Wednesday 21 October 2009

Dementia

This is just quick overview summarising the current ongoing work in the area of neurosciences, specifically dementia. Dementia (meaning ‘deprived of mind’) is a serious cognitive disorder which affects areas such as memory, attention, language and problem solving. It can be a result of a single brain injury or of a progressive long term illness. As we age, we will all experience some form of change in our cognitive ability which a normal sign of ageing. However it is when these changes seem to increase more than the expected level, that dementia is diagnosed.



Neurological disorders including dementia are set to rise in the future due to an ageing population.

Types:
The type of dementia is dependent on the pathophysiology. The different forms can be dependent on;
- Age (often the same illness can be given different names as they arise in different age groups)
- Gender (some types of dementia seem to be higher in women than in men)
- Pathology (the change in size and shape of the cells i.e. plaques, neurofibrillary tangles, lesions and the location of the changed area i.e. frontal lobe, temporal lobe.
Consequently the pathology in turn determines the symptoms that characterise the illness.

Diagnosis:
When a person is suffering from dementia, the clinician will usually take a clinical history to see if there is a familial link within the family. This will involve enquiring about the patient’s diet, sleep patterns, medications and a history recent illnesses such as stroke, heart disease, cholesterol, blood pressure and diabetes. A mini-mental state examination (MMSE) is also carried out to test the level of cognitive impairment in combination with other clinical diagnostic tests.

It is common practice to also conduct psychological tests and blood tests to exclude other possible causes. The clinical tests may involve scans and neuroimaging techniques (MRI, CAT) as well as an electroencephalography (EEG), analysis of the cerebrospinal fluid (CSF), tissue biopsies, genetic testing. When all other possible clinical causes have been eliminated then further testing of the cognitive domain is conducted to determine the type of dementia.

There are a number of different scales and assessment methods used to test the cognitive domain however used on their own they are not sufficient, as there is large variation between guidelines and thus the potential for misdiagnosis is possible. Often the histological examination of the brain post mortem is used confirm the diagnosis.

Treatment:
Something to bear in mind is that certain types of dementia are multifactorial meaning that they have numerous causes. For this section if we look specifically at Alzheimer’s and the treatments associated with this disease.

Prevention:
Prevention is the best course of treatment and a number of risk factors have been identified for Alzheimer’s disease;
- A diet that is healthy, low fat, rich in B vitamins and avoidance of alcohol and smoking
- Cognitive fitness - maintaining intellectual and physical activity is a protective risk factor against cognitive decline
- Reducing cardiovascular risk factors is beneficial i.e. hypercholesterolemia, hypertension, hyperhomocysteinemia, dietary saturate fats, cholesterol, antioxidants,diabetes mellitus, cardiovascular disease and cerebrovascular disease.
- the presence of the ε4 allele of the apolipoprotein E (apoE) gene has been identified as a strong genetic risk factor

Pharmaceutiacal:
Although there is no actual cure as this moment in time, there drugs avaliable to help alleviate the symptoms.
- Cardiovascular risk factors can be controlled by the use of antiplatelet drugs such as aspirin to decrease platelet aggregation and statins such as Atorvastatin to reduce serum cholesterol.
- The use of acetylcholinesterase inhibitors such as galantamine, donepezil and rivastigmine. It is thought that the degradation of acetylcholine is a contributing factor and so these drugs slow down the degradation, allowing levels to remain elevated and prevent further neuronal damage.
- Other drugs include the regulation of neurotransmitters using glutamate, NSAIDS and statins.
- Pharmaceutical intervention such as antidepressants, neuroleptics and mood-stabilizers help alleviate the behavioral changes.

The future:
There are numerous groups working on different theories and possible treatments; selections of which are described below.
- Improvements in diagnostic criteria to allow earlier detection thus leading to more positive outcomes.
- Numerous pharmaceutical drugs such as Protollin, Dimebon,
Rember are currently undergoing clinical trials.
- Recent work at the University of Manchester has shown that the herpes simplex virus (usually found in cold sores) may be linked to the build of plaques associated with Alzheimer’s. If this is the case then anti viral agents may be used to treat Alzheimer’s.
- To reduced the levels of amyloid protein that cause plaques by using immunotherapy or the development of a vaccine.
- Using the brain’s own neuroprotective strategies to protect against possible causes such as stroke. This novel approach is called ischemic ‘postconditioning’ that involves the activation of the protein kinase Akt, may go onto to produce a suitable treatment.
- the role of metals such as aluminium and spices such as tumeric have also been highlighted in recent work.

Rather than give up on life as so many dementia patients do, I discovered that a few people I know, regularly keep journals throughout their illness. The purpose of this is sort of two fold; firstly it helps the person keep track of their thoughts thus giving their mental capacity a workout and secondly it may help give carers an insight into how the patient is feeling and try and solve some of the problems that they may be facing. During my research, I also found that quite a few people who suffer from dementia or have loved ones living with this illness have set up online blogs.

This I feel is a great idea because for the sufferers it is a way to maintain their intellectual ability as I mentioned before and for the carers it is a way to release some of those feelings of frustration and helplessness. The fact that their journals are online mean that anyone can read them and know that they are not alone with this illness, that they have someone to share their thoughts and feelings with. Personally from the patients that I've seen that is one of the key things; the fear/feeling of isolation and to alleviate some of those fears can only be a positive step forward.

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