Alzheimer’s Disease
- Fysiobasen
- 10 hours ago
- 13 min read
Alzheimer’s disease is a progressive neurodegenerative disorder that gradually leads to loss of cognitive abilities and increasing functional impairment. It is the most common cause of dementia and represents a major health challenge in ageing populations worldwide¹. The condition is characterized by structural and biochemical changes in the brain that eventually result in neuronal loss and disruption of communication between nerve cells.
From a broader health perspective, Alzheimer’s disease affects far more than memory alone. As the disease progresses, it can influence behaviour, emotions, sleep patterns and the ability to perform everyday activities. In the most advanced stages, individuals often become fully dependent on others for daily care².
Over recent decades, Alzheimer’s disease has received increasing attention in medical and scientific research. Despite extensive investigation, no curative treatment currently exists. However, several medical and non-medical interventions may help slow the progression of the disease and improve quality of life for individuals living with the condition⁴.
Prevalence and Epidemiology
Alzheimer’s disease is the most common form of dementia, accounting for approximately 60–80% of all dementia cases⁴. Its prevalence increases significantly with age, making it particularly relevant in societies with longer life expectancy.
Among individuals aged 60–64 years, the prevalence is below one percent, but the proportion rises markedly with advancing age. In people older than 85 years, prevalence may reach 20–40 percent⁴.
The disease was first described by the German neurologist Alois Alzheimer in 1907, after examining the brain of a patient with severe memory impairment and cognitive decline⁵.
Globally, dementia is a rapidly growing public health issue. According to the World Alzheimer Report, a new case of dementia occurs approximately every three seconds worldwide, and the majority of cases occur in low- and middle-income countries⁶.
Risk Factors
The development of Alzheimer’s disease is influenced by a combination of biological, genetic and lifestyle-related factors. Age remains the most significant risk factor, but several additional elements may increase susceptibility.
Commonly identified risk factors include:
• increasing age
• genetic predisposition
• family history of dementia
• traumatic brain injury
• Down syndrome
• cardiovascular risk factors
Lifestyle-related conditions such as midlife obesity, hypertension and diabetes are also associated with a higher likelihood of developing Alzheimer’s disease later in life¹³.
One of the most widely studied genetic factors is the APOE-ε4 allele, which significantly increases the risk of developing the disease¹¹.
In rare cases, Alzheimer’s disease is caused by mutations in specific genes that lead to early-onset disease. These include:
• amyloid precursor protein (APP)
• presenilin-1 (PSEN1)
• presenilin-2 (PSEN2)¹²
However, these genetic mutations account for less than five percent of all Alzheimer’s cases.
Pathological Mechanisms
Alzheimer’s disease develops through a complex cascade of biological processes within the brain. Two hallmark pathological features characterize the condition: amyloid-β plaques outside neurons and neurofibrillary tangles within neurons.
Amyloid-β peptides accumulate and aggregate to form plaques that disrupt normal neuronal communication. At the same time, abnormal changes occur in the tau protein, resulting in the formation of neurofibrillary tangles within nerve cells¹⁴¹⁵.
These pathological processes contribute to:
• synaptic dysfunction
• progressive neurodegeneration
• impaired neurotransmission
• gradual loss of neurons
The earliest pathological changes often occur in the entorhinal cortex and hippocampus, regions crucial for memory formation and spatial navigation. As the disease progresses, degeneration spreads to other areas of the cerebral cortex⁹¹⁶.
Chronic inflammation in the brain is also believed to contribute to disease progression. Persistent activation of microglial cells can lead to the release of inflammatory mediators, which may further damage neurons and accelerate neurodegeneration⁴.
Symptoms and Clinical Development
The clinical progression of Alzheimer’s disease is typically slow and gradual. Early symptoms are often subtle and may initially resemble normal age-related changes.
One of the earliest indicators is a reduced ability to form and retain new memories. Over time, patients may develop difficulties with attention, language and executive functioning.
Common symptoms include:
• memory impairment
• reduced concentration
• difficulty with problem-solving
• disorientation
• language disturbances
• impaired visuospatial abilities
Psychological and behavioural symptoms are also common and may include:
• depression
• anxiety
• apathy
• irritability
• agitation
• delusions or hallucinations⁴.
Stages of Alzheimer’s Disease
The progression of Alzheimer’s disease is often divided into three main stages.
Early Stage
In the early stage, individuals can often function relatively independently and may continue working or participating in social activities.
Typical symptoms include:
• mild memory problems
• word-finding difficulties
• challenges with planning
• subtle personality changes
Moderate Stage
During the moderate stage, symptoms become more pronounced and individuals typically require increasing assistance in daily life.
Common features include:
• significant memory loss
• increasing confusion
• repetitive behaviour
• difficulty performing daily tasks
• increased need for supervision
Late Stage
In the advanced stage of the disease, severe functional impairment occurs.
Typical characteristics include:
• severely limited communication
• profound cognitive decline
• loss of walking ability
• swallowing difficulties
• increased susceptibility to infections
• incontinence
At this stage, individuals are usually completely dependent on caregivers.
Diagnosis
The diagnosis of Alzheimer’s disease is based on a combination of clinical assessment, cognitive testing and imaging techniques. The goal is both to confirm the presence of the disease and to exclude other potential causes of cognitive decline.
Common diagnostic approaches include:
• neuropsychological testing
• magnetic resonance imaging (MRI)
• positron emission tomography (PET)
• cerebrospinal fluid analysis
These investigations may reveal biomarkers associated with amyloid-β and tau pathology in the brain¹⁹.
Research suggests that biological markers of Alzheimer’s disease may be detectable many years before clinical symptoms appear, providing opportunities for earlier identification and monitoring of the disease.
Screening Tools
Various screening instruments are commonly used to detect cognitive impairment.
Examples include:
• Mini-Mental State Examination (MMSE)
• Mini-Cog
• Clock Drawing Test
• Neurobehavioral Cognitive Status Examination²⁰.
These tools provide a rapid assessment of memory, attention, language and other cognitive domains.
Treatment and Management
At present, there is no cure for Alzheimer’s disease. Therefore, treatment focuses on:
• slowing symptom progression
• preserving function as long as possible
• supporting independence
• improving quality of life
Management typically involves both pharmacological and non-pharmacological approaches.
Non-pharmacological strategies may include:
• cognitive stimulation
• structured daily routines
• social engagement
• environmental adaptations
Physical Activity and Supportive Interventions
Physical activity has received increasing attention as a supportive intervention for people living with dementia.
Exercise may influence brain health through several biological mechanisms, including increased production of:
• brain-derived neurotrophic factor (BDNF)
• insulin-like growth factor-1 (IGF-1)
• vascular endothelial growth factor (VEGF)
These factors are associated with neuroplasticity and may support memory and executive functioning²³.
Although research findings vary, many studies indicate that regular physical activity can improve both physical function and overall quality of life in individuals with dementia.
Music therapy has also been explored as a complementary intervention. Some studies suggest that music may reduce stress levels and support emotional regulation in individuals with moderate to severe dementia²⁵.
Role of Caregivers
Caregivers play a crucial role in supporting individuals with Alzheimer’s disease. However, the caregiving role can be demanding and often involves long-term emotional and physical challenges.
Caregivers frequently experience increased levels of:
• stress
• fatigue
• anxiety
• depression
Healthcare professionals should therefore also provide support, guidance and resources to caregivers in order to prevent burnout and ensure sustainable long-term care.
Medical Treatment
Although Alzheimer’s disease cannot currently be cured, several medications are used to manage symptoms and support daily functioning.
Commonly prescribed medications include:
• cholinesterase inhibitors such as donepezil
• partial NMDA receptor antagonists
• antidepressants for mood symptoms
• anxiolytics for anxiety or agitation
• antiparkinsonian medications for movement symptoms
• anticonvulsants or sedatives for behavioural disturbances
These medications are generally intended to reduce symptoms rather than reverse the underlying disease process.
Additional treatment strategies such as antioxidants, anti-inflammatory agents and estrogen replacement therapy have also been explored, although the evidence supporting their effectiveness remains limited²⁶²⁷.
A newer medication, aducanumab, has been approved by the FDA with the aim of reducing amyloid-β plaques in the brain. However, the clinical effectiveness and long-term benefits of this treatment remain controversial⁴.
Physiotherapy in Alzheimer’s Disease
Physiotherapy can play an important role throughout the course of Alzheimer’s disease, although the goals of treatment will change as the condition progresses.
In the early stages, physiotherapy often focuses on supporting the patient’s mobility, activity level, and independence. Many individuals with early Alzheimer’s disease are still able to live at home, remain socially active, and participate in everyday tasks. In this phase, physiotherapy may help preserve function over time and support continued participation in family and community life.
In more advanced stages, the focus often shifts toward maintaining basic functions for as long as possible. In this context, the physiotherapist may help to:
• maintain gait function
• preserve transfer ability
• reduce fall risk
• support balance and postural control
• facilitate activity within the home
• reduce the burden on family members and caregivers
Home assessment may also be important. The physiotherapist can identify risk factors in the home and suggest measures that make the environment safer and more functional. This may help delay the need for institutional care.
Physical Activity and Exercise
Physical activity should be an integrated part of the management of Alzheimer’s disease. Regular movement may be important for physical function, balance, gait pattern, and quality of life. In many patients, exercise may help reduce functional decline and support everyday independence²⁸²⁹.
There is also growing interest in how exercise may influence cognition. Several mechanisms have been proposed, including effects on neuroplasticity, cerebral circulation, and the production of growth factors in the brain. Physical activity has been associated with increased levels of:
• brain-derived neurotrophic factor (BDNF)
• insulin-like growth factor 1 (IGF-1)
• vascular endothelial growth factor (VEGF)
These mechanisms may theoretically support memory, executive function, and overall brain health²⁸²⁹.
Research suggests that different forms of exercise may have different strengths. Some reviews indicate that resistance training may be particularly relevant for slowing cognitive decline in people with cognitive impairment, whereas combined exercise programs often appear to be beneficial for global cognition and executive function³⁰.
This does not mean that one type of exercise is suitable for everyone. Exercise programs must be adapted to the individual’s baseline function, motivation, comorbidities, fall risk, and stage of disease.
Gait, Balance, and Falls
In Alzheimer’s disease, gait and balance are not solely matters of motor function. Walking is closely linked to attention, executive functioning, and the ability to process sensory information. When these systems are impaired, the consequences for safe movement in everyday life can be significant³¹.
Older adults with cognitive impairment have a substantially higher risk of falls and fall-related injuries than those without cognitive impairment³¹. This is clinically important because falls in dementia often have major consequences, including reduced function, fear of movement, fractures, and increased care needs.
Factors that may contribute to falls in individuals with Alzheimer’s disease include:
• reduced executive function
• impaired attention
• reduced visuospatial orientation
• poor balance control
• impaired vision
• slower reaction time
Reduced visual acuity has also been linked to poorer executive function, which may in turn negatively affect balance³². This highlights that fall risk assessment in Alzheimer’s disease should be broad and should include more than strength and balance alone.
In physiotherapy practice, the assessment should often include:
• gait speed
• dual-task situations
• postural control
• vision-related challenges
• environmental risk factors
Practical Content of Physiotherapy Interventions
Interventions should be simple, repetitive, and meaningful. For many patients, concrete and familiar activities are more effective than abstract exercises. Training should often be structured with clear routines, predictable repetition, and low cognitive complexity.
Relevant interventions may include:
• gait training
• lower-limb strengthening exercises
• balance training
• functional transfer exercises
• upright activity throughout the day
• simple coordination exercises
• activity linked to everyday tasks
The aim is not necessarily high intensity, but rather regularity, safety, and functional transfer to daily life.
Diet and Nutrition
Diet has also been highlighted as a factor that may influence both risk and progression in Alzheimer’s disease. There is no single nutrient that alone appears to protect against the disease, but an overall dietary pattern may be relevant³⁴³⁵.
A diet with the following characteristics has received particular attention:
• low intake of unhealthy fats
• high intake of omega-3 fatty acids
• plenty of vegetables
• plenty of fruit
• adequate vitamin C intake
• folate
There has also been interest in coenzyme Q10, vitamin E, ginkgo, and various anti-inflammatory approaches, but the evidence is not strong enough for these to be considered established treatments³⁵.
In clinical practice, nutrition becomes especially important because individuals with Alzheimer’s disease may later develop problems related to appetite, meal structure, recognition of food, and swallowing function. Nutritional follow-up is therefore important for maintaining function, energy levels, and preventing malnutrition.
Differential Diagnoses
Alzheimer’s disease must be distinguished from other conditions that can produce dementia-like symptoms. This is important for prognosis, treatment, and follow-up.
Relevant differential diagnoses include:
• Pick’s disease
• Lewy body dementia
• frontotemporal dementia
• cognitive impairment caused by polypharmacy
• other potentially reversible causes of dementia
In practice, this means that dementia assessment should never be limited too early to a single explanatory model. The clinical picture, rate of progression, associated symptoms, imaging findings, and laboratory results must all be interpreted together.
Importance of Caregivers
The burden of Alzheimer’s disease does not affect only the person who is ill. Family members and other caregivers often take on an extensive and long-term role, particularly when the disease progresses into the moderate and late stages.
Many attempt to manage the patient’s daily needs, contact with healthcare services, practical matters at home, and long-term planning. This can result in considerable psychological and physical strain.
Common difficulties among caregivers may include:
• stress
• sleep problems
• emotional exhaustion
• depression
• social burden
Support for relatives should therefore be part of the overall care pathway. Caregivers often need information, guidance, respite, and help understanding disease progression. Good support for caregivers may also indirectly improve the patient’s situation.
Alzheimer’s Disease in Low-Resource Health Systems
Dementia is also a growing problem in low- and middle-income countries. More than half of all people living with dementia reside in these countries, and the numbers are expected to rise rapidly in the coming years³⁶³⁷.
In many low-resource health systems, Alzheimer’s disease remains under-recognized and undertreated. Several factors contribute to this:
• limited public awareness of the disease
• restricted access to healthcare services
• few diagnostic resources
• limited availability of adapted cognitive assessment tools
• stigma and misunderstanding surrounding dementia
When symptoms are not recognized as signs of illness, many people do not seek healthcare. As a result, the disease is often identified late and patients do not receive the support and treatment they need³⁸.
The surrounding environment may also provide little cognitive stimulation if family members do not understand that behavioural changes are caused by disease rather than intentional behaviour³⁹.
Another challenge is that many cognitive assessment tools were originally developed and validated in high-income countries. These tools do not always perform equally well in different cultural, linguistic, and educational contexts. There is therefore a need for better local adaptation and validation of assessment tools in low- and middle-income countries⁴⁰.
Clinical Summary
Alzheimer’s disease is a complex and progressive brain disorder that affects far more than memory alone. As the condition develops, behaviour, emotions, motor function, balance, sleep rhythm, and the ability to function in daily life are also affected.
Management must therefore be broad and multidisciplinary. Medications may reduce certain symptoms, but treatment is largely about preserving function, safety, and quality of life. Physiotherapy, physical activity, nutritional support, environmental adaptation, and support for caregivers are all central components of good management.
At the same time, the disease must be understood within a broader societal context. Alzheimer’s disease is not only an individual diagnosis but also a growing public health challenge that requires better diagnostics, more tailored care, and stronger support systems internationally.
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