Mechanism of constipation in Parkinson's disease and related factors that affect the severity of constipation

Abstract

Objective To investigate the mechanism of Parkinson's disease constipation (PDC) and the related factors that affect the severity of constipation. Methods Twenty-seven PDC patients were enrolled as study group and thirty functional consitipation (FC) patients as control group which were selected randomly in outpatient clinic of the First Affiliated Hospital of Nanjing Medical University from April 2014 to August 2014. Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn-Yahr Scale, medication for PD, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale (HAMA), Mini Mental State Examination, Patient Assessment of Constipation Symptoms were performed for PD. All subjects underwent anorectal manometry to analyze the anal resting pressure, intra-rectum pressure during defecation, anal residual pressure, sensor parameters and other relevant parameters, and multiple regression analysis was used to evaluate the correlations between clinical assessment scales and the severity of constipation. Results Anal pressure on squeezing (mmHg, 1 mmHg=0.133 kPa), intra-rectum pressure during defecation (mmHg), anal residual pressure (mmHg) in PDC were significantly different from the FC patients (197.7±62.7 vs 245.3±64.5, 30.4±17.1 vs 48.1±19.8, 84.2±28.1 vs 102.8±34.9, t=-2.822, -3.598, -2.189, all P<0.05); the proportions of rectum inadequate defecatory propulsion in PDC were 81% (22/27) and in FC were 53% (16/30), statistically significant difference existing between these two groups (χ2=5.067, P<0.05). The severity of constipation in PD was related with UPDRS score, HAMA score (r=0.58, 0.63, all P<0.05). Conclusions Significant differences in anal pressure on squeezing, intra-rectum pressure during defecation and anal residual pressure are seen between PDC and FC. When categorized into subgroups, the proportions of inadequate defecatory propulsion in PDC are significantly higher than that in FC. UPDRS score, HAMA score are markedly correlated with the severity of constipation in PD. Key words: Parkinson disease; Constipation; Severity of illness index; Rectum; Manometry