An Overview of Dementia with Lewy Bodies

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In a country with an ageing population, dementia is a big challenge to the health care system. Currently, around 850,000 people in the UK have been diagnosed with a form of dementia. As it is a neurodegenerative disease, people living with dementia begin to lose the ability to live independently, and it can have profound changes in people’s lifestyles. Unfortunately, it is incurable, but there is a lot of research going on, so there is the hope of better treatments, and even a cure.

But what is dementia? As mentioned earlier, dementia is a progressive neurodegenerative disorder. In other words, cells in the brain slowly begin to die, until the victim’s inevitable death. However, the disease can occur anywhere in the brain, meaning that symptoms can vary significantly between dementia patients. Also, there is a clear distinction between dementia and normal ageing. Though the body and parts of the brain naturally decline over time through the process of ageing, dementia does not play a part in this. The most common, and arguably the most famous type of dementia, is Alzheimer’s disease. This is characterised by the build-up of amyloid plaques and neurofibrillary tau tangles, that result in a loss of nerve cells. However, the second most common type of dementia is less known. It is referred to as Dementia with Lewy Bodies (DLB).

This type of dementia is characterised by an abnormal build-up of Lewy bodies, which are made of alpha-synuclein proteins. The build-up of Lewy bodies usually starts in the Substantia Nigra, the part of the brain responsible for reward and movement. This causes a characteristic symptom of Parkinsonism: slowness of movement and trouble of walking. The damage spreads to other parts of the brain, causing further damage, but the exact mechanisms of this spread are still unknown. The additional damage can cause fluctuations in cognitive function, delusions and hallucinations.

Diagnosis of DLB isn’t an easy task. The symptoms of DLB overlap with other disorders such as Parkinson’s disease, Alzheimer’s disease and other forms of dementia, and as a reult, diagnosing DLB is challenging. Doctors talk to the patient and their close relatives, to discuss the types of symptoms. A neurological exam can also be performed to suggest the possibility of DLB, and scans such as CT and MRI scans can be used to rule out other differential diagnoses, and confirm the cause as DLB. Unfortunately, the diagnosis can be life-changing. Patients often become incapable to work as much, and require a lot of help for basic activities. Not only can this be a financial strain on families, but it also places extensive responsibilities upon them, to take care of their loved ones. It’s important to realise that dementia, in general, affects many people, even if it is only one member of a family that has the disease.

With dementia in general, the psychological and social challenges on both the patient and their relatives can be overlooked. However, it’s crucial to acknowledge and address them because actions can be taken to improve the patient’s quality of life for as long as they live.

One such challenge is the result of hallucinations. Unlike an illusion, people see objects that don’t actually exist. For example, imagine someone having a hallucination of a crocodile under their bed. People with no neurological issues would be able to understand that they are probably hallucinating. But, with patients with impaired cognition, such as DLB patients, the crocodile can be very real and a threat. This can understandably be quite distressing and disturbing for a patient. In some cases, psychosis can follow, which can be a traumatic experience for both patients and caregivers.

Another challenge is the fluctuations in cognition. In simple terms, it’s as if the patient becomes someone else: their awareness changes, their views change and even their motivation changes. The issue here is that the fluctuations are random, both in duration and frequency, which can make it a challenge for carers. Though the patient may not be aware that his cognition is different, the changes can be obvious and frightening to an observing carer or loved one. There is a chance that carers develop psychological disorders such as anxiety or stress, as shown in a study referenced below. In addition, it can hamper a person’s social life. Fluctuations could occur during a conversation, and if the other person is unaware of what’s going on, it may be very off-putting.

So DLB has physical, psychological and social challenges, and these progressively get worse until the patient dies. So what can be done to boost a patient’s quality of life during this? As there are many symptoms of DLB, patients often take a variety of medication to manage them. For example, a common dementia drug is cholinesterase inhibitors, such as Donepezil. This slows down the breakdown of the neurotransmitter acetylcholine, which can improve cognitive function. Anti-psychotic drugs could be important if psychosis ever occurs, or if there is a decline in mental health. However, these drugs could cause antipsychotic sensitivity, raise the heart rate, cause confusion or even tremors. Thus, they must be prescribed with caution. For movement symptoms, dopamine agonists such as L-DOPA are useful, as they are converted to dopamine, which counteracts the death of dopamine-producing cells in the short run.

Overall, DLB is a very complex and intriguing disease. Not only are it’s pathological mechanisms poorly understood, but it also has many impacts that exceed physical symptoms. Though there are some treatments available, there are many prescriptions that have to be taken, and many of them will have unpleasant side-effects. But there is hope! In Japan, a clinical trial on the use of epilepsy treatments on DLB patients is showing promise, with patients improving motor symptoms without a compromise in psychological symptoms. Perhaps there will be a day when dementia may be cured, neutralising one of the biggest global killers in an ageing population.


References

  1. Alzheimer’s Society. n.d. Diagnosis Of Dementia With Lewy Bodies. [online] Available at: <https://www.alzheimers.org.uk/about-dementia/types-dementia/dementia-with-lewy-bodies-diagnosis#content-start> [Accessed 13 May 2020].
  2. Zweig, Y. and Galvin, J., 2014. Lewy body dementia: the impact on patients and caregivers. Alzheimer’s Research & Therapy, 6(2), p.21.
  3. Oxford Medical Education. n.d. Dementia – Oxford Medical Education. [online] Available at: <http://www.oxfordmedicaleducation.com/geriatrics/dementia/> [Accessed 13 May 2020].
  4. https://www.nhs.uk/conditions/dementia-with-lewy-bodies/
  5. Cdc.gov. n.d. The Truth About Aging And Dementia | CDC. [online] Available at: <https://www.cdc.gov/aging/publications/features/dementia-not-normal-aging.html> [Accessed 15 May 2020].
  6. https://www.lbda.org/go/epilepsy-treatment-shows-promise-dlb-0

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