Overlapping central nervous system (CNS) and peripheral nervous system (PNS) demyelination is a rare clinical entity, more frequently seen in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and multiple sclerosis (MS). This case report showcases a patient with atypical CIDP and CNS demyelination lesions. Demographic data, disease course, treatment responsiveness, neurological examination, laboratory tests, nerve conduction studies (NCS), and brain and spinal cord MRI were registered. The case highlights the difficulty of diagnosis establishment and treatment selection, given the atypical course of the disease and limited answers to the indicated therapies. The data from our report suggest that specific and widely available immunological targets are necessary for diagnosing combined central and peripheral demyelination cases appropriately. The association of different immunotherapeutic agents may be necessary to induce and maintain disease remission.