II. Epidemiology

  1. Incidence
    1. Adult: 50-60%
    2. Child: 7%
  2. Frequency
    1. May be daily in up to 20% of patients

III. Pathophysiology

  1. Idiopathic
  2. Postulated to have onset in hyperactive Lower Motor Neurons with involuntary discharges
  3. Factors that do NOT appear related to Leg Cramps
    1. Hypovolemia or Dehydration
    2. Electrolyte disturbance (Sodium, Potassium, Magnesium, Calcium, Glucose)
    3. Renal Function test abnormalities (Creatinine)
    4. Liver Function Test abnormalities (Bilirubin, albumin, ALT)

IV. Risk Factors

V. Symptoms

  1. Timing
    1. Nocturnal (may interfere with sleep)
    2. Duration may last 9 minutes or more per episode
    3. Episodes may recurr throughout night
  2. Distribution
    1. Posterior calf Muscles (most common)
    2. Foot
    3. Thigh
  3. Characteristics
    1. Spasm or tightening (visible Muscle Contractions)
    2. Muscle Seizure or Tetany
    3. Muscle twinges
  4. Severity
    1. Intense pain

VI. Exam

  1. Nocturnal Leg Cramps will have no identifying physical findings
  2. Exam should focus on identifying another condition from the differential diagnosis
    1. Neurologic Exam
      1. Distal Sensation (Peripheral Neuropathy)
      2. Tremor or Gait Abnormality (e.g. Parkinsonism)
    2. Vascular exam
      1. Diminished pedal pulses or Ankle-Brachial Index (Claudication)
      2. Varicose Veins (Venous Insufficiency)

VII. Differential Diagnosis

  1. See Leg Pain
  2. Peripheral Vascular Disease (Claudication)
    1. Exertional Muscle ache or cramp relieved with rest
  3. Restless Leg Syndrome
    1. Does not cause Muscle tightening or pain
  4. Hypnic Myoclonus
    1. Jerking suddenly only at the onset of sleep
  5. Periodic Limb Movements
    1. Painless, repetitive, brief (seconds) of slow leg movements (esp. foot dorsiflexion)
  6. Peripheral Neuropathy
    1. Paresthesias or numbness type pain
  7. Statin-Induced Myopathy
    1. Muscle aches or cramps without Muscle Contractions

VIII. Labs

  1. Typically normal in Nocturnal Leg Cramps
  2. Lab evaluation is only indicated if suspected cause on the differential diagnosis (e.g. Peripheral Neuropathy due to Vitamin B12 Deficiency)

IX. Complications

X. Management

  1. Identify and treat comorbid conditions
    1. Peripheral Vascular Disease
    2. Peripheral Neuropathy
    3. Venous Insufficiency
    4. Restless Leg Syndrome
  2. Decrease dose or switch medications from potentially causative agents
    1. Diuretics
    2. Inhaled Beta Agonists (e.g. Albuterol)
    3. Nifedipine
  3. Preventive measures prior to bedtime
    1. Passive Stretching (specific gastrocnemius Muscle or calf stretches)
      1. Foot dorsiflexion may help to extinguish a cramp once it has occurred
    2. Deep massage
    3. Apply hot or cold packs
    4. Maintain adequate hydration
    5. Low-level Exercise for a few minutes prior to bed
      1. Stationary bike
      2. Treadmill
  4. Medications that may be considered (minimal evidence to support these)
    1. Non-Dihydropyridine Calcium Channel Blocker (Diltiazem or Verapamil)
    2. Gabapentin (Neurontin)
    3. Carisoprodol (Soma)
    4. Vitamin B12 Supplementation
    5. Magnesium Supplementation (consider in pregnancy or deficiency)
  5. Medications not found helpful in Nocturnal Leg Cramps
    1. NSAIDs
    2. Calcium Supplementation
  6. Medications not recommended due to potential harm and marginal benefit
    1. Quinine sulfate
      1. Risk of serious Drug Interactions, Hypersensitivity Reactions and Thrombocytopenia
      2. FDA in 2010 recommended avoiding quinine for Leg Cramps as risks outweigh benefits
        1. http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm218424.htm

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Cramps of lower extremities (C0023218)

Concepts Sign or Symptom (T184)
SnomedCT 102550009, 156778004, 203135001
English CRAMPS LEGS, Leg cramp, Muscle cramps in leg, Cramp(s);leg, cramping leg, leg muscle cramp, cramping legs, leg cramp, leg muscle cramps, cramps in legs, muscle cramps in leg, Leg Cramps, Cramps - leg, Leg cramp (finding), Leg Cramp, Leg cramps, Cramps of lower extremities, Cramp legs, Cramps in legs, Cramps leg, Cramps legs, leg cramps
Dutch kramp van benen, kramp van onderste extremiteiten, kramp benen, kramp been, kramp in benen, beenkramp
French Crampes aux jambes, Crampes dans les jambes, Crampes des membres inférieurs, Crampe dans les jambes, CRAMPES DES MEMBRES INFERIEURS
German Kraempfe der unteren Extremitaeten, Beinkrampf, Kraempfe Bein, Kraempfe Beine, Krampf Beine, Kraempfe in den Beinen, BEINKRAEMPFE
Italian Crampi delle gambe, Crampi della gamba, Crampi alla gamba, Crampo delle gambe, Crampi degli arti inferiori
Portuguese Cãibra nas pernas, Cãibras na perna, Cãibra das pernas, Cãibras da perna, Cãibras das pernas, Cãibras das extremidades inferiores, CAIMBRAS NOS MEMBROS INFERIORES
Spanish Calambre en las piernas, Calambres en la pierna, Calambres en las piernas, Calambres en las extremidades inferiores, CALAMBRES EN EEII, calambres en la pierna, calambres musculares en la pierna (hallazgo), calambres musculares en la pierna
Japanese 下肢痙攣, 両下肢痙攣, カシケイレン, リョウカシケイレン
Czech Křeč dolních končetin, Křeče dolní končetiny, Křeče v dolních končetinách, Křeče dolních končetin, Křeče doních končetin
Hungarian Lábgörcs, Görcsök a lábakban, Alsó végtagok görcsei, Görcsök a lábban, Láb-görcsök, Láb görcsök

Ontology: Charleyhorse (finding) (C0277823)

Concepts Sign or Symptom (T184)
ICD10 M62.831
SnomedCT 54981004
English Charleyhorse (finding), Charley Horse, Charleyhorse, Charley-horse, Charley horse
Dutch spierkramp in een been
French Foulure du muscle quadriceps crural
German Muskelkater
Italian Contrattura muscolare da eccessi atletici
Portuguese Espasmo muscular
Spanish Contractura de masa muscular del muslo, inflamación muscular (hallazgo), inflamación muscular
Japanese チャーリーホース, チャーリーホース
Czech Namožení svalu
Hungarian Lábizomgörcs

Ontology: Nocturnal leg muscle cramps (C0860058)

Concepts Sign or Symptom (T184)
Dutch niet-ketotisch hyperglycaemisch hyperosmolair coma
French Crampes musculaires nocturnes aux jambes
German naechtliche Beinmuskelkraempfe
Italian Crampi muscolari notturni agli arti inferiori
Portuguese Cãibras nocturnas dos músculos das pernas
Spanish Calambres nocturnos en los músculos de las piernas
Japanese 夜間下肢痙攣, ヤカンカシケイレン
Czech Noční křeče svalů dolních končetin
Hungarian Nocturnalis láb-izomgörcsök
English Nocturnal leg muscle cramps