A patient with muscle pain after a journey to Central Africa: Myocardial involvement in proximal myotonic myopathy

History and admission findings: A 36-year-old man reported feeling generally unwell and experiencing shooting and tearing pain, especially in the thighs and over the precordium, just after returning from a five-week holiday in Central Africa. An active sportsman in his youth (fencing) he was known to have incomplete right bundle branch block in the ECG and a raised concentration of gamma-glutamyl transferase, of unknown aetiology. Physical examination on admission was negative except for discrete weakness on head bending and slightly delayed finger stretching after making a fist. Investigations: Multiple tests excluded tropical diseases. There were abnormal T waves in leads III and V-1 of the EGG. Serum concentrations of creatine kinase (CK; maximally 822 U/l), gamma-glutamyl transaminase (gamma-GT; 446 U/l), glutamyl-pyruvate transaminase (GPT; 510 U/l) and of glutamate-oxalate transaminase (COT; 108 U/l) were all elevated. Erythrocyte sedimentation rate and C-reactive protein were within normal limits. Treatment and course: At first the suspected diagnosis was myocarditis and he was placed on bed-rest, monitored and treated symptomatically. Because the levels of CK, gamma-GT, GPT and COT improved only transiently, there were no signs of inflammatory disease and the muscle pains continued, biopsies of skeletal muscle and the liver were done. They revealed nonspecific liver changes and a noninflammatory myopathy. As congenital myopathy was suspected he was transferred to the neurology department where the diagnosis of proximal myotonic myopathy (PROMM) was established. Conclusion: We assume that an unknown viral infection triggered the illness that, in addition to the usual nonspecific symptoms, accentuated the signs of the existing multi-system proximal myotonic myopathy.