High-resolution diffusion tensor imaging in the substantia nigra of de novo Parkinson disease

Vaillancourt, David E.; Spraker, Mathew; Prodoehl, Janey; Abraham, Ivy; Corcos, Daniel M.; Zhou, Xiaohong Joe; Comella, Cynthia L.; Little, Deborah M.

doi:10.1212/01.wnl.0000340982.01727.6e

Cited by 405 publications

(363 citation statements)

References 27 publications

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“…Seven of 9 studies included patients taking antiparkinsonian medications, medication details were unavailable for one, 6 and the final study 13 included only medicationnaive patients. The study on early, medication-naive patients 13 found on post hoc analysis that the caudal region of the SN had sensitivity and specificity of 100% for differentiating patients with PD from controls. This study, along with another, 24 did not find an association between disease severity and FA in SN.…”

Section: Resultsmentioning

confidence: 99%

“…It is not known, however, if these techniques can robustly identify patients with PD, a necessity for translation into a viable biomarker, and conclusions on diagnostic accuracy cannot be drawn from our meta-analysis results. Tantalizingly, post hoc receiver operator characteristic analysis in the caudal SN in one small, early-stage study 13 of nonmedicated patients showed 100% sensitivity and specificity for distinguishing patients with PD from healthy controls. Such work, however, remains experimental and requires replication.…”

Section: Resultsmentioning

confidence: 99%

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Diffusion tensor imaging in parkinsonian syndromes

2013

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Objectives: We performed a systematic review to assess alterations in measures of diffusion tensor imaging (DTI) in parkinsonian syndromes, exploring the potential role of DTI in diagnosis and as a candidate biomarker. Methods:We searched EMBASE and Medline databases for DTI studies comparing parkinsonian syndromes or related dementias with controls or another defined parkinsonian syndrome. Key details for each study regarding participants, imaging methods, and results were extracted. Estimates were pooled, where appropriate, by random-effects meta-analysis. Results:Of 333 results, we identified 43 studies suitable for inclusion (958 patients, 764 controls). DTI measures detected alterations in all parkinsonian syndromes, with distribution varying differentially with disease type. Nine studies were included in a meta-analysis of the substantia nigra in Parkinson disease. A notable effect size was found for lowered fractional anisotropy in the substantia nigra for patients with Parkinson disease vs controls (20.639, 95% confidence interval 20.860 to 20.417, p , 0.0001).Conclusion: DTI may be a promising biomarker in parkinsonian syndromes and have a future role in differential diagnosis. Larger cohort studies are required to investigate some encouraging preliminary findings. Given the complexity of the parkinsonian syndromes, it is likely that any potential DTI biomarker would be used in combination with other relevant biomarkers. Differences in natural history and therapy options make early and accurate diagnosis of parkinsonian syndromes important. 1 Emission tomography (SPECT or PET) has a role but it can be expensive, with limited availability, and requires radioactive tracers. 2 There is particular interest in the potential of advanced structural MRI techniques to differentiate among parkinsonian syndromes and to offer candidate biomarkers, facilitating early or premanifest diagnosis and monitoring of disease progression.Diffusion tensor imaging (DTI) is an MRI technique assessing the orientation and integrity of white matter tracts in vivo by measuring the diffusion of water molecules in neural fibers 3 and it also shows promise for studying gray matter areas. It estimates both the degree of directionality using anisotropy (frequently fractional anisotropy [FA]) and the overall movement of molecules (mean diffusivity [MD]; trace; apparent diffusion coefficient [ADC]). These measurements can either be extracted locally in predefined regions using region of interest (ROI) analysis or tractography or, alternatively, globally using voxel-based analysis (VBA) or tract-based spatial statistics (TBSS). Disruptions to microstructural tissue integrity, such as those found in the neurodegeneration of parkinsonian syndromes can be associated with alterations in anisotropy and diffusivity measures. 3 We therefore performed a systematic review of the literature to assess

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Diffusion tensor imaging in parkinsonian syndromes

2013

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“…More recently, some investigators have applied diffusion tensor imaging and demonstrated reduced fractional (FA) in the region thought to correspond to ascending nigrostriatal fibers [2], although this finding has not yet been reproduced. One group has demonstrated reduced FA in the substantia nigra itself, with outstanding sensitivity and specificity in caudal regions [3], while others have suggested that FA may be reduced in other regions [4,5], perhaps representing alterations in white matter integrity or in functional connectivity. Yet another group has suggested that diffusion tensor imaging measures of nigrothalamic connectivity combined with a modified T1 nigral volumetric study have improved sensitivity and specificity for PD [6].…”

Section: Magnetic Resonance Imagingmentioning

confidence: 99%

Neuroimaging in Parkinson's Disease

Stoessl

2011

Neurotherapeutics

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“…The most common finding in many DTI studies was a reduction in fractional anisotropy (FA) in the substantia nigra of PD patients (Chan et al, 2007;Du et al, 2011;Peran et al, 2010;Vaillancourt et al, 2009;Yoshikawa, Nakata, Yamada, & Nakagawa, 2004), and the reduction in FA values in the substantia nigra was inversely correlated with the severity of the clinical symptoms of PD patient (Chan et al, 2007). Extranigral WM changes have been observed in PD patients.…”

Section: Structural Connectivitymentioning

confidence: 99%