Intravenous Immunoglobulin (IVIG) is a concentrated blood product derived from the plasma of thousands of healthy donors, composed primarily of antibodies. Peripheral neuropathy, or nerve damage, causes symptoms like numbness, tingling, and muscle weakness. IVIG is a well-established therapy for certain immune-mediated neuropathies. This article explores IVIG side effects to clarify when a reaction is a temporary inconvenience versus a true worsening of the underlying neurological condition.
Understanding IVIG Treatment for Neuropathy
IVIG is used to treat autoimmune-related neuropathies. The treatment is indicated for disorders such as Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and Multifocal Motor Neuropathy (MMN), where IVIG acts as an immune modulator to dampen the harmful autoimmune response. By supplying a large, diverse pool of antibodies, the therapy can neutralize autoantibodies and suppress inflammation that damages the nerve sheaths.
IVIG is administered directly into a vein over several hours. Dosing is calculated based on body weight, often involving a high dose divided over two to five days and repeated monthly for maintenance. This process is generally well-tolerated and is considered a safer alternative compared to long-term steroid use. The goal is to stabilize the immune system, prevent further neurological decline, and improve muscle strength and sensory function.
Immediate and Temporary Side Effects
Most patients receiving IVIG experience mild, transient adverse effects. These reactions are systemic and not typically a sign that the underlying nerve damage is worsening. Common immediate effects include flu-like symptoms such as headache, fever, chills, and muscle aches.
These temporary effects usually occur during the infusion or within the first 24 hours and resolve spontaneously. Severity is often related to the infusion rate. Other common reactions include fatigue, nausea, back pain, and temporary blood pressure fluctuation. Symptoms are managed by slowing the infusion rate or using pre-medications like acetaminophen or antihistamines.
A delayed, temporary headache may last 24 to 72 hours following the infusion. These self-limiting symptoms are the body’s temporary reaction to the concentrated protein, not progression of the neuropathy. Patients must differentiate these expected, transient reactions from true neurological deterioration.
Specific Neurological Risks and Exacerbation
While IVIG is generally safe, rare but serious adverse events can occur, which might mimic or directly cause new neurological symptoms. Aseptic meningitis is one such complication, occurring in a small percentage of patients. This reaction involves non-infectious inflammation of the membranes surrounding the brain and spinal cord, presenting with a severe headache, neck stiffness, and sensitivity to light.
A serious, rare concern is the risk of thromboembolic events, such as stroke or transient ischemic attack (TIA). IVIG temporarily increases plasma viscosity, elevating the risk of clotting, especially in patients with pre-existing risk factors like advanced age or vascular disease. A stroke results in sudden loss of neurological function, which might be incorrectly perceived as worsening neuropathy.
Acute kidney injury is a rare complication, occurring indirectly due to IVIG, especially with older formulations containing sucrose stabilizers. While this does not directly worsen neuropathy, severe renal dysfunction is a systemic complication that requires immediate attention. True paradoxical worsening of the autoimmune neuropathy immediately following IVIG is uncommon, though some patients may experience a temporary flare-up before beneficial effects appear.
Monitoring and Patient Guidance
Minimizing adverse effects begins with careful preparation, including ensuring the patient is well-hydrated before the infusion. Adequate hydration, often achieved through oral fluids or intravenous saline, helps reduce the risk of kidney complications and systemic reactions like headache. The infusion must be started slowly and gradually increased while the patient is closely monitored.
Patients should be vigilant for specific warning signs requiring immediate medical evaluation. These include:
- Sudden onset of a severe, unrelenting headache accompanied by a stiff neck, which could indicate aseptic meningitis.
- Signs of a thromboembolic event, such as sudden weakness on one side of the body.
- Difficulty speaking.
- Severe localized pain in a limb.
Regular monitoring of blood work, including kidney function tests, may also be performed to catch potential issues early. The goal of this infusion is to stabilize the immune system and prevent further neurological decline, ultimately aiming for improved muscle strength and sensory function.