We aimed to evaluate prevalence, phenotype, and therapeutic realities of pain in patients with Parkinson disease (PD). Therefore, we assessed 181 outpatients with PD using a cross-sectional approach applying the German Pain Questionaire (DSF), the PainDetect, and a self-developed Parkinson Disease Pain Questionaire (UPDPQ) covering detailed therapeutic aspects. Furthermore, we investigated the association between pain and PD-disease characteristics, quality of life (PDQ-39), depression, and anxiety (HADS-D, HADS-A). Overall, prevalence of pain was high (95.4%); 91.1% suffered from chronic pain, but in only 22.3% of them, pain disorder was diagnosed. Pain impaired everyday-life moderately to very severely in 48.4% of patients and was the most distressing symptom in 10.2% of all patients. Pain was localized mainly in the back (71.4%) or joints (52.4%), frequently occurred as pain attacks (79%) but appeared with neuropathic character in only 15.3% of patients. Most patients (74.2%) received some kind of pain treatment, mainly provided by orthopedists (62.0%) or general practitioners (50.0%). Physiotherapy (61.3%), pain killers (54.4%), or massage (35.5%) were the most frequent therapeutic measures. Rehabilitative therapy (96.3%) and physiotherapy (89.5%) were rated as most effective, but with vastly temporary effects. 53.3% of patients attributed PD as the main cause for their pain, but only 33.6% found relief from anti-parkinsonian drugs. High levels of pain were associated with higher scores of depression and anxiety, and lower quality of life. Results suggest that pain in PD is frequent, complex, and quality-of-life-impairing but under-diagnosed and unsystematically treated and indicate need to systematically investigate pathophysiology-based treatment strategies.

Although chronic pain affects all age ranges, it is particularly common in the elderly. One potential explanation for the high prevalence of chronic pain in the older population is impaired functioning of the descending pain inhibitory system which can be studied in humans using conditioned pain modulation (CPM) paradigms. In this study we investigated (i) the influence of age on CPM and (ii) the role of expectations, depression and gender as potential modulating variables of an age-related change in CPM. 64 healthy volunteers of three different age groups (young = 20–40 years, middle-aged = 41–60 years, old = 61–80 years) were studied using a classical CPM paradigm that combined moderate heat pain stimuli to the right forearm as test stimuli (TS) and immersion of the contralateral foot into ice water as the conditioning stimulus (CS). The CPM response showed an age-dependent decline with strong CPM responses in young adults but no significant CPM responses in middle-aged and older adults. These age-related changes in CPM responses could not be explained by expectations of pain relief or depression. Furthermore, changes in CPM responses did not differ between men and women. Our results strongly support the notion of a genuine deterioration of descending pain inhibitory mechanisms with age.

Altered sensory perception has been found in patients with autism spectrum disorders (ASD) and might be related to aberrant sensory perception thresholds. We used the well-established, standardized Quantitative sensory testing (QST) protocol of the German Research Network on Neuropathic Pain to investigate 13 somatosensory parameters including thermal and tactile detection and pain thresholds in 13 ASD adults and 13 matched healthy controls with normal IQ values. There were no group differences between somatosensory detection and pain thresholds. Two ASD patients showed paradoxical heat sensations and another two ASD subjects presented dynamic mechanical allodynia; somatosensory features that were absent in controls. These findings suggest that central mechanisms during complex stimulus integration rather than peripheral dysfunctions probably determine somatosensory alterations in ASD.