End-of-dose wearing off in Parkinson disease: a 9-question survey assessment

We have previously reported that the use of a 32-symptom Wearing-off Questionnaire (WOQ-32) identified wearing off more frequently than a clinician's evaluation or the complications subscale of the Unified Parkinson Disease Rating Scale (UPDRS). However, this prototype tool was not designed for clinical practice and required simplification for daily use. Although wearing off is a commonly understood concept among neurologists caring for Parkinson disease patients, there are a number of definitions in the literature. For the purpose of this study and to include both motor and nonmotor parkinsonian symptoms, wearing off was defined as a generally predictable recurrence of motor and nonmotor symptoms that precedes scheduled doses of anti-parkinsonian medication and usually improves after those doses. Using this definition, retrospective analysis and expert opinion were used to identify the 9 most predictive and relevant of the symptoms previously identified as part of the WOQ-32. The resulting 9-symptom questionnaire (WOQ-9) identified 158 (95.8%) of the 165 subjects captured by the 32-Symptom Wearing-off Questionnaire as having wearing off, excluding 7 subjects reporting only balance difficulty (n = 3), numbness (n = 2), difficulty standing (n = 1), and abdominal discomfort (n = 1). Subjects reporting wearing off with the WOQ-9 were significantly younger, had been longer diagnosed with Parkinson disease, experienced a longer duration of levodopa therapy, exhibited a higher UPDRS total score, had higher levodopa equivalent dosages, and increased dyskinesia compared with patients not identified as wearing off with the WOQ-9. No statistical differences were noted with respect to sex, UPDRS subsection scores, Schwab & England Scale, or Hoehn & Yahr Scale.     

The controversy concerning plasma homocysteine in Parkinson disease patients treated with levodopa alone or with entacapone: effects of vitamin status

Levodopa treatment of Parkinson disease results in hyperhomocysteinemia (HHcy) as a consequence of levodopa methylation by catechol-O-methyltransferase (COMT). Although inhibition of COMT should theoretically prevent or reduce levodopa-induced HHcy, results from several prospective studies are conflicting. Our review of these studies suggests that the ability of COMT inhibition to reduce or prevent levodopa-induced HHcy in Parkinson disease patients may be attributed to differences in the vitamin status of the study participants. In patients with low or low-normal folate levels, levodopa administration is associated with a greater increase in homocysteine and concomitant entacapone administration is associated with a greater reduction in homocysteine.     

Effects of nicotine on depressive-like behavior and hippocampal volume of female WKY rats

The observed high incidence of smoking amongst depressed individuals has led to the hypothesis of ‘self medication” with nicotine in some of these patients. The inbred Wistar–Kyoto (WKY) rats exhibit depressive-like characteristics as evidenced by exaggerated immobility in the forced swim test (FST). One aim of this study was to investigate whether nicotine may have an antidepressant-like effect in these animals. Moreover, because of human postmortem studies indicating a reduction of the hippocampus volume in depressed patients, it was of interest to determine whether such an anatomical anomaly may also be manifested in WKY rats and whether it would be affected by chronic nicotine treatment. Adult female WKY and their control Wistar rats were administered nicotine consecutively (0.2 mg/kg, i.p., once or twice daily for 14 days) and their activity in an open field, as well as their immobility in FST were assessed either 15 min or 18 h after the last injection. Another set of animals was treated twice daily with 0.2 mg/kg nicotine for 14 days and sacrificed on day 15 for stereological evaluation of the hippocampal volume. When tested 15 min after the last injection, once or twice daily nicotine exacerbated the immobility in the FST in WKY rats only. When tested 18 h after the last injection, only twice daily nicotine treatment resulted in less immobility in the FST in WKY rats. Open field locomotor activity was not affected by any nicotine regimen. WKY rats had significantly less hippocampal volume (approximately 20%) than Wistar rats which was not altered by nicotine. These findings further validate the use of WKY rats as an animal model of human depression and signify the importance of inherent genetic differences in final behavioral outcome of nicotine.