What is Alzheimer’s dementia?

Alzheimer’s dementia is the most common type of dementia. This disease is named after Alois Alzheimer the doctor who first described the condition in 1906. Although Alzheimer’s dementia usually occurs in older people, it is not believed to be part of the normal ageing process. You may have heard the term Alzheimer’s disease (as opposed to Alzheimer’s dementia). Alzheimer’s disease represents the brain changes that cause the dementia.


What causes Alzheimer’s dementia?

The cause of Alzheimer’s dementia is not fully understood. In this disease certain protein molecules accumulate excessively outside and inside the brain cells and this may lead to parts of the brain not working properly and eventually dying. There is also a shortage of important chemicals in the brain which transmit signals between cells. There is a huge research effort to try to get a better understanding of Alzheimer’s disease.


Signs and symptoms of Alzheimer’s dementia

Alzheimer’s dementia usually starts gradually with memory problems. A person’s ability to remember recent events in particular is affected. There may be difficulty recalling where items such as keys, money, glasses are kept. A person may find it difficult to remember appointments or forget to pay bills. Some people may ask the same question repeatedly over the course of hours or even minutes. Memory for past events is usually not affected initially.

The symptoms get progressively worse. Often the person may struggle to think of a word when speaking or find it hard to keep up with conversation in groups and may prefer to keep quiet. The person might get lost in unfamiliar places and find it harder to manage complex tasks such as managing finances. Many people may eventually need help with basic tasks such as washing and dressing.

People with Alzheimer’s dementia may get low in mood or lose confidence. Some people develop hallucinations (seeing or hearing things which are not there) or delusions (false beliefs- for example thinking that items are being stolen or that the neighbours are listening to them through the wall). Sleep problems can occur. The disease varies from person to person and the condition can be helped with medication.


Alzheimer’s dementia diagnosis

In order to make a diagnosis of Alzheimer’s dementia the doctor will need to obtain a detailed history of symptoms. Each type of dementia has a different pattern of symptoms. For example in Alzheimer’s dementia the first symptom is usually memory loss and the onset is gradual. A neuropsychological test will be carried out by a psychologist. This test will look at the functioning of different parts of the brain. The test will examine the person’s memory, reading and writing skills. Parts of the test will require the person to copy complex patterns and recognize pictures of objects.  The psychologist will then prepare a summary of the results.

A brain scan will also form part of the diagnostic process. There are different types of brain scans but Magnetic Resonance Imaging (MRI) scans are most useful for dementia diagnosis. The purpose of the scan is twofold. The scan will help identify brain conditions that may cause symptoms similar to Alzheimer’s disease. These include strokes, tumours and a condition called hydrocephalus (excess brain fluid). The second purpose of the scan is to look for signs of Alzheimer’s dementia. The brain in Alzheimer’s dementia may be shrunken especially in a part of the brain called the hippocampus which is responsible for our short term memory function.



Blood tests need to be carried out to rule out certain conditions which can impact on the memory. A low blood count (anaemia), thyroid problems and vitamin deficiencies need to be identified and treated. The doctor looks at all the information gathered and makes a diagnosis.


Treatment of Alzheimer’s dementia


There are drug and non-drug treatments available for Alzheimer’s dementia.


Anti-dementia medication

There are at present 2 types of medications specifically licensed in the UK for the treatment of the memory and thinking problems in Alzheimer’s dementia. Although there is no cure for Alzheimer’s dementia both types of medication can slow down the speed at which the disease progresses. The first type of medication is called a cholinesterase inhibitor. This medication increases the level of a chemical messenger in the brain which plays a role in memory and learning.  There are 3 cholinesterase inhibitors available – donepezil, galantamine and rivastigmine. All 3 medications are equally effective but some people may have fewer side effects with one drug compared to another. The most common side effects are diarrhoea, nausea and stomach discomfort. The side effects are usually mild and go away in a few days. The cholinesterase inhibitors are most effective in the mild and moderate stages of the Alzheimer’s dementia.

Donepezil is available in tablet form and galantamine and rivastigmine in capsule form. . Galantamine and rivastigmine can be obtained in liquid form which may suit people who have difficulty swallowing tablets or capsules. Rivastigmine is also obtained in a patch which can be attached to the body.

The second type of medication is called memantine. This medication prevents the effect of a chemical in the brain called glutamate from damaging brain cells. Memantine is available in tablet and in liquid form. The commonest side effects are drowsiness, dizziness, headaches and constipation. The side effects often become less noticeable with time. Memantine is licensed for use in the moderate and severe stages of the disease.

The doctor may sometimes use a combination of cholinesterase inhibitors and memantine.

Other medications

A number of medications may be used for the symptoms of Alzheimer’s dementia. Antidepressant medication may be considered if low mood is present.. Antipsychotic medication such as risperidone may be used when hallucinations (seeing or hearing things which are not there) or delusions (false beliefs) are present.

Non-drug treatment of Alzheimer’s Dementia

Psychological treatments such as memory training and cognitive stimulation should be considered as part of the treatment process.

Course and prognosis of Alzheimer’s dementia

Alzheimer’s disease gets progressively worse but the course can vary from person to person. The drug treatments can slow down the speed at which the disease progresses. There is also an international effort to try to develop better treatments and eventually cure the condition.