Metabolic Alterations in Parkinson's Disease After Thalamotomy, as Revealed by 1H MR Spectroscopy


Objective: To determine, using proton magnetic resonance spectroscopy ( 1H MRS) whether thalamotomy in patients with Parkinson's disease gives rise to significant changes in regional brain metabolism. Materials and Methods: Fifteen patients each underwent stereotactic thalamotomy for the control of medically refractory parkinsonian tremor. Single-voxel 1H MRS was performed on a 1.5T unit using a STEAM sequence (TR/TM/TE, 2000/14/20 msec), and spectra were obtained from substantia nigra, thalamus and putamen areas, with volumes of interest of 7-8ml, before and after thalamotomy. NAA/Cho, NAA/Cr and Cho/Cr metabolite ratios were calculated from relative peak area measurements, and any changes were recorded and assessed. Results: In the substantia nigra and thalamus, NAA/Cho ratios were generally low. In the substantia nigra of 80% of patients (12/15) who showed clinical improvement, decreased NAA/Cho ratios were observed in selected voxels after thalamic surgery (< 0.05). In the thalamus of 67% of such patients (10/15), significant decreases were also noted (< 0.05). Conclusion: Our results suggest that the NAA/Cho ratio may be a valuable criterion for the evaluation of Parkinson's disease patients who show clinical improvement following surgery. By highlighting variations in this ratio, 1H MRS may help lead to a better understanding of the pathophysiologic processes occurring in those with Parkinson's disease.


Nuclear Engineering and Radiation Science

Keywords and Phrases

Metabolism; Parkinson's Disease; Proton Magnetic Resonance Spectroscopy ( 1H MRS); Thalamotomy

Document Type

Article - Journal

Document Version


File Type





© 2002 Korean Radiological Society, All rights reserved.

Publication Date

01 Jan 2002