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Genetic and Rare Diseases Information Center (GARD)

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Paraneoplastic Neurologic Disorders

Other Names for this Disease
  • PND
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Your Question

If the symptoms of paraneoplastic neurologic disorders are caused by cancer, why do the symptoms appear before cancer is diagnosed? What is the prognosis for people with a paraneoplastic neurologic disorder?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What are paraneoplastic neurologic disorders?

Paraneoplastic neurologic disorders are a group of rare degenerative conditions that are triggered by a person's immune system response to a cancerous tumor. Researchers believe these disorders occur when cancer-fighting antibodies or white blood cells known as T cells mistakenly attack normal cells in the nervous system. Paraneoplastic neurologic disorders typically develop after mid-adulthood and are most common in people with lung, ovarian, lymphatic, or breast cancer. Symptoms generally develop over a period of days to weeks and usually occur prior to tumor detection. These symptoms may include difficulty in walking and/or swallowing, loss of muscle tone, loss of fine motor coordination, slurred speech, memory loss, vision problems, sleep disturbances, dementia, seizures, sensory loss in the limbs, and vertigo. Paraneoplastic neurologic disorders include Lambert-Eaton myasthenic syndrome, stiff-person syndrome, encephalomyelitis (inflammation of the brain and spinal cord), myasthenia gravis, cerebellar degeneration, limbic and/or brainstem encephalitis, neuromyotonia, and opsoclonus (involving eye movement) and sensory neuropathy.[1]
Last updated: 11/25/2008

Why do the symptoms of a paraneoplastic neurologic disorder appear before cancer is diagnosed?

The symptoms of a paraneoplastic neurologic disorder are caused by the presence of a cancerous tumor.[1] At first, the tumor is often too small to be detected. Even though the tumor is small, the body responds by producing cancer-fighting antibodies or white blood cells known as T cells. Researchers believe these disorders occur when the body mistakenly attacks normal cells in the nervous system. Two-thirds of patients with a paraneoplastic neurologic disorder develop neurologic symptoms before any cancer is detected.[2]
Last updated: 11/25/2008

What is the prognosis for people with a paraneoplastic neurologic disorder?

The prognosis for people with a paraneoplastic neurologic disorder depends on the type of paraneoplastic disorder and the type of cancer with which they are diagnosed.[1] There are no cures for paraneoplastic disorders and resulting progressive neurological damage. Treatment of the underlying tumor may stabilize a person's neurologic symptoms.[2] Less often, treatment of the tumor improves the neurologic symptoms.
Last updated: 11/25/2008

  • NINDS Paraneoplastic Syndromes Information Page. National Institute of Neurological Disorders and Stroke Website. February 14, 2007; Accessed 11/25/2008.
  • Dalmau J, Rosenfeld M. Paraneoplastic neurologic syndromes. In: Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKenna WG. Abeloff's Clinical Oncology, 4th ed. Philadelphia: Churchill Livingstone; 2008; 767-778.