Alzheimers New Zealand

Diagnosis and assessment

A full assessment of your condition is essential in order to be sure about a diagnosis of dementia or Alzheimer's disease. Memory loss or deteriorating cognitive function may have other medical causes which are treatable.

A diagnosis should be sought as early as possible, as it will:

  • help you plan for the future
  • enable you to benefit from medication available
  • help you get advice and support

There is no straight-forward test for dementia.  A diagnosis is usually made by excluding other conditions such as depression, side effects of medication, infections, vitamin deficiencies, thyroid gland problems and brain tumours.  Therefore it is important a full medical examination is carried out. This examination should include:

  • a complete physical examination
  • a detailed medical history
  • blood and urine tests
  • memory and skills tests
  • an assessment of your mood or emotional status

Sometimes it may also include:

  • X rays or scans or brain scan (CT or MRI)
  • spinal fluid sampling or brainwave recording (EEG)
  • a visit to a specialist such as a neurologist, psychiatrist or geriatrician
  • visiting a clinical psychologist for cognitive testing

If you do not understand what these tests are for or what the results mean, ask your GP to explain them to you. It might be easier to have someone with you who can ask questions if you don't think you can take all the information in. 

The way in which the person's problems have developed is very important and usually the doctor will have a number of questions to ask the relative about the changes that have occured in the person. Sometimes it is not possible to immediately exclude every possibility and the diagnosis may rest on how the person changes over the following months.

Specialist assessment
Your GP may ask a specialist for help in establishing a diagnosis.  If you are under the age of 65 you may be referred to a psychiatrist or neurologist who specialises in disorders of the brain and nerve pathways.  If you are over 65 years you are more likely to be referred to the services for the elderly team or to a psychogeriatrician.

You should expect to have a full discussion with the specialist about your condition. It will also help the specialist if he/she is able to talk to a close relative or friend.  All this may take some time.  For example, the specialist will have to make sure that your memory difficulties are not caused by other conditions such as stress or depression.  Conditions such as stress or depression are often temporary, whereas dementia is generally progressive and permanent.  Some people have both depression and dementia, which makes the diagnosis even more difficult. For more information about mental health, go to www.likeminds.org.nz.

The specialist may refer you back to your GP after your diagnosis has been made.  From here, your GP may offer you a range of services. You may feel you do not need such services at present.  It is still important, however, to find out what is available for the future. Practical help and support are available from a wide range of people.

Suggestions:
Write down the specific problems you are facing, along with examples, and take the list along when you see the GP or specialist.  Make sure the diagnosis is as specific as possible. If you are not happy with your GP, talk to your local Alzheimers organisation as they may be able to offer you helpful advice about how to change your GP.
If your doctor is reluctant to investigate the person's problems, be persistant. 

It is important to distinguish between different types of dementia because they have different causes, progression and treatment.  However an accurate diagnosis is not always possible.