Objectives: To describe a case of equine muscular dystrophy with myotonia. Methods: A 5-year-old horse presented with hypertrophy and delayed relaxation of the muscles of the hindlimbs from age 2 months. Testicular atrophy developed from 2 years of age. Action and percussion myotonia was associated with weakness in these muscles, and EMG showed diffuse myotonic discharges and myopathic features. Biopsy of the gluteal muscle showed adipose and connective tissue infiltration, marked variation in muscle fibre size, and moth-eaten, ring and whorled fibres. Results: Injection of apamin, a peptide blocker of calcium-activated potassium channels, which inhibits myotonia in human myotonic dystrophy, was ineffective in blocking myotonic discharges. Discharges promptly abated with 2% lidocaine injection. Conclusions: Myotonia in this horse is associated with dystrophic changes similar to human myotonic dystrophy, though there are some pharmacological differences. © 2001 Elsevier Science Ireland Ltd.
Montagna P., Liguori R., Monari L., Strong P.N, Riva R., Di Stasi V., et al. (2001). Equine muscular dystrophy with myotonia. CLINICAL NEUROPHYSIOLOGY, 112(2), 294-299 [10.1016/S1388-2457(00)00511-3].
Equine muscular dystrophy with myotonia
Montagna P.;Liguori R.;Di Stasi V.;Gandini G.;Cipone M.
2001
Abstract
Objectives: To describe a case of equine muscular dystrophy with myotonia. Methods: A 5-year-old horse presented with hypertrophy and delayed relaxation of the muscles of the hindlimbs from age 2 months. Testicular atrophy developed from 2 years of age. Action and percussion myotonia was associated with weakness in these muscles, and EMG showed diffuse myotonic discharges and myopathic features. Biopsy of the gluteal muscle showed adipose and connective tissue infiltration, marked variation in muscle fibre size, and moth-eaten, ring and whorled fibres. Results: Injection of apamin, a peptide blocker of calcium-activated potassium channels, which inhibits myotonia in human myotonic dystrophy, was ineffective in blocking myotonic discharges. Discharges promptly abated with 2% lidocaine injection. Conclusions: Myotonia in this horse is associated with dystrophic changes similar to human myotonic dystrophy, though there are some pharmacological differences. © 2001 Elsevier Science Ireland Ltd.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
