CSF Testing For Alzheimer’s Disease

Alzheimer’s Disease

Approximately 50% to 70% of patients with Alzheimer’s disease are not correctly diagnosed in primary care today and 25% to 30% of patients who are told they have Alzheimer’s dementia are misdiagnosed. 

An accurate diagnosis of Alzheimer’s dementia provides patients with valuable diagnostic and prognostic information. It also extends the time for possible treatment. 

Blood and cerebrospinal fluid-based biomarkers promise to revolutionize the diagnosis and prognosis of Alzheimer’s disease patients.

Frequently Asked Questions

  • Up until recently, there was no single test that could diagnose Alzheimer’s disease. Physicians would use medical history, cognitive testing, and MRIs to make a diagnosis.
  • Now there are two tests for Alzheimer’s disease. One is a blood test that looks for an abnormal protein that is associated with Alzheimer’s disease. The other tests looks for an abnormal protein in the cerebrospinal fluid (CSF).


  • CSF is a fluid that surrounds the brain and the spinal cord made naturally by the brain. In early Alzheimer’s disease, the CSF can show abnormal proteins that are found in patients who go one to develop Alzheimer’s disease.
  • Through your family doctor or local lab.
  • We offer CSF testing for Alzheimer’s disease at Danforth Neurology.
  • Unfortunately, the test is not covered by OHIP, so there is a fee to the patient.
  • Please call us for more information at 647-558-6518
  • Approximately 20% of patients who get their blood tested for Alzheimer’s disease will receive an indeterminate result. For these patients, a confirmatory CSF test is indicated to confirm whether or not they are at risk for getting Alzheimer’s disease.
  • For patients with an abnormal blood test result, definitive testing of the CSF or a PET scan of the brain is recommended.
  • CSF testing requires a procedure called a lumbar puncture or spinal tap. It is a test that we do in the clinic. It takes about 30 minutes from start to finish.
  • During a lumbar puncture, after freezing the area, a small needle is inserted between two bones in your low back. Fluid is collected and sent to the lab for testing.
  • Plan to rest at home for the rest of the day after the procedure. No restrictions are recommended from the next day on. Side effects of the procedure include a brief, mild headache.
  • Medical benefits
    • Getting tested for Alzheimer’s will help your doctor confirm your diagnosis. 
    • There are treatments for Alzheimer’s disease available in the US that will hopefully be approved in Canada soon. 
    • There is some evidence that an earlier diagnosis may give patients with Alzheimer’s disease a better chance to improve with treatment.
  • Additional benefits listed by the Alzheimer’s Association include a chance to prioritize your health, emotional and social benefits, more time to plan for the future and cost savings.
  • Learn more at https://www.alz.org/alzheimers-dementia/diagnosis/why-get-checked.