In this study, we have tried to elicit whether pain can be an early clinical marker of the future development of PD, in the absence of motor signs.

In this coupled hospital and community based observational study, 500 persons(more than 50yrs) from an urban community were assessed regarding the presence of different pain syndromes by verbal questionnaire and review of medical records. The likelihood ratio(LR) of prodromalPD (MDS research criteria for prodromalPD) were estimated in these subjects divided into 2groups: control group(LR<80%), & prodromalPD group(LR>80%). Prevalence of different pain syndromes was assessed in 95PD patients(less than 2yrs disease duration) (clinicalPD group) by interviewing patients and relatives and reviewing past medical records. ICD-9-CM diagnostic codes were used to classify different pain syndromes.

Among the 500subjects(314males,186female),32(6.4%) showed an LR>80%. The pain was significantly more in the prodromalPD group[23(71.8%)] compared to the control group[144(30.76%)]. In the clinicalPD group, pain prevalence is 63.15%, which was comparable to the prodromalPD group. ClinicalPD and prodromalPD group were significantly more associated with cervicalgia, shoulder pain, pain in the pelvic region & thigh joint, backache & low back pain compared to the control group. ClinicalPD & prodromalPD group were also significantly more associated with frozen shoulder, RLS & nocturnal leg cramp compared to control group.

Different pain syndromes were significantly more in the prodromal group compared to the control group, while the prodromalPD and clinicalPD group were comparable regarding the presence & distribution of pain. This is indirect evidence that pain can be an essential early clinical marker of PD, but longitudinal studies are indicated to evaluate the predictability of pain for the development of PD.