How is chronic inflammatory demyelinating polyneuropathy diagnosed?

Diagnosis of CIDP can be challenging, as neuropathy can be caused by many different causes and CIDP has several variants. It is not uncommon for CIDP to go undiagnosed for a long time as symptoms can be vague initially. Careful and thorough evaluation by neurologists/neuromuscular specialists is important in establishing the diagnosis.

Diagnostic tests that may be performed to confirm the diagnosis of CIDP include the following:

• Electromyogram (EMG) and nerve conduction studies (NCS). A test that measures the electrical activity of a muscle or a group of muscles, and the nerves. The diagnosis of CIDP is based on an EMG/NCS pattern of multifocal demyelination, typically involving both sensory and motor nerves.
• Blood tests
• Magnetic resonance imaging (MRI) to look for thickening of the nerve roots and signs of chronic inflammation.
• Lumbar puncture (spinal tap). A special needle is placed into the lower back, into the spinal canal, which is the area below the spinal cord. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is elevated spinal fluid protein without many inflammatory cells. CSF is the fluid that bathes your child's brain and spinal cord.
• Nerve Biospy. Infrequently, atypical cases may require nerve biopsy to look for evidence of chronic demyelination and inflammation.

Treatment of chronic inflammatory demyelinating polyneuropathy

The key to medically managing CIDP is early detection. If treated early, most CIDP patients respond well to therapy that can limit nerve damage and contribute to improved function and quality of life and, at times, even cure the disorder altogether.

The chronic nature of CIDP requires long-term and multidisciplinary care. Accommodations in the home and school may be needed to facilitate daily living activities and learning. Ongoing physical and occupational therapies are important to strengthen muscles, improve range of motion and prevent joint contracture.

There are three standard immunomodulating treatments for CIDP:

• Corticosteroids (Prednisone®, prednisolone) – These drugs are similar to naturally occurring anti-inflammatory hormones made by the body, and can be used as an initial treatment. Corticosteroids have proven effective in treating individuals with CIDP. They often improve strength, are conveniently taken by mouth, and are inexpensive. However, in high doses, the side effects of corticosteroids can limit long-term use.
• Intravenous immunoglobulin (IVIG) – High-dose intravenous immunoglobulin (IVIG) has proven effective. It is the only drug that has FDA, Canadian and European approval for treatment of CIDP. IVIG contains naturally occurring antibodies obtained from healthy volunteers. IVIG is given through a vein over the course of several hours. Newer preparations of higher concentrations that can be given under the skin (subcutaneous) also received FDA approval for  CIDP adult patients.
• Plasma exchange (PE) or plasmapheresis (PLEX) – This is a process for removing harmful substances in the blood’s plasma. Blood is removed from the patient and returned to the body without the liquid plasma portion of the blood. This treatment is effective only for a few weeks and may require chronic intermittent treatments, and it is typically reserved for refractory patients.

In 2020, CHOP's Division of Neurology was designated as a Center of Excellence by the GBS/CIDP Foundation International. This designation recognizes medical facilities for the diagnosis and treatment of GBS and CIDP, MMN and related neuropathies — and CHOP is the very first pediatric program to receive this distinction. Currently, there are 56 facilities with this designation worldwide.