diagnosing dementia PET Scan

Welcome to the third article in our series about dementia. Our previous articles, "Diagnosing Dementia: Steps To Early Identification" and "Dementia Testing: Types Of Data Needed To Make A Diagnosis", explain how this condition is diagnosed in Australia after a specialist has collated information from a range of tests. There are several types of dementia and this process will identify which version you have developed.

Any brain syndrome which causes multiple problems with a person’s intellect is called dementia. According to Ozcare, Alzheimer’s Disease is the most common type of dementia in Australia, accounting for over half of dementia cases. Vascular Disease and Lewy Body Disease are common causes as well.

Alzheimer’s Disease

As people age, this happens to the brain.

  • Shrinkage of nerve cells
  • Plaques (protein deposits) develop
  • Increased damage from free radicals (unstable molecules in the body)

A person with Alzheimer’s Disease has large numbers of plaques, particularly in the hippocampus which controls memory. In addition, a person with Alzheimer’s will have twice as much damage from free radicals in the front and side part of the brain as others who age normally. A PET scan can confirm this.

A specialist will test to see if these problems are present.

  • Deterioration in language abilities
  • Difficulty performing simple motor activities e.g. buttoning a shirt
  • Impaired ability to recognise objects
  • Major difficulties with planning, making decisions, organising tasks and performing activities in sequence

Vascular Disease

This is caused by a reduced blood flow to the brain. A narrowing or blockage of blood vessels in the brain can prevent cells in the brain and spinal cord from receiving nutrients and oxygen. This can be the result of strokes, diabetes and high blood pressure. CT and MRI tests can identify where the blockage is occurring.

Your specialist will look for overly strong reflexes, walking problems and weakness in the arms and legs. Delusions, confusion, depression and urinary problems may also be signs. Whilst memory impairment is a sign of both Vascular Dementia and Alzheimer’s, a specialist can distinguish the difference because Vascular Dementia sufferers will display problems with reflexes, walking and muscle weakness first.

Lewy Body Disease

Deposits of misfolded proteins inside the primary cells of the brain and spinal cord cause Lewy Body Disease. These form in the brain stem and stop chemical messengers in the brain and nervous system from functioning properly. Your specialist will look for movement problems such as tremors, stiffness and stooped posture. He or she will also check for blood pressure fluctuations and variable heart rate.

Unlike Alzheimer’s Disease, impaired memory is not one of the first symptoms. Your specialist will assess your attention span and ability to reason. He or she will also test your visuospatial perception. Inability to do these tasks may indicate Lewy Body Disease.

  • Judge depth correctly
  • See the world in 3D
  • Understand how objects appear in space
  • Navigate properly

Your specialist will ask whether you have a history of severe sleep problems, hallucinations (including tastes, smells and sounds), swallowing difficulties, impotence, changes in how much you sweat and episodes of tiredness followed by bouts of alertness. These can also be symptoms.

Other Causes

Other conditions such as Parkinson’s Disease, Pick’s Disease and Wernicke-Korsakoff Syndrome can be responsible for dementia in those who are middle-aged and older. Your specialist will conduct extra tests along with an extensive review of your lifestyle and family’s medical history.

The Benefits of Diagnosis

A diagnosis which accurately pinpoints the cause of your dementia has major benefits. You can make lifestyle changes and receive treatments that are specific to your condition. This greatly improves your chances of slowing down impairments and enjoying a quality of life.


Image credit: "Brain X-ray, Science Museum" (cropped) by Robin VanMourik. (Creative Commons Attribution-NoDerivs 2.0 Generic License)


Comments (0)

Add a Comment

Allowed tags: <b><i><br>Add a new comment:

Senior Gems

Watch a brief video of the Senior Helpers Senior Gems® program -- a positive approach to Alzheimer’s and dementia care -- and learn how you can receive our complimentary Senior Gems® DVD!