title: Criteria in diagnosing nocturnal leg cramps: a systematic review.
abstract: BACKGROUND
  Up to 33% of the general population over 50 years of age are affected by nocturnal leg cramps. Currently there are no generally accepted clinical characteristics, which identify nocturnal leg cramps. This study aims to identify these clinical characteristics and to differentiate between them and the characteristics of restless leg syndrome and periodic limb disorder.
  
  
  METHODS
  A systematic literature study was executed from December 2015 to May 2016. This study comprised of a systematic literature review of randomized clinical trials, observational studies on nocturnal and rest cramps of legs and other muscles, and other systematic and narrative reviews. Two researchers independently extracted literature data and analyzed this using a standardized reviewing protocol. Modified versions of the Cochrane Collaboration tools assessed the risk of bias. A Delphi study was conducted to assess agreement on the characteristics of nocturnal leg cramps.
  
  
  RESULTS
  After systematic and manual searches, eight randomized trials and ten observational studies were included. On the basis of these we identified seven diagnostic characteristics of nocturnal leg cramps: intense pain, period of duration from seconds to maximum 10 minutes, location in calf or foot, location seldom in thigh or hamstrings, persistent subsequent pain, sleep disruption and distress.
  
  
  CONCLUSIONS
  The seven above characteristics will enhance recognition of the condition, and help clinicians make a clear distinction between NLC and other sleep-related musculoskeletal disorder among older adults.
authors.affiliation: Research Group Healthy Ageing, Allied Health Care and Nursing, Hanze University of Applied Sciences, Groningen, The Netherlands. hhallegraeff@gmail.com.|SOMT University Campus, Institute for Master Education in Musculoskeletal Therapies, Amersfoort, The Netherlands. hhallegraeff@gmail.com.
authors.forename: Joannes
authors.initials: J
authors.lastname: Hallegraeff
authors.affiliation: Research Group Healthy Ageing, Allied Health Care and Nursing, Hanze University of Applied Sciences, Groningen, The Netherlands.|University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.
authors.forename: Mathieu
authors.initials: M
authors.lastname: de Greef
authors.affiliation: Research Group Healthy Ageing, Allied Health Care and Nursing, Hanze University of Applied Sciences, Groningen, The Netherlands.|University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: Krijnen
authors.affiliation: Research Group Healthy Ageing, Allied Health Care and Nursing, Hanze University of Applied Sciences, Groningen, The Netherlands.|University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.
authors.forename: Cees
authors.initials: C
authors.lastname: van der Schans
mesh_terms: D006801:Humans; D009120:Muscle Cramp / Q000150:complications / Q000175:diagnosis*; D012148:Restless Legs Syndrome / Q000150:complications / Q000175:diagnosis*; D020922:Sleep-Wake Transition Disorders / Q000175:diagnosis* / Q000209:etiology
keywords: Aged; Cramps; Diagnosis; Nocturnal; Restless legs syndrome; Sleep-wake transition disorder