POEMS syndrome presenting with acute demyelinating polyneuropathy: increased terminal latency indices and uniform demyelination.

We herein report a case of polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes (POEMS) syndrome presenting with acute Guillain-Barré syndrome (GBS)-like features. The patient was healthy, except for mild dilated cardiomyopathy. She was unable to walk within ten days of the onset of weakness. A nerve conduction study (NCS) showed length-dependent, symmetric and non-focal demyelinating features with increased terminal latency indices (TLIs) in the lower limbs. Following the administration of intravenous immunoglobulin infusion, the proximal weakness of the lower extremities improved; however, the pleural effusion was aggravated and ascites newly developed. On further work-ups, splenomegaly, M-protein and sclerotic bone changes were observed. This case suggests that, although rare, POEMS syndrome can present with acute demyelinating polyneuropathy resembling GBS and that characteristic NCS features such as increased TLI and uniform demyelination are helpful for the early diagnosis of POEMS syndrome.