As the symptoms of dementia can develop slowly and are frequently similar to other conditions it can be difficult to make a person’s diagnosis, particularly in the early stages. However, health professionals are able to observe the pattern of symptoms and perform a few simple tests over a period of time to measure any change.
Although the tests currently performed are fairly accurate, a definitive diagnosis can still only be made after death by examining the brain tissue during a post mortem.
One of the memory tests commonly performed is the mini mental state examination in which a doctor asks the patient some questions relating to a number of factors including language recall and attention. Usually an MMSE score of 20 to 24 is taken to indicate mild Alzheimer’s, those scoring 10 to 20 are considered to have moderate Alzheimers, and a score below 10 suggests severe Alzheimer’s.
A doctor can sometimes differentiate between the diseases which cause dementia by taking a CT scan or sometimes an MRI scan of the brain. More specialist imaging techniques, such as SPECT or PET scans are very expensive and generally used by scientists to develop accurate methods of diagnosing dementia and to measure the effects of possible treatments.
The Hachinsky Ischaemic Scale
Can be used to help in the diagnosis of vascular dementia. It is a scale used by doctors to rate the clinical features presented by a patient during an examination. A score of seven or higher usually indicates vascular dementia, either alone or combined with Alzheimer’s disease.
Other medical conditions
Can sometimes help a doctor to diagnose a disease more accurately. For example, someone with high blood pressure, irregular heart rhythms, or who has had a stroke is more likely to develop vascular dementia.
Making earlier diagnosis possible is just one area into which ART funds research. A swift identification is important because it helps a doctor to rule out other illnesses with similar symptoms to dementia, such as depression. It also enables new drugs to be prescribed which can, for a time, improve the quality of life for both patient and carer; and gives both the patient and their family valuable time to prepare and plan for the future. Accurate early diagnosis could also mean that future treatments can be given before the brain is damaged.
Very rarely, dementia can be reversed; for example, if it is due to thyroid hormone deficiency or deficiency of vitamin B12 or folic acid. It is therefore important that all patients with dementia are screened for these treatable causes.