Enzyme histochemistry on muscle biopsies as an aid in the diagnosis of diseases of the equine neuromuscular system: a study of six cases

Equine metabolic myopathies with emphasis on the diagnostic approach comparison with human myopathies A review

This review gives an overview of the presently known human and equine metabolic myopathies with emphasis on the diagnostic approach. Metabolic myopathies are muscle disorders caused by a biochemical defect of the skeletal muscle energy system, which results in inefficient muscle performance. Myopathies can arise in different levels of the metabolic system. In this review the metabolic myopathies are categorized in disorders of the carbohydrate metabolism, lipid metabolism, mitochondrial myopathies (other than those described in lipid metabolism), disorders of purine metabolism, primary disorders involving ion channels and electrolyte flux and secondary or acquired metabolic myopathies.

Quantitative motor unit action potential analysis of skeletal muscles in the Warmblood horse

Motor unit action potential (MUP) analysis in human medicine is a valuable and important diagnostic technique enabling discrimination between myogenic and neurogenic problems. This study establishes normative data in subclavian, triceps and lateral vastus muscles for clinical application of MUP analysis in the Warmblood horse, and examines whether muscle differences are present. Electromyographic (EMG) needle examination and MUP analysis were performed of the triceps, lateral vastus and subclavian muscles in 7 awake, nonsedated, Warmblood horses age 4-10 years. The amplitude, duration, number of phases and turns were calculated from the recorded superimposed MUPs together with intramuscular and rectal temperatures. No significant differences were found in duration of insertional activity between the 3 muscles. The mean +/- s.d. duration of the insertional activity was 526 +/- 1483 ms. The MUP amplitude of all 3 muscles differed significantly, with the highest amplitude (427 +/- 3.20 microV) in the triceps and the lowest (220 +/- 2.08 microV) in the subclavian muscle. The number of turns of the lateral vastus (3.0 +/- 1.22) was significantly higher than that of the triceps muscle (2.7 +/- 1.51). No differences were found in MUP duration (5.9-6.4 ms).