Quality of life in patients with Charcot-Marie-Tooth disease

Clinical trials in Charcot-Marie-Tooth disorders: a retrospective and preclinical assessment

Objective

This study aimed to evaluate the progression of clinical and preclinical trials in Charcot-Marie-Tooth (CMT) disorders.

Background

CMT has historically been managed symptomatically and with genetic counseling. The evolution of molecular and pathologic understanding holds a therapeutic promise in gene-targeted therapies.

Methods

ClinicalTrials.gov from December 1999 to June 2022 was data extracted for CMT with preclinical animal gene therapy trials also reviewed by PubMed search.

Results

The number of active trials was 1 in 1999 and 286 in 2022. Academic settings accounted for 91% and pharmaceutical companies 9%. Of the pharmaceutical and academic trials, 38% and 28%, respectively, were controlled, randomized, and double-blinded. Thirty-two countries participated: the United States accounted for 26% (75/286). In total, 86% of the trials were classified as therapeutic: 50% procedural (21% wrist/elbow surgery; 22% shock wave and hydrodissection therapy), 23% investigational drugs, 15% devices, and 11% physical therapy. Sixty-seven therapeutic trials (49%) were designated phases 1-2 and 51% phases 3-4. The remaining 14% represent non-therapeutic trials: diagnostic testing (3%), functional outcomes (4%), natural history (4%), and standard of care (3%). One-hundred and three (36%) resulted in publications. Phase I human pharmaceutical trials are focusing on the safety of small molecule therapies (n = 8) and AAV and non-viral gene therapy (n = 3). Preclinical animal gene therapy studies include 11 different CMT forms including viral, CRISPR-Cas9, and nanoparticle delivery.

Conclusion

Current CMT trials are exploring procedural and molecular therapeutic options with substantial participation of the pharmaceutical industry worldwide. Emerging drug therapies directed at molecular pathogenesis are being advanced in human clinical trials; however, the majority remain within animal investigations.

Treatment of Charcot-Marie-Tooth neuropathies

Charcot-Marie-Tooth (CMT) is a heterogeneous group of inherited neuropathies that affect the peripheral nerves and slowly cause progressive disability. Currently, there is no effective therapy. Patients' management is based on rehabilitation and occupational therapy, fatigue, and pain treatment with regular follow-up according to the severity of the disease. In the last three decades, much progress has been made to identify mutations involved in the different types of CMT, decipher the pathophysiology of the disease, and identify key genes and pathways that could be targeted to propose new therapeutic strategies. Genetic therapy is one of the fields of interest to silence genes such as PMP22 in CMT1A or to express GJB1 in CMT1X. Among the most promising molecules, inhibitors of the NRG-1 axis and modulators of UPR or the HDACs enzyme family could be used in different types of CMT.

Indexes for motor performance assessment in job integration/reintegration of people with neuromuscular disorders: A systematic review

Individuals of working age affected by neuromuscular disorders frequently experience issues with their capacity to get employment, difficulty at work, and premature work interruption. Anyway, individuals with a disability could be able to return to work, thanks to targeted rehabilitation as well as ergonomic and training interventions. Biomechanical and physiological indexes are important for evaluating motor and muscle performance and determining the success of job integration initiatives. Therefore, it is necessary to determinate which indexes from the literature are the most appropriate to evaluate the effectiveness and efficiency of the return-to-work programs. To identify current and future valuable indexes, this study uses a systematic literature review methodology for selecting articles published from 2011 to March 30, 2021 from Scopus, Web of Science, and PubMed and for checking the eligibility and the potential bias risks. The most used indexes for motor performance assessment were identified, categorized, and analyzed. This review revealed a great potential for kinetic, kinematic, surface electromyography, postural, and other biomechanical and physiological indexes to be used for job integration/reintegration. Indeed, wearable miniaturized sensors, kinematic, kinetic, and sEMG-based indexes can be used to control collaborative robots, classify residual motor functions, and assess pre-post-rehabilitation and ergonomic therapies.

Utility of carpal tunnel release and ulnar decompression in CMT1A and HNPP

INTRODUCTION/AIMS

Carpal and cubital tunnel syndrome (CTS, CuTS) are common among patients with hereditary neuropathy with liability to pressure-palsies (HNPP) and Charcot-Marie-Tooth-1A (CMT1A), and may impact quality of life. We aimed to evaluate the utility of nerve decompression surgeries in these patients.

METHODS

Medical records were reviewed for patients with PMP22 mutation confirmed in Mayo Clinic laboratories from January 1999 to December 2020, who had CTS and CuTS and underwent surgical decompression.

RESULTS

CTS occurred in 53.3% of HNPP and 11.5% of CMT1A, while CuTS was present in 43.3% of HNPP and 5.8% of CMT1A patients. CTS decompression occurred in 10-HNPP and 5-CMT1A patients, and CuTS decompression with/without transposition was performed in 5-HNPP and 1-CMT1A patients. In HNPP, electrodiagnostic studies identified median neuropathy at the wrist in 9/10 patients and ultrasound showed focal enlargements at carpal and cubital tunnels. In CMT1A, median and ulnar sensory responses were all absent, and the nerves were diffusely enlarged. After CTS surgery, pain, sensory loss, and strength improved in 4/5 CMT1A, and 6/10 HNPP patients. Of clinical, electrophysiologic and ultrasound findings, only activity-provoked features significantly correlated with CTS surgical benefit in HNPP patients (odds ratio=117.0:95% CI 1.94>999.99, p=0.01). One CMT1A and one HNPP patient improved with CuTS surgery while 2 HNPP patients worsened.

DISCUSSION

CTS symptom improvement post-surgery can be seen in CMT1A and (less frequent) in HNPP patients. CuTS surgery commonly worsened course in HNPP. Activity-provoked symptoms in HNPP best informed benefits from CTS surgery.

Employment status of patients with Charcot-Marie-Tooth type 1A

Previous studies showed that being unemployed is associated with lower quality of life in patients with Charcot-Marie-Tooth type 1A (CMT1A). The aim of this study was to assess the differences between CMT1A patients capable of working and CMT1A patients incapable of working due to CMT1A. Forty-four patients with genetically confirmed CMT1A were included. Medical Research Council (MRC) Sum Score, Charcot-Marie-Tooth Neuropathy Score (CMTNS), CMT Examination Score (CMTES), Overall Neuropathy Limitations Scale (ONLS), Beck Depression Inventory (BDI), Krupp's Fatigue Severity Scale (FSS), and Falls Efficacy Score (FES) were used. Whole cohort was divided into two groups: 1. CMT1A patients capable of working (employed and unemployed not due to CMT) and 2. CMT1A patients incapable of working due to CMT1A (unemployed due to CMT and retired due to CMT). At time of testing, 38.6% patients were employed, 13.6% were unemployed due to CMT, 6.8% were unemployed but not due to CMT, and 40.9% were retired early due to disability caused by CMT. Patients retired due to CMT1A at the age of 43 ± 10 years. ONLS total score and physical work appeared as significant independent predictors of being incapable of working due to CMT1A. Patients incapable of working were almost four times more likely to have fatigue (OR = 3.7, 95% CI 1.0-13.1, p < 0.05) and 11 times more likely to have fear of falling (OR = 11.0, 95% CI 2.0-59.7, p < 0.01). Patients with more severe functional disability and physical type of job were most likely incapable of working due to CMT1A. Incapability of working was associated with fatigue and fear of falling.

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.

Physical Activity Assessment in the Charcot Population

Charcot neuroarthropathy is a degenerative disorder that significantly impairs a patient's functional capacity. It has been reported that a Charcot patient's quality of life is significantly impacted by the disease state. The aim of this study is to compare measured energy expenditure to a patient's perceived quality of life and physical ability. The study enrolled 43 patients by set inclusion and exclusion criteria. Patients' total energy expenditure was measured with doubly labeled water. The patients also completed 2 quality of life assessments: 36-Item Short Form Survey (SF-36) and International Physical Activity Questionnaire-Long Form (IPAQ-LF). The measured energy expenditure was then compared to the patient's perceived functional capacity. Scores reaching statistical significance included general health (60 ± 21; p = .011), pain (62 ± 27; p = .025), emotional (61 ± 40; p < .017), physical limitation (45 ± 39; p < .0001), and physical function (50 ± 29; p < .001). SF-36 survey variables that did not reach statistical significance included mental (73 ± 26; p = .690), energy (55 ± 21; p = .205), and social (74 ± 26; p = .105). The IPAQ-LF and physical activity level (PAL) were compared. No identified variation was noted between the 2 test methods (p = .57). The patients' PAL was measured at 1.4 ± 0.42, which is comparable to the general population. Data from this study identify the Charcot population as comparable to the general population. The inferences taken from this study indicate that this population suffers from poor health outlooks compared with the general population but may be overestimating the level of perceived disability.

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.

Management of flexible cavovarus foot in patients with Charcot-Marie-Tooth disease: midterm results

INTRODUCTION

Charcot-Marie-Tooth disease (CMT) is a hereditary motor sensory neuropathy that frequently results in a cavovarus foot in the adult. Surgical treatment allows correction of the deformity while preserving an adequate range of motion.

OBJECTIVE

The objective of this study was to assess the result of posterior tibial tendon transfer, first metatarsal ascent osteotomy, and calcaneal valgus osteotomy in the treatment of cavovarus foot secondary to CMT.

MATERIAL AND METHODS

Retrospective cohort of CMT patients who received surgical treatment of their cavovarus foot. Collected data included demographics, CMT genetic variant, neurologic involvement, surgical technique, range of motion, functionality, radiology, and postoperative satisfaction.

RESULTS

16 patients met the inclusion criteria, mostly women (62.5%) with the CMT1A variant (62.5%), and a mean age of 39.5 years. 13 patients required additional surgical techniques: lengthening of the Achilles tendon, interphalangeal arthrodesis and/or plantar fascia section. 2 patients underwent a secondary procedure: subtalar arthrodesis due to persistence of the varus deformity, and a lengthening of the extensor hallux longus due to initial undercorrection. The mean follow-up was 42 months. Significant differences (p = 0.003) were observed between the pre-surgical AOFAS and at 12 months postoperatively (37.25 vs. 86.5). 75% of the patients reported «excellent» or «good» satisfaction after surgery. All radiographic parameters showed significant improvement.

CONCLUSIONS

The combination of the aforementioned surgical techniques for the cavovarus foot in CMT results in adequate functionality, good radiological correction and a high degree of satisfaction, avoiding primary arthrodescent surgery.

Critical Issues and Imminent Challenges in the Use of sEMG in Return-To-Work Rehabilitation of Patients Affected by Neurological Disorders in the Epoch of Human–Robot Collaborative Technologies

Patients affected by neurological pathologies with motor disorders when they are of working age have to cope with problems related to employability, difficulties in working, and premature work interruption. It has been demonstrated that suitable job accommodation plans play a beneficial role in the overall quality of life of pathological subjects. A well-designed return-to-work program should consider several recent innovations in the clinical and ergonomic fields. One of the instrument-based methods used to monitor the effectiveness of ergonomic interventions is surface electromyography (sEMG), a multi-channel, non-invasive, wireless, wearable tool, which allows in-depth analysis of motor coordination mechanisms. Although the scientific literature in this field is extensive, its use remains significantly underexploited and the state-of-the-art technology lags expectations. This is mainly attributable to technical and methodological (electrode-skin impedance, noise, electrode location, size, configuration and distance, presence of crosstalk signals, comfort issues, selection of appropriate sensor setup, sEMG amplitude normalization, definition of correct sEMG-related outcomes and normative data) and cultural limitations. The technical and methodological problems are being resolved or minimized also thanks to the possibility of using reference books and tutorials. Cultural limitations are identified in the traditional use of qualitative approaches at the expense of quantitative measurement-based monitoring methods to design and assess ergonomic interventions and train operators. To bridge the gap between the return-to-work rehabilitation and other disciplines, several teaching courses, accompanied by further electrodes and instrumentations development, should be designed at all Bachelor, Master and PhD of Science levels to enhance the best skills available among physiotherapists, occupational health and safety technicians and ergonomists.

Validation of a new hand function outcome measure in individuals with Charcot-Marie-Tooth disease

The symptomatology of Charcot-Marie-Tooth (CMT) disease mainly involves the feet and the hands. To date, there is no consensus on how to evaluate hand function in CMT. The aim of this study is to correlate the data of the engineered glove Hand Test System (HTS) with specific tests and the CMT examination score (CMTES). We analyzed 45 patients with the diagnosis of CMT using HTS, which measures the hand dexterity by specific sequences performed at maximum velocity. We completed the evaluation with the CMTES, tripod pinch and hand grip strength tested by a dynamometer, thumb opposition test (TOT), and Sollerman Hand function test (SHFT), and we conducted a test-retest with 20 normal subjects. Finger tapping (FT) and index-medium-ring-little (IMRL) sequence showed a significant correlation with CMTES (FT: dominant hand (DH): P = .036; non-dominant hand (NDH): P = .033; IMRL: DH: P = .009; NDH: P = .046). TOT correlated with CMTES significantly in both hands (P < .0001). tripod pinch showed a statistically significant correlation with CMTES (DH: P = .002; NDH: P = .005). Correlation between the hand grip and CMTES was significant only in DH (DH: P = .002). SHFT had a significant correlation with the CMTES (DH: P = .002). Test-retest showed a good reliability. HTS parameters correlate with CMTES confirming that this tool is sensitive to the hand deficits. In conclusion, we can state that HTS is a good, simple to use, and objective instrument to evaluate the hand function of CMT patients, but more studies on responsiveness and sensitivity are needed.

High glucose level as a modifier factor in CMT1A patients

Charcot-Marie-Tooth disease type 1A (CMT1A) is the most common type of hereditary neuropathy worldwide and diabetes mellitus (DM) is the most frequent cause of peripheral neuropathy in the Western world. CMT1A typically manifest as a predominant motor neuropathy, while, DM-related neuropathy often manifests as a predominant sensory disorder. There are some evidences that CMT1A patients that also had DM had a more severe neuropathy. Although the real frequency and the underlying mechanisms related to this association has not yet been addressed in the literature. We sought to characterize the phenotypic variability of CMT1A patients with persistent high glucose levels (DM or impaired glucose tolerance [IGT]). Nineteen patients with CMT1A and DM (CMTdiab), seven with CMT1A and IGT (CMTintol) and 27 with CMT1A without comorbidities were analyzed. They were evaluated through clinical assessment, application of the following scales: visual analogue scale, McGill, CMTNS, SF-36 and COMPASS 31 and electrophysiological studies. Patients CMTdiab had a more severe motor and sensory neuropathy, more intense autonomic symptoms and worse quality of life. Surprisingly, proximal weakness and temporal dispersion on nerve conduction studies are frequently observed in this group. Patients CMTintol also had a more severe neuropathy. Curiously, we observed that the association of CMT1A and glucose metabolism disorders (CMTglic) clustered in some families. Patients CMTglic develop a more severe neuropathy. As there is yet no cure to CMT1A, a strict blood sugar control may be a useful measure.

Charcot-Marie-Tooth Disease and Other Genetic Polyneuropathies

PURPOSE OF REVIEW

Genetic polyneuropathies are rare and clinically heterogeneous. This article provides an overview of the clinical features, neurologic and electrodiagnostic findings, and management strategies for Charcot-Marie-Tooth disease and other genetic polyneuropathies as well as an algorithm for genetic testing.

RECENT FINDINGS

In the past 10 years, many of the mutations causing genetic polyneuropathies have been identified. International collaborations have led to the development of consortiums that are undertaking careful genotype-phenotype correlations to facilitate the development of targeted therapies and validation of outcome measures for future clinical trials. Clinical trials are currently under way for some genetic polyneuropathies.

SUMMARY

Readers are provided a framework to recognize common presentations of various genetic polyneuropathies and a rationale for current diagnostic testing and management strategies in genetic polyneuropathies.

Hand Rehabilitation Treatment for Charcot-Marie-Tooth Disease: An Open Label Pilot Study

Objective

Charcot-Marie-Tooth neuropathy affects mainly and early the lower limbs, but hands deformities are a relevant problem, which involves the quality of life of the patients. Unfortunately, there are few studies about the evaluation of the upper limbs and very rare works about the rehabilitation. A treatment study at the moment is missing and it is important to search rehabilitation exercises to improve the dexterity and the quality of life of the patients.

Methods

We recruited 9 patients with clinical and genetic diagnosis of CMT and we proposed a rehabilitation protocol which includes muscle recruitment, stretching and proprioceptive exercises for the hand with the duration of 4 weeks (two sessions for week). We evaluated the patients before and one week after the treatment with Thumb Opposition Test, Sollerman Hand Function Scale, dynamometry (tripod pinch and hand grip).

Results

The rehabilitation protocol has been well tolerated and there were not dropouts. We did not observe any worsening in every scale we used. Every parameter tested showed an improvement especially in the right/dominant hand.

Conclusion

This study demonstrates that this three phases treatment is well tolerated by patients, it is not detrimental for the hands status and perfectly reproducible by professionals. Moreover, this could be the basis for future randomized single blind projects.

Outcome measures in the clinical evaluation of ambulatory Charcot-Marie-Tooth 1A subjects

BACKGROUND

The outcome measures (OMs) in clinical trials for Charcot-Marie-Tooth disease (CMT) still represent an issue. A recent study highlighted that three additional clinical OMs, the 10-Meter Walk Test (10MWT), the 9-Hole Peg Test, and foot dorsal flexion dynamometry, further improve discrimination between severely and mildly affected patients. Another study has recently assessed the validity and reliability of the 6-Minute Walk Test (6MWT).

AIM

The aim of this study was to identify the most useful scales in the clinical evaluation of CMT1A patients.

DESIGN

Observational study of the baseline data collected in a multicenter, prospective, randomized, single blind, controlled study to evaluate the efficacy and safety of an innovative rehabilitation protocol based on treadmill training, stretching, respiratory, and proprioceptive exercises (TreSPE study) in CMT1A patients.

SETTING

The outpatient service of the four Italian centers involved, which are specialized in hereditary neuropathies.

POPULATION

Fifty-three subjects with a clinical and genetically confirmed diagnosis of CMT1A.

METHODS

At baseline, in addition to the CMT Neuropathy Score, all subjects underwent walking evaluation (6MWT, 10MWT), balance assessment (Berg Balance Scale [BBS], Short Physical Performance Battery [SPPB]) and a subjective evaluation of quality of life (SF36) and walking ability (Walk12).

RESULTS

Analyzing the baseline data, as expected, we found a strong correlation between walk and balance evaluation, proving the validity of these tests in investigating the functional impairment of CMT1A subjects. Particularly, we found that subjects with better balance control walk at higher speed and perceive less limitations in their physical activities or motor skills. This can be reconducted to the fact that ankle stability depends upon different factors such as anatomy integrity, muscle strength and proprioception.

CONCLUSIONS

We identify the 6MWT, 10MWT, and SPPB as the most useful scales, in addition to the CMTNS, to evaluate the functional impairment of CMT1A patients who retain their walking capability and we suggest the use of SPPB because of its rapidity to assess balance and gait disorders in clinical settings.

CLINICAL REHABILITATION IMPACT

In the clinical practice it is important to evaluate patients comprehensively but rapidly. These outcome measures can help us to correctly assess balance and walking ability in CMT1A patients.

Locomotor and skeletal muscle abnormalities in trembler J neuropathic mice

INTRODUCTION

Patients with hereditary peripheral neuropathies exhibit characteristic deformities of the hands and feet and have difficulty ambulating. To examine to what extent neuropathic animals recapitulate these deficits, we studied trembler J (TrJ) mice, which model early-onset demyelinating neuropathy.

METHODS

A cohort of 4-month-old female wild type and neuropathic mice were evaluated for locomotor measurements, neuromuscular function, and skeletal muscle proteolysis and morphometry.

RESULTS

Utilizing the DigiGait imaging system, we identified pronounced alterations in forepaw and hindpaw angles and a decrease in hindpaw area on the treadmill in neuropathic rodents. Torque production by the tibialis anterior (TA) muscle was significantly weakened and was paralleled by a decrease in myofiber cross-sectional area and an increase in muscle tissue proteolysis.

DISCUSSION

Our findings in TrJ mice reflect the phenotypic presentation of the human neuropathy in which patients exhibit weakness of the TA muscle resulting in foot drop and locomotor abnormalities. Muscle Nerve 57: 664-671, 2018.

Effects of Self-Selected Exercise on Strength in Charcot-Marie-Tooth Disease Subtypes

BACKGROUND

Preliminary studies have supported the utility of exercise as a treatment for Charcot-Marie-Tooth disease (CMT) patients. Despite being the most common inherited neuropathy, there remains a paucity of guidelines for CMT management.

METHODS

A retrospective chart review was performed on 297 CMT patients. Self-reported exercise and strength results from standardized dynamometer testing were obtained from adult patients' first visits. Values were converted and analyzed based on previously reported age- and sex-matched normative values.

RESULTS

Participants with CMT2 had greater strength values than those with CMT1 in hand grip, elbow flexion, and dorsiflexion (p<0.05). Participants with CMT1 and CMT2 who exercised were statistically significantly stronger in elbow flexion and dorsiflexion than those who did not exercise.

CONCLUSIONS

These preliminary results suggest that self-directed exercise is associated with greater strength in CMT patients of both CMT1 and CMT2 subtypes. Self-directed exercise may be a convenient, sustainable, and effective method of improving strength and decreasing disability in this population. Future research should explore the type of exercise prescription that best addresses the needs of the CMT population.

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.

The influence of somatosensory and muscular deficits on postural stabilization: Insights from an instrumented analysis of subjects affected by different types of Charcot-Marie-Tooth disease

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We studied the role of sensory and muscular deficits in balance impairments in CMT.

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Large sensory fibers and dorsi-flexor muscles affect the dynamic phase of stabilization.

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Small sensory fibers and plantar-flexor muscles influence the static phase of balance.

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Residual sensory and muscle functions must be evaluated for a proper rehabilitation.

Charcot–Marie–Tooth (CMT) disease is the most common hereditary neuromuscular disorder. CMT1 is primarily demyelinating, CMT2 is primarily axonal, and CMTX1 is characterized by both axonal and demyelinating abnormalities. We investigated the role of somatosensory and muscular deficits on quiet standing and postural stabilization in patients affected by different forms of CMT, comparing their performances with those of healthy subjects. Seventy-six CMT subjects (CMT1A, CMT2 and CMTX1) and 41 healthy controls were evaluated during a sit-to-stand transition and the subsequent quiet upright posture by means of a dynamometric platform. All CMT patients showed altered balance and postural stabilization compared to controls. Multivariate analysis showed that in CMT patients worsening of postural stabilization was related to vibration sense deficit and to dorsi-flexor's weakness, while quiet standing instability was related to the reduction of pinprick sensibility and to plantar-flexor's weakness. Our results show that specific sensory and muscular deficits play different roles in balance impairment of CMT patients, both during postural stabilization and in static posture. An accurate evaluation of residual sensory and muscular functions is therefore necessary to plan for the appropriate balance rehabilitation treatment for each patient, besides the CMT type.

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.

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.

Tibialis posterior tendon transfer corrects the foot drop component of cavovarus foot deformity in Charcot-Marie-Tooth disease

BACKGROUND

The foot drop component of cavovarus foot deformity in patients with Charcot-Marie-Tooth disease is commonly treated by tendon transfer to provide substitute foot dorsiflexion or by tenodesis to prevent the foot from dropping. Our goals were to use three-dimensional foot analysis to evaluate the outcome of tibialis posterior tendon transfer to the dorsum of the foot and to investigate whether the transfer works as an active substitution or as a tenodesis.

METHODS

We prospectively studied fourteen patients with Charcot-Marie-Tooth disease and cavovarus foot deformity in whom twenty-three feet were treated with tibialis posterior tendon transfer to correct the foot drop component as part of a foot deformity correction procedure. Five patients underwent unilateral treatment and nine underwent bilateral treatment; only one foot was analyzed in each of the latter patients. Standardized clinical examinations and three-dimensional gait analysis with a special foot model (Heidelberg Foot Measurement Method) were performed before and at a mean of 28.8 months after surgery.

RESULTS

The three-dimensional gait analysis revealed significant increases in tibiotalar and foot-tibia dorsiflexion during the swing phase after surgery. These increases were accompanied by a significant reduction in maximum plantar flexion at the stance-swing transition but without a reduction in active range of motion. Passive ankle dorsiflexion measured in knee flexion and extension increased significantly without any relevant decrease in passive plantar flexion. The AOFAS (American Orthopaedic Foot & Ankle Society) score improved significantly.

CONCLUSIONS

Tibialis posterior tendon transfer was effective at correcting the foot drop component of cavovarus foot deformity in patients with Charcot-Marie-Tooth disease, with the transfer apparently working as an active substitution. Although passive plantar flexion was not limited after surgery, active plantar flexion at push-off was significantly reduced and it is unknown whether this reduction was the result of a tenodesis effect or calf muscle weakness.

Clinical spectrum and gender differences in a large cohort of Charcot-Marie-Tooth type 1A patients

INTRODUCTION

Heterogeneous clinical presentation and gender differences were reported in Charcot-Marie-Tooth disease type 1A (CMT1A).

METHODS

This report examined demographic and clinical data collected during a randomised controlled trial, to describe the clinical spectrum of a large and well-defined cohort of CMT1A patients.

RESULTS

Among the 189 symptomatic patients screened, three patients (1.6%) reported first symptoms in the upper limbs, which may be misleading when establishing the clinical diagnosis. The quality of life (QoL) of patients was significantly deteriorated compared to the standard population, and slightly better compared to multiple sclerosis patients. According to the literature, patients reported several disorders which may be associated with CMT1A, including auditory dysfunction (7.9%), Carpal Tunnel Syndrome (CTS) (7.9%) or sleep apnoea (4.2%). Compared to available data, we reported more patients with CTS and fewer patients with sleep apnoea. Women were more affected by CTS than men (11% and 2.8%, respectively). Women also reported an earlier onset of symptoms than men (8.6±9.5 years and 13.1±14 years, respectively), higher deterioration of their QoL and higher disability of their upper limb, assessed by Overall Neuropathy Limitation Scale (p=0.023).

CONCLUSIONS

This information will be useful for better understanding of this disease and for designing future clinical studies.

The utilization of occupational therapy services for persons with Charcot-Marie-Tooth disease

The purpose of this study was to investigate the utilization of occupational therapy services in persons with Charcot-Marie-Tooth (CMT) disease, to better understand if services are being provided, the types of interventions being provided, and satisfaction of services. Using survey methods, an online questionnaire was made available to persons with CMT listed on association websites worldwide. One hundred and fifteen persons with CMT, residing in all geographical regions within the United States and seven other countries participated in the study. Around half of all participants had received occupational therapy services. Twelve interventions were identified as being provided for persons with CMT. Although the majority of individuals receiving occupational therapy services did not feel like it improved their quality of life, the majority of individuals would recommend occupational therapy services to others and would return to an occupational therapist. Of those participants not receiving occupational therapy, the majority felt they would benefit from occupational therapy services. The results suggest that occupational therapy services are not being well utilized for this population. A low response rate limits generalization, thus further research is necessary.

Quality of life and measures of quality of life in patients with neuromuscular disorders

In this review we present an overview of quality of life (QOL) and QOL measures in neuromuscular disorders. We discuss the characteristics of QOL measures used in neuromuscular research, highlighting differences between generic versus disease-specific and global versus health-related QOL instruments. The phenomenon of response shift is reviewed. Commonly used QOL instruments are reviewed for amyotrophic lateral sclerosis, muscle diseases, myasthenia gravis, and polyneuropathy. We also review some of what is known about QOL for patients with these neuromuscular disorders.

Quality of life in rare genetic conditions: a systematic review of the literature

Quality of life (QoL) refers to an individual's sense of overall well-being encompassing physical, psychological, emotional, social, and spiritual dimensions. Although genetics healthcare providers strive to promote patient well-being, and the term QoL is often invoked to refer to this outcome, there is lack of clarity as to what actually constitutes QoL from the patient's perspective. This systematic literature review aims to summarize and integrate research findings to help elucidate how healthcare providers can more effectively enhance the QoL of patients affected with rare genetic conditions. Eligible studies were those that measured QoL as a primary outcome variable using a validated, multi-dimensional scale. Detailed criteria were used to rate quality of design, methodology, and analytic rigor. Fifty-eight studies were selected for inclusion in the review, and a narrative synthesis of the data was performed. A central theme emerging from the literature is that, although genetic conditions have the potential to have significant negative consequences for individuals' lives, having a genetic condition does not necessarily entail poor QoL. Evidence demonstrates that factors beyond the physical manifestations of the disease, such as psychological well-being, coping, and illness perceptions, influence QoL and may serve as potent targets for intervention. The field of research on QoL in rare genetic conditions will be advanced by uniting around a clear conceptualization of QoL and using more rigorous methodology with comprehensive measures of global QoL.

Health-related quality of life in patients with cryptogenic polyneuropathy compared with the general population

PURPOSE

To evaluate the quality of life (QOL) in patients with cryptogenic polyneuropathy.

METHOD

Two validated instruments (SF-36 and EQ-5D) were sent to 86 patients with a 72% response rate (44 men, 18 women). As reference, 2721 individuals (1292 men, 1429 women; 59% response rate) from the general population responded to the same QOL instruments.

RESULTS

Compared to the general population, QOL was significantly more affected in patients with polyneuropathy concerning motor functions, with 42% of the patients reporting problems with walking, 7% having difficulties with washing and dressing, and 31% having problems with usual activities (work, study, household work, and family or leisure activities). The EQ-5D results showed that 85% of the patients were suffering from pain compared to 56% of the general population. Mental health was preserved among patients with polyneuropathy. Mobility was declining with increasing age in patients, but was not affected by disease duration.

CONCLUSIONS

Our study showed that patients with cryptogenic polyneuropathy have a lower QOL compared to the general population, although mental health scores did not differ between the groups. This information may be helpful when explaining the disease and its impact on newly diagnosed patients.

Quality of life in children with Charcot-Marie-Tooth disease

The authors studied the health-related quality of life of children aged 5 to 18 years with Charcot-Marie-Tooth disease of varying types and severity and compared it with the general pediatric population. To capture and compare the quality-of-life data across a broad range of ages, the Child Health Questionnaire was completed by parents of 127 children with Charcot-Marie-Tooth disease. Affected children exhibited lower physical, psychological, and social well-being than the general pediatric population, with subsequent worsening of many domains with age. The type of Charcot-Marie-Tooth disease influenced some physical and behavioral quality-of-life domains, while gender, body size, and ethnicity did not. Parent characteristics had generally little impact on the reporting of their child's quality of life, although parents with Charcot-Marie-Tooth disease reported higher bodily pain in their children than those without. Overall, quality of life is negatively affected by the presence and severity of Charcot-Marie-Tooth disease in childhood.

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

To investigate the prevalence of fatigue, daytime sleepiness, reduced sleep quality, and restless legs syndrome (RLS) in a large cohort of patients with Charcot-Marie-Tooth disease (CMT) and their impact on health-related quality of life (HRQoL). Participants of a web-based survey answered the Epworth Sleepiness Scale, the Pittsburgh Sleep Quality Index, the Multidimensional Fatigue Inventory, and, if the diagnostic criteria of RLS were met, the International RLS Severity Scale. Diagnosis of RLS was affirmed in screen-positive patients by means of a standardized telephone interview. HRQoL was assessed by using the SF-36 questionnaire. Age- and sex-matched control subjects were recruited from waiting relatives of surgical outpatients. 227 adult self-reported CMT patients answered the above questionnaires, 42.9% were male, and 57.1% were female. Age ranged from 18 to 78 years. Compared to controls (n = 234), CMT patients reported significantly higher fatigue, a higher extent and prevalence of daytime sleepiness and worse sleep quality. Prevalence of RLS was 18.1% in CMT patients and 5.6% in controls (p = 0.001). RLS severity was correlated with worse sleep quality and reduced HRQoL. Women with CMT were affected more often and more severely by RLS than male patients. With regard to fatigue, sleep quality, daytime sleepiness, RLS prevalence, RLS severity, and HRQoL, we did not find significant differences between genetically distinct subtypes of CMT. HRQoL is reduced in CMT patients which may be due to fatigue, sleep-related symptoms, and RLS in particular. Since causative treatment for CMT is not available, sleep-related symptoms should be recognized and treated in order to improve quality of life.

Hip flexor fatigue limits walking in Charcot-Marie-Tooth disease

Charcot-Marie-Tooth (CMT) disease results in distal lower limb weakness that affects walking. In this study we assess the role of the hip flexors in compensating for distal weakness while walking and the effects of prolonged walking on these putative compensatory strategies. Eighteen subjects with CMT disease were compared with 14 matched controls while they walked on a treadmill to a predetermined point of perceived effort. A significant reduction was observed in peak hip flexor velocity during walking and hip flexor maximal voluntary contraction. In a second session following selective fatigue of the hip flexors, hip flexor velocity decreased immediately on walking, and walking duration was greatly reduced. This study suggests that hip flexors compensate for distal weakness and that fatigue in the hip flexors can limit walking duration. Treatments directed toward improving proximal muscle strength may therefore help to delay onset of hip flexor fatigue and thus prolong walking duration.

Long-term results of reconstruction for treatment of a flexible cavovarus foot in Charcot-Marie-Tooth disease

BACKGROUND

Cavovarus foot deformity is common in patients with Charcot-Marie-Tooth disease. Multiple surgical reconstructive procedures have been described, but few authors have reported long-term results. The purpose of this study was to evaluate the long-term results of an algorithmic approach to reconstruction for the treatment of a cavovarus foot in these patients.

METHODS

We evaluated twenty-five consecutive patients with Charcot-Marie-Tooth disease and cavovarus foot deformity (forty-one feet) who had undergone, between 1970 and 1994, a reconstruction consisting of dorsiflexion osteotomy of the first metatarsal, transfer of the peroneus longus to the peroneus brevis, plantar fascia release, transfer of the extensor hallucis longus to the neck of the first metatarsal, and in selected cases transfer of the tibialis anterior tendon to the lateral cuneiform. Each patient completed standardized outcome questionnaires (the Short Form-36 [SF-36] and Foot Function Index [FFI]). Radiographs were evaluated to assess alignment and degenerative arthritis, and gait analysis was performed. The mean age at the time of follow-up was 41.5 years, and the mean duration of follow-up was 26.1 years.

RESULTS

Correction of the cavus deformity was well maintained, although most patients had some recurrence of hindfoot varus as seen on radiographic examination. The patients had a lower mean SF-36 physical component score than age-matched norms, and the women had a lower mean SF-36 physical component score than the men, although this difference was not significant. Smokers had lower mean SF-36 scores and significantly higher mean FFI pain, disability, and activity limitation subscores (p < 0.0001). Seven patients (eight feet) underwent a total of eleven subsequent foot or ankle operations, but no patient required a triple arthrodesis. Moderate-to-severe osteoarthritis was observed in eleven feet. With the numbers studied, the age at surgery, age at the time of follow-up, and body mass index were not noted to have a significant correlation with the SF-36 or FFI scores.

CONCLUSIONS

Use of the described soft-tissue procedures and first metatarsal osteotomy to correct cavovarus foot deformity results in lower rates of degenerative changes and reoperations as compared with those reported at the time of long-term follow-up of patients treated with triple arthrodesis.

Pressure characteristics in painful pes cavus feet resulting from Charcot-Marie-Tooth disease

Charcot-Marie-Tooth (CMT) disease often presents with peripheral muscle imbalance associated with a painful cavus (medial high-arched) foot deformity which becomes increasingly severe and rigid as the disease progresses. The purpose of this study was to investigate the effect of pes cavus on foot pain and dynamic plantar pressure in CMT, and to explore the relationships between plantar pressure and pain. Sixteen participants diagnosed with CMT and painful pes cavus were assessed for foot posture, ankle dorsiflexion range of motion, levels of foot pain, functional impairment, health-related quality of life and plantar pressure distribution while walking. Plantar pressure parameters (mean pressure, peak pressure, pressure-time integral) and contact duration were measured using the Novel Pedar in-shoe capacitance transducer system and the foot was divided into rearfoot, midfoot and forefoot regions for analysis. Increasing cavus foot deformity was associated with more widespread foot pain and increased pressure under the forefoot and midfoot regions. In contrast, peak pressure decreased under the rearfoot. Neither relationship was found between foot pain intensity and any of the pressure variables, nor was ankle dorsiflexion range of motion correlated with pain location, intensity or degree of pes cavus. Although pes cavus in CMT is associated with substantial pain and dysfunction, there is no clear link between foot pain and plantar pressure. The more severe the degree of pes cavus, however, the more pressure develops under the lateral margin of the foot; probably as a result of the changed foot-ground contact seen during gait.

Benefits of interval-training on fatigue and functional capacities in Charcot-Marie-Tooth disease

Exercise intolerance and undue fatigue are common complaints in patients with Charcot-Marie-Tooth (CMT) disease. Reduced physical ability is due directly to the disease, but it is also due to physical deconditioning. The aim of this study was to test whether 24 weeks of interval-training exercise (ITE) cycling can significantly improve physiological, neuromuscular, and functional capacities and alleviate fatigue in CMT patients. Eight CMT patients (4 CMT1A and 4 CMT2) participated in ITE for 3 nonconsecutive days per week. Cardiovascular fitness, muscle strength, fatigue resistance, and functional capacities were measured before and after 12 weeks of supervised hospital training and again after another 12 weeks of unsupervised home training. Training was well tolerated. There were significant improvements in cardiorespiratory capacities, isokinetic concentric strength, and functional ability measurements. All patients experienced an improvement in their self-reported visual analogic scale for fatigue and pain during training. However, there was no significant change in their isometric force production and indices of fatigue resistance after training. Although the improvement in exercise tolerance may be due in part to reversal of the deconditioning effect of their related sedentary lifestyle, this clinical trial suggests that ITE can benefit CMT patients especially in their functional performance and subjective perception of pain and fatigue. Moreover, the improvement observed at the end of the first supervised period ITE was maintained after the second unsupervised home period, although there was no further improvement in performance and tolerance.

Foot drop and plantar flexion failure determine different gait strategies in Charcot-Marie-Tooth patients

OBJECTIVE

To describe the temporal, kinetic, kinematic, electromyographic and energetic aspects of gait in Charcot-Marie-Tooth patients with foot drop and plantar flexion failure.

METHODS

A sample of 21 patients fulfilling clinical, electrodiagnostic and genetic criteria for Charcot-Marie-Tooth disease were evaluated by computerized gait analysis system and compared to a group of matched healthy subjects. Patients were classified as having isolate foot drop (group 1) and association of foot drop and plantar flexion failure (group 2).

RESULTS

While it was impossible to detect a reliable gait pattern when the group of patients was considered as a whole and compared to healthy subjects, we observed two distinctive gait patterns when patients were subdivided as group 1 or 2. Group 1 showed a gait pattern with some characteristics of the "steppage pattern". The complex motor strategy adopted by this group leads to reduce the swing velocity and to preserve the step length in spite of a high energy consumption. Group 2 displayed a "clumsy pattern" characterized by very slow gait with reduced step length, a broader support area and great reduction in the cadence. This group of patients is characterized by a low energy consumption and greater energy recovery, due above all to the primary deficit and the various compensatory mechanisms.

CONCLUSIONS

Such between-group differences in gait pattern can be related to both primary motor deficits and secondary compensatory mechanisms. Foot drop and plantar flexion failure affect the overall gait strategy in Charcot-Marie-Tooth patients.