The prevalence and the burden of pain in patients with Huntington disease: a systematic review and meta-analysis

Prevalence and burden of pain across the entire spectrum of Huntington's disease

BACKGROUND

Pain is an important symptom in Huntington's disease (HD), however, not systematically studied and understood. The objective of the current study is to assess the prevalence of pain, pain interference in daily activities, painful conditions, analgesic use and the severity of the pain burden across different disease stages and 'Age at symptom Onset' groups. Additionally, the association between pain and disease burden was investigated.

METHODS

A cross-sectional analysis was conducted within two large data sets, which included different types of pain scales. Multivariable logistic regression analyses and analyses of variance were performed to compare the pain levels with those in the general population. The analyses were adjusted for sex and age. Locally Estimated Scatterplot Smoothing was used to test the association between pain and the HD pathology score: a measure of disease burden.

RESULTS

The mean prevalence of pain in the HD population was 40% and for pain interference around 35% in both data sets. Patients in the early, middle and late stage of HD experience more pain burden compared with what is reported in patients with chronic pain (p<0.01). A positive and significant association was demonstrated between pain and disease burden. Patients in late stage HD with pain use significantly less analgesics compared with the general population (5% vs 13%, respectively (p<0.01)).

CONCLUSIONS

Pain is a prevalent and important symptom in HD. Severe pain burden in the HD population is present and positively associated with disease burden. Risk for undertreatment with analgesics is nevertheless present. Awareness of pain in HD needs to be increased, both clinically and scientifically.

The Prevalence of Pain in Chronic Diseases: An Umbrella Review of Systematic Reviews

Since pain is common in many diseases, it is important to summarize the precise prevalence data on pain and high-impact pain, which frequently worsens the quality of life and work activities. This umbrella review aims to estimate the prevalence of pain among patients with different chronic diseases/conditions. We followed the PRISMA guidelines. We identified the following areas addressing the prevalence of pain: (1) pain in cancer patients; (2) neurodegenerative diseases; (3) chronic heart failure; (4) chronic obstructive pulmonary disease; (5) chronic kidney diseases; (6) liver diseases and failure; (7) nursing home seniors; and (8) postamputation (phantom) pain. We included systematic reviews and meta-analyses that reported pain in patients from the mentioned populations. The prevalence of pain in chronic diseases is high, in some cases even higher than the cardinal symptoms of these diseases/conditions. Most patients who suffer from any of these diseases/conditions can develop chronic pain at later stages. Pain in chronic diseases does not receive enough attention and is not properly managed. Future studies are warranted to establish a more precise prevalence of chronic pain and develop better methods of pain screening, detection, and management.

Pain in Huntington's disease and its potential mechanisms

Pain is common and frequent in many neurodegenerative diseases, although it has not received much attention. In Huntington's disease (HD), pain is often ignored and under-researched because attention is more focused on motor and cognitive decline than psychiatric symptoms. In HD progression, pain symptoms are complex and involved in multiple etiologies, particularly mental issues such as apathy, anxiety and irritability. Because of psychiatric issues, HD patients rarely complain of pain, although their bodies show severe pain symptoms, ultimately resulting in insufficient awareness and lack of research. In HD, few studies have focused on pain and pain-related features. A detailed and systemic pain history is crucial to assess and explore pain pathophysiology in HD. This review provides an overview concentrating on pain-related factors in HD, including neuropathology, frequency, features, affecting factors and mechanisms. More attention and studies are still needed in this interesting field in the future.

Palliative care in advanced Huntington's disease: a scoping review

BACKGROUND

As Huntington's disease (HD) is a progressive disease for which there is no cure yet, patients in the advanced stage of HD may benefit from palliative care.

OBJECTIVE

To review the literature focusing on palliative care in advanced stage HD, and the level of evidence.

METHODS

Publications between 1993 and October 29th, 2021 from 8 databases (Embase, Web of Science, Cochrane, Emcare, PsycINFO, Academic Search Premier, PMC PubMed Central and Pubmed) were included. The literature was deductively classified based on topics that are part of the definition of palliative care, or as care-related topics that emerged from the literature. Levels of evidence I (high) - V (low) were determined as defined by the Joanna Briggs Institute.

RESULTS

Our search resulted in 333 articles, 38 of which were included. The literature covered four domains of palliative care: physical care, psychological care, spiritual care, and social care. Four other topics in the literature were: advance care planning, end-of-life needs assessments, pediatric HD care, and need for health care services. Most literature was underpinned by a low level of evidence, except for the topics on social care (Level III-V), advance care planning (Level II-V) and end-of-life needs assessments (Level II-III).

CONCLUSIONS

To deliver adequate palliative care in advanced HD, both general and HD-specific symptoms and problems need to be addressed. As the level of evidence in existing literature is low, further research is essential to improve palliative care and to meet patient's wishes and needs.

Pathogenesis of Huntington's Disease: An Emphasis on Molecular Pathways and Prevention by Natural Remedies

BACKGROUND

Huntington's disease is an inherited autosomal dominant trait neuro-degenerative disorder caused by changes (mutations) of a gene called huntingtin (htt) that is located on the short arm (p) of chromosome 4, CAG expansion mutation. It is characterized by unusual movements, cognitive and psychiatric disorders.

OBJECTIVE

This review was undertaken to apprehend biological pathways of Huntington's disease (HD) pathogenesis and its management by nature-derived products. Natural products can be lucrative for the management of HD as it shows protection against HD in pre-clinical trials. Advanced research is still required to assess the therapeutic effectiveness of the known organic products and their isolated compounds in HD experimental models.

SUMMARY

Degeneration of neurons in Huntington's disease is distinguished by progressive loss of motor coordination and muscle function. This is due to the expansion of CAG trinucleotide in the first exon of the htt gene responsible for neuronal death and neuronal network degeneration in the brain. It is believed that the factors such as molecular genetics, oxidative stress, excitotoxicity, mitochondrial dysfunction, neuroglia dysfunction, protein aggregation, and altered UPS leads to HD. The defensive effect of the natural product provides therapeutic efficacy against HD. Recent reports on natural drugs have enlightened the protective role against HD via antioxidant, anti-inflammatory, antiapoptotic, and neurofunctional regulation.

Hospice Care Experiences Among Decedents With Huntington's Disease

CONTEXT

Little is known about the hospice care experiences of those with Huntington's Disease (HD).

OBJECTIVES

Our objective is to provide the first national characterization of hospice care quality for patients with HD and their families.

METHODS

We used national Consumer Assessment of Healthcare Providers and Systems (CAHPS) Hospice Survey data to examine caregiver-reported experiences of hospice care. We analyzed data from 550 caregivers of patients with HD and 1,098,819 caregivers of patients without HD who died January 2016-June 2019 while receiving hospice care from 3,845 hospices nationwide. Outcomes (on a 0-100 scale) were eight publicly-reported quality of care measures, and four individual survey items about receiving help for specific symptoms. Analyses were propensity-score weighted and adjusted for patient and caregiver characteristics.

RESULTS

Experiences of care among patients with HD were similar to or better than for patients without HD. Across all hospice and care settings, the only significant difference was for Providing Emotional, and Spiritual Support (90.9 [HD] vs. 88.2 [non-HD], a medium effect size, P < 0.01). However, patients with HD more often received care in settings with worse experiences for all patients; within the same hospice and same setting of care, measure scores were significantly higher for patients with HD compared to those without HD (2.3-4.6 points higher on a 0-100 scale) for all measures except Getting Hospice Care Training.

CONCLUSION

Our findings highlight the benefits of hospice care for those with HD and their families and may be useful for patients with HD when making decisions regarding options for end-of-life care.

Disease Burden of Huntington's Disease (HD) on People Living with HD and Care Partners in Canada

Background:

Huntington’s disease (HD) has been shown to reduce health-related quality of life (HRQoL) and affect healthcare resource utilization (HRU) among patients and care partners internationally but has not been studied specifically in the Canadian context.

Objective:

To characterize the burden of HD on individuals with HD and care partners of individuals with HD in Canada.

Methods:

An online survey was distributed (September 14–November 23, 2020) through patient organizations to collect data on demographic and clinical characteristics, as well as: HRQoL, measured using the 36-Item Short-Form Health Survey (SF-36v1); HRU, measured using the Client Service Receipt Inventory (CSRI); and care partner burden, measured using the Caregiver Strain Index (CSI) and Huntington’s Disease Quality of Life Battery for Carers (HDQoL-C). Descriptive statistics were used to report data and compare subgroups.

Results:

A total of 62 adult individuals with HD (or their proxies) and 48 care partners met defined eligibility criteria. The mean [standard deviation] age was 51.2 [13.8] and 58.1 [13.9] years for individuals with HD and care partner respondents, respectively. For individuals with HD, the greatest HRQoL burden (i.e., lowest score) was for the SF-36v1 Role –Physical scale (46.8 [42.9]). HRU was higher for some services (e.g., general practitioner visits) for respondents who had experienced motor onset transition. Among care partners, 55.3% experienced high strain, as indicated by the CSI. The HDQoL-C showed the greatest HRQoL burden in feelings about life (45.1 [17.9]).

Conclusion:

This study quantified the substantial burden on individuals with HD and care partners in Canada, addressing a critical knowledge gap that can affect the availability of and access to healthcare services.

Lower Prevalence of Chronic Pain in Manifest Huntington's Disease: A Pilot Observational Study

Pain is a minor problem compared with other Huntington Disease (HD) symptoms. Nevertheless, in HD it is poorly recognized and underestimated. So far, no study evaluated the presence of chronic pain in HD. The aim of this pilot study was to evaluate the presence and features of chronic pain in a cohort of HD gene carriers. An observational cross-sectional study was conducted in a cohort of HD gene carriers compared to not gene carriers (n.134 HD subjects, n.74 not gene mutation carriers). A specific pain interview, alongside a neurological, cognitive and behavioural examination, was performed in order to classify the type of pain, subjective intensity. A significant prevalence of "no Pain" in HD was found, which tended to increase with HD progression and a reduced frequency of pain in the last 3 months. A clear difference was found between manifest and premanifest HD in terms of intensity of pain, which did not change significantly with HD progression; however, a tendency emerges to a progressive reduction. No significant group difference was present in analgesic use, type and the site of pain. These findings could support a lower prevalence of chronic pain in manifest HD. Prevalence and intensity of chronic pain seem directly influenced by the process of neurodegeneration rather than by an incorrect cognitive and emotional functioning.

The prevalence of pain in Huntington's disease in a large worldwide cohort

INTRODUCTION

Pain could be an unknown non-motor symptom in Huntington's Disease (HD). The aim is therefore, to study the prevalence of pain interference, painful conditions and analgesic use across the different stages of HD and compare these levels to non-HD gene mutation carriers.

METHODS

A cross-sectional analysis of the Enroll-HD study was conducted in premanifest, manifest HD gene mutation carriers (n = 3989 and n = 7,485, respectively) and in non-HD gene mutation carriers (n = 3719). To investigate group differences, multivariable logistic regression analysis was performed with pairwise comparisons.

RESULTS

In the HD mutation carriers, the overall prevalence of pain interference was 34% (95% CI 31%-35%), of painful conditions 17% (95% CI 15%-19%) and analgesic use 13% (95% CI 11%-15%). Compared to non-mutation carriers, the prevalence of pain interference was significantly higher in the middle stage of HD (33% [95% CI 31%-35%] vs 42% [95% CI 39%-45%], P = 0,02), whereas the prevalence of painful conditions was significant lower in the late and middle stage of HD (17% [95% CI 16%-18%] vs 12% [95% CI 10%-14%], 15% [95% CI 13%-17%], P < 0,01]. No significant group difference was present in analgesic use.

CONCLUSIONS

The prevalence of pain interference increases as HD progresses, however, the prevalence of painful conditions and analgesics do not increase accordingly. Further studies are necessary to investigate the aetiology of pain in HD and the risk for undertreatment of pain.

Morphine produces better thermal analgesia in young Huntington mice and are associated with less neuroinflammation in spinal cord

BACKGROUND

Huntington's disease (HD) is an inherited disease characterized by both mental and motor dysfunctions. Our previous studies showed that HD mice demonstrate a diminished pain response. However, few studies have focused on the relationship between HD and morphine analgesia. The purpose of this study is to investigate and compare the analgesic effects of morphine in HD and wild-type (WT) mice.

METHODS

We used clinically similar transgenic HD mice (7-10 weeks of age with motor dysfunction at 8-9 mo of age) carrying a mutant Huntington CAG trinucleotide repeats to evaluate morphine analgesia. The morphine (10 mg/kg subcutaneously) analgesia was evaluated with a tail-flick in hot water (52°C). Mice spinal cords were harvested at the end of the analgesia studies. An immunofluorescence assay and western blotting were used to identify changes in the cells and cytokines.

RESULTS

Our data demonstrate that preonset young HD mice exhibited a better analgesic response to morphine than the WT mice. Western blotting and an immunohistological examination of the lumbar spinal cord tissue indicated less activation of glial cells and astrocytes in the HD mice compared with the WT mice. The production levels of tumor necrosis factor α and interleukine-1β were also lower in the young HD mice.

CONCLUSION

Our data demonstrate better morphine analgesic and less pain-related cytokine responses at the spinal cord level for HD mice. Further studies are needed to determine the morphine analgesia mechanism in HD.

Proenkephalin Decreases in Cerebrospinal Fluid with Symptom Progression of Huntington's Disease

OBJECTIVE

Identifying molecular changes that contribute to the onset and progression of Huntington's disease (HD) is of importance for the development and evaluation of potential therapies.

METHODS

We conducted an unbiased mass-spectrometry proteomic analysis on the cerebrospinal fluid of 12 manifest HD patients (ManHD), 13 pre-manifest (preHD), and 38 controls. A biologically plausible and significant possible biomarker was validated in samples from a separate cohort of patients and controls consisting of 23 ManHD patients and 23 controls.

RESULTS

In ManHD compared to preHD, 10 proteins were downregulated and 43 upregulated. Decreased levels of proenkephalin (PENK) and transthyretin were closely linked to HD symptom severity, whereas levels of 15 upregulated proteins were associated with symptom severity. The decreased PENK levels were replicated in the separate cohort where absolute quantitation was performed.

CONCLUSIONS

We hypothesize that declining PENK levels reflect the degeneration of medium spiny neurons (MSNs) that produce PENK and that assays for PENK may serve as a surrogate marker for the state of MSNs in HD. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Clinical Manifestation of Juvenile and Pediatric HD Patients: A Retrospective Case Series

BACKGROUND

Studies on the clinical manifestation and course of disease in children suffering from Huntington's disease (HD) are rare. Case reports of juvenile HD (onset ≤ 20 years) describe heterogeneous motoric and non-motoric symptoms, often accompanied with a delay in diagnosis. We aimed to describe this rare group of patients, especially with regard to socio-medical aspects and individual or common treatment strategies. In addition, we differentiated between juvenile and the recently defined pediatric HD population (onset < 18 years).

METHODS

Out of 2593 individual HD patients treated within the last 25 years in the Huntington Centre, North Rhine-Westphalia (NRW), 32 subjects were analyzed with an early onset younger than 21 years (1.23%, juvenile) and 18 of them younger than 18 years of age (0.69%, pediatric).

RESULTS

Beside a high degree of school problems, irritability or aggressive behavior (62.5% of pediatric and 31.2% of juvenile cases), serious problems concerning the social and family background were reported in 25% of the pediatric cohort. This includes an attempted rape and robbery at the age of 12, as problems caused by the affected children, but also alcohol-dependency in a two-year-old induced by a non-HD affected stepfather. A high degree of suicidal attempts and ideations (31.2% in pediatric and 33.3% in juvenile group) was reported, including drinking of solvents, swallowing razor blades or jumping from the fifth floor with following incomplete paraparesis. Beside dopaminergic drugs for treatment of bradykinesia, benzodiazepines and tetrabenazine for treatment of dystonia, cannabinoids, botulinum toxin injection and deep brain stimulation were used for the improvement of movement disorders, clozapine for the treatment of tremor, and dopa-induced hallucinations and zuclopenthixole for the treatment of severe aggressive behavior.

CONCLUSIONS

Beside abnormalities in behavior from an early age due to HD pathology, children seem to have higher socio-medical problems related to additional burden caused by early affected parents, instable family backgrounds including drug abuse of a parent or multiple changes of partners. Treatment required individualized strategies in many cases.