While providing osteopathic manipulative treatment to patients with Parkinson's disease at the clinic of the New York College of Osteopathic Medicine of New York Institute of Technology, physicians noted that these patients may exhibit particular cranial findings as a result of the disease. The purpose of this study was to compare the recorded observations of cranial strain patterns of patients with Parkinson's disease for the detection of common cranial findings. Records of cranial strain patterns from physician-recorded observations of 30 patients with idiopathic Parkinson's disease and 20 age-matched normal controls were compiled. This information was used to determine whether different physicians observed particular strain patterns in greater frequency between Parkinson's patients and controls. Patients with Parkinson's disease had a significantly higher frequency of bilateral occipitoatlantal compression (87% vs. 50%; P < .02) and bilateral occipitomastoid compression (40% vs. 10%; P < .05) compared with normal controls. Over subsequent visits and treatments, the frequency of both strain patterns were reduced significantly (occipitoatlantal compression, P < .01; occipitomastoid compression, P < .05) to levels found in the control group.