Fibromyalgia and peripheral neuropathy are chronic pain conditions known for persistent pain and other debilitating symptoms. A common question is whether these distinct conditions can occur together. This article explores each condition, their potential overlap, and how medical professionals approach diagnosis.
Understanding Fibromyalgia
Fibromyalgia is a chronic disorder characterized by widespread musculoskeletal pain. This pain is often described as a constant, dull ache, typically affecting both sides of the body and above and below the waist. The condition also commonly involves fatigue, sleep disturbances, and cognitive difficulties, often called “fibro fog.” Fibromyalgia is understood as a disorder of central pain processing, where the brain and spinal cord amplify pain signals, leading to heightened pain sensitivity. It is not considered an inflammatory or autoimmune disease.
Understanding Peripheral Neuropathy
Peripheral neuropathy involves damage to the peripheral nerves, which are located outside the brain and spinal cord. These nerves transmit information between the central nervous system and the rest of the body, including limbs and organs. Common symptoms include numbness, tingling, weakness, or burning pain, frequently starting in the hands and feet. This condition can arise from various causes, such as diabetes, infections, injuries, or certain autoimmune diseases. Peripheral neuropathy can affect different nerve types, including sensory, motor, and autonomic nerves.
The Connection Between Fibromyalgia and Peripheral Neuropathy
It is possible for individuals to experience both fibromyalgia and peripheral neuropathy concurrently. Recent research highlights a significant connection, particularly concerning small fiber neuropathy (SFN). SFN involves damage to the small nerve fibers in the skin, which transmit pain and temperature sensations. Studies indicate that a notable subset of individuals diagnosed with fibromyalgia may also exhibit evidence of SFN.
This overlap can explain some widespread pain and sensory symptoms often attributed solely to fibromyalgia. Symptoms of SFN, such as burning, tingling, numbness, or electric shock-like sensations, can closely mimic or contribute to the pain experienced by those with fibromyalgia, making diagnosis complex. While these conditions can co-occur, they are still considered distinct entities with different underlying mechanisms. The presence of SFN in some fibromyalgia patients suggests a potential peripheral nervous system contribution to their pain experience, alongside central pain processing abnormalities.
Differentiating the Conditions
Healthcare professionals employ a comprehensive approach to distinguish between fibromyalgia and peripheral neuropathy, or to diagnose both if present. This process begins with a thorough medical history and a detailed physical examination. The physical exam for fibromyalgia may include assessing specific tender points, while for neuropathy, it involves evaluating sensory and motor function.
Diagnostic tests confirm or rule out each condition. For peripheral neuropathy affecting larger nerve fibers, nerve conduction studies (NCS) and electromyography (EMG) are commonly performed. These tests measure nerve and muscle electrical activity to assess damage. However, these tests often appear normal in cases of small fiber neuropathy or fibromyalgia.
To diagnose small fiber neuropathy, a skin biopsy (punch biopsy) is frequently used to measure the density of intraepidermal nerve fibers, which can be reduced in SFN. Blood tests also rule out other conditions that might cause neuropathy, such as diabetes or vitamin deficiencies. Specialists like neurologists and rheumatologists often collaborate to make accurate diagnoses, particularly when symptoms are complex or overlap. Accurate diagnosis is crucial for guiding targeted management strategies.