title: Paraneoplastic neurological syndromes: unusual presentations of cancer. A practical review.
abstract: BACKGROUND
  Paraneoplastic neurological syndromes (PNS) are uncommon and imperfectly understood and, therefore, are frequently underdiagnosed.
  
  
  METHODS
  We review the current literature on the clinical presentation, diagnosis, pathophysiology and treatment of PNS.
  
  
  RESULTS
  PNS are a heterogeneous group of neurologic disorders caused by an immune response to an underlying malignancy. A 3-step diagnostic process is necessary to establish the diagnosis. We review the role of onconeural antibodies in the diagnosis and pathogenesis of PNS and describe recent advances in treatment, focusing on paraneoplastic encephalomyelitis, limbic encephalitis, paraneoplastic cerebellar degeneration, opsoclonus-myoclonus syndrome, subacute sensory neuronopathy and Lambert-Eaton myasthenic syndrome
  
  
  CONCLUSIONS
  PNS often antedate the diagnosis of cancer, offering an opportunity for detecting cancer at an earlier and curable stage. Tests for paraneoplastic antibodies are often negative and do not rule out the diagnosis of a paraneoplastic syndrome. Certain clinical presentations should suggest a paraneoplastic syndrome, even in the absence of paraneoplastic antibodies, and prompt a thorough search for occult malignancy.
authors.affiliation: Department of Medicine, John H. Stroger, Jr. Hospital of Cook County, Chicago, IL, USA. tareqbk410@hotmail.com
authors.forename: Tareq
authors.initials: T
authors.lastname: Braik
authors.forename: Arthur T
authors.initials: AT
authors.lastname: Evans
authors.forename: Margaret
authors.initials: M
authors.lastname: Telfer
authors.forename: Susan
authors.initials: S
authors.lastname: McDunn
mesh_terms: D000912:Antibodies, Neoplasm / Q000378:metabolism; D001323:Autoantibodies / Q000378:metabolism; D006801:Humans; D015624:Lambert-Eaton Myasthenic Syndrome / Q000175:diagnosis; D020363:Limbic Encephalitis / Q000175:diagnosis; D053578:Opsoclonus-Myoclonus Syndrome / Q000175:diagnosis; D020362:Paraneoplastic Cerebellar Degeneration / Q000175:diagnosis; D020364:Paraneoplastic Polyneuropathy / Q000175:diagnosis; D020361:Paraneoplastic Syndromes, Nervous System / Q000175:diagnosis* / Q000209:etiology / Q000276:immunology
chemical_list: D000912:Antibodies, Neoplasm; D001323:Autoantibodies