[A case of Down's syndrome with chronic inflammatory demyelinating polyradiculoneuropathy].

A 19-year-old male patient with Down's syndrome accompanied by relapsing and steroid-dependent chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) was reported. He had been well until the beginning of June 1988, and he rapidly developed a gait disturbance and symmetrical numbness in his arms and legs at the end of that month. He also suffered from difficulty in swallowing and dyspnea soon afterward. A physical examination revealed the specific clinical features of Down's syndrome, but no particular signs. Neurological examination showed the following abnormal findings; fixed nystagmus, diminished gag reflex, flaccid tetraparesis, and distal dominant dysesthesia of upper and lower extremities. Deep tendon reflexes were diminished and Babinski's sign was negative. No autonomic dysfunction was detected. Routine hematology and biochemistry screening test revealed normal level except for increasing GPT and IgG. Protein and gamma globulin values in cerebrospinal fluid (CSF) were elevated without pleocytosis. Nerve conduction velocities were slighty reduced. Pulse therapy and corticosteroid treatment improved on clinical course and CSF results. CIDP probably results from an abnormal immune responsiveness. Down's syndrome has often been taken for autoimmune abnormality. It is of great interest whether there is a close connection of autoimmune abnormality between Down's syndrome and CIDP. This might be the first case report of Down's syndrome associated with CIDP, judging from our survey of the literature in Japan and other countries.