A Rasch Analysis of the Charcot-Marie-Tooth Neuropathy Score (CMTNS) in a Cohort of Charcot-Marie-Tooth Type 1A Patients

The Charcot-Marie-Tooth Neuropathy Score (CMTNS) was developed as a main efficacy endpoint for application in clinical trials of Charcot-Marie-Tooth disease type 1A (CMT1A). However, the sensitivity of the CMTNS for measuring disease severity and progression in CMT1A patients has been questioned. Here, we applied a Rasch analysis in a French cohort of patients to evaluate the psychometrical properties of the CMTNS. Overall, our analysis supports the validity of the CMTNS for application to CMT1A patients though with some limitations such as certain items of the CMTNS being more suitable for moderate to severe forms of the disease, and some items being disordered. We suggest that additional items and/or categories be considered to better assess mild-to-moderate patients.

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.

Poor compliance with ankle-foot-orthoses in Charcot-Marie-Tooth disease

AIM

The aim of this study is to evaluate the compliance with ankle-foot orthoses (AFOs) in patients previously prescribed and affected with Charcot-Marie-Tooth disease (CMT).

METHODS

Twenty-five Italian patients (8 males 17 females; mean age: 41.6 years, range 16-54) with severe bilateral footdrop (leg-sole angle alpha >105 degrees ) alone or associated with other problems (rotation, plantarflexor failure, knee flexor failure) were examined by a physiatrist (with measurement of the leg-sole angle alpha' with their footwear) and interviewed by a psychologist.

RESULTS

Only 5 patients (20%) used AFOs (3 prefabricated polypropylene AFOs, 2 custom-made short AFOs incorporated in high-top boots) with satisfactory functional results (alpha' <=94 degrees ; reported increased mobility and no more falls). The interview revealed that all patients had a bad relationship with their own body. The 3 subjects using prefabricated AFOs said that they hated them and one of them complained of pain. Patients not using AFOs justified their decision with statements such as: ''I am not yet ready to accept them'' (n=3) or ''I can still manage without them for a while'' (n=2) or both (n=15). Four patients had experienced pain during the trial, 2 had not found proper shoes to accommodate them and 12 were absolutely not interested in AFOs and, therefore, had not gone to an orthotist.

CONCLUSION

Compliance with AFOs is poor. Patients with CMT discard AFOs because they highlight their disability, are not essential for their limited daily walking and are uncomfortable. We suggest that prescription of AFOs be accompanied with psychological support and that research of more comfortable and cosmetically acceptable solutions for the problem of footdrop be stimulated.

The development of a model of fatigue in neuromuscular disorders: a longitudinal study

BACKGROUND

Severe fatigue is reported by the majority of patients with three relatively common types of neuromuscular disorders.

OBJECTIVE

This study aimed to identify predictors of fatigue in a longitudinal study and to develop a model of fatigue in patients with three neuromuscular disorders.

METHODS

One hundred ninety-eight patients [60 facioscapulohumeral muscular dystrophy (FSHD), 70 adult-onset myotonic dystrophy (MD), and 68 hereditary motor and sensory neuropathy type I (HMSN-I) patients] were studied twice during an 18-month period. Fatigue severity was assessed by the Checklist Individual Strength. A multidimensional assessment method was used, including self-report questionnaires, a daily Self-Observation List, and physical activity (actometer). Muscle strength was determined using the Medical Research Council scale. Structural equation modeling was used to develop and test a model of factors contributing to the persistence of experienced fatigue.

RESULTS

Muscle strength, self-reported physical activity, sleep disturbances, and pain at baseline contributed directly or indirectly to fatigue and impairment at follow-up. Lower muscle strength contributed to lower levels of physical activity, which, in turn, contributed to fatigue severity. The model showed excellent fit for the whole group of neuromuscular disorders. In FSHD, pain also contributed to physical activity. A model with the actometer as measurement for actual physical activity instead of self-report showed an excellent model fit in FSHD and HMSN but an insufficient fit in MD.

CONCLUSION

The model of perpetuating factors for fatigue in FSHD and HMSN is different from the model in MD. The main difference is in physical (in)activity. These differences have implications for interventions based on these models.

Psychiatric disorders appear equally in patients with myotonic dystrophy, facioscapulohumeral dystrophy, and hereditary motor and sensory neuropathy type I

OBJECTIVES

To study the presence of psychiatric comorbidity assessed by the use of a structured clinical interview and self-reported questionnaires in a large sample of patients with adult-onset myotonic dystrophy (DM), facioscapulohumeral muscular dystrophy (FSHD), and hereditary motor and sensory neuropathy type I (HMSN-I), and to assess whether psychiatric comorbidity is related to fatigue severity and/or muscle strength.

METHODS

In a cohort of 217 patients with a neuromuscular disorder (79 DM, 65 FSHD and 73 HMSN-I patients) overall psychiatric comorbidity was studied cross-sectionally with the structured clinical interview for DSM-IV axis I disorders. Self-reported psychopathology, fatigue severity and muscle strength were assessed with the Beck Depression Inventory, Symptom Checklist-90, General Health Questionnaire-12, Checklist Individual Strength and muscle strength [Medical Research Council (MRC)-scale].

RESULTS

In all three neuromuscular disorders (DM, FSHD and HMSN), 10-12% of the patients met DSM IV clinical criteria for current psychiatric disorders. Lifetime psychiatric disorders were found in 32% of patients in all three patient groups. The most common psychiatric disorders were depression and phobias. A comparison of patients with and without current psychiatric disorder showed that fatigue severity and muscle strength (MRC) were not related to psychiatric comorbidity.

CONCLUSION

Psychiatric disorders appear equally in patients with DM, FSHD and HMSN-I and are not related to fatigue or muscle strength in these patients.

Experienced and physiological fatigue in neuromuscular disorders

OBJECTIVE

Fatigue has been described as a typical symptom of neurological diseases. It might be caused both by changes at the peripheral and at the central level. This study measured the level of experienced fatigue and physiological correlates of fatigue in three genetically defined neuromuscular disorders.

METHODS

Sixty-five facioscapulohumeral dystrophy (FSHD), 79 classical myotonic dystrophy (DM), 73 hereditary motor and sensory neuropathy type I (HMSN) patients and 24 age-matched healthy controls made a 2-min sustained maximal voluntary contraction of the biceps brachii muscle. Experienced fatigue at the current moment was assessed with the abbreviated fatigue questionnaire just before the physiological measurement. Peripheral fatigue was quantified by comparing the amplitudes of an initial and a final stimulated force response during rest. Muscle fibre conduction velocity was determined from a 5-channel surface EMG recording in order to show peripheral changes during the contraction. Central aspects of fatigue were measured using superimposed electrical endplate stimulation.

RESULTS

Patients showed an increased level of experienced fatigue. Total physiological and peripheral fatigue were smaller in patients compared to controls, and central fatigue was normal. The most interesting result of this study was the presence of a large central activation failure (CAF) in all groups of neuromuscular patients; they showed CAF values of 36-41% already directly at the start of sustained contraction, whereas the control group showed only 12%. CAF slightly correlated with the level of experienced fatigue just before the test.

CONCLUSIONS

The cause of the large CAF in patients is unclear. Reduced concentration, motivation or effort can lead to lower central activation. In neuromuscular patients especially fear of physical activity or fear to damage the muscle or nerve tissue may contribute. Besides, also physiological feedback mechanisms or changes at the motocortical level may be a cause of reduced central activation.

SIGNIFICANCE

For the clinician it is important to know that experienced fatigue is part of the clinical spectrum of neuromuscular patients. Besides, the weakness in these patients is aggravated by reduced central activation. Potentially, both problems could be subject of an intervention.

Variables influencing quality of life and disability in Charcot Marie Tooth (CMT) patients: Italian multicentre study

The purpose of this study was to assess the variables that influence quality of life (QoL) and disability in patients with Charcot-Marie-Tooth disease (CMT). We performed a prospective multicentre study using validated clinical disability and QoL measurements. Multivariate analysis was performed using QoL as a dependent variable and duration of symptoms, age, gender and CMT type, depression and disability measurements as independent variables. We enrolled 211 patients. QoL was highly significantly deteriorated with respect to the Italian normative sample. The physical aspect of QoL was mainly related to disability but it does not increase with the age, probably because of an adaptation between expectation and reality. The mental QoL is influenced by depression (hence we have to consider this aspect approaching CMT patients). Moreover, we observed that women complained of more severe symptoms than men. Finally, some CMT subtypes are related to more severe bodily pain symptoms than others. Multiperspective assessment of CMT showed new aspects of this disease, mainly regarding (1) differences between men and women and (2) the crucial role of pain and depression.

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

The authors evaluated quality of life in Charcot-Marie-Tooth disease by administering the Medical Outcome Study Short Form-36 (SF-36) questionnaire to 121 Italian patients. Patients scored lower on all of the SF-36 scales compared with Italian normative data. Scores were lower in nonworking vs working patients, women vs men, and older vs younger patients, but not between patients with demyelinating vs axonal forms or between patients who had undergone orthopedic foot surgery vs those who had not.

The Charcot-Marie-Tooth syndrome: perceptions of disability and projected use of DNA diagnostic tests

The Charcot-Marie-Tooth group of disorders cause significant morbidity in a proportion of the individuals affected. We have shown that there is a significant correlation between the objective neurological assessment of their dysfunction and the individual's subjective perception of their disability. We have also documented the observation that individuals expressing an intention to use prenatal DNA diagnostic services and terminate an "affected" fetus are more severely affected by their disorder than those who would not, or who were unsure about their use of molecular genetic testing.

[An autopsy case of neuronal type Charcot-Marie-Tooth disease (HMSN type II) with nerve deafness and psychiatric symptoms]

The clinical and pathological findings of a 41-year-old male patient with atypical Charcot-Marie-Tooth disease were reported. There were 3 cases of subarachnoid haemorrhage, 2 nerve deafness and 2 hereditary motor and sensory neuropathy (HMSN) in his family. He had suffered from progressive nerve deafness since 5 years old and gait disturbance since 37 years old. He had been admitted to the psychiatric hospital 3 times because of hallucinatory-delusional state and behavior abnormalities. Neurological examinations at 39 years old revealed that he had mental deterioration (IQ 66), nerve deafness, diffuse muscle atrophy, most marked distally, sensory disturbance, areflexia, positive Romberg's sign, orthostatic hypotension, dysphagia and slurred speech. MCV of median nerve was 27.8 m/sec, and SCV was not evoked. EEG revealed nonspecific dysfunction of the brain. He died of ileus-like condition at 41 years old. General autopsy showed haemorrhagic infarction of the jejunum and ileum due to compression of the superior mesenteric artery and vein by an adhesion band of connective tissue formed after previous appendectomy. Neuropathological examinations revealed axonal degeneration and loss of myelinated fibers with schwannosis of anterior and posterior spinal nerve roots as well as peripheral nerves. The posterior roots were more severely affected than the anterior ones. Ganglion cells of the posterior root ganglia showed remarkable degeneration and loss. There was severe degeneration of the posterior columns, especially in the gracilis, of the spinal cord. Nerve cells in the anterior horns and Clarke's columns also displayed conspicuous atrophy or central chromatolysis followed by gliosis. There was slight degeneration of the posterior spinocerebellar tracts.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary essential fatty acids, vitamin E, and Charcot-Marie-Tooth disease

Twenty patients with type I Charcot-Marie-Tooth disease received dietary supplementation with the essential fatty acids (EFA), linoleic and gamma-linolenic acids, and vitamin E. A 3-month blinded trial of placebo (paraffin oil and vitamin E, 81.6 IU/d) was followed by 1 year of 3 grams daily of EFA and vitamin E. Serum fatty acid values doubled, but total esterified fatty acid proportions did not change. Arachidonic acid proportions correlated with the amount of prostaglandin-mediated lymphocyte suppression measured at the same times. Improvement demonstrated at the end of the placebo period by neuropsychological tests and neurologic examination was maintained during the 1 year of EFA supplementation. This effect may reflect a membrane stabilization benefit of vitamin E.

[Hereditary motor-sensory neuropathy type I with mental disorders]

The author describes a rare coexistence of psychic disturbances with sensorimotor hereditary neuropathy type I in a generation.