There’s a chance you’ve heard of restless legs syndrome — a disorder that causes an irresistible urge to kick, flick, and jitter your legs — but have you ever heard of restless arms syndrome? In a new case report, researchers describe the unusual presentation of a man with this little-known condition, raising concerns this disorder might be more common than previously realized.
Reported in the BMJ, pain therapists from the Bavarian State Medical Association in Munch described a 66-year-old patient who was experiencing an increasing amount of uncontrolled or involuntary movements of the arms over the past 20 years. Over this period of time, he had also been suffering from mounting pain in his back and shoulders. The man had visited a bunch of medical specialists over the past two decades, but none were able to deliver any relief.
Aside from occurring in the arms, the condition sounded remarkably similar to restless legs syndrome, a common condition of the nervous system that causes an overwhelming and irresistible urge to move the legs. People with the condition describe an uncomfortable, painful, electrical buzzing, or itchy feeling in their legs that’s only eased by movement. It’s often defined as a sleep disorder since the symptoms tend to occur when a person is resting or attempting to sleep. Along with having a big impact on sleep quality, the condition can drastically damage a person's quality of life and may even raise the risk of suicide or self-harm.
The cause of restless legs syndrome is idiopathic, which is doctor-speak for “we don’t know.” Most researchers suspect it might have something to do with the nervous system and a neurotransmitter called dopamine, which is involved in controlling muscle movement. Alternatively, some cases may be linked to an underlying health condition, such as iron deficiency anemia or kidney failure. One thing that's more certain is that the condition appears to run in families.
Severe cases of restless legs syndrome have been known to also affect the arms, but this unusual case appeared to exclusive to the upper extremities.
"In the last two years, these symptoms had worsened massively and the essential International Restless Legs Syndrome Study Group diagnostic criteria were fully met, except that the symptoms were exclusively in the upper limbs,” the study authors write.
The patient first made contact with the doctors behind this report in 2017. At that time, they ran a treatment that included behavioral therapy, trigger point anesthesia injections, acupuncture treatment, and more, which temporarily eased symptoms, but ultimately failed to solve the problem. A later physical and neurological examination in October 2020 failed to show anything unusual.
Eventually, after ruling out other possibilities, the doctors put him on the drug Restex, which contains levodopa, a dopamine precursor used in the management of restless legs syndrome, as well as Parkinson's disease. The drug appeared to work, bringing rapid relief to his symptoms and significantly improving his quality of life.
The study authors explain that restless arms syndrome appears to be very rare, with very few cases described in medical literature. Nevertheless, they suspect it might be more common than most doctors currently appreciate.
“Very few RAS [restless arms syndrome] patients... have been described to date, suggesting that RAS may be an extremely rare disease. However, the exact prevalence of RAS is largely unknown,” they conclude. “It is possible that RAS is underdiagnosed, especially in milder and transient forms.”