A 37-year-old right-handed man presented after two episodes of weakness. During the first episode, he developed painful paresthesias followed by quadriparesis. A presumptive diagnosis of an immune mediated polyradiculoneuropathy, such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) or multifocal mononeuropathy (MMN) was made. Details of diagnostic tests from this evaluation were unavailable. He was treated with intravenous immunoglobulins with which muscle strength partly improved.