Health status in non-dystrophic myotonias: close relation with pain and fatigue

To determine self-reported health status in non-dystrophic myotonias (NDM) and its relationship to painful myotonia and fatigue. In a cross-sectional study, 32 NDM patients with chloride and 30 with sodium channelopathies, all off treatment, completed a standardised interview, the fatigue assessment scale (FAS), and the 36-item Short-Form Health Survey (SF-36). Beside formal assessment of pain, assessment of painful or painless myotonia was determined. The domain scores of the SF-36 were compared with Dutch community scores. Apart from the relationship among SF-36 scores and (1) painful myotonia and (2) fatigue, regression analyses in both NDM groups were conducted to determine the strongest determinants of the SF-36 domains general health perception, physical component (PCS) and mental component summary (MCS). All physically oriented SF-36 domains in both NDM groups (P ≤ 0.01) and social functioning in the patients with sodium channelopathies (P = 0.048) were substantially lower relative to the Dutch community scores. The patients with painful myotonia (41.9%) scored substantially (P < 0.05) lower on most SF-36 domains than the patients without painful myotonia (58.1%). Fatigued patients (53.2%) scored substantially lower (P ≤ 0.01) on all SF-36 domains than their non-fatigued counterparts (46.8%). The regression analysis showed that fatigue was the strongest predictor for the general-health perception and painful myotonia for the physical-component summary. None of the patients showed below-norm scores on the domain mental-component summary. The impact of NDM on the physical domains of patients’ health status is substantial, and particularly painful myotonia and fatigue tend to impede their physical functioning

Efficacy and safety profile of prolonged release oxycodone in combination with naloxone (OXN PR) in Parkinson’s disease patients with chronic pain

Pain is a relevant and often underestimated non-motor symptom affecting the quality of life of patients with Parkinson's disease (PD). Although some pain symptoms can be effectively treated by dopaminergic medication, a correct diagnosis of the different types and distribution of pain in PD is challenging, and accordingly, its treatment remains troublesome. We evaluated the efficacy and the safety of a prolonged release oral formulation of oxycodone hydrochloride combined with naloxone hydrochloride dehydrate, in a fixed ratio of 2:1 (OXN PR). A total of 16 PD patients with history of pain with a minimum intensity of four on numerical rating scale (NRS) received low-dose OXN PR (5/2.5 mg twice daily) and were observed for a period of 8 weeks. The primary efficacy measure was the pain severity measured with NRS and Brief Pain Inventory (BPI). Secondary efficacy measured the safety profile by recording the occurrence of side effects, clinical global impression of change (CGI-C), Parkinson's disease sleep scale 2 (PDSS-2), Bowel function index (BFI). Data were collected and analyzed using descriptive statistics. Patients who completed the study (14 out of 16) reported a significant pain relief as observed by the reduction of NRS and BPI scores. No adjustment of dopaminergic therapy was required. No significant changes were observed in bowel function and constipation symptoms as measured by the BFI during the 8-week period. Similarly, no changes were observed in PDSS-2 score, whereas an improvement was recorded by CGI-C compared to baseline. Low-dose oral OXN PR was efficacious for the management of pain symptoms of patients with PD. More importantly, patients did not experience significant side effects, such as constipation or sedation. Our study provides evidence that opioids can be used to treat pain symptoms in PD patients

Pain in Parkinson´s Disease: A Cross-Sectional Study of Its Prevalence, Types, and Relationship to Depression and Quality of Life

Pain is an important and distressing symptom in Parkinson's disease (PD). Our aim was to determine the prevalence of pain, its various types and characteristics, as well as its impact on depression and quality of life (QoL) in patients with PD. How pain differs in early- and advanced-stage PD and male and female PD patients was of special interest. One hundred PD patients on dopaminergic medications had a neurological examination and participated in a structured interview on pain characteristics and completed standardized questionnaires. A total of 76% of the patients had pain. The following types of pain were present: musculoskeletal pain accounted for 41% of the total pain, dystonic pain for 17%, central neuropathic pain for 22%, radicular pain for 27%, and other pains (non-radicular low back pain, arthritic, and visceral pain) made up 24%. One type of pain affected 29% of all the subjects, two types 35%, three types 10%, and four types of pain were reported by 2%. All types of pain were more prevalent in advanced-stage PD subjects than in early-stage PD subjects, except for arthritic pain (subclassified under"other pain"). The frequency and intensity of actual, average, and worst experienced pain were significantly more severe in advanced-stage subjects. PD subjects with general pain and in advanced stages were more depressed and had poorer QoL. Depression correlated with worst pain in the last 24 hours and with pain periodicity (the worst depression score in patients with constant pain). QoL correlated with average pain in the last 7 days. Pain is a frequent problem in PD patients, and it worsens during the course of the disease

Influence of Dopaminergic Medication on Conditioned Pain Modulation in Parkinson's Disease Patients

Pain is highly prevalent in patients with Parkinson's disease (PD), but little is known about the underlying pathophysiological mechanisms. The susceptibility to pain is known to depend on ascending and descending pathways. Because parts of the descending pain inhibitory system involve dopaminergic pathways, dysregulations in dopaminergic transmission might contribute to altered pain processing in PD. Deficits in endogenous pain inhibition can be assessed using conditioned pain modulation (CPM) paradigms.Applying such a paradigm, we investigated i) whether CPM responses differ between PD patients and healthy controls, ii) whether they are influenced by dopaminergic medication and iii) whether there are effects of disease-specific factors. 25 patients with idiopathic PD and 30 healthy age- and gender-matched controls underwent an established CPM paradigm combining heat pain test stimuli at the forearm and the cold pressor task on the contralateral foot as the conditioning stimulus. PD patients were tested under dopaminergic medication and after at least 12 hours of medication withdrawal.No significant differences between CPM responses of PD patients and healthy controls or between PD patients "on" and "off" medication were found. These findings suggest (i) that CPM is insensitive to dopaminergic modulations and (ii) that PD is not related to general deficits in descending pain inhibition beyond the known age-related decline. However, at a trend level, we found differences between PD subtypes (akinetic-rigid, tremor-dominant, mixed) with the strongest impairment of pain inhibition in the akinetic-rigid subtype.There were no significant differences between CPM responses of patients compared to healthy controls or between patients "on" and "off" medication. Differences between PD subtypes at a trend level point towards different pathophysiological mechanisms underlying the three PD subtypes which warrant further investigation and potentially differential therapeutic strategies in the future

Clinical Trials on Management of Pain in Parkinson’s Disease

Pain is highly prevalent in Parkinson’s disease (PD). It is one of the most common nonmotor symptoms of PD, and it may precede motor symptoms by several years. There are various types of pain described in PD, reflecting its heterogeneity and multifactorial origin. Pain in PD has been reported to differ between gender, early and advanced stages of PD, motor and nonmotor subtypes, and to fluctuate during on and off states. For the management of pain, it is crucial to separate PD-related pain from pain of other origins. Pain has a negative impact on the overall quality of life in PD patients. Early recognition and holistic assessment of pain are therefore important for personalized medicine delivery. When conducting a clinical trial in pain, study methodology and design need to be tailored to the multifaceted features of PD pain. The used assessment tools ideally have to be specific and sensitive to these features. In this book chapter, we discuss and outline the evaluation of PD-related pain, review PD general and specific pain assessment tools, and discuss relevant clinical trials addressing treatment of pain in PD.</p