[A case of chronic inflammatory demyelinating polyradiculoneuropathy complicated by phrenic nerve palsy]

We report on a patient with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) complicated by phrenic nerve palsy. A 50-year-old man was admitted to our hospital due to dyspnea and numbness in his limbs. On admission, severe muscle atrophy, weakness, and sensory disturbance were seen in the distal part of his extremities. Deep tendon reflexes were absent in all the limbs. Routine blood examinations showed no abnormal findings except for mild hyperglycemia (fasting blood sugar 145 mg/dl). Right phrenic nerve palsy was observed on a chest roentgenogram and % vital capacity (%VC) was 56%. Cerebrospinal fluid showed elevated levels of total protein (116 mg/dl) and IgG (16.9 mg/dl). Sural nerve biopsy revealed severe loss of myelinated fibers with demyelination and onion-bulb formation. After immunoadsorption plasmapheresis, the phrenic nerve palsy improved rapidly and %VC recovered to 76%. Although phrenic nerve palsy is rare in patients with CIDP, it is important to take notice of this condition, because phrenic nerve palsy is critical when it occurs bilaterally or when it develops in patients who have suffered from respiratory diseases. Immunoadsorption plasmapheresis is one of the effective treatments for CIDP, especially in patients with serious complications such as phrenic nerve palsy.