Cognition and mood in Parkinson's disease in subthalamic nucleus versus globus pallidus interna deep brain stimulation: the COMPARE trial.

OBJECTIVE: Our aim was to compare in a prospective blinded study the cognitive and mood effects of subthalamic nucleus (STN) vs. globus pallidus interna (GPi) deep brain stimulation (DBS) in Parkinson disease. METHODS: Fifty-two subjects were randomized to unilateral STN or GPi DBS. The co-primary outcome measures were the Visual Analog Mood Scale, and verbal fluency (semantic and letter) at 7 months post-DBS in the optimal setting compared to pre-DBS. At 7 months post-DBS, subjects were tested in four randomized/counterbalanced conditions (optimal, ventral, dorsal, and off DBS). RESULTS: Forty-five subjects (23 GPi, 22 STN) completed the protocol. The study revealed no difference between STN and GPi DBS in the change of co-primary mood and cognitive outcomes pre- to post-DBS in the optimal setting (Hotelling's T(2) test: p = 0.16 and 0.08 respectively). Subjects in both targets were less "happy", less "energetic" and more "confused" when stimulated ventrally. Comparison of the other 3 DBS conditions to pre-DBS showed a larger deterioration of letter verbal fluency in STN, especially when off DBS. There was no difference in UPDRS motor improvement between targets. INTERPRETATION: There were no significant differences in the co-primary outcome measures (mood and cognition) between STN and GPi in the optimal DBS state. Adverse mood effects occurred ventrally in both targets. A worsening of letter verbal fluency was seen in STN. The persistence of deterioration in verbal fluency in the off STN DBS state was suggestive of a surgical rather than a stimulation-induced effect. Similar motor improvement were observed with both STN and GPi DBS.

Testosterone therapy in men with Parkinson disease: results of the TEST-PD Study.

BACKGROUND: Testosterone deficiency has been reported in patients with Parkinson disease (PD), Alzheimer disease, and Huntington disease. It is not known whether testosterone therapy (TT) in men with borderline hypogonadism and neurodegenerative diseases will be of substantial benefit. Previously, we reported that testosterone deficiency is more common in patients with PD compared with age-matched control subjects, and we also reported in 2 small open-label studies that some nonmotor symptoms responded favorably to TT. OBJECTIVE: To define the effects of TT on nonmotor and motor symptoms in men with PD and probable testosterone deficiency. DESIGN: Double-masked, placebo-controlled, parallel-group, single-center trial. PATIENTS: Two experimental groups: patients with PD who were receiving either TT or placebo. INTERVENTIONS: Participants received either the study drug by intramuscular injection (200 mg/mL of testosterone enanthate every 2 weeks for 8 weeks) or placebo (isotonic sodium chloride solution injections). In patients in each group, the testosterone serum concentration was obtained at each study visit. During 2 study visits, testosterone levels were blindly evaluated and the intramuscular testosterone dose was increased by 200 mg/mL if the free testosterone value failed to double from the baseline value. MAIN OUTCOME MEASURES: The primary outcome variable was the St Louis Testosterone Deficiency Questionnaire, and secondary outcome measures included measures of mood, cognition, fatigue, motor function, and frequency of adverse events. At the end of the double-blind phase, all patients were offered open-label TT and were followed up after 3 and 6 months. RESULTS: Fifteen patients in the placebo group (mean age, 69.9 years), receiving a mean total levodopa equivalent dose of 924 mg/d, had a baseline free testosterone level of 47.91 pg/mL, compared with 15 patients in the TT group (mean age, 66.7 years), receiving an average total levodopa equivalent dose of 734 mg/d, who had a baseline free testosterone level of 63.49 pg/mL. Testosterone was generally well tolerated. More subjects in the TT group experienced lower extremity edema (40% vs 20%). In 2 patients, 1 in each group, prostate-specific antigen levels were elevated from baseline. The improvement in the TT group compared with the placebo group (1.7 vs 1.1) on the St Louis Testosterone Deficiency Scale was not statistically significant. In addition, there were no significant differences in motor and nonmotor features of PD between the 2 groups, although a few subscales showed improvements (Hopkins Verbal Learning Test, P<.04; and Backward Visual Span subtrial, P<.03). However, long-term open-label TT resulted in delayed but sustained improvement in subjects in the TT group who continued to receive treatment (n = 6) compared with subjects in the placebo group who elected not to receive TT (n = 3). CONCLUSIONS: Testosterone therapy was generally well tolerated in elderly men with PD and probable testosterone deficiency. While there was no significant difference in the motor and nonmotor scales between the TT and placebo groups at the end of 8 weeks compared with baseline, this may be due to several study limitations, including small sample size, a strong placebo effect with intramuscular therapy, and short follow-up that did not allow measurement of delayed effects of TT in some subjects. Until more definitive studies are reported, practitioners should be particularly cautious in treatment of low testosterone concentrations in men with PD and borderline testosterone deficiency, and careful consideration should be given to the risks vs the benefits of TT.