Alzheimer’s Disease: A Growing Global Health Concern
Healthful Vitality | 04/11/2019 | By Dr. Subarna Ghosh | Alzheimer’s Disease: A Growing Global Health Concern
Alzheimer’s disease (AD) is a brain disorder of an irreversible nature, which is characterized by progressive deterioration of an individual’s cognitive function. In AD, a decline in cognitive function chiefly affects a person’s memory, thought process, orientation, judgment, comprehension, and learning ability. Impairment of vital mental processes as seen in Alzheimer’s can significantly impact an individual’s day-to-day activities leading to disability and dependence. This article explores Alzheimer’s disease: a growing global health concern.
Globally, Alzheimer’s disease is the leading cause of dementia, which refers to a constellation of co-occurring symptoms (syndrome) indicating impairment of the brain’s mental processes. Globally, it is estimated that approximately 24 million people are affected by dementia, with a large proportion (over 11 million people) suffering from Alzheimer’s. The condition mainly affects the elderly (≥ 65 years of age). The incidence of Alzheimer’s is higher in women than men of the same age. Alzheimer’s disease is ranked amongst the top causes of disease-related death worldwide. It is an increasing global health concern as it is a debilitating condition of an irreversible nature.
Causes and Risk Factors
Despite extensive research, the exact causes of Alzheimer’s disease remain unknown. However, research suggests that certain environmental, developmental, and genetic factors play a key role in the development and progression of the disease. The main risk factors associated with Alzheimer’s disease include the following:
- Advancing age (key risk factor)
- Family history of Alzheimer’s
- Gene mutations:
- Amyloid precursor protein (APP), presenilin-1 (PS-1), and presenilin- 2 (PS-2) are three genes that are associated with early-onset (<60 years of age) Alzheimer’s (very rare)
- The primary gene associated with late-onset (>65 years of age) Alzheimer’s is apolipoprotein (Apo) E4 (key risk factor)
- Existing learning difficulties
- Head trauma
- Untreated depression
- Certain risk factors for heart disease have also been linked to Alzheimer’s. These include the following:
- Diabetes
- Elevated homocysteine levels (an amino acid)
- Elevated lipids levels (hyperlipidemia)
Signs and Symptoms
Alzheimer’s disease is an irreversible, progressive disorder, which means that the signs and symptoms of the condition appear gradually over years and worsen in severity over time. The signs and symptoms of the condition progressively affect several brain functions, all of which are related to cognition. Alzheimer’s does not affect the consciousness of the patient.
The most commonly seen initial symptom of Alzheimer’s is memory loss. Initially, however, memory loss won’t be severe. The patient experiences only minor memory issues. Some examples of mild memory problems seen in Alzheimer’s are as follows:
- Forgetting words or names of places and objects
- Finding it difficult to recall names of places, persons, and objects
- Geographic disorientation. In such cases, patients may forget the way to their home
Over time, memory loss can worsen and is accompanied by a host of other signs and symptoms, such as:
- Difficulty in decision making
- Issues with language and speech
- Difficulty in performing day-to-day activities
- Hallucinations
- Delusions
- Depression
- Agitation
- Progressive, slow loss of self-awareness
Diagnosis
In most cases, a patient is diagnosed with Alzheimer’s disease based on the signs and symptoms experienced by the patient. A clinical history of the patient’s signs and symptoms is usually obtained from the patient and the family members to make an initial diagnosis of the condition. Following initial assessment of the patient, assessment of the patient’s cognitive function via a mental status examination is an important component of the diagnostic evaluation of the condition. Other laboratory and imaging studies are used as an adjunct to support the diagnosis of Alzheimer’s. These investigative methods include the following:
- Imaging studies of the brain such as magnetic resonance imaging (MRI) scan and positron emission tomography (PET) scan can be useful in the diagnosis of Alzheimer’s if they show evidence of certain brain abnormalities such as,
- Brain atrophy (decrease in the size of the brain)
- Neurodegeneration (progressive loss of neurons (type of brain cells), even leading to death of the neurons)
- Laboratory studies include biomarker testing for Alzheimer’s. Important biomarkers of Alzheimer’s are low CSF (cerebrospinal fluid) AB42, along with, brain amyloid-beta protein deposition, and elevated CSF tau.
Depending on the signs and symptoms of the patient, Alzheimer’s disease is categorized into three phases:
- Preclinical Alzheimer’s Disease: Mild memory loss with no other accompanying symptoms. Patient can perform everyday activities comfortably without any assistance.
- Mild Cognitive Impairment (MCI): Mild issues with memory and thinking. Patient’s daily activities are not compromised.
- Clinical Alzheimer’s Disease: Memory, thought, and behavioural disturbances are noted that increase in severity gradually over time. Various imaging and biomarker tests are used for such patients to understand the extent of the disease, which can assist in prompt management of the condition.
Alzheimer’s Disease: Treatment
At present, there is no known cure or preventive measure for Alzheimer’s disease. Therapy for Alzheimer’s primarily aims to alleviate the symptoms in order to improve the patient’s quality of life. Treatment also focuses on improving the behavioural disturbances Alzheimer’s patients experience such as, agitation, depression, anxiety, and sleeplessness.
Therapeutic approaches for Alzheimer’s can be divided into two categories, which are as follows:
- Non-Pharmacologic Therapy
- Relaxing activities (listening to music, cooking, etc) are helpful in improving the cognitive functioning of the patient. These activities also improve the patient’s mood and assist to manage emotional and behavioural disturbances.
- Pharmacologic Therapy: Medications approved by the Food and Drug Administration (FDA) in the United States are as follows:
- Rivastigmine (Exelon), galantamine (Razadyne), and donepezil (Aricept) are used for mild to moderate Alzheimer’s disease.
- Memantine (Namenda) and donepezil (Aricept) are used for moderate to severe forms of Alzheimer’s disease.
Alzheimer’s Disease: Support for Patient, Family Members, and Caregivers
Alzheimer’s disease is a debilitating condition that can adversely affect the emotional state of the patient, the family members, and the caregivers. Hence, a strong support network is vital in order to cope with the condition and its negative effects on everyday activities. Programs that educate patient and families about the various aspects of Alzheimer’s and teach coping methods, along with, ways to overcome caregiving challenges can be very helpful. Such measures can greatly assist the management of the condition and help family members to care effectively for their loved one with Alzheimer’s disease.
(Also Read: Top 10 Global Health Issues)
References
- Bondi MW, Edmonds EC, Salmon DP. Alzheimer’s Disease: Past, Present, and Future. J Int Neuropsychol Soc. 2017;23(9-10):818-831. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5830188/
- Amirrad et al. Alzheimer’s Disease: Dawn of a New Era. J Pharm Pharm Sci. 2017; Vol 20: 184-225. https://journals.library.ualberta.ca/jpps/index.php/JPPS/article/view/29185/21354
- World Health Organization (WHO) Fact Sheet: Dementia https://www.who.int/news-room/fact-sheets/detail/dementia
- Ljubenkov.P.A. & Geschwind. M.D. Alzheimer’s disease. Seminars in Neurology. 2016; Vol 36: 4; pp: 397-404. https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0036-1585096
- Oxford Medicine Online: Epidemiology of Alzheimer’s Disease http://oxfordmedicine.com/view/10.1093/med/9780199569854.001.0001/med-9780199569854-chapter-3.