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Nocturnal Leg Cramp

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Nocturnal Leg Cramp, Nocturnal Leg Muscle Cramp, Night Leg Cramp, Night Cramp, Leg Cramp, Charley Horse

  • See Also
  • Epidemiology
  1. Incidence
    1. Adult: 50-60%
    2. Child: 7%
  2. Frequency
    1. May be daily in up to 20% of patients
  • 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)
  • Risk Factors
  • 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
  • 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)
  • 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
  • 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)
  • Complications
  • 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