Pain in Parkinson's Disease Associated withCOMTGene Polymorphisms

Abstract

Background. PD patients present high incidence of pain with unknown pathogenesis.Objective. We investigated the relation ofCOMTpolymorphismsrs4633andrs6267with PD pain.Subjects and Methods. One hundred PD patients and 105 controls were evaluated with simplified Mc GILL pain scale and VAS scale. PD patients were assessed with H&Y grade, UPDRS score, and HAMD scale. Polymorphismsrs4633andrs6267were detected by PCR and direct sequencing.Results. Fifty-seven percent of PD patients experienced pain, consisting of PD-related pain (64.91%) (the majority was dystonia pain) and non-PD-related pain (35.09%) (psychogenic pain was most frequent). The frequency ofrs6267genotype “GT/TT” and allele “T” was higher in PD pain. No difference was observed in frequencies ofrs4633between PD pain and without pain. UPDRS and depression score were higher in PD pain. The onset age was earlier in PD-related pain (57.43 ± 19.71) than non-PD-related pain (63.36 ± 6.88).Conclusion. PD patients possess a high prevalence of pain. Dystonia pain was the most frequent type of PD-related pain.COMTgeners6267allele “T” associated with PD pain. PD pain was influenced by disease severity and depression. PD onsets earlier in patients with PD-related pain than non-PD-related pain.