Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is a rare neurological disorder where the body’s immune system attacks the protective covering, or myelin sheath, of the peripheral nerves. These nerves transmit signals between the brain, spinal cord, and the rest of the body. The resulting damage to the myelin interrupts these signals, leading to a progressive loss of sensation and muscle function. Because its symptoms often develop slowly and can be mistaken for other conditions, CIDP is frequently a challenge to diagnose initially.
Early Sensory Changes
The first symptoms of CIDP frequently involve changes in sensation, typically manifesting in the extremities. Patients often report tingling, prickling, or numbness (paresthesia) that begins in the toes and fingers. This sensory disturbance is often symmetrical, affecting both sides of the body equally.
A characteristic pattern seen in CIDP is the “glove-and-stocking” distribution, where sensory loss is confined to the hands and feet, resembling gloves and stockings. This occurs because the longest nerve fibers, which reach the extremities, are often the first damaged. Sensory issues can also include dysesthesia (an unpleasant, abnormal sense of touch) or a reduced ability to feel vibration or a pinprick.
As the condition progresses, the loss of sensation can extend up the limbs, moving toward the knees and elbows. This loss of feeling, particularly affecting nerve fibers that transmit information about body position (proprioception), significantly affects balance and coordination. An early sign may be increased clumsiness or difficulty maintaining balance, especially when walking in the dark or when the eyes are closed.
Initial Motor Difficulties
Concurrent with or shortly following sensory changes, individuals with CIDP begin to experience symmetrical muscle weakness, often starting in the legs and progressing upward. This motor impairment affects both proximal muscles (hips and shoulders) and distal muscles (hands and feet). The weakness results from the immune attack slowing or blocking the electrical signals necessary for muscle contraction.
Early physical tasks that become noticeably difficult include climbing stairs, rising from a low chair, or lifting objects overhead. Weakening of muscles responsible for lifting the front part of the foot can lead to foot drop. Foot drop results in a dragging of the toes or a high-stepping, slapping gait as the individual attempts to compensate.
Fine motor skills also become impaired as weakness affects the hands and forearms. Tasks requiring manual dexterity, such as buttoning a shirt, zipping a zipper, or turning a key, may become challenging. Furthermore, the disease typically causes a loss or weakening of the deep tendon reflexes, which a doctor may observe during a routine physical examination.
The Chronic Nature of CIDP Symptoms
The timeline and pattern of symptom progression define CIDP, setting it apart from acute nerve disorders. For a diagnosis, muscle weakness and sensory changes must progress for a minimum of eight weeks. This chronic timeline distinguishes it from conditions like Guillain-Barré Syndrome (GBS), where symptoms usually peak within a few weeks.
The disease course typically follows one of two patterns: a slowly progressive worsening over months or a relapsing-remitting course. In the progressive form, symptoms gradually increase in severity without periods of improvement. The relapsing-remitting form involves flare-ups followed by periods of partial or complete recovery, only for the symptoms to return later.
The symptoms almost always present in a bilateral pattern, meaning both sides of the body are affected at the same time and to a similar degree. This symmetrical presentation is a significant feature that helps clinicians identify CIDP. Understanding this chronic and often fluctuating nature is essential.
Seeking Confirmation and Next Steps
Recognizing these initial sensory and motor changes is the first step toward receiving a proper diagnosis. Anyone experiencing gradual, symmetrical weakness and numbness that persists for several weeks should consult a healthcare provider, ideally a neurologist. Early diagnosis is important because timely treatment can prevent permanent nerve damage and minimize long-term disability.
The neurologist will typically order specialized tests to confirm the diagnosis and rule out other causes of peripheral neuropathy. The most important diagnostic procedures are electrodiagnostic studies, including nerve conduction studies (NCS) and electromyography (EMG). These tests measure the speed and strength of electrical signals in the peripheral nerves and muscles, revealing the characteristic nerve demyelination.
Other procedures, such as a lumbar puncture to analyze the cerebrospinal fluid, may also be used to look for elevated protein levels without an increase in white blood cells. Ultimately, a diagnosis of CIDP is established by combining the patient’s specific pattern of chronic symptoms with the objective findings from these specialized neurological tests.