Inflammatory neuropathy occurs when the body’s immune system mistakenly attacks its peripheral nerves, leading to damage and impaired function. These nerves, extending outside the brain and spinal cord, transmit signals controlling movement, sensation, and automatic bodily processes. When damaged, this disrupts communication between the brain and body.
The impact varies significantly among individuals, depending on which nerves are affected and the extent of damage. Challenges can include mobility, changes in sensation, and issues with involuntary bodily functions like heart rate or digestion.
The Inflammatory Process in Neuropathy
The peripheral nervous system connects the central nervous system (brain and spinal cord) to the limbs and organs. These nerves are composed of nerve fibers, many of which are insulated by a protective fatty layer called the myelin sheath. This myelin sheath allows electrical signals to travel rapidly and efficiently along the nerve.
In inflammatory neuropathy, the immune system erroneously targets components of these peripheral nerves. This misguided attack can involve the myelin sheath, leading to demyelinating neuropathy, or it can directly target the nerve fibers themselves, resulting in axonal neuropathy.
Damage to the nerve structures disrupts their ability to transmit signals effectively. For instance, when the myelin sheath is damaged, nerve impulses slow down or can even be completely blocked, similar to how a frayed electrical wire might fail to conduct electricity properly. This interference with signal transmission underlies the symptoms.
Major Forms of Inflammatory Neuropathy
Guillain-Barré Syndrome (GBS) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) are two major forms of inflammatory neuropathy. GBS is an acute, rapidly progressing condition, often appearing after an infection. Symptoms typically begin with tingling and muscle weakness in the feet and legs, then quickly ascend to affect the arms and upper body, potentially leading to severe paralysis and breathing difficulties within days or weeks.
In contrast, CIDP is a chronic condition characterized by progressive or relapsing-remitting muscle weakness and sensory loss that worsens over at least eight weeks. Unlike GBS, CIDP symptoms develop more slowly and can fluctuate. CIDP is an autoimmune disorder where the immune system attacks the myelin sheath of peripheral nerves, similar to GBS, and its chronic nature often necessitates long-term treatment.
Multifocal Motor Neuropathy (MMN) is a rare disorder where the immune system attacks specific motor nerves, primarily causing asymmetrical muscle weakness and cramping in the limbs, often starting in the hands. MMN typically involves minimal to no sensory symptoms like numbness or pain. Vasculitic neuropathy arises from inflammation of the blood vessels that supply the nerves, leading to nerve tissue damage due to reduced blood flow. This condition can present with pain, numbness, and weakness, often affecting nerves in an asymmetric pattern.
Recognizing the Symptoms
Symptoms of inflammatory neuropathy vary based on the specific nerves affected and the condition’s progression. Many people first experience changes in sensation, such as numbness, tingling, or a burning feeling, often starting in the hands and feet before potentially spreading upwards. These sensory disturbances can make it difficult to perceive touch, temperature, or pain normally.
Muscle weakness is another common symptom, often appearing symmetrically. This weakness can make everyday activities challenging, such as walking, climbing stairs, lifting objects, or gripping small items. Over time, muscle weakness may lead to muscle atrophy.
In some cases, inflammatory neuropathy can also affect autonomic nerves, which control involuntary bodily functions. Autonomic symptoms might include changes in heart rate or blood pressure, digestion issues, or sweating abnormalities. The severity of symptoms can differ and may progress, impacting daily life and requiring medical attention.
Diagnosis and Treatment
Diagnosing inflammatory neuropathy involves a comprehensive approach combining symptom review, medical history, and diagnostic tests. A neurological examination helps assess muscle strength, reflexes, and sensory responses, providing initial clues about nerve function. To further evaluate nerve health, nerve conduction studies (NCS) and electromyography (EMG) are commonly performed. NCS measures how fast electrical signals travel along nerves, while EMG assesses the electrical activity of muscles, helping to identify nerve damage or dysfunction.
A spinal tap, also known as a lumbar puncture, collects cerebrospinal fluid (CSF) from the lower back. This fluid is analyzed for elevated protein levels, a characteristic finding in conditions like Guillain-Barré Syndrome. Blood tests are also conducted to rule out other conditions that might mimic inflammatory neuropathy or to identify specific antibodies that indicate an autoimmune response. In select instances, a nerve biopsy can provide additional diagnostic information.
Treatment for inflammatory neuropathy focuses on reducing inflammation, managing symptoms, and promoting recovery. Immunomodulatory therapies are central, with Intravenous Immunoglobulin (IVIg) and Plasma Exchange (Plasmapheresis) as primary interventions for both acute and chronic forms. IVIg administers a concentrated solution of antibodies to regulate the immune system and neutralize harmful autoantibodies. Plasmapheresis is a procedure that removes a patient’s blood, separates the plasma containing harmful antibodies, and returns the blood cells with a replacement fluid, effectively filtering out the immune system components that are attacking the nerves.
Corticosteroids, such as prednisone, are also used to suppress the immune system and reduce inflammation, particularly in conditions like CIDP. These treatments aim to halt the immune attack and allow the nerves to begin healing. Symptomatic management, including pain relief, physical therapy, occupational therapy, and sometimes speech therapy, improves function and quality of life. Treatment plans are often individualized and may be long-term, especially for chronic conditions like CIDP.