Gastrointestinal dysfunction in PD patients with morning akinesia

Introduction: It is well established that gastroparesis is common in PD causing delayed gastric emptying of L-dopa with a delayed onset of symptomatic effect. However, little is known about which measures can be used to identify patients that have this problem. Methods: The AM-IMPAKT study is a Phase IV study designed to assess the effect of apomorphine HCl subcutaneous injection in L-dopa-treated PD patients with morning akinesia. At screening, patient gastrointestinal function was assessed using the SCOPA-Autonomic (SCOPA-AUT) scale and the Gastroparesis Cardinal Symptom Index (GCSI). We present an interim baseline analysis of gastrointestinal function in 50 patients who have completed the study. Patients were categorized according to duration of PD (0-5, 6-10, 11-15 & 15+ years). Results: In this interim population, mean±SD age was 63.9±11.1 years and duration of levodopa treatment was 49.6±81.6 months. In these patients with delayed time-to- ON, GSCI was variable, although bloating and postprandial fullness subscores were increased. In contrast, baseline SCOPA-AUT total scores ranged from 15.2-16.8, and were driven mainly by GI dysfunction (scores 4.0-5.0) and urinary dysfunction (scores 5.0-6.5). Abnormal SCOPAAUT total and subscores were already present in patients with PD duration of 0-5 years, and scores were similar to patients with a longer disease duration. Conclusions: In PD patients with morning akinesia, the SCOPA-AUT appears to be helpful in identifying underlying gastroparesis. Once recognized, the presence of gastroparesis suggests that non-oral drug delivery may be useful to ensure a rapid and reliable ON in patients with morning akinesia.