Fatigue, reduced sleep quality and restless legs syndrome in Charcot-Marie-Tooth disease: a web-based survey

Respiratory involvement and sleep-related disorders in CMT1A: case report and review of the literature

Sleep-disordered breathing has been reported in Charcot-Marie-Tooth disease (CMT) type 1A in association with diaphragmatic weakness and sleep apnea syndrome, mainly of the obstructive type (OSA). Improvement has been observed not only in sleep quality but also in neuropathy symptoms in CMT1A patients with OSA following the initiation of continuous positive airway pressure. We report the cases of two siblings affected by CMT1A associated with hemidiaphragm relaxatio necessitating nocturnal non-invasive ventilation (NIV). Two twins, now 42 years old, with a family history of CMT1A, received a genetic diagnosis of CMT1A at the age of 16. Over the years, they developed a slowly worsening gait disorder and a decline in fine motor hand movements, currently presenting with moderate disability (CMTES:13). At the age of 40, they both started complaining of daytime sleepiness, orthopnea, and exertional dyspnea. They received a diagnosis of relaxatio of the right hemidiaphragm associated with impairment of nocturnal ventilation and they both have benefited from nocturnal NIV. Disorders of breathing during sleep may be underestimated in CMT1A since routine investigations of sleep quality are rarely performed. Our two clinical cases and a literature review suggest the importance of inquiring about symptoms of excessive daytime sleepiness and respiratory disturbances in individuals with CMT1A, even in the absence of severe neuropathy. In the presence of compatible symptoms, a pneumological assessment, along with an overnight polysomnogram and lung function tests, should be performed. Recognizing sleep-related symptoms is essential for providing accurate treatment and improving the quality of life for patients with CMT1A.

Daytime sleepiness and sleep quality in Charcot-Marie-Tooth disease

BACKGROUND

Sleep abnormalities have been reported in Charcot-Marie-Tooth disease (CMT), but data are scanty. We investigated their presence and correlation in a large CMT patients' series.

METHODS

Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI) were administered to CMT patients of the Italian registry and controls. ESS score > 10 indicated abnormal daytime somnolence, PSQI score > 5 bad sleep quality. We analyzed correlation with disease severity and characteristics, Hospital Anxiety and Depression Scale (HADS), Modified Fatigue Impact Scale (MFIS), Body Mass Index, drug use.

RESULTS

ESS and PSQI questionnaires were filled by 257 and 253 CMT patients, respectively, and 58 controls. Median PSQI score was higher in CMT patients than controls (6 vs 4, p = 0.006), with no difference for ESS score. Abnormal somnolence and poor sleep quality occurred in 23% and 56% of patients; such patients had more frequently anxiety/depression, abnormal fatigue, and positive sensory symptoms than those with normal ESS/PSQI. Moreover, patients with PSQI score > 5 had more severe disease (median CMT Examination Score, CMTES, 8 vs 6, p = 0.006) and more frequent use of anxiolytic/antidepressant drugs (29% vs 7%, p < 0.001).

CONCLUSIONS

Bad sleep quality and daytime sleepiness are frequent in CMT and correlated with anxiety, depression and fatigue, confirming that different components affect sleep. Sleep disorders, such as sleep apnea and restless leg syndrome, not specifically investigated here, are other factors known to impact on sleep quality and somnolence. CMT patients' management must include sleep behavior assessment and evaluation of its correlated factors, including general distress and fatigue.

Frequency, entity and determinants of fatigue in Charcot-Marie-Tooth disease

BACKGROUND AND PURPOSE

Fatigue, a disabling symptom in many neuromuscular disorders, has been reported also in Charcot-Marie-Tooth disease (CMT). The presence of fatigue and its correlations in CMT was investigated.

METHODS

The Modified Fatigue Impact Scale (MFIS) was administered to CMT patients from the Italian Registry and a control group. An MFIS score >38 indicated abnormal fatigue. The correlation with disease severity and clinical characteristics, the Hospital Anxiety and Depression Scale and Epworth Sleepiness Scale scores, and drug use was analysed.

RESULTS

Data were collected from 251 CMT patients (136 women) and 57 controls. MFIS total (mean ± standard deviation 32 ± 18.3, median 33), physical (18.9 ± 9.7, 20) and psychosocial (2.9 ± 2.4, 3) scores in CMT patients were significantly higher than controls. Abnormal fatigue occurred in 36% of the patients who, compared to patients with normal scores, had more severe disease (median CMT Examination Score 9 vs. 7), more frequent use of foot orthotics (22% vs. 11%), need of support for walking (21% vs. 8%), hand disability (70% vs. 52%) and positive sensory symptoms (56% vs. 36%). Patients with abnormal fatigue had significantly increased frequency of anxiety/depression/general distress (Hospital Anxiety and Depression Scale), somnolence (Epworth Sleepiness Scale), obesity (body mass index ≥ 30) and use of anxiolytic/antidepressant or anti-inflammatory/analgesic drugs.

CONCLUSIONS

Fatigue is a relevant symptom in CMT as 36% of our series had scores indicating abnormal fatigue. It correlated with disease severity but also with anxiety, depression, sleepiness and obesity, indicating different components in the generation of fatigue. CMT patients' management must include treatment of fatigue and of its different generators, including general distress, sleepiness and obesity.

Role of Sport Activity on Quality of Life in Charcot-Marie-Tooth 1A Patients

The present study aims to investigate the benefits induced by physical activity/practiced sport in Charcot-Marie-Tooth 1A (CMT1A). Patients were divided into sport and no-sport groups according to their sports performance habit. Thirty-one patients were enrolled, of which 14 practiced sports and 17 did not. Clinical assessments were administered to evaluate disability, self-esteem, depression, quality of life, and pain. Statistical analysis revealed significant differences in terms of gender in the no-sport group compared to the sport group (p = 0.04). Regarding the quality of life, physical function (p = 0.001), general health (p = 0.03), social function (p = 0.04), and mental health (p = 0.006) showed better patterns in the sport group than no-sport group. Moreover, neuropathic pain was reduced in the sport group according to the Neuropathic Pain Symptom Inventory (p = 0.001) and ID-PAIN (p = 0.03). The other administered questionnaires showed no significant differences. Our study confirms that CMT1A patients, who practice sports, with a similar severity of disability, may have a better physical quality of life while suffering less neuropathic pain than their peers who do not practice sports. Results recommend the prescription of sport in CMT1A patients.

Physical and Mental Aspects of Quality of Life in Patients With Charcot-Marie-Tooth Disease Type 1A

Introduction

Charcot-Marie-Tooth type 1A (CMT1A) comprises ~50% of all CMT cases. CMT1A is a slowly progressive motor and sensory neuropathy that leads to significant disability. We aimed to investigate the quality of life (QoL) in Serbian patients with CMT1A and to assess sociodemographic and clinical features associated with their QoL.

Material and Methods

Forty-five genetically confirmed patients with CMT1A were included −60% women [age 50.4 ± 12.6 years, disease duration 22 (12.5–31.5) years]. SF-36, Medical Research Council (MRC) Sum Score, CMT Examination Score (CMTES), Overall Neuropathy Limitation Scale (ONLS), Beck Depression Inventory (BDI), and Krupp's Fatigue Severity Scale (FSS) were used in the study.

Results

Regarding SF-36, Mental Health and Social Functioning were the scales with the best achievements, whereas Role Physical was the worst domain. Worse QoL in patients with CMT1A was associated with elder age (rho = −0.34, p < 0.05), longer disease duration (rho = −0.31, p < 0.05), more pronounced muscle weakness measured by MRC-SS (rho = 0.43, p < 0.01), presence of tremor (p < 0.05), worse CMTES (rho = −0.68, p < 0.01), more severe disability in upper (rho = −0.70, p < 0.01) and lower limbs (rho = −0.61, p < 0.01) measured by ONLS scores, use of walking aids (p < 0.01), and with depression (p < 0.01) and fatigue (p < 0.01). Worse scores on CMTES (beta = −0.43, p < 0.01), BDI (beta = −0.39, p < 0.01), and FSS (beta = −0.36, p < 0.01) were significant independent predictors of worse QoL in patients with CMT1A (adjusted R² = 0.77, p < 0.001).

Conclusion

Besides impairment made directly by CMT1A itself, QoL in these patients was also strongly affected by the presence of depression and fatigue. Since CMT1A is still not a curable disease, it is of interest to identify factors associated with QoL that are amenable to treatment.

Quality of life in hereditary neuropathy with liability to pressure palsies is as impaired as in Charcot-Marie-Tooth disease type 1A

To date, only one study assessed quality of life (QoL) in patients with hereditary neuropathy with liability to pressure palsies (HNPP). We aimed to fill in this gap by investigating QoL in a cohort of patients with HNPP compared to Charcot-Marie-Tooth type 1A (CMT1A) patients, as well as to analyze sociodemographic and clinical features associated with QoL in HNPP. Eighteen genetically confirmed HNPP patients were age-and gender-matched with 18 CMT1A patients. SF-36 questionnaire was used to assess QoL. Medical Research Council (MRC) Sum Score, CMT Neuropathy Score (CMTNS), Overall Neuropathy Limitation Scale Score (ONLS), Falls Efficacy Score (FES), Visual Analog Pain Scale, Beck Depression Inventory (BDI) and Fatigue Severity Scale (FSS) were also used in our study. Although HNPP patients were less clinically impaired, no difference was observed in these two cohorts regarding SF-36 scores. Worse QoL in HNPP patients was associated with lower education (p < 0.01), physical work (p < 0.05), higher number of clinically affected nerves during the disease course (p < 0.01), worse MRC-SS score (p < 0.01), worse ONLS score (p < 0.01), and with more severe pain (p < 0.01), depression (p < 0.01), and fatigue (p < 0.01). Worse pain at the moment of testing appeared as a significant independent predictor of worse QoL in HNPP patients (β = - 0.93, p < 0.001). QoL was similarly impaired in patients with HNPP and patients with CMT1A. We identified different factors associated with QoL in HNPP, and many of these factors are amenable to treatment which is of special interest in these still incurable disease.

Challenges in Treating Charcot-Marie-Tooth Disease and Related Neuropathies: Current Management and Future Perspectives

There is still no effective drug treatment available for Charcot-Marie-Tooth neuropathies (CMT). Current management relies on rehabilitation therapy, surgery for skeletal deformities, and symptomatic treatment of pain; fatigue and cramps are frequent complaints that are difficult to treat. The challenge is to find disease-modifying therapies. Several approaches, including gene silencing, to counteract the PMP22 gene overexpression in the most frequent CMT1A type are under investigation. PXT3003 is the compound in the most advanced phase for CMT1A, as a second-phase III trial is ongoing. Gene therapy to substitute defective genes or insert novel ones and compounds acting on pathways important for different CMT types are being developed and tested in animal models. Modulation of the Neuregulin pathway determining myelin thickness is promising for both hypo-demyelinating and hypermyelinating neuropathies; intervention on Unfolded Protein Response seems effective for rescuing misfolded myelin proteins such as P0 in CMT1B. HDAC6 inhibitors improved axonal transport and ameliorated phenotypes in different CMT models. Other potential therapeutic strategies include targeting macrophages, lipid metabolism, and Nav1.8 sodium channel in demyelinating CMT and the P2X7 receptor, which regulates calcium influx into Schwann cells, in CMT1A. Further approaches are aimed at correcting metabolic abnormalities, including the accumulation of sorbitol caused by biallelic mutations in the sorbitol dehydrogenase (SORD) gene and of neurotoxic glycosphingolipids in HSN1.

Health-related Quality of Life and Satisfaction with German Health Care Services in Patients with Charcot-Marie-Tooth Neuropathy

BackgroundCharcot-Marie-Tooth (CMT) neuropathies entail a large group of diseases with different gene mutation patterns, which produce heterogeneous phenotypes. Although health-related quality of life (HRQOL) is significantly impaired, a comprehensive assessment of HRQOL in CMT patients in Germany considering phenotypical heterogeneity represented a research gap.ObjectiveThe aim was to assess HRQOL and the satisfaction with health care in CMT patients in Germany.MethodsCMT patients >  15 years with a genetically confirmed CMT subtype were recruited through a national CMT patient registry. HRQOL was assessed using the EQ-5D-5L questionnaire. Furthermore, subjective impairments in daily or work activities and satisfaction with health care were assessed using 4-point scales.ResultsHRQOL in CMT patients (n = 385) was impaired compared to the German population. Most patients reported problems in the dimension mobility (89.6%), pain/discomfort (89.4%) and usual activities (81.0%). Except for patients with hereditary neuropathy with liability to pressure palsy (HNPP), we found no differences in HRQOL between the CMT subtypes. 72.0%of CMT patients were satisfied with available health care services. However, patients reported to expect more CMT-specific knowledge and support as well as easier prescription and cost coverage procedures from health professionals and insurances.ConclusionsThe patient-reported outcomes in the assessed CMT cohort elucidate the need for more specific health care services that also address the heterogeneous phenotypes. Although the assessment has been limited to the German health services setting, insights may be applicable to CMT-specific care in other national settings.

Performance fatigability during gait in adults with Charcot-Marie-Tooth disease

BACKGROUND

Fatigue is common in people with Charcot-Marie-Tooth (pwCMT) disease. However, no studies have characterized performance fatigability during gait in this population. Characterizing performance fatigability during gait, and assessing its relation to life satisfaction could improve understanding and treatment of mobility challenges in pwCMT.

RESEARCH QUESTIONS

How do gait outcomes change with fatigue in pwCMT? Do these changes relate to life satisfaction?

METHODS

31 pwCMT completed a 6-minute, fast-as-possible walk while gait outcomes were captured via inertial sensors. Gait outcomes were separated into six sequential bins of equal size. The mean value, variability, and asymmetry (step time only) of outcomes were calculated for each bin. Perceived fatigue and general life satisfaction were assessed via questionnaire.

RESULTS

Of the five mean gait outcomes measured, four showed statistically significant changes over the 6-minute fast-as-possible walk: velocity (reduced; p = 0.008); cadence (reduced; p < 0.001), step time (increased; p < 0.001), and trunk ROM (increased; p = 0.032). Of the four variability and one asymmetry outcomes, only stride length variability changed during the walking task (p = 0.015), decreasing from bins 1-2, and remaining stable for bins 2-6. Changes in velocity, cadence, step time were related to general life satisfaction (0.038 < ps<0.04), but not perceived fatigue (ps>0.343).

SIGNIFICANCE

pwCMT exhibit statistically significant changes in mean gait outcomes, but not variability outcomes, across a 6-minute, fast-as-possible walking bout. Changes correlated to life satisfaction, suggesting performance fatigability during gait could be a target for rehabilitation for pwCMT. Perceived fatigue did not correlate to gait fatigue, underscoring the differentiation between perceived fatigue and performance fatigability.

Development and Validation of the Pediatric Charcot-Marie-Tooth Disease Quality of Life Outcome Measure

OBJECTIVE

Charcot-Marie-Tooth disease (CMT) reduces health-related quality of life (QOL), especially in children. Defining QOL in pediatric CMT can help physicians monitor disease burden clinically and in trials. We identified items pertaining to QOL in children with CMT and conducted validation studies to develop a pediatric CMT-specific QOL outcome measure (pCMT-QOL).

METHODS

Development and validation of the pCMT-QOL patient-reported outcome measure were iterative, involving identifying relevant domains, item pool generation, prospective pilot testing and clinical assessments, structured focus-group interviews, and psychometric testing. Testing was conducted in children with CMT seen at participating sites from the USA, United Kingdom, and Australia.

RESULTS

We conducted systematic literature reviews and analysis of generic QOL measures to identify 6 domains relevant to QOL in children with CMT. Sixty items corresponding to those domains were developed de novo, or identified from literature review and CMT-specific modification of items from the pediatric Neuro-QOL measures. The draft version underwent prospective feasibility and face content validity assessments to develop a working version of the pCMT-QOL measure. From 2010 to 2016, the pCMT-QOL working version was administered to 398 children aged 8 to 18 years seen at the participating study sites of the Inherited Neuropathies Consortium. The resulting data underwent rigorous psychometric analysis, including factor analysis, test-retest reliability, internal consistency, convergent validity, item response theory analysis, and longitudinal analysis, to develop the final pCMT-QOL patient-reported outcome measure.

INTERPRETATION

The pCMT-QOL patient-reported outcome measure is a reliable, valid, and sensitive measure of health-related QOL for children with CMT. ANN NEUROL 2021;89:369-379.

Nerve Decompression and Restless Legs Syndrome: A Retrospective Analysis

Introduction

Restless legs syndrome (RLS) is a prevalent sleep disorder affecting quality of life and is often comorbid with other neurological diseases, including peripheral neuropathy. The mechanisms related to RLS symptoms remain unclear, and treatment options are often aimed at symptom relief rather than etiology. RLS may present in distinct phenotypes often described as “primary” vs. “secondary” RLS. Secondary RLS is often associated with peripheral neuropathy. Nerve decompression surgery of the common and superficial fibular nerves is used to treat peripheral neuropathy. Anecdotally, surgeons sometimes report improved RLS symptoms following nerve decompression for peripheral neuropathy. The purpose of this retrospective analysis was to quantify the change in symptoms commonly associated with RLS using visual analog scales (VAS).

Methods

Forty-two patients completed VAS scales (0–10) for pain, burning, numbness, tingling, weakness, balance, tightness, aching, pulling, cramping, twitchy/jumpy, uneasy, creepy/crawly, and throbbing, both before and 15 weeks after surgical decompression.

Results

Subjects reported significant improvement among all VAS categories, except for “pulling” (P = 0.14). The change in VAS following surgery was negatively correlated with the pre-surgery VAS for both the summed VAS (r = −0.58, P < 0.001) and the individual VAS scores (all P < 0.01), such that patients who reported the worst symptoms before surgery exhibited relatively greater reductions in symptoms after surgery.

Conclusion

This is the first study to suggest improvement in RLS symptoms following surgical decompression of the common and superficial fibular nerves. Further investigation is needed to quantify improvement using RLS-specific metrics and sleep quality assessments.

Underestimated associated features in CMT neuropathies: clinical indicators for the causative gene?

INTRODUCTION

Charcot-Marie-Tooth neuropathy (CMT) is a genetically heterogeneous group of peripheral neuropathies. In addition to the classical clinical phenotype, additional features can occur.

METHODS

We studied a wide range of additional features in a cohort of 49 genetically confirmed CMT patients and performed a systematic literature revision.

RESULTS

Patients harbored a PMP22 gene alteration (n = 28) or a mutation in MPZ (n = 11), GJB1 (n = 4), LITAF (n = 2), MFN2 (n = 2), INF2 (n = 1), NEFL (n = 1). We identified four novel mutations (3 MPZ, 1 GJB1). A total of 88% presented at least one additional feature. In MPZ patients, we detected hypertrophic nerve roots in 3/4 cases that underwent spinal MRI, and pupillary abnormalities in 27%. In our cohort, restless legs syndrome (RLS) was present in 18%. We describe for the first time RLS associated with LITAF or MFN2 and predominant upper limb involvement with LITAF. Cold-induced hand cramps occurred in 10% (PMP22,MPZ,MFN2), and autonomous nervous system involvement in 18% (PMP22,MPZ, LITAF,MFN2). RLS and respiratory insufficiency were mostly associated with severe neuropathy, and pupillary abnormalities with mild to moderate neuropathy.

CONCLUSIONS

In CMT patients, additional features occur frequently. Some of them might be helpful in orienting genetic diagnosis. Our data broaden the clinical spectrum and genotype-phenotype associations with CMT.

Management of Charcot-Marie-Tooth disease: improving long-term care with a multidisciplinary approach

Charcot–Marie–Tooth (CMT) disease is the most common inherited neuropathy and one of the most common inherited diseases in humans. The diagnosis of CMT is traditionally made by the neurologic specialist, yet the optimal management of CMT patients includes genetic counselors, physical and occupational therapists, physiatrists, orthotists, mental health providers, and community resources. Rapidly developing genetic discoveries and novel gene discovery techniques continue to add a growing number of genetic subtypes of CMT. The first large clinical natural history and therapeutic trials have added to our knowledge of each CMT subtype and revealed how CMT impacts patient quality of life. In this review, we discuss several important trends in CMT research factors that will require a collaborative multidisciplinary approach. These include the development of large multicenter patient registries, standardized clinical instruments to assess disease progression and disability, and increasing recognition and use of patient-reported outcome measures. These developments will continue to guide strategies in long-term multidisciplinary efforts to maintain quality of life and preserve functionality in CMT patients.

Evaluation of Respiratory Muscle Strength and Pulmonary Function in Patients with Charcot-Marie-Tooth Disease Type 2

The aim of this study was to evaluate the pulmonary condition in a large family with Charcot-Marie-Tooth disease type 2 (CMT2). Eighteen participants diagnosed with CMT2 and 20 healthy individuals were evaluated by spirometry and maximal expiratory and maximal inspiratory pressures (MEP and MIP, respectively). Clinical disability was measured with CMT neuropathy score (CMTNS; range 0-36). One control group (CG) comprising 20 individuals, matched for age, sex and body mass index, were used for comparison. Eight patients were female (44.5%) and 10 patients were male (55.5%); mean age was 31.8 years (range 11-79) and CMTNS range was 6-26. Differences between CMT2 and CG in the spirometry and respiratory muscle strength were statistically significant for all dimensions. There were significant correlations between CMTNS and MIP (Pearson = -0.581) and MEP (Pearson = -0.5090). The results of this study show that patients with CMT, in spite of not showing clinical signs of advanced respiratory impairment, may present subclinical respiratory changes. The respiratory comprise in the CMT disease can be silent and insidious without presenting characteristic clinical signals.

Sleep pattern in Charcot-Marie-Tooth disease type 2: report of family case series

OBJECTIVES

Charcot-Marie-Tooth (CMT) disease is the most prevalent hereditary motor and sensory polyneuropathy, and a condition in which sleep has rarely been studied, particularly in relation to the type 2 (CMT2). Thus, we aimed to characterize the sleep patterns of a family affected by CMT2 disease.

METHODS

Sixteen volunteers with CMT2 from the same multigenerational family agreed to participate in the study (refusal rate = 31%). All participants answered sleep questionnaires and came to the sleep laboratory to perform a diagnostic polysomnography (PSG). Clinical manifestation and severity of the disease were also evaluated.

RESULTS

56% of the sample were male and 44% female, with a mean age of 32 ± 17 years, of normal weight (body mass index 21 ± 3 kg/m(2)); 64% presented moderate to severe CMT2. Regarding subjective sleep, 31% had excessive daytime sleepiness and 75% reported poor sleep quality. The PSG results revealed that CMT2 patients had an increase in stage N3 and a reduction in REM sleep, in addition to a high arousal index. Although 81% of the sample were snorers, only 13% had an apnea-hypopnea index (AHI) > 5. However, a positive correlation was found between the severity of disease and the AHI.

CONCLUSIONS

Taken together, these data show that CMT2 disease is characterized by important changes in sleep architecture, probably due to sleep fragmentation. Although these alterations may worsen with disease severity, it seems that they are not related to sleep breathing or movement disorders.

Exploratory study of physical activity in persons with Charcot-Marie-Tooth disease

OBJECTIVES

To explore and describe the perceived facilitators and barriers to physical activity, and to examine the physical activity correlates in people with Charcot-Marie-Tooth (CMT) disease.

DESIGN

Cross-sectional survey study.

SETTING

Community-living subjects.

PARTICIPANTS

Swedish people with CMT disease (N=44; men, 54.5%; median age, 59.5 y [interquartile range, 45.3-64.8 y]).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The survey included open-ended questions and standardized self-reported scales measuring physical activity, fatigue, activity limitation, self-efficacy for physical activity, fall-related self-efficacy, social support, and enjoyment of physical activity. Physical activity was measured by the Physical Activity Disability Survey-Revised.

RESULTS

Qualitative content analysis revealed that personal factors such as fatigue, poor balance, muscle weakness, and pain were important barriers for physical activity behavior. Facilitators of physical activity were self-efficacy for physical activity, activity-related factors, and assistive devices. Multiple regression analysis showed that self-efficacy for physical activity (β=.41) and fatigue (β=-.30) explained 31.8% of the variation in physical activity (F2,40=10.78, P=.000).

CONCLUSIONS

Despite the well-known benefits of physical activity, physical activity in people with CMT disease is very sparsely studied. These new results contribute to the understanding of factors important for physical activity behavior in people with CMT disease and can guide health professionals to facilitate physical activity behavior in this group of patients.

Rehabilitation in Charcot-Marie-Tooth disease type 1

Charcot-Marie-Tooth disease is the most common inherited peripheral neuropathy with a prevalence of approximately 1 in 2,500 [1]. The most common subtype is the autosomal dominant type 1A, which is caused by an intrachromosomal duplication on chromosome 17p11.2 [2,3]. A consecutive primary loss of the myelin sheath leads to secondary axonal degeneration. Characteristic clinical findings include distally pronounced muscle wasting, secondary skeletal deformities, sensory loss, and reduced deep tendon reflexes [4,5]. The individual clinical phenotypes vary, even among monozygotic twins [6]. They range from sub-clinical manifestations to rare cases of wheelchair-bound patients. Overall, the quality of life is significantly impaired [7]. Despite ongoing research, no curative treatments are currently available [8]. A recently published ascorbic acid trial showed no significant effect on the clinical phenotype of CMT1A patients [9,32,36]. Nevertheless, physical therapy and moderate exercises are proven to be positively disease-modifying. While a cure lies beyond the scope of physical therapy, it may prevent the rapid aggravation of the clinical phenotype [10,11,17]. Recent studies suggest that CMT patients experience physical as well as mental benefits from rehabilitation programmes, but they also perceive that the performed exercises were not specifically designed to their needs [11]. In fact, there is little evidence-based data and no common consensus on rehabilitation in patients suffering from Charcot-Marie-Tooth disease.

Quality-of-life in Charcot-Marie-Tooth disease: the patient's perspective

This study determines the impact of symptoms associated with Charcot-Marie-Tooth disease on quality-of-life. Charcot-Marie-Tooth patients in the Inherited Neuropathies Consortium Rare Diseases Clinical Research Network Contact Registry were surveyed. The survey inquired about 214 symptoms and 20 themes previously identified as important to Charcot-Marie-Tooth patients through patient interviews. Symptom population impact was calculated as the prevalence multiplied by the relative importance of each symptom identified. Prevalence and symptom impact were analyzed by age, symptom duration, gender, Charcot-Marie-Tooth type, and employment status. 407 participants returned the survey, identifying foot and ankle weakness (99.7%) and impaired balance (98.6%) as the most prevalent themes. Foot and ankle weakness and limitations with mobility were the themes with the highest impact. Both symptom prevalence and impact gradually increased with age and symptom duration. Several themes were more prevalent in women with Charcot-Marie-Tooth, including activity limitations, pain, fatigue, hip-thigh weakness, and gastrointestinal issues. All of the themes, except emotional or body image issues, were more prevalent among unemployed individuals. There were minimal differences in symptom prevalence between Charcot-Marie-Tooth types. There are multiple symptoms that impact Charcot-Marie-Tooth quality-of-life in adults. These symptoms have different levels of importance, are readily recognized by patients, and represent critical areas of Charcot-Marie-Tooth health.

Charcot-Marie-Tooth disease, psychiatric indicators and quality of life: a systematic review

This study is aimed to conduct a systematic literature review regarding the associations between psychiatric symptoms, functional impairments, and quality of life in patients with CMT (Charcot–Marie–Tooth). The PUBMED, PsycInfo, SCIELO, and LILACS electronic databases were used, and the following search terms were employed: CMT, HMSN (hereditary motor and sensory neuropathy), mental disorder, quality of life, psychiatry, psychiatric, and psychological without the use of time-limit filters. According to the adopted inclusion criteria, 20 studies were included and appraised. These studies indicated that patients with CMT exhibited an increased trend toward depressive symptoms compared with the general population. In addition, CMT patients were exposed to a higher risk of reduced quality of life and significant sleep impairment. Considering the comorbidity of CMT with other psychiatric disorders, the heterogeneity of the instruments used to evaluate the psychiatric symptoms compromised the ability to compare the studies examined. Our results indicate a need for a systematic evaluation of these conditions to minimize the impairments and decreased quality of life caused by CMT.

Patients with CMT exhibited an increased trend toward depressive symptoms compared with the general population. In addition, CMT patients were exposed to a higher risk of reduced quality of life and significant sleep impairment.

Restless leg syndrome in different types of demyelinating neuropathies: a single-center pilot study

OBJECTIVE

to determine the prevalence of restless legs syndrome (RLS) in a cohort of patients with demyelinating neuropathies.

METHODS

Patients were retrospectively recruited from our cohort of different forms of demyelinating neuropathies, including chronic inflammatory demyelinating neuropathy (CIDP), Charcot-Marie-Tooth 1A (CMT1A), and hereditary neuropathy with liability to pressure palsies (HNPP) referred to our Department of Neurology in a 10-year period. The validated 4-item RLS questionnaire was used for diagnosis of RLS. All patients with RLS who fulfilled criteria underwent a suggested immobilization test to confirm the diagnosis. A group of outpatients referred to the sleep disorders unit and data from published literature were used as controls.

RESULTS

Prevalence of RLS in demyelinating neuropathy group was higher than prevalence observed in control population (p = 0.0142) or in the literature data (p = 0.0007). In particular, in comparison with both control population and literature data, prevalence of RLS was higher in CIDP group (p = 0.0266 and p = 0.0063, respectively) and in CMT1A group (p = 0.0312 and p = 0.0105, respectively), but not in HNPP (p = 1.000 and p = 0.9320, respectively).

CONCLUSIONS

our study confirms a high prevalence of RLS in inflammatory neuropathies as CIDP and, among inherited neuropathies, in CMT1A but not in HNPP. Considering that this is only a small cohort from a single-center retrospective experience, the link between RLS and neuropathy remains uncertain, and larger multicenter studies are probably needed to clarify the real meaning of the association between RLS and neuropathy.

Patient identification of the symptomatic impact of charcot-marie-tooth disease type 1A

OBJECTIVE

The burden of Charcot-Marie-Tooth type 1A (CMT1A), the most common inherited peripheral neuropathy, including impact on patient quality of life (QOL) is not well understood. This study aims to qualitatively describe the range of symptoms associated with CMT1A and impact on QOL.

METHODS

We performed qualitative interviews with 16 adult CMT1A patients. Each interview was analyzed using a qualitative framework technique to identify and index symptoms by theme.

RESULTS

Sixteen patients provided 656 quotes. One hundred forty-five symptoms of importance were identified representing 20 symptomatic themes. Symptoms associated with difficulty with mobility and ambulation, specific activity impairment, and emotional distress were the most frequently mentioned.

CONCLUSIONS

Multiple symptoms contribute to CMT1A disease burden, some previously underrecognized. Improved recognition of underrecognized symptoms will optimize patient care and QOL.

Sleep disorders in Charcot-Marie-Tooth disease type 1

INTRODUCTION

Obstructive sleep apnoea (OSA) and restless legs syndrome (RLS) have been reported in Charcot-Marie-Tooth disease (CMT) type 1A and axonal subtypes of CMT, respectively. The aim of this case-control study was to investigate both prevalence and severity of OSA, RLS and periodic limb movements in sleep (PLMS) in adult patients with genetically proven CMT1.

PATIENTS AND METHODS

61 patients with CMT1 and 61 insomnic control subjects were matched for age, sex, and Body Mass Index. Neurological disability in patients with CMT was assessed using the Functional Disability Scale (FDS). RLS diagnosis was based on a screening questionnaire and structured clinical interviews. All participants underwent overnight polysomnography.

RESULTS

OSA was present in 37.7% of patients with CMT1 and 4.9% of controls (p<0.0001). The mean Apnoea Hypoponea Index (AHI) was significantly higher in patients with CMT1 than in control individuals (9.1/h vs 1.2/h). RLS was present in 40.9% of patients with CMT1 and in 16.4% of controls (p<0.001). In the CMT1 group, OSA was significantly more common in men and RLS in women. The AHI correlated with both age and the FDS score, the latter being a significant independent predictor of OSA. PLMS were found in 41.0% of patients with CMT1, but were not correlated with measures of sleep quality.

CONCLUSIONS

In addition to known risk factors, CMT may predispose to OSA. RLS is highly prevalent not only in axonal subtypes of CMT but also in primarily demyelinating subforms of CMT. PLMS are common in CMT1, but do not significantly impair sleep quality.

Fatigue in patients with epilepsy and its association with depression and sleep quality

OBJECTIVE

It was to evaluate the relationships between fatigue and excessive daytime sleepiness, sleep quality, depression and anxiety.

METHODS

This was a cross-sectional study on 98 unselected adult patients with epilepsy (PWE) at a tertiary center. It used clinical-sociodemographic characteristics, fatigue measured by the SF-36 vitality subscale (VsSF-36) and the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index and Beck Depression and Anxiety Inventories.

RESULTS

We observed that our patients presented vitality or fatigue similar to drivers with chronic headaches evaluated in the same city. Fatigue was related to depression, anxiety and sleep quality, but not to daytime sleepiness. A multiple linear regression analysis was conducted and we observed that fatigue was independently correlated with depression and quality of sleep. However, no significant difference was observed regarding seizure frequency or number of antiepileptic drugs.

CONCLUSION

Fatigue needs to be studied more in PWE, and its risk factors need to be controlled, along with sleep quality and psychiatric disorders.

Charcot-Marie-Tooth disease: an overview of genotypes, phenotypes, and clinical management strategies

Charcot-Marie-Tooth (CMT) disease, which encompasses several hereditary motor and sensory neuropathies, is one of the most common neuromuscular disorders. Our understanding of the molecular genotypes of CMT and the resultant clinical and electrophysiological phenotypes has increased greatly in the past decade. Characterized by electrodiagnostic studies into demyelinating (type 1) and axonal (type 2) forms, subsequent genetic testing often provides an exact diagnosis of a specific subtype of CMT. These advancements have made diagnostic paradigms fairly straightforward. Still, the nature and extent of neuromuscular disability is often complex in persons with CMT, and no curative treatments are yet available. Genotypically homologous animal models of CMT have improved exploration of disease-modifying treatments, of which molecular genetic manipulation and stem cell therapies appear to be the most promising. Research is also needed to develop better rehabilitative strategies that may limit disease burden and improve physical performance and psychosocial integration. Clinical management should be multidisciplinary, including neurologists, physiatrists, neurogeneticists, neuromuscular nurse practitioners, and orthopedists, along with physical and occupational therapists, speech-language pathologists, orthotists, vocational counselors, social workers, and other rehabilitation clinicians. Goals should include maximizing functional independence and quality of life while minimizing disability and secondary morbidity.

Ascorbic acid and sodium-dependent vitamin C transporters in the peripheral nervous system: from basic science to clinical trials

SIGNIFICANCE

Ascorbic acid and sodium-dependent vitamin C transporters (SVCT) have been shown to have important functions in the peripheral nervous system (PNS). Ascorbic acid is known to promote myelination in vitro in Schwann cell/dorsal root ganglion co-cultures by the formation of a collagen- and laminin-containing extracellular matrix.

RECENT ADVANCES

Recently, the function of ascorbic acid and SVCT2 in the PNS has been shown in vivo as well. Several studies on ascorbic acid treatment of Charcot-Marie-Tooth neuropathy 1A (CMT1A) have been completed and showed no clinical benefit.

CRITICAL ISSUES

Possible reasons for the failure of ascorbic acid in CMT1A treatment are discussed in this review. More preclinical trials, ideally using different animal models, should be considered before the initiation of clinical trials in humans. More knowledge about ascorbic acid transport kinetics and inter-individual differences in humans is necessary for future studies.

FUTURE DIRECTIONS

Further research into ascorbic acid transport mechanisms in the PNS is warranted. Especially the effects of transgenic or pharmacologic SVCT2 up-regulation on PNS myelination and remyelination will be an interesting area of research in the future. Furthermore, the potential use of ascorbic acid for peripheral neuropathies other than CMT1A would be a possible future research direction.

Strategies for the treatment of restless legs syndrome

Restless legs syndrome (RLS) is a common neurological disorder of unknown etiology that is managed by therapy directed at relieving its symptoms. Treatment of patients with milder symptoms that occur intermittently may be treated with nonpharmacological therapy but when not successful, drug therapy should be chosen based on the timing of the symptoms and the needs of the patient. Patients with moderate to severe RLS typically require daily medication to control their symptoms. Although the dopamine agonists, ropinirole and pramipexole have been the drugs of choice for patients with moderate to severe RLS, drug emergent problems like augmentation may limit their use for long term therapy. Keeping the dopamine agonist dose as low as possible, using longer acting dopamine agonists such as the rotigotine patch and maintaining a high serum ferritin level may help prevent the development of augmentation. The α2δ anticonvulsants may now also be considered as drugs of choice for moderate to severe RLS patients. Opioids should be considered for RLS patients, especially for those who have failed other therapies since they are very effective for severe cases. When monitored appropriately, they can be very safe and durable for long term therapy. They should also be strongly considered for treating patients with augmentation as they are very effective for relieving the worsening symptoms that occur when decreasing or eliminating dopamine agonists.

Outcome measures and rehabilitation treatment in patients affected by Charcot-Marie-Tooth neuropathy: a pilot study

OBJECTIVE

: We evaluated the sensitivity of various rehabilitation and lung function scales to detect differences between people with Charcot-Marie-Tooth (CMT) disease and healthy controls. We also studied whether these measurements are sensitive to disclose changes in patients with CMT disease after rehabilitative treatment.

DESIGN

: Eight patients with different types of CMT participated in the study. Data were gathered at baseline; at the end of the treadmill training, stretching, respiratory, and proprioceptive exercise (TreSPE) treatment period; and after a washout period of 6 mos. The following instruments were used for data collection: Medical Research Council scale for lower limb strength; Tinetti Balance Scale; Physical Performance Battery; ankle angle, oxygen consumption, and lung function tests; peak treadmill velocity and slope; time to walk 6 m; and CMT Neuropathy Score. The participants underwent TreSPE treatment twice every week for 8 wks.

RESULTS

: All rehabilitative measures were significantly worse in subjects with CMT disease than in healthy controls. Lung function was always normal except for the maximum expiratory pressure and maximum inspiratory pressure. No dropouts or worsening in any of the different outcome measures were observed after TreSPE. The ankle angle and the time to walk 6 m were the only measures that significantly improved after treatment.

CONCLUSIONS

: The rehabilitative outcome measures used in this protocol are useful in detecting clinical impairment in people with CMT disease. Lung function tests were confirmed to be minimally abnormal in patients with CMT disease. The TreSPE treatment, besides being safe and well tolerated, induced some training effects in CMT neuropathy, in the absence of lung function amelioration and effort tolerance. Follow-up showed that CMT patients should be treated at least twice every year because a regression of all outcome measures to the baseline state was found after a 6-mo washout period.

Restless legs syndrome: a comprehensive overview on its epidemiology, risk factors, and treatment

PURPOSES

Restless legs syndrome (RLS) is underdiagnosed and poorly understood by clinicians and the general public alike; accordingly, a broad literature review with information most relevant to general practice is needed to help dispel misconceptions and improve level of care.

METHODS

Specifically, this review comprehensively provides an epidemiological analysis of RLS and examines the risk factors and treatment options for RLS by compiling the findings of past RLS studies. These RLS studies were identified through a retrospective PubMed search. The epidemiological analysis was conducted by calculating a weighted mean average of all the relevant general population RLS prevalence studies, separated into geographical/racial categories.

RESULTS

A comprehensive analysis of RLS epidemiological studies finds the prevalence rate of RLS to be 5-15% in the general population with 2.5% of adults having symptoms severe enough to require medical intervention. Some of the risk factors for RLS include female gender, pregnancy, low iron levels, lower socioeconomic status, poor health, elderly age, comorbidity with Parkinson's disease, positive family history of RLS, and comorbidity with psychiatric disorders. A wide array of treatment options exist for RLS including pharmacological and nonpharmacologic interventions.

CONCLUSIONS

Clinicians' understanding of RLS enigma has recently improved due to the increased intensity of RLS research over the past decade. This review summarizes the current findings in the RLS field as well as providing guidelines for future RLS-related research.

Charcot-Marie-Tooth 1A patients with low level of impairment have a higher energy cost of walking than healthy individuals

The study aimed at quantifying the walking energy cost of a group of Charcot-Marie-Tooth 1A patients (CMT1A), with low severity of walking impairment, in comparison with healthy individuals. Oxygen uptake was measured in 8 patients (age-range 20-48 years; Barthel >90; Tinetti >20) and 8 healthy individuals, matched for age and gender, when walking on a circuit for 5-min at their self-selected speeds ("slow", "comfortable" and "fast"). Both comfortable and fast speeds were lower in patients than in the control group (0.92±0.16 vs 1.16±0.22 and 1.27±0.27 vs 1.61±0.22 m s⁻¹, respectively; P<0.05), whereas walking energy cost per unit of distance was higher in patients than in the control group (P<0.05) at both "comfortable" (2.27±0.35 vs 1.92±0.21 J kg⁻¹m⁻¹) and "fast" speed (3.05±0.35 vs 2.37±0.42 J kg⁻¹m⁻¹). CMT1A patients, therefore, choose to walk slower but with higher metabolic cost compared to healthy individuals, despite no clinically evident walking impairment, which is likely due to altered walking patterns.