1st February 2024

Alzheimer’s Dementia

This is the commonest form of dementia in the UK and globally as well. 50-75% of patients with dementia experience Alzheimer’s type of dementia. It is also a common form of young onset dementia, constituting one-third of dementia seen in people less than 65 years. 

An individual with Alzheimer’s dementia usually presents with memory loss and cognitive difficulties. They have trouble thinking, organising, problem-solving and communicating.

Associations/ risk factors

1. Age: Generally, 1% less than 65 years, 5% around 65 years and increases steadily to 40% by 80 years of age 
2. Familial: 5% of all cases
3. Genes: ApoE4, Presenilin 1/ 2 (young onset dementia)
4. Head injury- People who have sustained head injury are at risk of dementia in general and Alzheimer’s in particular. 
5. Females: 2 times more than males
6. Poor educational attainment
7. Sedentary lifestyle
8. Down’s syndrome, Learning disability
9. Depression
10. Medical illnesses like Diabetes, Hypertension, Stroke, Hyperlipidaemia, Obesity

Pathophysiology

In Alzheimer’s dementia, there is an accumulation of two different abnormal structures. These, in turn, affect the entire brain, causing shrinkage of the brain.

1. Beta Amyloid plaques
   • These are dense protein and cellular deposits that accumulate outside and around nerve cells in the brain. This leads to cell death and dementia.
2. Neurofibrillary tangles
   • This is hyperphosphorylated tau protein. The tau proteins start folding and clumping, resulting in these twisted fibres inside the nerve cells, causing dementia.

Clinical Features

1. Memory
   • They usually have an insidious onset with a gradual progression of memory difficulties. It can include both short and long-term memory loss. Impaired ability to learn and remember new information.
     • Losing keys and glasses
     • Forgetting the names of people
     • Forgetting medications
     • Missing appointments
     • Repeating conversations
2. Orientation
   • They might experience problems such as poor orientation to time, place and people.
     • Waking up in the night- and being active
     • Losing track of days and dates
3. Language and Communication
   • Dysphasia, difficulty in word finding, Difficulty in understanding conversations and communicating
     • Speaking, reading and writing problems
     • Errors during conversations
4. Executive function
   • Difficulty in initiating, planning and organising. Difficulty in problem-solving, judging and decision-making. Inability to manage finances and complex tasks
5. Visuospatial difficulties
   • Inability to recognise people, face
   • Inability to orient to clothes, routes
   • Wandering
   • Parking car
   • Climbing up and down the stairs
6. Activities of Daily Living
   • Initially, complex activities like cooking, shopping, and organising can be impacted
   • Later, simple activities like bathing, showering, eating, swallowing, dressing, and walking can be impacted
7. Behavioural and Psychological Symptoms of dementia
   • Depression
   • Anxiety
   • Psychosis
     • Delusions
     • Hallucinations
   • Agitation
     • Argumentative
     • Verbally, physically challenging behaviour
   • Emotional lability
     • Easily upset
     • Mood swings
   • Apathy
   • Motor disturbances
     • Restless
     • Wandering behaviour
   • Sleep cycle disturbances
   • Social disinhibition

Evaluation

1. Detailed history is taken from family members who know him well.
2. Thorough physical examination
3. Neurological Examination
   • Gait, coordination
   • Sensory
   • Motor
4. Vision, Auditory problems
5. Systemic Examination
6. Blood investigations:
   • FBC, ESR, CRP, Urea & Electrolytes, Calcium, HbA1c, LFT, TFT, Serum B12 & Folate
   • Radiology, serology, ECG, Neuroimaging based on needs
7. Cognitive assessment:
   • AMTS
   • MMSE- Mini-mental state examination
   • 10-point cognitive screener
   • 6 CIT- 6 item Cognitive impairment test
   • Mini-Cog
   • ACE-R- Addenbrooke’s Cognitive Examination- Revised
   • MOCA – Montreal Cognitive Assessment
8. Carers assessment

Differential Diagnosis

• Normal age-related Memory difficulties
• Mild Cognitive impairment
• Mixed dementia
• Depression
• Delirium
• Medical causes:
  • Hypothyroidism, B12 deficiency, adverse drug effects
• Sensory difficulties
• NPH- Normal Pressure Hydrocephalus

Management

Generally, a biopsychosocial approach is employed in Psychiatry.

Bio

• Acetylcholinesterase inhibitors- Donepezil, Galantamine, Rivastigmine
• NMDA antagonist- Memantine

Psycho

• Psychoeducation
• Cognitive stimulation therapy
• Cognitive rehabilitation
• Group reminiscence therapy
• Skills training for the family to manage behavioural changes

Social

• Occupational therapy- To assess risks at home and arrange for handrail and stair lift
• Physiotherapy- to assess mobility and arrange walking aids
• Social services- Day care, respite care, meals on wheels
• Music, art, dance, pet, massage therapies

Prognosis

Dementia, in general, is a progressive condition. There is no treatment available to cure it. Dementia and Alzheimer’s disease are the leading cause of death for women. It accounts for about 13% of deaths among women and is the second leading cause of death among men. It is almost half of that of women (7%)

Mild cognitive decline has a life expectancy of about 10 years. It drops down as the severity increases from moderate to severe cognitive decline, from 3-8 years to less than 4 years respectively.

References

• Gunhild Waldemar and Burns, A.S. (2017). Alzheimer’s disease. Oxford: Oxford University Press.
• Dening, T., Thomas, A., Stewart, R. and J -P Taylor (2020). Oxford textbook of old age psychiatry. Oxford: Oxford University Press.
• Taylor, J.-P. and Underwood, B.R. (2020). Alzheimer’s disease. Oxford Textbook of Old Age Psychiatry, pp.443–478. doi:https://doi.org/10.1093/med/9780198807292.003.0030.
• bestpractice.bmj.com. (n.d.). Alzheimer’s disease – Symptoms, diagnosis and treatment | BMJ Best Practice. [online] Available at: https://bestpractice.bmj.com/topics/en-gb/317?q=Alzheimer%27s%20disease&c=suggested [Accessed 21 Feb. 2023].
• bestpractice.bmj.com. (n.d.). Assessment of dementia – Differential diagnosis of symptoms | BMJ Best Practice. [online] Available at: https://bestpractice.bmj.com/topics/en-gb/242.
• bestpractice.bmj.com. (n.d.). Assessment of memory deficit – Differential diagnosis of symptoms | BMJ Best Practice. [online] Available at: https://bestpractice.bmj.com/topics/en-gb/710
• Alzheimer’s Society (2019). Alzheimer’s Society – United against dementia | Alzheimer’s Society. [online] Alzheimers.org.uk. Available at: https://www.alzheimers.org.uk
• Anon, (n.d.). Dementia Care Central Homepage. [online] Available at: https://www.dementiacarecentral.com/