Chronic pain in persons with myotonic dystrophy and facioscapulohumeral dystrophy

Mouse models of non-dystrophic and dystrophic myotonia exhibit nociplastic pain-like behaviors

Pain is a prominent and debilitating symptom in myotonic disorders, yet its physiological mechanisms remain poorly understood. This study assessed preclinical pain-like behavior in murine models of pharmacologically induced myotonia and myotonic dystrophy type 1 (DM1). In both myotonia congenita and DM1, impairment of the CLCN1 gene, which encodes skeletal muscle voltage-gated CLC-1 chloride channels, reduces chloride ion conductance in skeletal muscle cells, leading to prolonged muscle excitability and delayed relaxation after contraction. We used the CLC-1 antagonist anthracene-9-carboxylic acid (9-AC) at intraperitoneal doses of 30 or 60 mg/kg and HSA LR20b DM1 mice to model CLC-1-induced myotonia. Our experimental approach included in vivo pain behavioral testing, ex vivo calcium imaging, and whole-cell current-clamp electrophysiology in mouse dorsal root ganglion (DRG) neurons. A single injection of 9-AC induced myotonia in mice, which persisted for several hours and resulted in long-lasting allodynic pain-like behavior. Similarly, HSA LR20b mice exhibited both allodynia and hyperalgesia. Despite these pain-like behaviors, DRG neurons did not show signs of hyperexcitability in either myotonic model. These findings suggest that myotonia induces nociplastic pain-like behavior in preclinical rodents, likely through central sensitization mechanisms rather than peripheral sensitization. This study provides insights into the pathophysiology of pain in myotonic disorders and highlights the potential of using myotonic mouse models to explore pain mechanisms and assess novel analgesics. Future research should focus on the central mechanisms involved in myotonia-induced pain and develop targeted therapies to alleviate this significant clinical burden.

The facioscapulohumeral muscular dystrophy - health index: Italian validation of a disease-specific measure of symptomatic burden

PURPOSE

The aim of this study was to adapt the Facioscapulohumeral Muscular Dystrophy - Health Index (FSHD-HI) to an Italian population affected by FSHD by translating, validating, and testing this instrument in an Italian cohort.

MATERIALS AND METHODS

Italian FSHD patients were interviewed regarding the form and content of the translated instrument. Subsequently, forty FSHD patients were recruited to test the reliability (Intraclass Correlation Coefficient, ICC for test-retest; and Cronbach's Alpha for Internal consistency), known groups (Mann-Whitney U test and Area Under the Curve, AUC) and concurrent validity (Pearson's and Spearman's Rank Correlation Coefficient) of the instrument by serially completing the FSHD-HI and an extensive set of tests measuring the neuromotor, psychological and cognitive functions, and perceived quality of life (QoL) aspects.

RESULTS

The Italian translation of the FSHD-HI and its subscales were highly relevant to patients, had a high internal consistency (Cronbach's Alpha = 0.90), optimal test-retest reliability (ICC= 0.95), and was significantly associated with motor function, respiratory function, and QoL assessments.

CONCLUSIONS

Overall, the Italian FSHD-HI is a valid and well-suited measurement of the multi-dimensional aspects of disease burden in FSHD patients.

Effectiveness of conservative non-pharmacological interventions in people with muscular dystrophies: a systematic review and meta-analysis

INTRODUCTION

Management of muscular dystrophies (MD) relies on conservative non-pharmacological treatments, but evidence of their effectiveness is limited and inconclusive.

OBJECTIVE

To investigate the effectiveness of conservative non-pharmacological interventions for MD physical management.

METHODS

This systematic review and meta-analysis followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and searched Medline, CINHAL, Embase, AMED and Cochrane Central Register of Controlled Trial (inception to August 2022). Effect size (ES) and 95% Confidence Interval (CI) quantified treatment effect.

RESULTS

Of 31,285 identified articles, 39 studies (957 participants), mostly at high risk of bias, were included. For children with Duchenne muscular dystrophy (DMD), trunk-oriented strength exercises and usual care were more effective than usual care alone in improving distal upper-limb function, sitting and dynamic reaching balance (ES range: 0.87 to 2.29). For adults with Facioscapulohumeral dystrophy (FSHD), vibratory proprioceptive assistance and neuromuscular electrical stimulation respectively improved maximum voluntary isometric contraction and reduced pain intensity (ES range: 1.58 to 2.33). For adults with FSHD, Limb-girdle muscular dystrophy (LGMD) and Becker muscular dystrophy (BMD), strength-training improved dynamic balance (sit-to-stand ability) and self-perceived physical condition (ES range: 0.83 to 1.00). A multicomponent programme improved perceived exertion rate and gait in adults with Myotonic dystrophy type 1 (DM1) (ES range: 0.92 to 3.83).

CONCLUSIONS

Low-quality evidence suggests that strength training, with or without other exercise interventions, may improve perceived exertion, distal upper limb function, static and dynamic balance, gait and well-being in MD. Although more robust and larger studies are needed, current evidence supports the inclusion of strength training in MD treatment, as it was found to be safe.

Small and large fiber neuropathy in adults with myotonic dystrophy type 1

Introduction

Myotonic dystrophy type 1 (DM1) is an inherited neuromuscular disorder that affects multiple organs. In this study, we investigated symptoms of pain and presence of small and large fiber neuropathy in the juvenile and adult form of DM1.

Method

Twenty genetically verified DM1 patients were included. Pain was assessed, and neurological examination and investigations of the peripheral nervous system by quantification of small nerve fibers in skin biopsy, quantitative sensory testing and nerve conduction studies were performed. Results from skin biopsies were compared to healthy controls.

Result

Seventeen patients reported chronic pain. Large and/or small fiber abnormalities were present in 50% of the patients. The intraepidermal nerve fiber density was significantly lower in the whole group of patients compared to healthy controls.

Conclusion

Small-fiber neuropathy might be an important cause of pain in DM1.

267th ENMC International workshop: psychological interventions for improving quality of life in slowly progressive neuromuscular disorders

This workshop aimed to develop recommendations for psychological interventions to support people living with slowly progressive neuromuscular disorders (NMD). The workshop comprised clinicians, researchers, people living with NMD and their relatives. First, participants considered the key psychological challenges presented by NMD and the impact of NMD on relationships and mental health. Later, several psychological approaches for enhancing well-being in NMD were described. The results of randomised controlled trials of Cognitive Behaviour Therapy and Acceptance and Commitment Therapy for improving fatigue, quality of life, and mood in adults with NMD were examined. Then the group considered ways to adapt therapies for cognitive impairments or neurodevelopmental differences that occur in some NMD, alongside ways to support children and adolescents with NMD and their family members. Based on the evidence from randomised controlled trials, carefully conducted observational studies, and the coherence of these data with the experience of those living with NMD, the group recommends that psychological interventions should be embedded in the routine clinical care offered to people living with NMD.

Pain and Motor Function in Myotonic Dystrophy Type 1: A Cross-Sectional Study

Pain is an underestimated finding in myotonic dystrophy type 1 (DM1). We provide a characterization of pain in terms of functional implications through a multidimensional assessment in patients with DM1, focusing on gender differences. We assessed pain through the Brief Pain Inventory (BPI) and its indexes (the Severity Index (SI) and the Interference Index (II)), balance/gait (the Tinetti Performance-Oriented Mobility Assessment (POMA)), functional abilities (the Functional Independence Measure (FIM)), and fatigue (the Fatigue Severity Scale (FSS)). We divided our sample into a mild (<4) and a moderate-severe group (≥4) based on BPI indexes. A between-group analysis was performed. We recruited 23 males and 22 females with DM1. A statistically significant difference was found for the FSS and the BPI-SI ≥ 4, and for all outcomes in the BPI-II ≥ 4 (p ≤ 0.003). In the female group, all outcomes except for the FIM were statistically significantly worse (p ≤ 0.004). Dividing our sample into four groups based on gender and the BPI, a statistically significant difference was found for FSS between the two groups with BPI-II ≥ 4 (with worsen score in the female one) (p < 0.002). Pain in DM1 patients is highly reported and gender related, with increased fatigue and poor balance/gait in the female group.

Carbamazepine for Chronic Muscle Pain: A Retrospective Assessment of Indications, Side Effects, and Treatment Response

Myopathies fall under the umbrella of rare diseases, however, muscle pain is a relevant, under-recognized symptom with limited treatment options. Carbamazepine is an oral sodium channel blocker approved for the treatment of seizures and neuropathic pain. In 54 individuals receiving carbamazepine for muscle pain, we retrospectively assessed the subjective treatment response, side effects, and reasons for carbamazepine discontinuation. The underlying diagnoses leading to muscle pain were diverse, ranging from metabolic (n = 5) and other hereditary (n = 9) to acquired (n = 2) myopathies and myotonia syndromes (n = 22). Under carbamazepine (daily dose 254 ± 138 mg), patients reported a significant reduction of pain, quantified by an 11-point numeric rating scale (−1.9 ± 1.8, p < 0.001). Compared to age- and sex-matched controls, our sensory assessment revealed a significant dysfunction of Aδ-nerve fibers in patients with chronic muscle pain. Neuropathic pain components identified by the painDETECT questionnaire or quantitative sensory testing did not seem to influence the reported treatment response. Side effects (n = 18) such as fatigue, elevated liver enzymes, and diarrhea, as well as lack of pain improvement (n = 6), led to carbamazepine discontinuation in 44.4% (24/54). Mediated by dysfunctional Aδ-nerve fibers, muscle pain is common in a variety of myopathies. Carbamazepine may reduce pain levels, but comes with therapy-limiting side effects.

Self-reported reduced sleep quality and excessive daytime sleepiness in facioscapulohumeral muscular dystrophy

INTRODUCTION/AIMS

Facioscapulohumeral muscular dystrophy (FSHD) causes weakness and secondary associations, such as respiratory complications and pain, that can be linked to abnormal sleep patterns. Limited studies have focused on sleep in FSHD. The purpose of this study was to identify the prevalence of, and clinical features associated with, self-reported lowered sleep quality (SQ) and excessive daytime sleepiness (DS) in a large group of participants with FSHD.

METHODS

We conducted a prospective survey of individuals with self-reported FSHD enrolled in the FSHD Society Registry. The survey consisted of demographic and clinical characteristics, the Pittsburgh Sleep Quality Index (PSQI), and the Epworth Sleepiness Scale. Descriptive statistics were evaluated, and associations between clinical characteristics and SQ and DS were explored using one-way analysis of variance tests. Small effect size was identified as 0.01 ≥ η2  > 0.06, medium was 0.06 ≥ η2  > 0.14, and large was 0.14 ≥ η2 .

RESULTS

Six hundred ninety individuals responded to the survey, equally distributed between men and women, and spanning the age range from under 12 to 74 years of age or older. Sixty-six percent of the respondents showed reduced SQ (PSQI > 5) (n = 392; 95% confidence interval [CI], 62.4-70.0), and 15% showed excessive DS (>10) (n = 89; 95% CI, 12.2-17.9). There was a significant association between SQ and DS. Nocturnal pain had a large significant effect on lowering SQ (P < .001, η2  = 0.192). Factors including age and gender had minor effects on SQ.

DISCUSSION

Physicians should monitor sleep quality of patients with FSHD as a routine part of care, with special attention to potentially modifiable factors. Future research should address the physiological effects of pain in sleep.

[Rare diseases in the differential diagnosis of myalgia]

Myalgia describes pain in the skeletal muscles. According to the current German clinical guidelines from 2020 (AWMF register number: 030/051), the initial diagnostic assessment consists of the anamnesis, clinical examination, electrophysiological examination and standard laboratory tests. Additional special examinations, such as molecular genetic investigations, special laboratory tests, medical imaging and muscle biopsy are only needed in certain cases. This article focuses on rare neurological diseases that are classically associated with myalgia. In this context etiologically different diseases are considered, whereby some genetically linked diseases (fascioscapulohumeral dystrophy, FSHD, dystrophia myotonica, McArdle's disease, Pompe's disease, limb girdle muscular dystrophy) are contrasted with diseases with an (auto)immune-related pathogenesis (stiff-person syndrome, Isaacs syndrome). The aspects relevant for the diagnosis are particularly highlighted. The therapeutic aspects of the diseases are not part of this article.

Chronic pain, psychological distress, and quality of life in males with Duchenne muscular dystrophy

AIM

To describe chronic pain in Duchenne muscular dystrophy (DMD) from children's/adolescents' perspectives, explore patient variables associated with self-reported pain, and examine the relationship between chronic pain, psychological functioning, and health-related quality of life (HRQoL).

METHOD

This observational study included a paediatric cohort (aged 8-18 years; median age 9 years 4 months) with DMD under multidisciplinary care (n = 45). Clinical data of the latest visit were extracted from the electronic health record and assessment of pain, psychological distress, and HRQoL were performed during the same visit.

RESULTS

Thirty-two patients reported pain during the previous 4 weeks, and 18 reported persistent or recurrent chronic pain. Average pain intensity of chronic pain was mild, with regions of the legs (n = 12), lower back (n = 6), hips (n = 6), and shoulder (n = 6) most frequently affected. Older age, higher body mass index, being non-ambulatory, wheelchair dependency, and spinal deformities were contextual variables related to the presence of chronic pain. Furthermore, chronic pain was significantly associated with psychological distress and reduced HRQoL in paediatric patients with DMD.

INTERPRETATION

Chronic pain in paediatric DMD is frequent and widespread, highlighting the need for pain to be addressed in the routine care of affected young people. Chronic pain may make a significant contribution to psychological distress and impaired HRQoL in paediatric patients with DMD.

[Rare diseases in the differential diagnosis of myalgia]

Myalgia describes pain in the skeletal muscles. According to the current German clinical guidelines from 2020 (AWMF register number: 030/051), the initial diagnostic assessment consists of the anamnesis, clinical examination, electrophysiological examination and standard laboratory tests. Additional special examinations, such as molecular genetic investigations, special laboratory tests, medical imaging and muscle biopsy are only needed in certain cases. This article focuses on rare neurological diseases that are classically associated with myalgia. In this context etiologically different diseases are considered, whereby some genetically linked diseases (fascioscapulohumeral dystrophy, FSHD, dystrophia myotonica, McArdle's disease, Pompe's disease, limb girdle muscular dystrophy) are contrasted with diseases with an (auto)immune-related pathogenesis (stiff-person syndrome, Isaacs syndrome). The aspects relevant for the diagnosis are particularly highlighted. The therapeutic aspects of the diseases are not part of this article.

Systemic Manifestations and Symptom Burden of Facioscapulohumeral Muscular Dystrophy in a Referral Cohort

INTRODUCTION/AIMS

The full spectrum of the clinical phenotype of facioscapulohumeral muscular dystrophy (FSHD), beyond skeletal muscle weakness, remains poorly characterized. In this study, we describe systemic manifestations and symptom burden in a large series of FSHD patients.

METHODS

We performed a retrospective chart review of FSHD patients seen at our institution between 2000 and 2017. We reviewed patients' responses to a comprehensive review of symptoms and the results of diagnostic testing for sensorineural hearing loss, cardiac disease, dysphagia, ocular abnormalities, and respiratory insufficiency. We assessed the association between disease manifestations and age of onset, genetic profile, and disease duration.

RESULTS

We identified 87 patients with FSHD. The most common reported symptoms included pain (71%), difficulty sleeping (41%), headaches (27%), and altered mood (24%). When tested, 7/16 (44%) patients had sensorineural hearing loss, 20/60 (33%) had cardiac arrhythmias or conduction defects, 17/45 (38%) had echocardiogram abnormalities, 12/25 (48%) had reduced forced vital capacity, and 4/10 (40%) had oropharyngeal dysphagia. However, patients with these abnormalities represented 8%, 23%, 20%, 14%, and 5% of total number of patients respectively, as uniform screening was lacking. Ocular pathology attributable to FSHD was not detected.

DISCUSSION

FSHD demonstrates a broad clinical phenotype. Increased vigilance among neurologists to screen for systemic manifestations of the disease is warranted. More uniform screening and future population-based studies are needed to compare the findings in FSHD patients to the general population.

Prevalence of Pain within Limb Girdle Muscular Dystrophy R9 and Implications for Other Degenerative Diseases

Our primary aim was to establish the prevalence of pain within limb girdle muscular dystrophy R9 (LGMDR9). As part of the Global FKRP Registry, patients are asked to complete the Short Form McGill Pain Questionnaire (SF-MPQ) annually. We used the results of this questionnaire to determine individuals’ maximum pain score and total pain score and examined overall pain intensity and associations between pain intensity and LGMDR9 genotypes, age, and ambulatory status. We also considered the pain descriptors used and pain progression over time. Of the 502 patients, 87% reported current pain and 25% reported severe current pain. We found no associations in pain severity between the different genotypes of LGMDR9. However, we did find statistically significant associations between pain severity and ambulatory status and between our paediatric and adult populations. We found pain descriptors to be more common words that one may associate with non-neural pain, and we found that a significant number of individuals (69%) reported a fluctuating pain pattern over time. We concluded that pain should be considered a significant issue among individuals with LGMDR9 requiring management. Implications regarding assessment of pain for other degenerative diseases are discussed.

Natural History of Facioscapulohumeral Dystrophy in Children: A 2-Year Follow-up

Background and Objectives

Data on the natural history of facioscapulohumeral dystrophy (FSHD) in childhood are limited and critical for improved patient care and clinical trial readiness. Our objective was to describe the disease course of FSHD in children.

Methods

We performed a nationwide, single-center, prospective cohort study of FSHD in childhood assessing muscle functioning, imaging, and quality of life over 2 years of follow-up.

Results

We included 20 children with genetically confirmed FSHD who were 2 to 17 years of age. Overall, symptoms were slowly progressive, and the mean FSHD clinical score increased from 2.1 to 2.8 (p = 0.003). The rate of progression was highly variable. At baseline, 16 of 20 symptomatic children had facial weakness; after 2 years, facial weakness was observed in 19 of 20 children. Muscle strength did not change between baseline and follow-up. The most frequently and most severely affected muscles were the trapezius and deltoid. The functional exercise capacity, measured with the 6-minute walk test, improved. Systemic features were infrequent and nonprogressive. Weakness-associated complications such as lumbar hyperlordosis and dysarthria were common, and their prevalence increased during follow-up. Pain and fatigue were frequent complaints in children, and their prevalence also increased during follow-up. Muscle ultrasonography revealed a progressive increase in echogenicity.

Discussion

FSHD in childhood has a slowly progressive but variable course over 2 years of follow-up. The most promising outcome measures to detect progression were the FSHD clinical score and muscle ultrasonography. Despite this disease progression, an improvement on functional capacity may still occur as the child grows up. Pain, fatigue, and a decreased quality of life were common symptoms and need to be addressed in the management of childhood FSHD. Our data can be used to counsel patients and as baseline measures for treatment trials in childhood FSHD.

Association of chronic pain with comorbidities and health care utilization: a retrospective cohort study using health administrative data

ABSTRACT

Health administrative data provide a potentially robust information source regarding the substantial burden chronic pain exerts on individuals and the health care system. This study aimed to use health administrative data to estimate comorbidity prevalence and annual health care utilization associated with chronic pain in Newfoundland and Labrador, Canada. Applying the validated Chronic Pain Algorithm to provincial Fee-for-Service Physician Claims File data (1999-2009) established the Chronic Pain (n = 184,580) and No Chronic Pain (n = 320,113) comparator groups. Applying the Canadian Chronic Disease Surveillance System coding algorithms to Claims File and Provincial Discharge Abstract Data (1999-2009) determined the prevalence of 16 comorbidities. The 2009/2010 risk and person-year rate of physician and diagnostic imaging visits and hospital admissions were calculated and adjusted using the robust Poisson model with log link function (risks) and negative binomial model (rates). Results indicated a significantly higher prevalence of all comorbidities and up to 4 times the odds of multimorbidity in the Chronic Pain Group (P-value < 0.001). Chronic Pain Group members accounted for 58.8% of all physician visits, 57.6% of all diagnostic imaging visits, and 54.2% of all hospital admissions in 2009/2010, but only 12% to 16% of these were for pain-related conditions as per recorded diagnostic codes. The Chronic Pain Group had significantly higher rates of physician visits and high-cost hospital admission/diagnostic imaging visits (P-value < 0.001) when adjusted for demographics and comorbidities. Observations made using this methodology supported that people identified as having chronic pain have higher prevalence of comorbidities and use significantly more publicly funded health services.

Pathomechanisms and biomarkers in facioscapulohumeral muscular dystrophy: roles of DUX4 and PAX7

Facioscapulohumeral muscular dystrophy (FSHD) is characterised by progressive skeletal muscle weakness and wasting. FSHD is linked to epigenetic derepression of the subtelomeric D4Z4 macrosatellite at chromosome 4q35. Epigenetic derepression permits the distal-most D4Z4 unit to transcribe DUX4, with transcripts stabilised by splicing to a poly(A) signal on permissive 4qA haplotypes. The pioneer transcription factor DUX4 activates target genes that are proposed to drive FSHD pathology. While this toxic gain-of-function model is a satisfying "bottom-up" genotype-to-phenotype link, DUX4 is rarely detectable in muscle and DUX4 target gene expression is inconsistent in patients. A reliable biomarker for FSHD is suppression of a target gene score of PAX7, a master regulator of myogenesis. However, it is unclear how this "top-down" finding links to genomic changes that characterise FSHD and to DUX4. Here, we explore the roles and interactions of DUX4 and PAX7 in FSHD pathology and how the relationship between these two transcription factors deepens understanding via the immune system and muscle regeneration. Considering how FSHD pathomechanisms are represented by "DUX4opathy" models has implications for developing therapies and current clinical trials.

The Prevalence, Characteristics and Impact of Chronic Pain in People With Muscular Dystrophies: A Systematic Review and Meta-Analysis

Chronic pain is a frequent, yet under-recognized and under-assessed problem in people with muscular dystrophies (MDs). Knowledge of the prevalence and characteristics of chronic pain, and its impact on function and quality of life is limited and lacks systematic exploration. This article aims to systematically review and synthesize existing literature that addresses chronic pain prevalence, characteristics and impact in people with different types of MDs. The present meta-analysis showed that the estimated prevalence of chronic pain in MDs is high and appears to be similar across different diagnostic groups: 68% (95% CI: 52%-82%) in FSHD, 65% (95% CI: 51%-77%) in DM, 62% (95% CI: 50%-73%) in BMD/DMD, and 60% (95% CI: 48%-73%) in LGMD, although it should be noted that heterogeneity was high in some diagnostic groups. On average, people with FSHD and DM present with moderate pain intensity. The lumbar spine, shoulders and legs are the most frequent sites of chronic pain among people with FSHD, DM, BMD/DMD, and LGMD, with little variation. Diffuse pain across multiple body sites was reported by a notable proportion of these individuals. Chronic pain has a negative impact on daily life activities in people with MDs, and may also contribute to decreased quality of life. The protocol for this review has been published on PROSPERO (CRD42020168096). PERSPECTIVES: This is the first systematic review and meta-analysis exploring the prevalence, and nature and impact of chronic pain in people with MDs. The present study demonstrates how common chronic pain is across various MD populations and highlights the need for better recognition and understanding of the nature and impact of pain from health professionals.

Pain in adult myotonic dystrophy type 1: relation to function and gender

Background

Pain is prevalent in myotonic dystrophy 1 (DM1). This study investigated whether CTG repeat size, disease duration, BMI and motor and psychological function were related to pain in adult patients with DM1, and if there were gender differences regarding intensity and location of pain.

Method

Cross-sectional design. Pain was investigated in 50 genetically confirmed DM1 patients by combining clinical assessment and self-reports of pain intensity and locations. Pain scoring results were related to CTG size, disease duration, muscle strength, walking capacity measured by 6-min walk test, activity of daily life by Katz ADL Index, respiratory function by Forced Vital Capacity and BMI. In addition, the degree of reported pain was related to Quality of life measured by WHOQOL-BREF; fatigue was measured by Fatigue severity scale; psychological functions were measured by Beck Depression Inventory, Beck Anxiety Inventory, IQ and Autism spectrum Quotient.

Results

Pain was reported in 84% of the patients and was significantly correlated with CTG size (r = 0.28 p = 0.050), disease duration (r = 0.38 p = 0.007), quality of life (r = − 0.37 p = 0.009), fatigue (r = 0.33 p = 0.02) and forced vital capacity (r = − 0.51, p = 0.005). Significant gender differences, with higher scores for females, were documented. In male subjects the number of pain locations was significantly correlated with quality of life and the autism quotient. In females, pain intensity was significantly correlated with activity, respiratory function and BMI.

Conclusions

Pain in DM1 was prevalent, with a strong association to lung function and other aspects of the disease. Significant gender differences were present for pain intensity and number of pain locations. How pain was related to other symptoms differed between male and female subjects. Our findings highlight the importance of assessments of pain in DM1 patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02124-9.

[Pain management in rare diseases]

In this article we address the relevance of rare diseases and their peculiarities with respect to pain therapy. Towards this end, four rare diseases (hemophilia, Morbus Fabry, dermatomyositis, and facioscapulohumeral dystrophy (FSHD)) will be presented and fundamental aspects of their pain therapies described. The diseases were chosen to showcase a pain therapy based on the WHO-step-by-step plan (hemophilia), a complex but established pain therapy (M. Fabry), and two less well established, individually adapted pain therapies (dermatomyositis, FSHD).

Myalgia in myositis and myopathies

Myalgia is a common symptom of various neuromuscular disorders: myalgia occurs in metabolic muscle diseases, inflammatory muscle diseases, dystrophic myopathies and myotonic muscle disorders. Myalgia leads to a significantly reduced quality of life. Other muscular symptoms that are present along with myalgia often provide the clue towards a diagnosis and include weakness, cramps and myotonia as well as the type of pain. In addition, extramuscular symptoms like an erythema in dermatomyositis can lead to the correct diagnosis. Basic diagnostic workup includes a detailed medical history, full neurologic assessment, laboratory tests, EMG and nerve conduction studies. Muscle imaging, genetic testing and muscle biopsy may be required to make a diagnosis. Whenever possible, treatment should aim to improve or correct the underlying cause for myalgia such as inflammation or hypothyroidism. Symptomatic therapy includes different avenues: Myotonia can be treated with mexiletine. Carbamazepine or phenytoin can be used in myotonic syndromes, particularly with muscle cramps. Pregabalin, gabapentin, or amitriptyline can be tried in conditions with myalgic pain. This review summarizes the symptoms, diagnostic strategies, and therapeutic approach in neuromuscular disorders that present with myalgia.

Patient-Reported Symptoms in Facioscapulohumeral Muscular Dystrophy (PRISM-FSHD)

OBJECTIVE

To determine the frequency and relative importance of the most meaningful symptoms in facioscapulohumeral muscular dystrophy (FSHD) and to identify the demographic and clinical features that are associated with the greatest disease burden in this population.

METHODS

We performed a cross-sectional study involving 328 participants with FSHD. Collectively, participants reported the prevalence and relative importance of 274 symptoms and 15 symptomatic themes. We assessed the association between symptomatic theme prevalence and participants' age, sex, disease duration, pain level, employment status, and education.

RESULTS

Participants answered >48,000 questions regarding their disease burden. The symptomatic themes with the highest prevalence in our sample were problems with shoulders or arms (96.9%), limitations with activities (94.7%), core weakness (93.8%), fatigue (93.8%), limitations with mobility and walking (93.6%), changed body image due to the disease (91.6%), and pain (87.7%). Problems with shoulders and arms and limitations with mobility and walking had the greatest effect on participants' lives. Employment status and the report of pain had the most extensive association with the prevalence of symptoms, with employment being associated with 8 of 15 of the symptomatic themes and pain being associated with 7 of 15 of the symptomatic themes. Men and women with FSHD experienced a similar prevalence of all symptomatic themes.

CONCLUSIONS

Adults with FSHD experience a variety of symptoms that play an important role in their disease burden. These symptoms have a variable prevalence and importance in the FSHD population and are associated with disease duration, employment status, and pain level.

Clinical features of facioscapulohumeral muscular dystrophy 1 in childhood

AIM

To explore the clinical course of patients presenting with facioscapulohumeral dystrophy type 1 (FSHD1) in childhood, with a view to identifying areas where they differed from older patients and where extra support or monitoring might be required.

METHOD

A retrospective case-notes review of children with FSHD1 seen at a tertiary paediatric neuromuscular centre between 2002 and 2016 was performed. Data collected included age at and nature of presentation, path to diagnosis, genetic testing results, motor function, and occurrence of extramuscular features and complications.

RESULTS

Eighteen children (11 females, seven males; mean [SD] age at latest review 13y 10mo [3y 9mo], range 8-19y) from 16 families were identified. Age at onset of FSHD1 correlated with the size of deletion (r=0.81) and most presentations were in children either younger than 5 years or older than 10 years. Children with onset before 5 years were more likely to present with non-muscular symptoms and to develop extramuscular pathology, including developmental and psychiatric issues, hearing or visual impairments, and problems involving respiratory function and nutrition. No cases of epilepsy or cardiac arrhythmia were identified but two children died.

INTERPRETATION

The complexity and severity of FSHD1 presenting in early childhood underlines the importance of a multidisciplinary approach to the disorder.

WHAT THIS PAPER ADDS

Young children often present with non-muscular pathology in facioscapulohumeral dystrophy type 1 (FSHD1), especially hearing loss. Age at onset in paediatric FSHD1 appears bimodal: under 5 years or in adolescence. Prolonged delays to diagnosis are common. Children with very early-onset FSHD1 may require nutritional and/or respiratory support. Developmental and psychiatric comorbidities are common.

Frequency of reported pain in adult males with muscular dystrophy

INTRODUCTION

The purpose of this study was to present and compare pain between adult males with Duchenne (DMD), Becker's (BMD), Limb-Girdle (LGMD) Facioscapulohumeral (FSHD) forms of Muscular Dystrophy (MD), and healthy controls (CTRL), using three different methods of assessment.

METHODS

Pain was assessed using 1) a whole body visual analogue scale (VAS) of pain, 2) a generalised body map and 3) a localised body map.

RESULTS

All types of MD reported more VAS pain than CTRL, with 97% of all MD participants reporting pain; however, no differences were reported between types of MD. The generalised body map approach identified more frequent pain in the shoulders of FSHD (93%) than other groups (13-43%), hips of DMD (87%) and LGMD (75%) than other groups (0-29%), and legs of all MD (64-78%) than CTRL (25%). The localised body map approach identified common areas of frequent pain across types of MD, posterior distal leg and distal back, as well as condition specific regions of frequent pain, for example posterior trapezius in FSHD, and anterior hip pain in DMD and LGMD.

CONCLUSIONS

Using a single pain value (VAS), increased pain was reported by adults with MD compared to CTRL, with no clear differences between different MD groups, suggesting pain is symptomatic of MD. The use of the generalised body map approach, and to an even greater extent the localised body map approach, identified specific areas of frequent pain relevant to each individual condition. These results indicate that whist the commonly used generalised approach can be used to identify broad anatomical regions, the localised approach provides a more comprehensive understanding of pain, reflective of clinical assessment, and should be utilised in future research.

[Can acupuncture help relieve muscle pain in muscular dystrophy?]

Les douleurs musculaires ou myofasciales en relation avec une dystrophie musculaire peuvent-elles être soulagées par une acupuncture centrée sur le muscle ? Après un rappel sur les notions-clés de « trigger points myofasciaux » et de manipulations spécifiques des aiguilles d’acupuncture, nous rapportons quelques cas cliniques complexes parmi les patients atteints de maladies musculaires (MNM) et de la maladie de Charcot Marie Tooth (CMT) chez qui les douleurs myofasciales n’ont pas pu être contrôlées par des traitements médicamenteux et/ou par des techniques physiques. Ces patients ont été vus en consultation externe entre 2010 et 2017 à l’hôpital Rothschild, dans le service de Médecine Physique et de Réadaptation (MPR), en lien avec le Centre de Référence neuromusculaire « Paris-Nord/Est/Île-de-France ». Après la consultation initiale, plusieurs protocoles de soins ont été proposés, parmi lesquels figurait l’acupuncture effectuée par un médecin MPR.

Isokinetic assessment of trunk muscles in facioscapulohumeral muscular dystrophy type 1 patients

Facioscapulohumeral muscular dystrophy type 1 is the third most common inherited myopathy. Its severity is proportionate to the loss of microsatellite D4Z4 repetitions, which are below 10. Patients suffer from weakness in facial muscles, shoulder girdles and ankle dorsiflexors. Trunk impairment is reported in few studies. To assess correlation between D4Z4 number of repetitions in facioscapulohumeral muscular dystrophy type 1 patients and trunk extensors and flexors isokinetic peak torque, 48 patients with southern Blot confirmed facioscapulohumeral muscular dystrophy type 1 were enrolled to perform clinical evaluation (Ricci's Clinical Severity Scoring, Berg Balance Scale, Functional Reach Test, timed up-and-go test, six-minute walk test, functional independence measure) and trunk isokinetic assessment. Trunk extensors and flexors isokinetic peak torque at 60°/sec were significantly correlated with number of D4Z4 microsatellite repetitions, sex, weight and age-independent (r = 0.391 [0.121; 0.662], p < 0.006 and r = 0.334 [0.028; 0.641], p < 0.033, respectively). Ricci's Clinical Severity Scoring was significantly correlated to trunk extensors isokinetic peak torque at 60°/sec, sex and weight-independent (r = -0.743 [-0.938; -0.548], p < 0.0001). This study demonstrates moderate correlation between pathologic compression of D4Z4 microsatellite array and trunk extensors isokinetic strength among facioscapulohumeral muscular dystrophy type I patients.

Pain and sleep quality in children with non-vascular Ehlers-Danlos syndromes

The objective of this study was to explore the factors contributing to quality of life in pediatric patients with non-vascular Ehlers-Danlos syndromes (EDS). Data were analyzed on 41 children with a diagnosis of non-vascular EDS from the de-identified data available from the National Institute on Aging (NIA) study of heritable disorders of connective tissue. Children under age 19 years were seen as part of a long-term evaluation project from 2003 to 2013 on a larger natural history of patients with heritable disorders of connective tissue. Data collected included medical history, physical examination findings, diagnostic study results, and responses on validated questionnaires. We reviewed a sub-cohort of children with a diagnosis of non-vascular EDS and explored pain severity and interference via the Brief Pain Inventory, and sleep quality via the Pittsburgh Sleep Quality Index. Pain severity had a strong correlation with pain interference, and both were similar to other disorders that include chronic pain reported in the literature. Sleep quality did not correlate with pain severity or interference, but all patients had poor sleep quality in comparison to historical controls. We conclude that pain and sleep are significant issues in the pediatric non-vascular EDS population, and future research may be directed toward these issues.

A Pediatric Review of Facioscapulohumeral Muscular Dystrophy

Facioscapulohumeral dystrophy is one of the most common forms of muscular dystrophies worldwide. It is a complex and heterogeneous disease secondary to insufficient epigenetic repression of D4Z4 repeats and aberrant expression of DUX4 in skeletal muscles. Type 1 facioscapulohumeral muscular dystrophy (FSHD) is caused by contraction of D4Z4 repeats on 4q35, whereas type 2 FSHD is associated with mutations of the SMCHD1 or DNMT3B gene in the presence of a disease-permissive 4qA haplotype. Classical FSHD is a slowly progressive disorder with gradual-onset of muscle atrophy and a descending pattern of muscle weakness. In contrast, early-onset FSHD is associated with a large deletion of D4Z4 repeats and a more severe disease phenotype, including early loss of independent ambulation as well as extramuscular manifestations, such as retinal vasculopathy, hearing loss, and central nervous system (CNS) involvement. However, the correlation between D4Z4 repeats and disease severity remains imprecise. The current standard of care guidelines offers comprehensive assessment and symptomatic management of secondary complications. Several clinical trials are currently underway for FSHD. New and emerging treatments focus on correcting the transcriptional misregulation of D4Z4 and reversing the cytotoxic effects of DUX4. Other potential therapeutic targets include reduction of inflammation, improving muscle mass, and activating compensatory molecular pathways. The utility of disease-modifying treatments will depend on selection of sensitive clinical endpoints as well as validation of muscle magnetic resonance imaging (MRI) and other biomarkers to detect meaningful changes in disease progression. Correction of the epigenetic defects using new gene editing as well as other DUX4 silencing technologies offers potential treatment options for many individuals with FSHD.

Prospective measurement of quality of life in myotonic dystrophy type 1

INTRODUCTION

Generic patient reported outcome measures have had varied success in tracking QoL in myotonic dystrophy type 1 (DM1).

AIM

To analyze changes of Individualized Neuromuscular Quality of Life questionnaire (INQoL) scores in clinic patients with DM1 over a 6-year period.

METHOD

Patients completed the INQoL at baseline and after a 6-year period through their attendance in a neurology outpatient clinic. Severity of muscular involvement in DM1 was analyzed using the Muscular Impairment Rating Scale (MIRS).

RESULTS

Ninety-nine DM1 patients completed a baseline visit. Sixty-seven of these patients were retested at an interval time. The overall INQoL score improved in our sample of patients (P<.05) as did the following subscales: myotonia (P<.05), pain (P<.05), activities (P<.01), social relationships (P<.01), and body image (P<.05). No changes were observed for the independence and emotions scales. There were no differences in mean change of INQoL scores between patients with worsened MIRS and those with no change in MIRS scale after follow-up (P>.05).

CONCLUSION

Individualized Neuromuscular Quality of Life questionnaire scores improved in our cohort of DM1 patients during a 6-year period. INQoL score did not correlate with progression of muscle weakness. This must be better understood before the selection of the instrument for use in trials to measure therapeutic benefit in DM1 patients.

Chronic pain has a strong impact on quality of life in facioscapulohumeral muscular dystrophy

Introduction

Earlier small case series and clinical observations reported on chronic pain playing an important role in facioscapulohumeral dystrophy (FSHD). The aim of this study was to determine the characteristics and impact of pain on quality of life (QoL) in patients with FSHD.

Methods

We analyzed patient reported outcome measures collected through the U.K. FSHD Patient Registry.

Results

Of 398 patients, 88.6% reported pain at the time of study. The most frequent locations were shoulders and lower back. A total of 203 participants reported chronic pain, 30.4% of them as severe. The overall disease impact on QoL was significantly higher in patients with early onset and long disease duration. Chronic pain had a negative impact on all Individualised Neuromuscular Quality of Life Questionnaire domains and overall disease score.

Discussion

Our study shows that pain in FSHD type 1 (FSHD1) is frequent and strongly impacts on QoL, similar to other chronic, painful disorders. Management of pain should be considered when treating FSHD1 patients. Muscle Nerve57: 380–387, 2018

Major involvement of trunk muscles in myotonic dystrophy type 1

OBJECTIVES

The motor impairments in Myotonic Dystrophy 1 (DM1) are assumed to progress from distal toward proximal parts of the extremities in the Juvenile and Adult forms of DM1. On occasion and late in progress spine deformity is observed. In this study we have examined whether and to what extent trunk muscles are impaired in DM1, and if this impairment is correlated with the duration of the disorder, walking capacity, mobility, balance, and CTG-repeats.

MATERIALS & METHODS

Manual muscle testing (MMT) of skeletal muscle strength in trunk and extremities, reassessment of the mutation size, time since first symptom, the 6 min walk test (6MWT), Rivermead mobility index (RIM) and Timed up & go (TUG) were sampled in 38 adult DM1 outpatients.

RESULTS

We found significant impairment in trunk muscles. Trunk muscle strength decreased significantly with increasing mutation size (r = -0.64, P < 0.001). Reduced walking capacity, mobility and balance were significantly related to decreased trunk muscle strength.

CONCLUSION

DM1 affects trunk muscle groups. The trunk impairments seem to occur relatively early in disease progression. Awareness of trunk impairments may be of importance for everyday functioning and for understanding the risk of injuries due to falls reported among DM1 patients. It may also help in identification of DM1 patients and considered outcome measure in future clinical trials.

Medication adherence in patients with myotonic dystrophy and facioscapulohumeral muscular dystrophy

Myotonic dystrophy (DM) and facioscapulohumeral muscular dystrophy (FSHD) are the two most common adult muscular dystrophies and have progressive and often disabling manifestations. Higher levels of medication adherence lead to better health outcomes, especially important to patients with DM and FSHD because of their multisystem manifestations and complexity of care. However, medication adherence has not previously been studied in a large cohort of DM type 1 (DM1), DM type 2 (DM2), and FSHD patients. The purpose of our study was to survey medication adherence and disease manifestations in patients enrolled in the NIH-supported National DM and FSHD Registry. The study was completed by 110 DM1, 49 DM2, and 193 FSHD patients. Notable comorbidities were hypertension in FSHD (44 %) and DM2 (37 %), gastroesophageal reflux disease in DM1 (24 %) and DM2 (31 %) and arrhythmias (29 %) and thyroid disease (20 %) in DM1. Each group reported high levels of adherence based on regimen complexity, medication costs, health literacy, side effect profile, and their beliefs about treatment. Only dysphagia in DM1 was reported to significantly impact medication adherence. Approximately 35 % of study patients reported polypharmacy (taking 6 or more medications). Of the patients with polypharmacy, the DM1 cohort was significantly younger (mean 55.0 years) compared to DM2 (59.0 years) and FSHD (63.2 years), and had shorter disease duration (mean 26 years) compared to FSHD (26.8 years) and DM2 (34.8 years). Future research is needed to assess techniques to ease pill swallowing in DM1 and to monitor polypharmacy and potential drug interactions in DM and FSHD.

The Dutch patients' perspective on oculopharyngeal muscular dystrophy: A questionnaire study on fatigue, pain and impairments

Research on oculopharyngeal muscular dystrophy focuses mainly on genetic and pathophysiological aspects. Clinically, oculopharyngeal muscular dystrophy is often considered as a disease with a relatively mild initial disease course with no or only mild functional disabilities. However the occurrence of fatigue, pain and functional impairments other than dysphagia has never been studied systematically. The aim of this study is therefore to assess the prevalence of fatigue, pain, and functional limitations, and the social participation and psychological well-being of oculopharyngeal muscular dystrophy patients. We performed a questionnaire study on fatigue, pain, functional impairments, social participation and psychological distress in 35 genetically confirmed oculopharyngeal muscular dystrophy patients with an average disease duration of 11.6 years. We showed that 19 (54%) of the patients experienced severe fatigue and also 19 (54%) experienced pain. Limitations in daily life activities and social participation were detected in 33 (94%) of the patients. Many patients reported pelvic girdle weakness and limitations in ambulation. Fatigue severity was related to functional impairments, while pain and disease duration were not. Psychological distress was not different from healthy adults. In conclusion, fatigue and pain are present among approximately half of the patients, and almost all patients are impaired in daily life activities, social participation and ambulation. These data should be taken into account in symptomatic management of oculopharyngeal muscular dystrophy.

What's in a name? The clinical features of facioscapulohumeral muscular dystrophy

Facioscapulohumeral muscular dystrophy (FSHD) is an inherited and progressive muscle disorder. Although its name suggests otherwise, it comprises weakness of the facial, shoulder and upper arm muscles, and also of the trunk and leg muscles. Its severity and disease course vary greatly and mild or early FSHD can be difficult to recognise. Knowledge of its subtle signs and symptoms can lead directly to the correct diagnosis without diagnostic delay and without needing multiple diagnostic procedures. We give an overview of the signs and symptoms of FSHD in severe as well as in mild cases, to facilitate correct and instant recognition of this relatively common muscle disorder.

Patient-Reported Impact of Symptoms in Myotonic Dystrophy Type 2 (PRISM-2)

OBJECTIVE

To determine the frequency and relative importance of the most life-affecting symptoms in myotonic dystrophy type 2 (DM2) and to identify the factors that have the strongest association with these symptoms.

METHODS

We conducted a cross-sectional study of adult patients with DM2 from a National Registry of DM2 Patients to assess the prevalence and relative importance of 310 symptoms and 21 symptomatic themes. Participant responses were compared by age categories, sex, educational attainment, employment status, and duration of symptoms.

RESULTS

The symptomatic themes with the highest prevalence in DM2 were the inability to do activities (94.4%), limitations with mobility or walking (89.2%), hip, thigh, or knee weakness (89.2%), fatigue (89.2%), and myotonia (82.6%). Participants identified the inability to do activities and fatigue as the symptomatic themes that have the greatest overall effect on their lives. Unemployment, a longer duration of symptoms, and less education were associated with a higher average prevalence of all symptomatic themes (p < 0.01). Unemployment, a longer duration of symptoms, sex, and increased age were associated with a higher average effect of all symptomatic themes among patients with DM2 (p < 0.01).

CONCLUSIONS

The lives of patients with DM2 are affected by a variety of symptoms. These symptoms have different levels of significance and prevalence in this population and vary across DM2 subgroups in different demographic categories.

Confirmatory factor analysis of the Korean version of the short-form McGill pain questionnaire with chronic pain patients: a comparison of alternative models

Background

The Short Form of the McGill Pain Questionnaire (SF-MPQ) is the most widely used assessment of the quality and intensity of pain. In previous validation studies, the factor structure of the SF-MPQ varied widely from various two-factor structures to a five-factor structure, although research on the SF-MPQ quite consistently supports its two-factor structure (i.e., sensory and affective) across different countries and languages. In Korea, the results of exploratory factor analysis of a Korea version of SF-MPQ (KSF-MPQ) showed 2-factor structure consisting of ‘sensory’ and ‘affective’ excluding two items such as splitting and heavy. As an attempt to further validate the KSF-MPQ, the purpose of this study was to confirm whether the KSF-MPQ model is an appropriate model for chronic pain patients in Korea by comparing several alternative models of the SF-MPQ.

Findings

A total of 150 chronic pain patients seeking treatment in Seoul, Korea, participated and completed the KSF-MPQ. Confirmatory factor analysis was conducted to evaluate the adequacy of the KSF-MPQ model and several alternative models. The results indicated that the adjusted KSF-MPQ model showed the best fit to the data among the models in chronic pain patients in Korea.

Conclusions

The results showed the KSF-MPQ is cross-culturally equivalent to the original questionnaire. Thus, the KSF-MPQ is valid measurement for assessing the quality and intensity of pain to chronic pain patients and may be helpful in clinical and research settings in Korea.

Multidimensional aspects of pain in myotonic dystrophies

To analyze the frequency and intensity of pain and its association with different characteristics of patients with myotonic dystrophy type 1 (DM1) and type 2 (DM2), 52 adult genetically confirmed DM1 and 44 DM2 patients completed the Brief Pain Inventory questionnaire (BPI). Frequency and average intensity of pain on numerical rating scale (0-10) were similar in DM1 and DM2 (88% vs. 86% and 4.6 ± 2.3 vs. 4.2 ± 1.8, respectively, p > 0.05). In DM1, average pain intensity showed strong association with longer duration of disease and inverse relation with cognition. In DM2, average pain intensity showed association with female gender and emotions. Average pain intensity correlated with Individualized Neuromuscular Quality of Life (INQoL) total score in both DM1 (rho = +0.30, p < 0.05) and DM2 patients (rho = +0.61, p < 0.01). In conclusion, the majority of DM1 and DM2 patients have mild to moderate pain. Our results open new opportunities for behavioral and cognitive interventions.

Pain location and intensity impacts function in persons with myotonic dystrophy type 1 and facioscapulohumeral dystrophy with chronic pain

INTRODUCTION

We examined the effects of pain site and intensity on function in patients with myotonic dystrophy type 1 (DM1) and facioscapulohumeral muscular dystrophy (FSHD) and chronic pain.

METHODS

Questionnaires assessing pain sites, pain extent (number of sites), pain intensity, and pain interference were completed by 182 individuals with DM1 (43%) or FSHD (57%) and chronic pain.

RESULTS

There was a positive association between pain extent and intensity with pain interference, and a negative association with psychological functioning in both DM1 and FSHD. Pain intensity at specific sites had differential impact beyond the effects of pain intensity alone. Head pain intensity independently affected psychological functioning, whereas leg, foot, hip, and knee pain contributed independently to the prediction of pain interference.

CONCLUSIONS

Pain site and intensity differentially modulates the effect of chronic pain on function in DM1 and FSHD patients. Researchers and clinicians should consider these factors when assessing and treating pain.

Longitudinal features of STIR bright signal in FSHD

INTRODUCTION

Magnetic resonance imaging of muscle shows short tau-inversion recovery (STIR) brightness in autosomal dominant facioscapulohumeral muscular dystrophy (FSHD1) suggestive of active inflammation/injury. We measured the longitudinal stability/progression of this potential disease biomarker.

METHODS

Nine subjects underwent calf MRI imaging over 2 years. Two radiologists evaluated qualitative muscle changes.

RESULTS

In 3/9 subjects, calf muscles demonstrated moderate/severe STIR hyperintensity at Time 1 that had progressed to fatty replacement 2 years later (Time 2). In the remaining subjects, moderate/severe muscle STIR abnormalities, when present, were consistent between exams. Mild STIR+ elevations had roughly similar patterns between exams.

CONCLUSIONS

Moderate/severe STIR hyperintensities often foreshadow fatty replacement over a 2-year interval. Whether longer time courses are required to observe muscle degeneration and fatty replacement in some subjects remains to be explored.

Symptom burden in persons with myotonic and facioscapulohumeral muscular dystrophy

OBJECTIVE

This study examines the prevalence of pain, fatigue, imbalance, memory impairment, and vision loss in persons with myotonic and facioscapulohumeral dystrophy and their association with functioning.

DESIGN

A survey (N = 170) included measures of severity (0-10 scales) and course of these symptoms as well as measures of social integration, home competency, mental health, and productive activity. Descriptive and regression analyses examined the associations between symptoms and functioning.

RESULTS

Fatigue (91%), imbalance (82%), and pain (77%) were the most commonly reported. The most severe symptom was fatigue (mean ± SD severity, 5.14 ± 2.81), followed by imbalance (4.95 ± 3.25). Symptoms were most likely to stay the same or worsen since onset. Controlling for potential medical and demographic confounds, symptoms were associated with 17% of the mental health variance, 10% of home competency, 10% of social integration, 16% of productive activity for myotonic dystrophy type 1, and 12% of productive activity for facioscapulohumeral muscular dystrophy.

CONCLUSIONS

Pain, fatigue, and imbalance are common in persons with muscular dystrophy. Interventions may be useful to mitigate their impact on functioning. Further research should examine these relationships to guide clinical practices.

Pain in adult patients with Pompe disease: a cross-sectional survey

BACKGROUND

Pompe disease is a rare hereditary metabolic myopathy caused by a deficiency of acid-α-glucosidase. We investigated the presence and severity of pain and its interference with daily activities in a large group of adults with Pompe disease, who we compared with an age-matched control group.

METHODS

Data were collected in a cross-sectional survey in Germany and The Netherlands. Pain was assessed using the short-form brief pain inventory (BPI). Patients also completed the Short Form-36 item (SF-36v2), the Hospital Anxiety and Depression Scale (HADS) and the Rotterdam Handicap Scale (RHS).

RESULTS

Forty-five percent of the 124 adult Pompe patients reported having had pain in the previous 24h, against 27% of the 111 controls (p=0.004). The median pain severity score in Pompe patients reporting pain was 3.1 (on a scale from 0 to 10), indicating mild pain; against 2.6 amongst controls (p=0.06). The median score of pain interference with daily activities in patients who reported pain was 3.3, against 1.3 in controls (p=0.001). Relative to patients without pain, those with pain had lower RHS scores (p=0.02), lower SF-36 Physical and Mental component summary scores (p<0.001 and p=0.049), and higher levels of depression and anxiety (p=0.005 and p=0.003).

CONCLUSIONS

To date, this is one of the largest studies on pain in a specific neuromuscular disorder. Nearly one in two Pompe patients had experienced pain in the previous 24h. Although pain severity and its interference with daily life were mild, pain was related to a reduced quality of life, less participation in daily life, and greater depression and anxiety. Its management should therefore be seen as part of clinical practice involving Pompe patients.

Considerations for neuropathic pain conditions in life care planning

Significant progress has been made in assessing and managing neuropathic pain. Newer, more effective treatments with minimal side effects are available. Despite advances in treatments, neuropathic pain remains a multifaceted phenomenon that can be difficult to alleviate. Diagnosis, mechanisms of injury, and treatment recommendations are critical components of life care plans for patients with neuropathic pain. A clear understanding of the underlying issues and careful coordination with neurologists and other treatment providers are key to providing optimal life care plans. Understanding that pain treatments vary over time and by individual patient is integral to comprehensive life care planning.

Pain in thalassaemia: the effects of age on pain frequency and severity

Pain is not a symptom generally associated with thalassaemia. However, providers have noted increasing patient reports of pain, creating an impetus for this prospective, observational assessment of pain in thalassaemia patients. The primary study goals were to assess pain prevalence, severity, location, and potential risk factors. This was a multicentre, prospective study of thalassaemia patients receiving care at 12 Thalassaemia Clinical Research Network sites. Pain was assessed using the Brief Pain Inventory. Two hundred and fifty-two thalassaemia patients ranging in age from 12 to 71 years (mean 28.8) were enrolled. Sixty-four per cent reported experiencing pain during the last 4 weeks, 22% of whom reported pain on a daily basis. Ordinal regression analysis of pain ratings demonstrated significant (P < 0.001) correlation of increased age with increased pain, irrespective of diagnosis, transfusion status, gender, bone density, chelator type or iron overload. Eighty-one per cent reported having pain for 1 year or longer and 31% reported pain for five or more years. Pain is a major cause of morbidity and an unrecognized problem for patients with thalassaemia. Age is the strongest predictor of frequency and severity. Little else is known about the aetiology and predictors of this pain syndrome.

Patient-identified disease burden in facioscapulohumeral muscular dystrophy

INTRODUCTION

The multitude of symptoms associated with facioscapulohumeral muscular dystrophy (FSHD) disease burden are of varying importance. The extent of these symptoms and their cumulative effect on the FSHD population is unknown.

METHODS

We conducted interviews with adult FSHD patients to identify which symptoms have the greatest effect on their lives. Each interview was recorded, transcribed, coded, and analyzed using a qualitative framework technique, triangulation, and a three-investigator consensus approach.

RESULTS

One thousand three hundred seventy-five quotes were obtained through 20 patient interviews. Two hundred fifty-one symptoms of importance were identified representing 14 themes of FSHD disease burden. Symptoms associated with mobility impairment, activity limitation, and social role limitation were most frequently mentioned by participants.

CONCLUSIONS

There are multiple themes and symptoms, some previously underrecognized, that play a key role in FSHD disease burden.

Focal and other unusual presentations of facioscapulohumeral muscular dystrophy

INTRODUCTION

Facioscapulohumeral dystrophy (FSHD) presents classically with facial and shoulder-girdle weakness. We report focal atypical presentations of FSHD. Our aim was to identify focal/unusual phenotypes in genetically confirmed FSHD cases.

METHODS

We undertook a retrospective review of an academic center database of the period from 1996 to 2011. Of 139 FSHD cases, 7 had atypical genetically confirmed disease. Clinical data were abstracted.

RESULTS

Seven cases (4 men) had a mean age of 37 years at onset (range 18-63 years) and mean 43 years at diagnosis (range 20-74 years). Presenting symptoms were monomelic lower limb (n = 3) or upper limb (n = 2) atrophy, or axial weakness (n = 2). Five patients had focal weakness on examination. CK was normal to borderline high. Two patients had a relative with FSHD. Coexistent unusual features included dyspnea (n = 1), S1 radicular pain with calf atrophy (n = 2), and peripheral neuropathy (n = 1). Almost all patients had myopathic EMG changes. DNA analysis showed a D4Z4 EcoRI fragment size ranging from 20 to 37 kilobases.

CONCLUSIONS

FSHD may present with focal weakness, dyspnea and myopathic EMG changes. These findings should raise the possibility of FSHD.