Equine muscular dystrophy with myotonia

P. Montagna, R. Liguori, L. Monari, P. N. Strong, R. Riva, V. Di Stasi, G. Gandini, M. Cipone

Research output: Contribution to journalArticlepeer-review


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.

Original languageEnglish
Pages (from-to)294-299
Number of pages6
JournalClinical Neurophysiology
Issue number2
Publication statusPublished - 2001


  • Apamin
  • EMG in myotonia
  • Equine
  • Muscular dystrophy
  • Myotonia
  • Myotonic dystrophy

ASJC Scopus subject areas

  • Clinical Neurology
  • Radiology Nuclear Medicine and imaging
  • Neurology
  • Sensory Systems
  • Physiology (medical)


Dive into the research topics of 'Equine muscular dystrophy with myotonia'. Together they form a unique fingerprint.

Cite this