This study examined functional, biochemical, and morphological characteristics of skeletal muscle in nine multiple sclerosis (MS) patients and eight healthy controls in an effort to ascertain whether intramuscular adaptations could account for excessive fatigue in this disease. Analyses of biopsies of the tibialis anterior muscle showed that there were fewer type I fibers (66 +/- 6 vs. 76 +/- 6%), and that fibers of all types were smaller (average downward arrow26%) and had lower succinic dehydrogenase (SDH; average downward arrow40%) and SDH/alpha-glycerol-phosphate dehydrogenase (GPDH) but not GPDH activities in MS vs. control subjects, suggesting that muscle in this disease is smaller and relies more on anaerobic than aerobic-oxidative energy supply than does muscle of healthy individuals. Maximal voluntary isometric force for dorsiflexion was associated with both average fiber cross-sectional area (r = 0.71, P = 0.005) and muscle fat-free cross-sectional area by magnetic resonance imaging (r = 0.80, P < 0. 001). Physical activity, assessed by accelerometer, was associated with average fiber SDH/GPDH (r = 0.78, P = 0.008). There was a tendency for symptomatic fatigue to be inversely associated with average fiber SDH activity (r = -0.57, P = 0.068). The results of this study suggest that the inherent characteristics of skeletal muscle fibers per se and of skeletal muscle as a whole are altered in the direction of disuse in MS. They also suggest that changes in skeletal muscle in MS may significantly affect function.

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(AAN) is charged with developing practice parameters for physicians. This evidence-based review addresses some of the major management issues in patients with ALS, and highlights the many areas in which more research is needed.Justification. ALS is a progressive, degenerative motor neuron disease of unknown cause. Muscle atrophy and spasticity in limb and bulbar muscles result in weakness and loss of ambulation, oropharyngeal dysfunction, weight loss, and ultimately respiratory failure. Although advances in understanding the pathophysiology of ALS have stimulated the development of new drug therapies, 1 the mainstay of treatment for ALS patients remains symptomatic management.The practice parameters presented here comprise the first recommendations for the management of ALS based on a prescribed review and analysis of the peer-reviewed literature. These practice parameters were developed to improve the care and the quality of life of people with ALS by providing a rational basis for managing the disease.Description of the process. A multidisciplinary task force, all with extensive ALS experience, included 19 physicians, 3 patients with ALS, 1 gastroenterologist, 1 pulmonologist, 1 occupational therapist whose mother has ALS, and 1 nurse. In addition, consultants with expertise on ethics, practice parameter development, and medical library research participated in the process. The task force agreed to investigate five areas: 1) informing the patient and the family about the diagnosis and prognosis (also called "breaking the news") of ALS; 2) symptomatic treatment; 3) nutrition, and decisions about percutaneous endoscopic gastroscopy (PEG); 4) respiratory insufficiency and mechanical ventilation; and 5) advance directives and palliative care. To help achieve this goal, they developed several guiding principles or attributes of care: Principles of ALS management1. High priority should be placed on patient self-determination or autonomy as an underlying assumption in the therapeutic relationship. Delivery of both information and care must take into consideration the cultural and psychosocial context of the patient and the family. 2. Patients and families need information that is timed appropriately for decision making, and delivered well in advance of major management crossroads, especially for respiratory care. Moreover, decision making is a dynamic process that may be subject to change as the disease becomes more severe.The investigators and institutions of the ALS Practice Parameters Task Force are listed in the Appendix on page 1320.

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