Health information to help you understand symptoms. It isn't a diagnosis.About OwieClear
Check symptoms

Paraneoplastic neurological syndromes

Also called: Paraneoplastic neurological syndromes

Nerve or brain problems caused by the immune system's response to a hidden cancer.

CheckCancer screening

Overview

Symptoms can appear before the cancer is found.

Treating the cancer and calming the immune system can help.

Symptoms

Common signs:

  • New nerve problems

Less common

  • Memory changes
  • Unsteadiness

When to get medical care

Call 911Seizures.
Get care todayNew or worse symptoms, or symptoms with fever.
See a doctor soonSymptoms that last or keep coming back.

Causes

Immune reaction to cancer.

Does it spread or run in families?

  • It isn't contagious. You can't catch it from someone else.

Who is more likely to get it

  • Smoking

Possible complications

Diagnosis

A clinician asks about your symptoms and may order tests.

The exam

A physical exam.

Tests

Tests, if needed:

  • Antibody tests:
  • Scans:

Treatment

Treatment depends on the cause and how severe it is.

Self-care

  • Keep cancer treatment on schedule
  • Do physical therapy

Prevention

To lower your risk or prevent problems:

  • Don't smoke

Which doctor treats this

  • Start with your primary care provider (family doctor or internist).
  • They may send you to a neurologist (brain and nerve doctor).

Living with it

Support groups and helplines

Children, pregnancy, and older adults

  • People with lung, breast, or ovarian cancer: Higher risk.

Pregnancy and breastfeeding

  • If you're pregnant or planning to be, tell your prenatal provider about this condition.
  • Don't start or stop any medicine on your own. Some are safe in pregnancy and some need to be changed.
  • Ask before taking any pain reliever. The FDA advises avoiding ibuprofen and naproxen after 20 weeks unless your doctor says to.
  • Breastfeeding: Most medicines are fine, but ask. The NIH LactMed database lists what's known about each one.

Outlook

Treating the cancer helps some people.

Getting ready for your visit

Bring a list of your symptoms and medicines.

What to bring

  • A list of your medicines and supplements
  • Notes on when symptoms started and what makes them better or worse

Questions to ask

  • What's causing this?
  • What treatment do you recommend?
  • Which cancers should I be screened for?

Research studies

Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.

Search ClinicalTrials.gov for studies on Paraneoplastic neurological syndromes

Sources

Last updated 2026-11-12.