Psychiatric Manifestations of Paraneoplastic Disorders

Paraneoplastic disorders can lead to severe psychiatric and behavioural symptoms. Rapid identification is required to ensure correct treatment and management to avoid misdiagnosis of a paraneoplastic neurologic disorder.

Paraneoplastic limbic encephalitis (PLE) is a rare neurological syndrome associated with cancer, and selectively affects limbic system structures, including the hippocampus, hypothalamus, and amygdala.[1] It is usually associated with small cell lung cancer. The encephalitis is caused by an altered immunologic response to a malignancy that has antigens that resemble limbic antigens. The inflammatory response, however, occurs away from the original neoplasm site. [2]

  • Individuals with a personal or family cancer history, smoking history, should be worked up for paraneoplastic involvement.
    • The most common tumours associated with paraneoplastic limbic encephalopathy are small cell lung cancer (SCLC) (about 75% of cases), germ-cell tumours (ovarian or testicular), thymoma, Hodgkin's lymphoma, and breast cancer.
  • The most common symptoms are a subacute cognitive (primarily amnestic) syndrome.
  • Depression, anxiety, personality changes, and emotional lability can often precede the cognitive impairment.
  • CSF evidence of inflammation
  • Elevated tumor markers (e.g. - CEA, CA-125, PSA)