Systemic Lupus Erythematosus (SLE) is a chronic autoimmune condition where the body’s immune system mistakenly attacks its own healthy tissues and organs, including the joints, skin, kidneys, and nervous system. For individuals with SLE, involuntary symptoms like hand shaking raise questions about direct causation. While tremors are not a common primary symptom of uncomplicated Lupus, SLE can cause shaking hands through its potential effects on the central nervous system.
The Link Between Lupus and Tremor
A typical, rhythmic hand tremor is generally not considered a frequent initial manifestation of systemic lupus erythematosus. However, involuntary shaking or movement disorders can occur when Lupus activity involves the brain or spinal cord. This complication is referred to as Neuropsychiatric SLE (NPSLE), which encompasses a wide array of neurological and psychiatric symptoms.
Movement disorders are a recognized, though relatively rare, component of NPSLE. Tremors may manifest as part of a larger neurological picture. It is important to distinguish a true tremor directly caused by the disease from other involuntary movements, such as chorea, which is characterized by sudden, unpredictable jerks and is more commonly linked to Lupus. Some individuals report that their tremors worsen during a disease flare, suggesting a direct connection to active systemic inflammation.
How Lupus Affects the Nervous System
Lupus affects the nervous system through complex pathways that contribute to neurological symptoms like tremor. The primary mechanism involves inflammation, where the autoimmune response damages small blood vessels in the brain, known as vasculitis. This inflammation can compromise the integrity of the blood-brain barrier, which normally protects the central nervous system.
Once the barrier is impaired, autoantibodies—the abnormal immune proteins characteristic of Lupus—can enter the brain tissue. Specific autoantibodies, such as anti-NMDAR, are thought to directly interfere with neuronal function. This attack on neural components can disrupt the brain’s motor control centers, leading to symptoms like seizures, cognitive impairment, or movement disorders, including tremor.
Another element is damage to the brain’s blood supply, often resulting from the pro-clotting state associated with Lupus, especially in those with antiphospholipid antibodies. These antibodies can cause microvascular thrombosis, or small blockages in tiny blood vessels, leading to reduced blood flow or small strokes within the brain. Damage to structures like the cerebellum or basal ganglia, which coordinate movement, can subsequently manifest as involuntary shaking. Also, demyelination, where the protective covering of nerve cells is stripped away by inflammation, can interfere with nerve signaling and contribute to neurological dysfunction.
Common Non-Lupus Causes of Hand Tremor
Since tremor is an uncommon symptom of uncomplicated Lupus, it is important to consider other, more frequent causes for involuntary hand shaking. The most prevalent cause of rhythmic shaking is essential tremor, a neurological condition separate from Lupus that often runs in families. This tremor typically occurs when the hands are active, such as when writing or holding an object, and is generally absent at rest.
A significant non-Lupus cause is medication-induced tremor, as many drugs used to manage SLE can have this side effect.
- Corticosteroids
- Immunosuppressants like cyclosporine
- Mycophenolate mofetil
- The antimalarial drug hydroxychloroquine
If a tremor begins shortly after starting a new treatment, a drug side effect is a probable explanation. Other common factors can also trigger or worsen a tremor, including excessive caffeine consumption or heightened anxiety and stress. Lupus patients are also at a higher risk for developing thyroid disorders; hyperthyroidism is a well-known cause of fine hand tremors. Low blood sugar (hypoglycemia) is another metabolic disturbance that can temporarily lead to physiological shaking.
When to Consult a Healthcare Provider
Any new onset or noticeable change in a hand tremor warrants a consultation with a healthcare provider, especially for someone diagnosed with SLE. It is helpful to document the characteristics of the tremor, noting the time of day it occurs, whether it happens at rest or during activity, and if it is accompanied by other symptoms. This information helps the provider determine if the shaking is a neurological complication of Lupus, a medication side effect, or an unrelated issue.
A rheumatologist or primary care physician can initiate an investigation to rule out medication-related causes or common metabolic issues like thyroid dysfunction. If a neurological cause is suspected, further testing, including blood work for specific autoantibodies or a brain scan like an MRI, may be necessary to assess for Neuropsychiatric SLE. Prompt evaluation of new neurological symptoms is important, as early diagnosis and appropriate treatment of NPSLE can significantly influence the outcome.