Comparison of gait patterns and functional measures between Charcot-Marie-Tooth disease type I and II in children to young adults

Gait Pattern in Charcot-Marie-Tooth Disease Type 1A According to Disease Severity

The aim of this study was to evaluate the characteristics of gait patterns in Charcot-Marie-Tooth disease type 1A (CMT1A) patients according to disease severity. Twenty-two CMT1A patients were enrolled and classified into two groups, according to the disease severity. The healthy control group consisted of 22 subjects with no gait impairment. Full barefoot three-dimensional gait analysis with temporospatial, kinematic, and kinetic data was performed among the mild and moderate CMT1A group and the control group. Minimal hip abduction, maximal hip extension generation, peak knee flexion moment at stance, ankle dorsiflexion at initial contact, maximal ankle plantarflexion at push-off and maximal ankle rotation moment at stance in the CMT1A group showed a significant difference compared to the control group (p < 0.05). In the moderate group, there were greater maximal hip flexion angles in swing, and smaller dorsiflexion angles at initial contact compared to the control group and mild group. CMT patients had typical gait characteristics and their gait patterns were different according to severity. The analysis of gait patterns in patients with CMT1A will help to understand gait function and provide important information for the treatment of patients with CMT in the future.

Natural history of ankle function during gait in youth with Charcot-Marie-Tooth disease types 1 and 2

BACKGROUND

Charcot-Marie-Tooth disease (CMT) can cause progressive muscle weakness and contracture, leading to gait abnormalities such as increased and delayed peak ankle dorsiflexion and reduced ankle power generation in terminal stance. Understanding strength loss on ankle function during gait is important for interpreting treatment outcomes and evaluating new therapies designed to improve gait.

RESEARCH QUESTION

Do ankle kinematics and kinetics vary as a function of age, disease progression with associated loss of muscle strength and CMT type in youth with CMT types 1 and 2?

METHODS

A prospective convenience sample of 45 participants with CMT1 and 2, ages 7-22 years, underwent comprehensive gait analysis. Seventeen patients underwent repeat analyses totaling 67 tests. Generalized mixed effects linear modeling was used to compare CMT1 versus CMT2 and to examine the effects of age on ankle strength, range of motion, kinematics, and kinetics within each CMT type.

RESULTS

Plantarflexor and dorsiflexor strength were less in CMT2 compared with CMT1 (p ≤ 0.05), while peak dorsiflexion in terminal stance (TST) was greater (p = 0.02). Peak plantarflexion moment and power generation were also less in CMT2 (p ≤ 0.02). In CMT1, peak dorsiflexion in TST increased with age through 13 years (p = 0.004); then plateaued in the normal range (p = 0.73). Peak ankle angle in mid-swing was closely related to the angle in TST (p < 0.001) following a similar pattern with age. In CMT2, no significant associations were observed between age, peak dorsiflexion in TST, and peak ankle angle in mid-swing (p ≥ 0.19). There were no consistent trends with age for individual patients with repeat tests.

SIGNIFICANCE

The heterogeneity of joint level impairments and gait kinematics and kinetics point to the importance of having an in-depth understanding of gait at the individual patient level using comprehensive gait analysis including valid and reliable strength measures.

Stance and swing phase ankle phenotypes in youth with Charcot-Marie-Tooth type 1: An evaluation using comprehensive gait analysis techniques

BACKGROUND

Charcot-Marie-Tooth disease (CMT) results in muscle weakness and contracture leading to a wide variety of gait issues including atypical ankle kinematics in both stance and swing. Knowledge of the stance and swing phase kinematic patterns for CMT type 1 (CMT1), the most common CMT type, will improve our understanding of expected gait outcomes and treatment needs to improve gait function.

RESEARCH QUESTION

What are the stance/swing phase ankle phenotypes in CMT1?

METHODS

A prospective convenience sample of 25 participants with CMT1, ages 7-19 years, underwent comprehensive gait analysis following standard procedures. Ankle phenotypes based on peak ankle dorsiflexion in terminal stance and mid-swing were defined and compared using linear mixed models.

RESULTS

Patients with CMT1 presented with three stance phase ankle phenotypes: 21 limbs (42 %) with reduced (mean 5°, SD 2°), 19 limbs (38 %) with typical (mean 11°, SD 1°) and 10 limbs (20 %) with excessive (mean 15°, SD 2°) peak dorsiflexion in terminal stance (p < 0.05). There were two swing phase phenotypes: 19 limbs (38 %) with typical (mean -1.7°, SD 1.5°) and 31 limbs (62 %) with excessive (mean -5.6°, SD 1.4°) plantarflexion in mid-swing (p < 0.002). Eleven patients (44 %) had ankles that were classified into different stance groups, and 9 patients (36 %) had ankles that were classified into different swing groups. The most common combination of stance/swing ankle phenotypes was decreased dorsiflexion in terminal stance with increased plantarflexion in mid-swing (16 sides, 32 %).

SIGNIFICANCE

This study shows that youth with CMT1 have multiple combinations of combined ankle kinematics for stance and swing. The ankle phenotypes identified in this study reflect contributions of both dorsi/plantarflexor weakness and plantarflexor contracture, which require different treatment approaches. Comprehensive gait analysis can distinguish between multiple ankle phenotypes to assist in determining the most appropriate treatment to improve gait for individual patients.

Foot Assessment Clinical Scales in Charcot-Marie-Tooth Patients: A Scoping Review

Introduction

Charcot-Marie-Tooth disease (CMT) is a slow and progressive peripheral motor sensory neuropathy frequently associated with the cavo-varus foot deformity. We conducted a scoping review on the clinical scales used to assess foot deviations in CMT patients and analyzed their metric properties.

Evidence Acquisition

A first search was conducted to retrieve all scales used to assess foot characteristics in CMT patients from the Medline, Web of Science, Google Scholar, Cochrane, and PEDro databases. A second search was conducted to include all studies that evaluated the metric properties of such identified scales from the same databases. We followed the methodologic guidelines specific for scoping reviews and used the PICO framework to set the eligibility criteria. Two independent investigators screened all papers.

Evidence Synthesis

The first search found 724 papers. Of these, 41 were included, using six different scales: "Foot Posture Index" (FPI), "Foot Function Index", "Maryland Foot Score", "American Orthopedic Foot & Ankle Society's Hindfoot Evaluation Scale", "Foot Health Status Questionnaire", Wicart-Seringe grade. The second search produced 259 papers. Of these, 49 regarding the metric properties of these scales were included. We presented and analyzed the properties of all identified scales in terms of developmental history, clinical characteristics (domains, items, scores), metric characteristics (uni-dimensionality, inter- and intra-rater reliability, concurrent validity, responsiveness), and operational characteristics (normative values, manual availability, learning time and assessors' characteristics).

Conclusions

Our results suggested the adoption of the six-item version of the FPI scale (FPI-6) for foot assessment in the CMT population, with scoring provided by Rasch Analysis. This scale has demonstrated high applicability in different cohorts after a short training period for clinicians, along with good psychometric properties. FPI-6 can help health professionals to assess foot deformity in CMT patients over the years.

Do different foot types affect the 6-min walk test capacity of younths with Charcot-Marie-Tooth neuropathy ?

BACKGROUND

The present study aimed to assess the gait capacity of youths with Charcot Marie Tooth disease (CMT), considering the different foot postures as a grouping variable.  METHODS: The total distance, the predicted distance, and gait velocity obtained during the six-minute walking test (6MWT) were compared between participants with and without CMT. In addition, part of the CMT group completed a 12-month follow-up. The study evaluated 63 participants (CMT group = 31; Non-CMT group = 32) aged 6 to 18, both sexes. Data included anthropometric measures, foot posture index (FPI), the distance (D6), percentage of predicted distance (%D6), and walking velocity(V) in 6MWT.

RESULTS

The D6% presented no significant difference between the types of feet in CMT or Non-CMT (p < 0.05, Kruskal Wallis test). CMT presented reduced values of D6, %D6, and V when compared to Non-CMT.

CONCLUSIONS

These findings indicate that gait performance was decreased in youths with CMT in comparison to non-CMT. Contrary to what was expected, the cavus foot type did not show lower gait capacity than the flatfoot, suggesting that the types of feet alone did not determine differences in gait capacity within the CMT group.

Counter-movement jump characteristics in children with Charcot-Marie-Tooth type 1a disease

BACKGROUND

Poor performance in sports, especially activities that require explosive movements, is a common reason for initial presentation of children with Charcot-Marie-Tooth type 1a (CMT1a) to the paediatric neuromuscular specialist.

RESEARCH QUESTION

The aim of this descriptive, retrospective study was to analyse counter-movement jump characteristics in children with CMT1a in comparison to those in typically developing children (TDC).

METHODS

This retrospective study included seven patients with CMT1a and 44 TDC from our data pool. All the participants performed counter-movement jumps, and jump height, peak force, time to peak force, average and peak rate of force development and net vertical impulse were then calculated. For statistical comparison by means of an independent Student's t-test, children with CMT1a were compared to seven sex- and age-matched TDC. Correlation coefficients were calculated to determine the relationship between the force-time variables and jump height.

RESULTS

Peak force, net vertical impulse and jump height values in the CMT1a group were significantly lower than those in the TDC group. There were no between-group differences in the time to peak force or average and peak rate of force development. In terms of task symmetry, the correlation between the time-force curve of the left and right leg in the CMT1a group was reduced as compared with that in the TDC group. In both groups, among the parameters measured, there was a significant correlation between jump height and net vertical impulse.

SIGNIFICANCE

This study showed that reduced jump performance in children with CMT1a, as demonstrated by decreased counter-movement jump height, was due to a reduced net impulse during this explosive movement task. This finding is critical for children with CMT1a and has to be considered in clinical management and activities of daily living (e.g. sports lessons in school).

Case Report: Early-Onset Charcot-Marie-Tooth 2N With Reversible White Matter Lesions Repeatedly Mimicked Stroke or Encephalitis

INTRODUCTION

Charcot-Marie-Tooth (CMT) disease is a rare group of peripheral neuropathies with high clinical and genetic heterogeneity. CMT type 2N (CMT 2N) is a rare subtype of CMT with few clinical reports. The clinical presentation mimics that of other diseases, frequently leading to misdiagnoses. We present a case of CMT 2N with reversible white matter lesions (WMLs), which repeatedly mimicked stroke or encephalitis. We include a literature review to the improve management of this disease.

CASE DESCRIPTION

An 8-year-old boy was admitted to the hospital with slurred speech and limb weakness that had persisted for 1 day. Physical examination revealed lethargy, dysarthria, and a positive bilateral Babinski sign. Cerebrospinal fluid (CSF) analysis showed no abnormalities. Brain magnetic resonance imaging (MRI) revealed symmetrical abnormal signal areas in the paraventricular white matter and corpus callosum. The patient was suspected of having viral encephalitis and recovered rapidly after treatment.He was hospitalized 3 years later for limb weakness, barylalia, and facial paralysis persisting for 1 day. MRI showed an abnormal signal in the bilateral corona radiata. He was suspected of having a stroke or encephalitis. He was completely recovered after treatment.After a second 3-year span, he was admitted for another stroke-like episode. Physical examination revealed facial-lingual hemiparesis, mild atrophy of the left thenar muscle, decreased muscle strength in the extremities, and disappearance of the tendon reflex. MRI revealed more pronounced abnormal signals in the bilateral centrum semiovale and corpus callosum. Antibodies against autoimmune encephalitis were negative. A nerve conduction velocity (NCV) study showed motor and sensory four-limb nerve demyelination with axonal damage, most notably at the distal end. His symptoms were resolved after active treatment. A follow-up MRI showed the complete disappearance of the abnormal white matter signal. Whole exon sequencing showed a heterozygous mutation [c.2093C > T(p.Ser698Phe)] in the alanyl-tRNA synthetase 1 gene (AARS1). His mutation, clinical features, and electrophysiological testing led to a diagnosis of CMT 2N.

DISCUSSION

Early-Onset CMT 2N with reversible WMLs can often mimic stroke or encephalopathy. Affected individuals may show an atypical posterior reversible encephalopathy syndrome (PRES) on MRI. Careful family history assessment, physical examination, nerve conduction studies, MRIs, and genetic testing are essential for early diagnosis. Further studies are required to confirm these findings.

Carbon Fiber-Based Twisted and Coiled Artificial Muscles (TCAMs) for Powered Ankle-Foot Orthoses

Ankle foot orthoses (AFOs) control the position and motion of the ankle, compensate for weakness, and correct deformities. AFOs can be classified as passive or powered. Powered AFOs overcome the limitations of passive AFOs by adapting their performance to meet a variety of requirements. However, the actuators currently used to power AFOs are typically heavy, bulky, expensive, or limited to laboratory settings. Thus, there is a strong need for lightweight, inexpensive, and flexible actuators for powering AFOs. In this technical brief, carbon fiber/silicone rubber (CF/SR) twisted and coiled artificial muscles (TCAMs) are proposed as novel actuators for powered AFOs. CF/SR TCAMs can lift to 12,600 times their weight with an input power of only 0.025 W cm-1 and are fabricated from inexpensive materials through a low-cost manufacturing process. Additionally, they can provide a specific work of 758 J kg-1 when an input voltage of 1.64 V cm-1 is applied. Mechanical characterization of CF/SR TCAMs in terms of length/tension, tension/velocity, and active-passive length/tension is presented, and results are compared with the performance of skeletal muscles. A gait analysis demonstrates that CF/SR TCAMs can provide the performance required to supplement lower limb musculature and replicate the gait cycle of a healthy subject. Therefore, the preliminary results provided in this brief are a stepping stone for a dynamic AFO powered by CF/SR TCAMs.

Neuropathic Pain and Rehabilitation: A Systematic Review of International Guidelines

Background: Neuropathic pain is an injury or disease of the central and/or peripheral somatosensory nervous system, and it has a significant impact on quality of life, especially since it is often refractory to treatment. Rehabilitative intervention is considered in various guidelines on neuropathic pain treatment, although not in an organic nor detailed way. The aim of this systematic review was to analyze the most indicated therapeutic strategies, providing rehabilitative recommendations in the management of neuropathic pain. Methods: A systematic review was performed according to PRISMA guidelines. The scientific search, carried out until July 2020, considered guidelines in English language of the last thirteen years. Results: Six guidelines were analyzed, from which emerges that a multidisciplinary approach, comprehensive of pharmacologic and nonpharmacologic interventions, should drive neuropathic pain management. A relevant role in non-pharmacological intervention is played by rehabilitation, through an adequate tailored rehabilitation program and physical therapies. Conclusion: This analysis highlights the importance of rehabilitation but also the lack of evidence on various rehabilitative practices. Arises hence the need for further studies in this field to better define a rehabilitative treatment strategy.

Changes in walking velocity and stride parameters with age in children with Charcot-Marie-Tooth disease

The purpose of this study is to assess how Charcot-Marie-Tooth disease, a group of inherited peripheral neuropathies that result in distal weakness, affects walking velocity over time in comparison to age-matched controls. Comprehensive gait analysis of 57 children (mean age 12.0, SD 3.7 years) compared to 76 age-matched controls (mean age 10.1, SD 3.4 years) demonstrated slower walking velocity (p<0.001) due to both shorter stride length (p<0.001) and diminished cadence (p=0.01). There was higher walking velocity (p<0.001), stride length (p=0.002) and cadence (p<0.001) in patients with dorsiflexor strength ≥3 and higher walking velocity (p=0.001) and cadence (p=0.03) in patients plantar flexor strength ≥4. Analysis of Charcot-Marie-Tooth type 1 and type 2 subgroups showed that walking velocity increased significantly with age in controls (p=0.001) but did not increase in children with either subtype (p>0.54). Stride length increased significantly with age in all groups (p<0.001) but at a slower rate in type 1 and 2 compared to controls. These differences contributed to increasing deficits in walking velocity and stride length with age in type 1 and 2 in comparison to controls, with deficits appearing earlier in type 2. Since the slower walking velocity in children with Charcot-Marie-Tooth disease is primarily due to short stride length, treatments that enable improved stride length, such as plantar flexor strengthening and bracing, may improve walking velocity and associated gait function.