Restless leg syndrome (RLS) is a condition in which people report the uncomfortable and irresistible urge to move their legs, most commonly in the evenings.
This is a powerful sensation where the person is driven to try and alleviate the feelings through movement to try and get the muscles to calm down. It is more than just trying to get settled and comfortable.
Originally called Ekbom disease, this condition typically improves when the person is able to get up and walk around. When the person is still, such as if they’re sitting in a classroom or on a plane, the sensation usually intensifies.
Even though this syndrome has existed for centuries, there is minimal awareness about RLS in the public.
If the symptoms associated with RLS occur during sleep and you also experience limb movements, it may be a sign of periodic limb movement disorder. PLMD can be debilitating as it causes frequent awakenings that result in significant daytime sleepiness.
What causes RLS and PLMD? The most common cause for RLS is iron deficiency. Typically, bloodwork should be done to check the person’s iron levels, its precursor ferritin, as well as several other vitamins that play a role in regulating movement. These include vitamin B12, magnesium, and folate.
RLS tends to run in families, and certain races are also more predisposed to this condition.
A 2013 study found RLS is prevalent in 0.1 % of Hispanics, 0.5% of Caucasians, 0.4% of African Americans, and 0.7% of others. The prevalence also varied by countries, with 4.9% in Spain, 8.6% in the UK and 7.6 % in the US. And more than 70% of patients with RLS can also have PLMD.
Several antidepressants like venlafaxine, sertraline, fluoxetine, amitriptyline, and antihistamines can exacerbate PLMD.
Treatment for RLS and PLMD. In adults, if iron levels are low, especially if the ferritin is less than 75 micrograms/dl then iron replacement is indicated. The enzyme that is responsible for making dopamine (the chemical in the brain that controls movements is iron-dependent.
If treatment with iron does not help, there are medications like ropinirole, pramipexole and a rotigotine patch that are dopamine agonists. Dosing adjustment should be administered carefully by an expert in this field. If prescribed too liberally, these medications are known to worsen the symptoms, causing restlessness to spread to the upper extremities and sometimes causing symptoms to occur during the day.
A word of caution: These dopamine-agonist medications have common side effects like dry mouth, headaches, and nausea, but compulsory behaviors like gambling are also known to occur. Also, narcotic medications like opiates are highly effective in treating RLS. Due to their side effects and dependency concerns, though, I use these only when I have exhausted other medications and resources.
Beyond medication, exercise and relaxation techniques help to soothe irritated muscles. It’s also important to check medications that you are taking, as RLS can be a side effect of certain antihistamines like diphenhydramine and anti-nausea medicines like metoclopramide. Most antidepressants are also known to exacerbate RLS.
There are also several devices on the market targeting RLS. These are either placed under the feet or strapped onto the legs, and they provide a vibrating movement to counterbalance the restless feeling.
For PLMD, the treatment is similar to the treatment regimen for RLS. Also, changing antidepressants will help.
When it comes to testing, sleep studies are rarely needed, except in rare situations when symptoms are worse during sleep (which often point to PLMD), or if other sleep disorders are suspected.