Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare autoimmune disorder affecting the nervous system. It damages the myelin sheath – the protective layer around nerve fibers – leading to progressive weakness, numbness, and impaired coordination. While CIDP can be debilitating if left untreated, most people respond well to therapies that suppress the immune system and reduce inflammation.
What Happens in CIDP?
The core problem in CIDP is an immune system malfunction where the body attacks its own nerves. This attack strips away the myelin sheath, disrupting nerve signals and causing a range of symptoms. Without myelin, nerves become vulnerable to damage, leading to weakness, tingling, and impaired motor control.
Types of CIDP
CIDP isn’t a single condition; it manifests in several subtypes:
- Typical CIDP: The most common form, affecting both sides of the body equally with muscle weakness and sensory changes.
- Multifocal Motor Neuropathy: Causes asymmetric weakness, affecting one side more than the other.
- Lewis-Sumner Syndrome: Similar to the above, with asymmetric weakness and sensory disturbances.
- Pure Sensory CIDP: Primarily affects sensation, causing numbness, pain, and balance issues without muscle weakness.
- Pure Motor CIDP: Causes weakness on both sides without sensory changes.
- Distal Acquired Demyelinating Symmetric (DADS) Neuropathy: Affects hands and feet but rarely spreads to arms or legs.
- Proximal Radiculopathy: Impacts arms and legs but typically spares hands and feet.
Symptoms to Watch For
CIDP progresses slowly, often over months. Symptoms include:
- Muscle weakness in limbs, shoulders, and hands.
- Decreased muscle mass.
- Tingling or numbness in fingers and toes.
- Poor balance and coordination.
- Difficulty walking or lifting objects.
- Reduced fine motor skills (e.g., buttoning clothes).
- Foot drop (inability to lift the front of the foot).
- In severe cases: swallowing problems, facial weakness, or double vision.
What Causes CIDP?
The exact cause remains unknown. However, it’s believed to be triggered by an overactive immune system mistakenly attacking the myelin sheath. Some variants involve specific antibodies (like neurofascin 155 or contactin 1) targeting nerves, but many cases lack identifiable antibodies.
Recent studies suggest possible links between CIDP and prior respiratory or gastrointestinal infections. It also appears more common with age and in people with autoimmune conditions like lupus or hepatitis.
Diagnosing CIDP: A Complex Process
Diagnosing CIDP isn’t straightforward. Doctors look for worsening weakness and sensory changes in at least two limbs over two months, plus diminished reflexes. Testing includes:
- Blood tests: To rule out diabetes, kidney issues, liver problems, and autoimmune diseases.
- Electromyography (EMG) and nerve conduction studies: To measure nerve function and detect demyelination.
- Lumbar puncture (spinal tap): To analyze cerebrospinal fluid for immune cells and protein levels.
- MRI: To visualize nerves in the lower back and assess response to contrast dye.
- Nerve biopsy: Rarely performed, but can confirm demyelination.
Treatment and Management
CIDP is treatable. Common approaches include:
- Corticosteroids: Reduce inflammation but have potential side effects.
- Intravenous Immunoglobulin (IVIG): Infusion of healthy immune proteins to calm the immune attack. Often preferred due to faster action and fewer side effects.
- Plasma Exchange: Filters harmful antibodies from the blood, providing temporary relief.
- Immunosuppressants: Azathioprine, cyclosporine, tacrolimus, and mycophenolate can suppress the immune system long-term.
- Emerging Therapies: Efgartigimod (Vyvgart Hytrulo) and rituximab show promise for treatment-resistant cases.
- Physical and Occupational Therapy: To strengthen muscles, regain coordination, and maintain independence.
Prognosis and Outlook
Most people with CIDP improve with treatment. Up to 40% achieve complete remission, while 90% experience improvement. However, nerve damage can become permanent if left untreated. Relapses occur in about half of cases.
Where to Find Support
- GBS/CIDP Foundation International: Provides research, education, and a global network of specialists.
- The Foundation for Peripheral Neuropathy: Raises awareness, educates patients, and supports research.
In conclusion, CIDP is a manageable autoimmune condition. Early diagnosis and treatment are critical to preventing long-term disability. With proper care, most individuals can regain function and maintain a good quality of life.
