Falling After Starting Running in a Case of Myoclonus Epilepsy Associated with Ragged-red Fibers with a 8344A>G mtDNA Mutation

Intern Med. 2018 Dec 1;57(23):3439-3443. doi: 10.2169/internalmedicine.1210-18. Epub 2018 Jul 6.

Abstract

Myoclonus epilepsy associated with ragged-red fibers (MERRF) is traditionally characterized by myoclonus, generalized epilepsy and ragged-red fibers. We herein report a 42-year-old man who complained of falling after starting running, symptoms resembling those of paroxysmal kinesigenic dyskinesia. He showed only slight muscle weakness of the right quadriceps femoris. Muscle pathology and a genetic analysis identified him as having MERRF with a 8344A>G mtDNA mutation. We diagnosed his symptoms as having been caused by slight quadriceps femoris muscle weakness and exercise intolerance. This case suggests that mitochondrial myopathy should be considered in cases with strong muscle symptoms for muscle weakness.

Keywords: MERRF; mitochondrial myopathy; paroxysmal exercise-induced dyskinesia; paroxysmal kinesigenic dyskinesia.

Publication types

  • Case Reports

MeSH terms

  • Accidental Falls*
  • Adult
  • DNA, Mitochondrial / genetics*
  • Diagnosis, Differential
  • Dystonia / diagnosis
  • Exercise Tolerance
  • Genetic Testing
  • Humans
  • MERRF Syndrome / diagnosis*
  • MERRF Syndrome / genetics*
  • MERRF Syndrome / physiopathology
  • Male
  • Muscle Weakness / etiology*
  • Muscle, Skeletal / physiopathology
  • Point Mutation*
  • Running / injuries*

Substances

  • DNA, Mitochondrial

Supplementary concepts

  • Familial paroxysmal dystonia