Patients with Parkinson disease (PD) with vs without central parkinsonian pain may be younger, have earlier disease onset, fewer comorbidities, and greater pain relief with antiparkinsonian therapies, according to a study published in the European Journal of Pain.
A total of 292 patients with PD were interviewed and asked to complete the Brief Pain Inventory and the Pain Disability Index questionnaires to assess their pain. Motor systems and functional independence in both off and on conditions were evaluated with the Unified Parkinson’s Disease Rating Scale (UPDRS)-III, the Hoehn & Yahr, Schwab and England Independence Scale, and the Freezing of Gait Questionnaire. The UPDRS II and III subscales were used to classify patients as having tremor-dominant, postural instability and gait difficulty (PIGD), or indeterminate phenotype. Anxiety, depression, and impulse control disorders were evaluated using the Hospital Anxiety and Depression Scale and the Questionnaire of Impulsive-Compulsive Control Disorders, respectively.
The prevalence of pain was 73% in this cohort, with a median duration of 5 years (interquartile interval, 2 to 12 years). Pain was characterized as musculoskeletal (63%), dystonia-related (27%), central parkinsonian (22%), and/or radicular or neuropathic (9%). Half of patients reported pain relief with antiparkinsonian medications. Patients with a predominant tremor phenotype had lower odds of having pain compared with patients with an akinetic rigid or a mixed phenotype (odds ratio, 0.430; 95% CI, 0.235-0.788; P =.006). Patients with vs without central parkinsonian pain were younger (P =.009), presented with earlier disease onset (P =.030), and had fewer comorbidities (P =.004), greater non-axial motor symptom severity in on conditions (P =.005), more pain-related disability (P =.006), and greater pain relief with antiparkinsonian medications (P <.001).
Study limitations include the small number of patients and its cross-sectional nature.
“Future clinical, neurophysiological, and neuroimaging studies of sensory symptoms ought to explore central parkinsonian pain as a manifestation of PD and the improvement of central parkinsonian pain should be considered as a treatment outcome in PD,” the researchers concluded.
Vila-Chã N, Cavaco S, Mendes A, et al. Unveiling the relationship between central parkinsonian pain and motor symptoms in Parkinson’s disease [published online May 9, 2019]. Eur J Pain. doi:10.1002/ejp.1413