parkinson disease (IPD) from drug-induced parkinsonism (DIP). Materials and Methods The institutional review board approved this study, and participants gave informed consent. This study enrolled patients with DIP (n = 20) and IPD (n = 29) who underwent N-3-fluoropropyl-2-β-carbomethoxy-3-β-(4-iodophenyl)nortropane ((18)F-FP-CIT) positron emission tomography (PET) and healthy participants (n = 20). All participants underwent 0.5 × 0.5 × 1.0 mm(3) oblique axial three-dimensional multiecho-data image combination imaging to view the nigrosome 1 with 3-T imaging. Two reviewers independently assessed the nigrosome 1 without clinical information. DIP was diagnosed when no abnormality was seen at (18)F-FP-CIT PET. Diagnostic sensitivity, specificity, and accuracy of the nigrosome 1 imaging were evaluated between the IPD and DIP patients and between the IPD patients and healthy participants. Interrater agreement was assessed with Cohen κ. Results Both reviewers agreed in 63 of 69 participants (91.3%) for the presence of any abnormality on either side of the nigrosome 1 (κ = 0.825). Findings in all 29 IPD patients (100%) and three of 20 DIP patients (15%) were rated as abnormal and in 17 of 20 DIP patients (85%) they were interpreted as normal on the basis of imaging of the nitgrosome 1 (sensitivity, 100% (29 of 29); specificity, 85.0% (17 of 20); accuracy, 93.9% (46 of 49) between IPD and DIP patients). Findings in 3 of 20 healthy participants (15.0%) were interpreted as abnormal on the basis of imaging the nigrosome 1 while in the other 17 of 20 healthy participants (85.0%) they were rated as normal (sensitivity, 100% [29 of 29]; specificity, 85.0% [17 of 20]; accuracy, 93.9% [46 of 49] between IPD patients and healthy participants [κ = 0.831]). Conclusion The imaging of nigrosome 1 with 3-T imaging can differentiate DIP from IPD with high accuracy and may help to screen patients who need dopamine transporter imaging in those suspected of having DIP. (©) RSNA, 2015 Online supplemental material is available for this article.

Nigrosome Imaging and Neuromelanin Sensitive MRI in Diagnostic Evaluation of Parkinsonism

“…) . Subsequent studies using 3T MRI have also been able to replicate this finding in most PD patients (refer to Table for list of studies) . This replication has generated considerable interest to use nigrosome imaging as a way of studying and diagnosing nigral pathology in PD.…”

Meta‐analysis of dorsolateral nigral hyperintensity on magnetic resonance imaging as a marker for Parkinson's disease

“…The 3 studies each included subjects with APDs or subjects with parkinsonism and normal dopaminergic radiotracer imaging . Data on these subjects with non‐PD parkinsonism were not included in the meta‐analysis because of an insufficient number of studies (≥4 studies needed for the meta‐analysis as described later), but analyzed descriptively.…”

“…Most patients with PD or other types of neurodegenerative parkinsonism studied so far lack DNH at least unilaterally (see Fig. A) . Although current evidence thus suggests that this novel MRI feature may be a marker for PD, available studies have mostly involved small samples and had heterogeneous control populations.…”

Magnetic resonance imaging for the diagnosis of Parkinson’s disease

“…Because nigrosome-1 is a histological concept, which refers to a calbindin-negative subregion in the SNc, the descriptive terms ‘Dorsolateral Nigral Hyperintensity’ (DNH) or ‘Nigral hyperintensity’ have been introduced (Reiter et al 2015; Bae et al 2016). Overall, in the studies published so far, loss of DNH had a high sensitivity (79–100%) and specificity (85–100%) to separate PD from controls (Schwarz et al 2014; Reiter et al 2015; Bae et al 2016; Kim et al 2016; Sung et al 2016). Moreover, a recent meta-analysis including 364 patients with PD and 331 controls from 10 studies showed an overall sensitivity and specificity of the absence of DNH for PD vs. controls of 98 and 95% and of 95 and 94% when including studies performed at 3.0 T only (Mahlknecht et al 2017).…”

“…This meta-analysis demonstrates a potential value in differentiating PD from uncertain movement disorders such as DIP, ET and dystonic tremor. Indeed, a recent study reported that patients with DIP could be discriminated from those with PD with high sensitivity and specificity (Sung et al 2016), while loss of DNH seems not to discriminate between PD and atypical parkinsonism due to MSA and PSP (Reiter et al 2015; Bae et al 2016; Kim et al 2016). …”