Determination of Parkinson Disease Laterality after Deep Brain Stimulation Using ¹²³I FP-CIT SPECT

Introduction Symptom laterality is one of the main characteristics of Parkinson disease (PD) and reported to be associated with motor and nonmotor symptom severity and prognosis. This study aimed to evaluate the changes of laterality after deep brain stimulation (DBS) and the association between dopamine transporter SPECT using ¹²³I FP-CIT (DAT SPECT) and symptom laterality in PD before and after DBS. Methods Nineteen patients with PD who received bilateral subthalamic nucleus DBS were enrolled. The clinical scores including Unified Parkinson Disease Rating Scale (UPDRS) and Hoehn and Yahr were evaluated at baseline, 6 months, and 1 year after DBS. Also, the patients underwent DAT SPECT before and 6 months and 1 year after DBS. Symptom and DAT laterality indices were determined based on the UPDRS part 3 and DAT SPECT, respectively. The association between DAT and symptom laterality was assessed at baseline and 6 months and 1 year after DBS. Results At baseline, 11, 6, and 2 among 19 patients had left-side-dominant, right-side-dominant, and symmetric motor symptom, respectively. Among 19 patients, there were 10 patients who showed changed symptom laterality within 1 year after DBS. The agreement between symptom laterality and DAT laterality was good to excellent at baseline and 6 months and 1 year after DBS (weighted κ = 0.742, 0.736, and 0.813). Furthermore, symptom and DAT laterality indices showed significant correlation at baseline (r = 0.542, P = 0.02), 6 months (r = 0.579, P = 0.01), and 1 year after DBS (r = 0.689, P = 0.02). Symptom laterality could be determined by DAT laterality index with areas under curve of 0.833 (P = 0.045), 0.982 (P < 0.001), and 1.000 (P < 0.001) at baseline and 6 and 12 months after DBS, respectively. Conclusions The symptom laterality could be altered after DBS and was well correlated with laterality evaluated by DAT SPECT. An objective evaluation of laterality using DAT SPECT would be helpful for the management of patients with PD especially for adjusting the DBS programming for fine balancing of the asymmetric symptom after DBS. The large-scale study is warranted for validation of this result.