Neuropathy associated with paraneoplastic neurological syndrome

: Paraneoplastic neurological syndromes (PNSs) are the remote effects of cancer on the nervous system. The peripheral nervous system is an important targets of PNS. The neuropathies associated with PNS are reviewed in this article. Among the various paraneoplastic neuropathies, the main classical syndorome of PNS is subacute sensory neuronopathy that involves the cell bodies of sensory neurons in the dorsal root ganglia. Its clinical symptoms include sensory ataxia. Onconeuronal antibodies such as anti-Hu and anti-CV2/CRMP5 antibodies are frequently associated with this syndrome. In contrast to this classical form of PNS, non-classical syndromes are considered as heterogeneous neuropathies. The clinical features of non-classical syndromes are variable and no evident association between a clinical phenotype and onconeuronal antibodies has been established. Early detection and treatment of cancer is an essential for management of PNS. Neuropathies with paraproteinemia are also important clinical entities of PNS. IgM M-protein is most likely to cause neuropathy. Patients with IgM paraproteinemic neuropathy is usually characterized by predominan distal and sensory impairment, prolonged distal motor latencies in nerve conduction studies, and the presence of anti-MAG and SGPG antibodies.