Episode 148: Leg Cramps

Episode 148: Leg CrampsFuture Dr. Weller explains the pathophysiology, management, and prevention of leg cramps. Hector Arreaza adds comments and anecdotes about leg cramps.  Written by Olivia Weller, MS4, American University of the Caribbean School of Medicine. Comments by Hector Arreaza, MD.You are listening to Rio Bravo qWeek Podcast, your weekly dose of knowledge brought to you by the Rio Bravo Family Medicine Residency Program from Bakersfield, California, a UCLA-affiliated program sponsored by Clinica Sierra Vista, Let Us Be Your Healthcare Home. This podcast was created for educational purposes only. Visit your primary care provider for additional medical advice.Definition: Known also as “Charlie horses,” leg cramps are defined as recurrent, painful, involuntary muscle contractions. They can last anywhere from seconds to several minutes, with an average of nine minutes per episode. They are usually nocturnal and thus may be associated with secondary insomnia. Location: A muscle cramp can happen in any muscle in the body, but they occur most commonly in the posterior calf muscles, but they can also involve the thighs or feet. They are more common in women than men and the risk increases with age.Although they are experienced by 7% of children and up to 60% of adults, the exact mechanism remains unknown and there is no definitive treatment at this time. PathophysiologyThere is one leading hypothesis for nocturnal cramps that occur in the posterior calf muscles, and it is related to your sleeping position. When you are laying down in bed your toes are pointed which causes passive plantar flexion while the muscle fibers are shortened maximally. This causes uninhibited nerve stimulation with high-frequency involuntary discharge from lower motor neurons, which causes cramping. Another possible etiology is nerve damage because neurologic conditions such as Parkinson’s disease are associated with a higher-than-normal incidence of cramps. Peripheral neuropathy, or damage to the connection between motor nerves and the brain can lead to hyperactive nerves when they are not being properly regulated. Thus, diabetes mellitus is a major risk factor for nocturnal cramps due to the high blood sugar levels damaging the small blood vessels which supply the muscles. Decreased blood flow has also been attributed as a cause of leg cramps. People with diseases that affect their vasculature, such as varicose veins or peripheral arterial disease also have a higher incidence of leg cramps. Decreased blood flow to the muscles means less delivery of oxygen and nutrients to the muscles which makes them more susceptible to fatigue. Muscle overuse is one of the dominant explanations for cramping. This can be related to doing too much high-intensity exercise without adequate stretching before and after. Pregnant women have added weight which puts extra strain on the muscles, along with sitting or standing for long periods of time, poor posture and flat feet. Notably, when we age, our tendons naturally shorten and they cannot work as hard, or as quickly which makes them more susceptible to overuse. Additionally, there are mineral deficiencies such as magnesium and potassium or decreased levels of B and D vitamins. With this in mind, people with renal failure that are on hemodialysis have an increased risk of nocturnal leg cramps. And finally, we have medications, some of which are related to mineral deficiencies. The main contributors are statins, diuretics, conjugated estrogens, gabapentin or pregabalin, Zolpidem, clonazepam, albuterol, fluoxetine, sertraline, raloxifene, and teriparatide (analog for parathyroid hormone). Management and preventionThere is no magic treatment to make them go away immediately, however, there are different remedies you can try to help facilitate. My Gr