1st February 2024

Background

Dementia is a broad umbrella term. There is a whole range of conditions that affect the memory and thinking of an individual. This, in turn, influences their day-to-day living.

Dementia is a decline in neurocognitive function. Dementia is a progressive condition that persistently causes the deterioration of memory and thinking abilities. The loss of cognitive functioning can range from loss of thinking to loss of remembering and reasoning. It can be mild to severe, ranging from little impact on daily functioning to complete dependence on others for even basic functioning.

Frontal lobe: It controls an individual’s ability to solve problems, control emotions, and make plans and decisions. It also controls speech and language along with motor skills.

Temporal lobe- It processes language, sound and music. It is important for memory and learning. It helps in recognising people’s faces.

Occipital lobe- It is helpful for visual perception.

Parietal lobe- It controls spatial awareness, hand-eye coordination, skills such as maths and spelling, and perception of hard and soft objects.

Classification/Classifying dementia 

There are different ways to classify dementia:

1. Based on aetiology
2. Based on the progress of dementia
3. Based on how common dementia is
4. Based on Degenerative or non-degenerative
5. Based on cortical or non-cortical

Table 1: Classification of dementia based on aetiology. Dementia Pathology: Dementia, Alzheimer’s Disease, Vascular Dementia. (2020). eMedicine. [online] Available at: https://emedicine.medscape.com/article/2003174-overview#a1

Metabolic Encephalopathy – an overview | ScienceDirect Topics. [online] Available at: https://www.sciencedirect.com/topics/medicine-and-dentistry/metabolic-encephalopathy#:~:text=Metabolic%20encephalopathy%20may%20then%20be%20difficult%20to%20distinguish[Accessed 15 May 2023].

Table 2: Classification of Dementia based on the progress of Dementia. Geschwind, M.D., Haman, A. and Miller, B.L. (2007). Rapidly Progressive Dementia. Neurologic Clinics, [online] 25(3), pp.783–807. doi:https://doi.org/10.1016/j.ncl.2007.04.001.

Table 3: Classification of Dementia based on Degeneration Rone-Adams, S., Stern, D.F., Olivier, T.W. and Blodgett, M.G. (2013). Understanding Dementia. Strength and Conditioning Journal, 35(4), pp.88–98. doi:https://doi.org/10.1519/ssc.0b013e31829ed301.

Table 4: Classification of Dementia based on how common Dementia is. Robinson, L., Tang, E. and Taylor, J.-P. . (2015). Dementia: timely diagnosis and early intervention. BMJ, [online] 350(jun15 14), pp.h3029–h3029. doi:https://doi.org/10.1136/bmj.h3029.

Table 5: Classification of Dementia based Cortical vs Non-Cortical. Contributors, W.E. (n.d.). What Is Dementia? [online] WebMD. Available at: https://www.webmd.com/alzheimers/types-dementia#:~:text=Alzheimer%27s%20and%20Creutzfeldt-Jakob%20disease%20are%20two%20forms%20of[Accessed 15 May 2023].

Epidemiology

The WHO has estimated that around 50 million people globally have dementia, with a 20% increase each year. As per the 2022 January census, there are 944,000 people with dementia in the UK. This is projected to increase to 1.6 million people in 2040. Important reasons include increasing lifespan and accelerated ageing. There are 40,000 people with Early-onset dementia. Alzheimer’s dementia is the commonest of all other types of dementia, constituting about 50-75%. Vascular dementia is the second most common type of dementia. Almost one-fifth of all cases of dementia are of this type. Roughly, around 150,000 people in the UK are diagnosed with Vascular dementia. Lewy Body dementia is the third most common and is seen in 10-15% of cases. Frontotemporal dementia is seen in about 2% of cases.

References

• Turner, M.A., Moran, N.F. and Kopelman, M.D. (2002). Subcortical dementia. British Journal of Psychiatry, 180(2), pp.148–151. doi:https://doi.org/10.1192/bjp.180.2.148.
• Aarsland, D., Larsen, J.P., Lim, N.G., Janvin, C., Karlsen, K., Tandberg, E. and Cummings, J.L. (1999). Range of neuropsychiatric disturbances in patients with Parkinson’s disease. Journal of Neurology, Neurosurgery & Psychiatry, 67(4), pp.492–496. doi:https://doi.org/10.1136/jnnp.67.4.492.
• Brown, R.G. and Marsden, C.D. (1988). ‘Subcortical dementia’: The neuropsychological evidence. Neuroscience, 25(2), pp.363–387. doi:https://doi.org/10.1016/0306-4522(88)90246-1.
• Cummings, J.L. (1986). Subcortical Dementia Neuropsychology, Neuropsychiatry, and Pathophysiology. British Journal of Psychiatry, 149(6), pp.682–697. doi:https://doi.org/10.1192/bjp.149.6.682.
• Dementia Statistics Hub. (2022). Numbers of people in the UK. [online] Available at: https://www.dementiastatistics.org/statistics/numbers-of-people-in-the-uk-2/
• Dementia UK (2011). Dementia UK. [online] Dementia UK. Available at: https://www.dementiauk.org
• NICE. (n.d.). CKS is only available in the UK. [online] Available at: https://cks.nice.org.uk/topics/dementia/background-information/causes/
• Emmady, P.D. and Tadi, P. (2022). Dementia. [online] Available at: https://www.ncbi.nlm.nih.gov/books/NBK557444/#article-20337.s2
• Anon, (n.d.). Dementia Care Central Homepage. [online] Available at: https://www.dementiacarecentral.com/
• Geschwind, M.D., Haman, A. and Miller, B.L. (2007). Rapidly Progressive Dementia. Neurologic Clinics, [online] 25(3), pp.783–807. doi:https://doi.org/10.1016/j.ncl.2007.04.001.