Special Investigations

Scanning the brain's blood flow or metabolism (SPECT or PET scanning)

It may be necessary to perform an SPECT or PET scan of the brain's blood flow or carbohydrate metabolism. More specialized scans of different types of signal systems in the brain can also be done. For Alzheimer's disease, Dementia with Lewy Bodies and frontotemporal dementia, changes can normally be observed in the brain's blood flow and metabolism.

EEG Examination

During an EEG examination (electroencephalographic examination), the doctor determines the brain's electrical activity. The examination is particularly used if epilepsy is suspected. During Alzheimer's disease the EEG may be changed

Special Blood Tests

For suspicion of rarer dementia diseases, it may be necessary to take some special blood tests. The doctors can use the blood tests to look for things such as whether the person has rare and often hereditary metabolic diseases.

Genetic Testing

If there is a suspicion that a person has a hereditary dementia disease, the doctors can in some instances make the diagnosis using a gene test. This is done via a blood test. There are many hereditary dementia diseases where the gene that causes the disease is unknown, and a gene test is consequently not possible. Today it is possible to examine for known hereditary types of Alzheimer's disease.

Cerebrospinal Fluid (CSF) Examination - Lumbar Puncture

During a lumbar puncture, fluid is extracted from around the spinal cord. In the spinal fluid, it is possible to examine whether there is an inflammatory reaction. Today it is also possible to determine the amount of some of the proteins that are changed during Alzheimer's disease: beta-amyloid and tau protein. The examination of the cerebrospinal fluid may help support an Alzheimer's diagnosis. This test is not done commonly for dementia.