title: Dengue-associated transient muscle dysfunction: clinical, electromyography and histopathological changes.
abstract: BACKGROUND
  Dengue is commonly associated with myalgia, but there is paucity of studies on the frequency, severity, and basis of muscle involvement. The aim of this study was to document the clinical, electromyographic, and histological changes in dengue-associated muscle dysfunction.
  
  
  METHODS
  Seropositive dengue patients admitted to the neurology ward during 2010 were enrolled in this study. Detailed medical history, including bleeding diathesis and organomegaly, were noted. Muscle power on a 0-5 scale, muscle tone, reflex, sensations and coordination were tested. Blood counts, hemoglobin, and serum chemistry, including creatine kinase (CK) evaluations, were carried out. Concentric needle electromyography (EMG) and muscle biopsy were performed when clinical conditions were suitable.
  
  
  RESULTS
  The study cohort comprised 39 patients with dengue, with a median age of 28 years. Of these, 31 patients showed evidence of muscle involvement-16 with clinical and 15 with subclinical muscle involvement. Eight of these patients had severe weakness and five had hyporeflexia. Thrombocytopenia was present in 26 patients, elevated serum creatinine in three patients and liver dysfunction in 31 patients. The median CK level was 837 (range 194-3,832) U/L. The EMG revealed polyphasic normal to short duration motor unit potentials, but spontaneous activity was absent. Muscle biopsy in three patients revealed interstitial hemorrhage with occasional necrosis and myophagocytosis. There was no vasculitis, but subtle inflammatory changes were present in one patient. The severity of muscle weakness correlated with the platelet count and CK level. All patients improved by 15 days of treatment initiation.
  
  
  CONCLUSIONS
  Dengue commonly results in benign and self-limiting transient muscle dysfunction.
authors: Department of Neurology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India. drukmisra@rediffmail.com
authors: U K
authors: UK
authors: Misra
authors: J
authors: J
authors: Kalita
authors: P K
authors: PK
authors: Maurya
authors: P
authors: P
authors: Kumar
authors: S K
authors: SK
authors: Shankar
authors: A
authors: A
authors: Mahadevan
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003402:Creatine Kinase / Q000378:metabolism*; D003715:Dengue / Q000150:complications* / Q000473:pathology; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D009135:Muscular Diseases / Q000209:etiology* / Q000473:pathology; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D003402:Creatine Kinase