title: A 6-Year-Old With Leg Cramps.
abstract: A 6-year-old girl presented with a history of leg pain and cramping that progressively worsened over a 2- to 3-week period of time. Her examination was notable for normal vital signs, limited range of motion of her left hip, and a limp. Inflammatory markers were slightly elevated, but the serum electrolytes, calcium, and magnesium, complete blood cell count and differential, and creatine kinase level were normal. She was hospitalized for further diagnostic evaluation and was noted to have abnormal muscle movements classified as myokymia (continuous involuntary quivering, rippling, or undulating movement of muscles). Electromyography confirmed the myokymia but did not reveal evidence of a myopathy or neuropathy, prompting additional evaluation for a systemic etiology.
authors.affiliation: Departments of Pediatrics, and Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; and University of Pennsylvania, Robert Wood Johnson Foundation Clinical Scholar Program, Philadelphia, Pennsylvania jenssenb@email.chop.edu.
authors.forename: Brian P
authors.initials: BP
authors.lastname: Jenssen
authors.affiliation: Departments of Pediatrics, and Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; and.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Lautz
authors.affiliation: Departments of Pediatrics, and Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; and.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Orthmann-Murphy
authors.affiliation: Departments of Pediatrics, and Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; and.
authors.forename: Sabrina W
authors.initials: SW
authors.lastname: Yum
authors.affiliation: Departments of Pediatrics, and Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; and.
authors.forename: Angela
authors.initials: A
authors.lastname: Waanders
authors.affiliation: Departments of Pediatrics, and Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; and.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Fox
mesh_terms: D002648:Child; D005260:Female; D006801:Humans; D007866:Leg; D009120:Muscle Cramp / Q000209:etiology; D020385:Myokymia / Q000209:etiology; D009447:Neuroblastoma / Q000150:complications / Q000175:diagnosis*; D020361:Paraneoplastic Syndromes, Nervous System / Q000150:complications / Q000175:diagnosis*