Evolving metabolic changes during the first postoperative year after subthalamotomy.
OBJECTIVE
Short-term benefit from unilateral subthalamotomy for advanced Parkinson disease (PD) is associated with metabolic alterations in key targets of subthalamic nucleus (STN) and globus pallidus (GP) output. In this study positron emission tomography (PET) scanning was used to assess these changes and their relation to long-term benefits of subthalamotomy.


METHODS
To determine whether the early postoperative changes persisted at longer-term follow up, the authors assessed six patients with advanced PD by using [18F]fluorodeoxyglucose-PET at 3 and 12 months postsurgery. The authors compared each of the postoperative images with baseline studies, and assessed interval changes between the short- and long-term follow-up scans. Clinical improvement at 3 and 12 months was associated with sustained metabolic decreases in the midbrain GP internus (GPi), thalamus, and pons of the lesioned side (p < 0.01). The activity of a PD-related multiregional brain network, which correlated with bradykinesia and rigidity, was reduced at both postoperative time points (p < 0.05). Comparisons of 3- and 12-month images revealed a relative metabolic increase in the GP externus (GPe) (p < 0.001), which was associated with worsening gait, postural stability, and tremor at long-term follow up.


CONCLUSIONS
These findings indicate that subthalamotomy may have differential effects on each of the functional pathways that mediate parkinsonian symptomatology. Sustained relief of akinesia and rigidity is associated with suppression of a pathological network involving the GPi and its output. In contrast, the recurrence of tremor may relate to changes in the function of an STN-GPe oscillatory network.
Trost
Maja
M
Center for Neurosciences, North Shore-Long Island Jewish Research Institute, Manhasset, USA.
Su
Philip C
PC
Barnes
Anna
A
Su
Sherwin L
SL
Yen
Ruoh-Fang
RF
Tseng
Ham-min
HM
Ma
Yilong
Y
Eidelberg
David
D
D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D005917:Globus Pallidus / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000601:surgery; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000601:surgery*; D011184:Postoperative Period; D020531:Subthalamic Nucleus / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000601:surgery; D020530:Subthalamus / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000601:surgery*; D013997:Time Factors; D014055:Tomography, Emission-Computed
D005947:Glucose