Long Term Response to Levodopa in Parkinson's Disease.

BACKGROUND: Levodopa is the most efficacious medication in controlling the motor symptoms of Parkinson's disease (PD). There continues to be a controversy as to whether levodopa remains effective after years of therapy. OBJECTIVE: To assess the long-term effectiveness of levodopa in PD patients. METHODS: The response to levodopa in PD patients undergoing a levodopa challenge for deep brain stimulation (DBS) surgery evaluation from June 1997 through March 2017 were evaluated. The patients were broken into four groups based on disease duration (Group I: 0- 5 years, Group II: 6- 10 years, Group III: 11- 15 years, and Group IV:≥16 years). Levodopa response was calculated based on the changes in Unified Parkinson's Disease Rating Scale (UPDRS) motor and activities of daily living (ADL) scores in the medication ON and OFF states. RESULTS: A total of 361 PD patients were included. The mean age in Group I was 59.4 years with a mean disease duration of 3.9 years (n = 29), Group II was 61 years with a mean disease duration of 8.1 years (n = 131), Group III was 64 years with a mean disease duration of 12.8 years (n = 143), and IV was 66.5 years with a mean disease duration of 18.5 years (n = 58). There was a significant improvement in UPDRS motor and ADL scores after the levodopa challenge for all groups. CONCLUSIONS: In a subgroup of PD patients who were evaluated for DBS surgery, there was a marked improvement in UPDRS motor and ADL scores which did not decrease with disease progression.

Nicotine differentially modulates antisaccade eye-gaze away from emotional stimuli in nonsmokers stratified by pre-task baseline performance.

RATIONALE AND OBJECTIVE: Studies indicate that nicotine enhances some aspects of attention and executive functioning and attenuates the attentional salience of emotionally negative distractors. The purpose of this study was to assess whether nicotine can enhance executive control over prepotent responses in emotional contexts in nonsmokers and whether such enhancement is greater in individuals with low baseline performance (BP). METHODS: The antisaccade task (AST) measures the inhibition of the tendency to glance in the direction of the onset of a visual stimulus and thus is an index of control over prepotent responses. Ten male and 14 female nonsmokers wore nicotine and placebo patches on counterbalanced days that included emotional picture primes and targets. RESULTS: There were significant beneficial effects of nicotine on antisaccade reaction time (RT). These beneficial effects occurred in individuals with poor and average BP, but not in high baseline performers. In slow baseline RT individuals, nicotine reduced RTs associated with negative targets in the left visual field (VF) and reduced RTs associated with positive and neutral targets in the right VF. In contrast, in the average baseline group, nicotine reduced RTs for positive targets in both VFs and neutral targets in the left VF. CONCLUSIONS: The results suggest that nicotine may produce its effects by enhancing executive functions and that the differential effects as a function of VF, target emotion, and group may also reflect lateralized differences in the effects of nicotine on brain reactivity to emotional stimuli.