Detection and application of neurochemical profile by multiple regional 1H-MRS in Parkinson's disease

Abstract

Introduction: The accurate diagnosis and monitoring of idiopathic Parkinson disease (PD), a progressive neurodegenerative disorder, has not been fully developed. This study sought to identify a neurochemical profile in multiple regions of the PD brain and healthy controls by proton magnetic resonance spectroscopy (¹H-MRS). We aimed to track changes of the brain neurochemical, quantify neuronal loss, and further determine the diagnostic value of ¹H-MRS.

Methods: PD patients and healthy controls recruited from Second Affiliated Hospital of Shantou University Medical College, Shantou, southern China, underwent ¹H-MRS. Chemical information was obtained for ratios of N-acetylaspartate to creatine (NAA/Cr), NAA to choline (NAA/Cho), and Cho to Cr for substantia nigra, globus pallidus, prefrontal lobe, hippocampus, cuneus gyrus, and dorsal thalamus regions.

Results: Compared to the 20 healthy controls (12 male, age 58.75 ± 5.03 years), the 42 patients (21 male, age 61.60 ± 6.40 years) showed lower NAA/Cr and NAA/Cho ratios in substantia nigra, globus pallidus, prefrontal lobe, hippocampus, cuneus gyrus and dorsal thalamus regions (p < .01); NAA/Cr and NAA/Cho ratios were reduced for both patients with unilateral and mild/no cognitive impairment (p < .01); Unified Parkinson's Disease Rating Scale score was inversely correlated with NAA/Cr ratios in the substantia nigra (r = -.32; p = .042).

Conclusion: NAA/Cr and NAA/Cho ratios may be useful metabolic biomarkers for early diagnosis of PD. Multi-voxel ¹H-MRS can provide information on brain neurochemistry and may be a promising technique for diagnosis of and monitoring neuronal loss in PD.

Keywords: N‐acetylaspartate (NAA); Parkinson's disease; proton magnetic resonance spectroscopy.

Figure 1

The regions of interest location on ¹H‐MRS images (1, 2), dorsal thalamus (3, 4), globus pallidus (5, 6), substantia nigra (7, 8), hippocampus (9, 10), cuneus gyrus (11, 12)

Figure 2

¹H‐MRS spectra obtained from a control subject (a) and a PD patient (b)

Figure 3

NAA/Cr ratios in substantia nigra, globus pallidus, prefrontal lobe, hippocampus, cuneus gyrus and dorsal thalamus for (a): healthy volunteers in left and right brain. (b): PD patients with unilateral impairment in the brain contralateral or ipsilateral to clinical sign and (c): PD patients with bilateral impairment in left and right brain