Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronic recurrent acquired immune-mediated disease of the peripheral nerves that presents with progressive sensory and motor deficits in all four limbs. Cranial nerve involvement is not as common as in Guillain-Barre syndrome, and central nervous system involvement including optic neuritis has rarely been reported in patients with CIDP. We recently experienced a case with classic CIDP involving bilateral facial and trigeminal nerves, right lower cranial nerves, and the right optic nerve.

Immune checkpoint inhibitors (ICIs) have emerged as one of the most promising therapeutic options for advanced cancers. While ICIs have improved survival in multiple cancers, their increased use is restricted by various immune-related adverse events. In this report we describe a patient with renal cell carcinoma who received a combination of ICIs, nivolumab plus ipilimumab, and who developed lumbosacral polyradiculoneuropathy. Corticosteroid use was an effective treatment for this patient.

Electrodiagnostic tests (EDX) is essential for the diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP). EDX could provide information about demyelinating pathology in the peripheral nerves. According to phenotypes, CIDP could be classified several phenotypes, which has different clinical manifestations, EDX could present a different distribution pattern of demyelinating lesions. In addition, EDX could be useful markers for predicting treatment response of prognosis of CIDP.