Date of Award


Degree Type

Selective Evidence-Based Medicine Review

Degree Name

Master of Science in Health Sciences - Physician Assistant

Department Chair

John Cavenagh, PhD, PA-C


OBJECTIVE: The objective of this selected EBM review is to determine whether or not the injection of botulinum toxin improves symptoms in patients with gastroparesis.

STUDY DESIGN: Review of two published, double blind randomized controlled trials and one published, open label pilot study were used for this review, which were found on PubMed.

OUTCOMES MEASURED: The outcome was the change in gastroparesis-associated symptoms, which was measured using the Gastroparesis Cardinal Scale Index (GCSI) and Gastroparesis Questionnaire. In the two double blind, randomized controlled trials by Arts et al. and Friendenberg et al., symptoms were quantified using the GCSI before and after the injection. Each of the 9 different gastroparesis-associated symptoms (nausea, regurgitation, vomiting, fullness, early satiety, postprandial fullness, loss of appetite, bloating and swollen abdomen) were graded from 0 (none) -5 (very severe), with higher scores indicating higher severity of symptoms. The total GCSI score was calculated by adding all individual symptoms severity scores. In the open-label pilot study conducted by Miller et al., the Gastroparesis Questionnaire was used to grade eight symptoms on a 5-point scale from 0 (none) to 4 (extreme). A total symptom score was determined as the sum of each the eight graded symptoms, with a maximum of 32.

RESULTS: In the study by Arts et al, symptoms improved significantly after the initial injection of saline or botulinum toxin. No additional improvement occurred after the second injection. In the study by Friedenberg et al, the group receiving botulinum toxin showed improvement in symptoms, however, it was not greater than the placebo group. In the study by Miller et al, symptom scores improved with botulinum toxin injection.

CONCLUSION: The results of the two double blind, randomized controlled trials show that the injection of botulinum toxin is not superior to placebo in improving symptoms of gastroparesis. The results of the open-label pilot study indicate that botulinum toxin does improve symptoms.