Use of dynamic tests of muscle function and histomorphometry of quadriceps muscle biopsies in the investigation of patients with chronic alcohol misuse and chronic fatigue syndrome

Drug-induced hyperammonaemia

Hyperammonaemia (HA) as a consequence of numerous primary or secondary causes, gives rise to clinical manifestations due to its toxic effects on the brain. The neurological consequences broadly reflect the ammonia level, duration and age, with paediatric patients being more susceptible. Drug-induced HA may arise due to either decreased ammonia elimination or increased production. This is associated most frequently with use of valproate and presents a dilemma between ongoing therapeutic need, toxicity and the possibility of an alternative cause. As there is no specific test for drug-induced HA, prompt discussion with a metabolic physician is recommended, as the neurotoxic effects are time-dependent. Specific guidelines for managing drug-induced HA have yet to be published and hence the treatment approach outlined in this review reflects that outlined in relevant urea cycle disorder guidelines.

Diagnostic and Pharmacological Potency of Creatine in Post-Viral Fatigue Syndrome

Post-viral fatigue syndrome (PVFS) is a widespread chronic neurological disease with no definite etiological factor(s), no actual diagnostic test, and no approved pharmacological treatment, therapy, or cure. Among other features, PVFS could be accompanied by various irregularities in creatine metabolism, perturbing either tissue levels of creatine in the brain, the rates of phosphocreatine resynthesis in the skeletal muscle, or the concentrations of the enzyme creatine kinase in the blood. Furthermore, supplemental creatine and related guanidino compounds appear to impact both patient- and clinician-reported outcomes in syndromes and maladies with chronic fatigue. This paper critically overviews the most common disturbances in creatine metabolism in various PVFS populations, summarizes human trials on dietary creatine and creatine analogs in the syndrome, and discusses new frontiers and open questions for using creatine in a post-COVID-19 world.

Is there morphological difference between branchiomeric and somitic muscles submitted to alcohol consumption? An experimental study in rats (Rattus norvegicus)

Alcoholism is considered a physical dependence disorder. More than 18 million people are alcoholics in the USA and England and between 1/3 to ½ of them present some kind of physical disorder. In general the literature is focused on alcoholic trunk muscle disorders. These muscles have different embryological origins if compared to the masticatory muscles. The aim of this research was to evaluate the effects of alcohol on the masticatory muscles in order to compare them with the somitic muscles. For this purpose, 15 male Wistar rats weighing around 250g were used. The rats were divided into three groups: Normal control (N), Alcoholic (A) and Isocaloric (I). Slices of the masseter muscle, temporalis muscle and rectus abdominal muscle were harvested and submitted to histochemical reactions (m-ATPase: acid and alkaline pre incubation and NADH-TR). The myofibers were classified in SO, FOG and FG. The results showed atrophy of the fast fibers (FG and FOG) in the masticatory muscles but this atrophy was not statistically significant in this study (p< 0.05). On the other hand, significant atrophy occurred in the rectus abdominal muscle (p<0.05). Based on these data it can concluded that the effect of alcohol on the branchiomeric jaw elevator muscles (masseter and temporalis muscles) is different compared to the effect on somitic muscle (rectus abdominal muscle).

Alcohol usage in sport and exercise

In this review we consider some of the acute and chronic effects of alcohol on human exercise and sport performance. The 1982 position stand of the American College of Sport Medicine on the use of alcohol in sport emphasized that there was little benefit for an athlete. Subsequent literature continues to demonstrate that there are adverse effects on performance. However, the literature is often confusing and disparate. We will attempt to explain the effects and speculate on the possible mechanisms. We divide the review into acute and chronic metabolic and physiological effects of alcohol on exercise performance, primarily in humans. We also review the epidemiological evidence of the associations between alcohol use and problem alcohol behaviors in various athletic groups. Finally, we review the limited data on the effectiveness of exercise therapy in the treatment of alcohol dependent patients. In spite of scientific evidence that alcohol use is, in general, detrimental (or of no benefit) to sport (exercise) performance, alcohol continues to be used by athletes both on a chronic basis and even immediately prior to sports participation. There is some encouraging but limited evidence that student-athlete alcohol use is decreasing and exercise can be effective as part of alcohol rehabilitation.

Malnutrition-induced hypokalemic myopathy in chronic alcoholism

CASE REPORT

A 42-year-old man with a history of Billroth II-gastrectomy, chronic alcoholism, and malnutrition developed acute tetraparesis, two days before admission. He presented with bilateral, proximal upper and lower limb weakness, limb girdle wasting, bilaterally reduced Achilles tendon reflexes, and bilateral stocking-type sensory disturbances. Laboratory data revealed hypokalemia (2.2 mmol/L), elevated creatine kinase (7282 U/L), metabolic alkalosis and reduced urine potassium, albumin, and total protein. Muscle biopsy showed atrophic, necrotic, and regenerating fibers, endomysial macrophages, and vacuolar degeneration, interpreted as hypokalemic myopathy. With the correction of the serum potassium, tetraparesis rapidly resolved. With other causes excluded, malnutrition and gastrectomy were considered responsible for hypokalemia in this patient with acute tetraparesis and chronic alcoholism.

Tension myalgia versus myoadenylate deaminase deficiency: a case report

Myalgia is a complaint associated with numerous medical conditions such as metabolic or hormonal abnormalities, toxic myopathies, tetanus, electrolyte disturbances, inflammatory diseases, and exertion-related pain. A diagnosis of tension myalgia or myofascial-type pain is often considered when no objective findings are seen in the evaluation. This is a report of a patient who was treated unsuccessfully for fibromyalgia for many years and who ultimately was diagnosed with a rare benign skeletal muscle metabolic disorder caused by myoadenylate deaminase deficiency. We discuss this enzyme deficiency and its importance for the physiatric community.

Fatigue in the chronic fatigue syndrome: a cognitive phenomenon?

What is the source of the perception of excessive fatigue in the chronic fatigue syndrome (CFS)? Studies of physiological response to aerobic activity, of muscle pathology and muscle function in CFS, are reviewed, and suggest that the subjective report of fatigue is not due to any peripheral impairment. In addition, current technological methods such as electroencephalography have failed to uncover the nature of any abnormality in the central motor unit. A physiological model which proposes that patients with CFS possess a reduced threshold for sensory fatigue signals is rejected, because it fails to account for recent findings. Instead, it is suggested that the perception of fatigue in CFS is enhanced by idiosyncrasies in cognitive processing. The implications of this view to our understanding of the perpetuation of CFS as a whole are explored.