Patient-Reported Experiences with a Low-Carbohydrate Ketogenic Diet: An International Survey in Patients with McArdle Disease.

The low-carbohydrate ketogenic diet (LCKD) has attracted increased attention in recent years as a potential treatment option for individuals with McArdle disease (glycogen storage disease type V), and despite the absence of strong scientific evidence of the LCKD's benefits, increased numbers of individuals with McArdle disease have tried a LCKD. The objective of this study was to collect patient-reported experiences with a LCKD. We aimed to estimate the immediate prevalence of individuals that had tried a LCKD in an international McArdle disease cohort, and we aimed to report on the patient-reported experiences with the diet, both positive and negative. A total of 183 responses were collected from individuals with McArdle disease from 18 countries. We found that one-third of the cohort had tried a LCKD, and almost 90% experienced some degree of positive effect, with the most prominent effects on McArdle disease-related core symptoms (e.g., activity intolerance, muscle pain, and muscle fatigue). Adverse effects were rare and generally rated as mild to moderate. These patient-reported findings underline the need for randomized clinical trials to decisively determine if a LCKD is a suitable nutritional strategy for patients with McArdle disease. The results from this study can prompt and contribute to the design of such a clinical trial.

Does grip strength reflect isokinetic muscle strength in lower limbs in patients with chronic inflammatory demyelinating polyneuropathy?

INTRODUCTION: Grip strength (GS) is a common measure of general muscle strength in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). However, it is important to investigate the correlation and responsiveness of GS compared with isokinetic muscle strength (IKS) and function of the lower limbs. METHODS: Seventy patients with CIDP were evaluated with GS, IKS, and functional measures of the lower limbs. Reevaluation was performed after 2 and 10/12 weeks. Correlation and response analyses were performed. RESULTS: GS correlated with IKS at the ankle (IKSankle ; maximum Spearman's rank-order correlation [RS ] = 0.58) and with walking performance (maximum RS = -0.38). IKSankle was more responsive to detect change (standardized response mean [SRM] = 0.57) than GS (SRM = 0.27). DISCUSSION: GS does not seem to be an appropriate surrogate measure of IKS and function of the lower limbs in patients with CIDP. Muscle Nerve 58: 449-452, 2018.

Aerobic anti-gravity exercise in patients with Charcot-Marie-Tooth disease types 1A and X: A pilot study.

Background: Charcot-Marie-Tooth (CMT) disease is a hereditary neuropathy associated with impaired walking capacity. Some patients are too weak in the lower extremity muscles to walk at gravity with sufficient intensity or duration to gain benefit. Aim: The aim was to investigate the effect of aerobic anti-gravity exercise in weak patients with CMT 1A and X. Methods: Five adult patients performed moderate-intensity aerobic anti-gravity exercise 3/week for 10 weeks. Results: There was a significant positive difference in Berg balance scale and postural stability test between test occasions, and walking distance in the 6-min walk test trended to increase. Conclusions: The study indicates that the anti-gravity treadmill training of patients with CMT should be pursued in larger CMT cohorts.

Axial myopathy: an overlooked feature of muscle diseases.

Classically, myopathies are categorized according to limb or cranial nerve muscle affection, but with the growing use of magnetic resonance imaging it has become evident that many well-known myopathies have significant involvement of the axial musculature. New disease entities with selective axial muscle involvement have also been described recently, but overall the axial myopathy is unexplored. We performed a PubMed search using the search terms 'myopathy', 'paraspinal', 'axial' and 'erector'. Axial myopathy was defined as involvement of paraspinal musculature. We found evidence of axial musculature involvement in the majority of myopathies in which paraspinal musculature was examined. Even in diseases named after a certain pattern of non-axial muscle affection, such as facioscapulohumeral and limb girdle muscular dystrophies, affection of the axial musculature was often severe and early, compared to other muscle groups. Very sparse literature evaluating the validity of clinical assessment methods, electromyography, muscle biopsy and magnetic resonance imaging was identified and reference material is generally missing. This article provides an overview of the present knowledge on axial myopathy with the aim to increase awareness and spur interest among clinicians and researchers in the field.