Restless Legs Syndrome (RLS), also known as Willis-Ekbom disease, is a neurological condition defined by an overwhelming, often irresistible, urge to move the limbs, typically accompanied by uncomfortable sensations. While the name suggests a focus on the lower body, the disorder is fundamentally systemic, originating in the central nervous system. This means the characteristic restlessness and unpleasant feelings can manifest in the upper limbs. The core diagnostic features remain consistent regardless of the location, centering on the relationship between rest, movement, and the time of day.
RLS Symptom Manifestation Outside the Legs
RLS symptoms are medically recognized to extend beyond the legs to other parts of the body, including the arms, hands, torso, and head. Research suggests that between 21% and 57% of individuals diagnosed with RLS also experience symptoms in their arms. This manifestation in the upper body generally occurs in people who already have RLS in their legs, usually in more severe cases.
In rare instances, an individual may experience symptoms exclusively in the arms, sometimes referred to as Restless Arms Syndrome (RAS). While RAS symptoms mirror those of RLS, the condition is thought to be uncommon and may be underdiagnosed due to its atypical location. For both RLS and RAS, the fundamental diagnostic criteria must be met: symptoms begin or worsen during periods of inactivity, are partially or fully relieved by movement, and are most severe in the evening or at night.
The presence of the disorder in the arms is often considered a sign of a more generalized or severe presentation of the underlying neurological dysfunction. This generalized involvement underscores that RLS is a sensorimotor disorder affecting the nervous system’s ability to regulate movement and sensation throughout the body.
Sensory Characteristics of Upper Body RLS
The sensations experienced in the arms, hands, and shoulders are analogous to those felt in the legs, though patients often struggle to describe them precisely. People report feelings that are deep within the limb, distinct from simple numbness or muscle cramps. Common descriptions include a crawling, creeping, or pulling sensation that feels almost electric.
Other sensory terms used to characterize the discomfort include a deep, dull ache, severe itchiness, a burning feeling, or a tingling sensation like pins and needles. These sensations can range from a mild annoyance to severe discomfort that significantly disrupts the ability to rest. This unpleasant feeling creates an overwhelming, irresistible urge to move the affected arm.
The motor response manifests as a necessity to stretch, shake, rub, or constantly reposition the arms and hands. This movement provides temporary relief, but the symptoms often return immediately once the limb is still. This cycle of intense discomfort while resting, followed by temporary relief upon movement, is often most pronounced when trying to relax or fall asleep at night.
Common Secondary Factors and Risk Profiles
The underlying mechanism of RLS symptoms, including those in the upper body, is strongly linked to a dysfunction in the brain’s dopamine system. Dopamine is a neurotransmitter that plays a crucial role in regulating movement, and an imbalance in its signaling pathways is a primary suspected cause. Several secondary factors can trigger or intensify RLS symptoms in the arms and legs.
Iron deficiency is the most common secondary cause, as iron is necessary for dopamine synthesis in the brain. Low iron stores, particularly low ferritin levels, are frequently observed in individuals with RLS and can drive a more generalized pattern of symptoms. Other medical conditions that contribute include chronic kidney disease, which is associated with RLS two to three times more often than in the general population, and diabetes.
Certain medications are known to worsen or trigger RLS symptoms, including some types of antidepressants, anti-nausea drugs, and certain antihistamines. Pregnancy, especially in the third trimester, is another well-known temporary risk factor, likely due to hormonal changes and potential iron or folate deficiencies.
Clinical Diagnosis and Treatment Approaches
A medical professional diagnoses RLS, even when symptoms are primarily in the arms, by relying on the four essential diagnostic criteria. The diagnosis is clinical, based on the patient’s description of symptoms, including the irresistible urge to move, worsening with rest, relief with movement, and evening/nighttime predilection. The doctor must also exclude other conditions that could mimic the symptoms, such as arthritis or nerve compression.
Non-Pharmacological Treatments
Blood tests are a standard part of the workup, focusing on measuring serum ferritin and transferrin saturation to check for iron deficiency. Addressing iron deficiency with supplements is a primary non-pharmacological treatment that can resolve symptoms in both the arms and legs. Lifestyle modifications are also recommended, such as avoiding known triggers like caffeine and alcohol, and incorporating moderate, regular exercise.
Pharmacological Treatments
When symptoms are frequent or severe, pharmacological treatments are necessary. Medications that increase dopamine signaling, known as dopamine agonists, are effective but must be used cautiously due to the risk of “augmentation,” where symptoms worsen or spread over time. Other first-line treatments include anti-seizure medications like gabapentin or pregabalin, which help reduce the unpleasant sensations in the limbs without the risk of augmentation.