Dementia

Dementia is a major neurocognitive disorder characterized by memory, decision-making, logical thinking, and social abilities. These changes are severe enough to interfere with the patient’s daily activities and occupational functioning.

Memory loss is often one of the earliest signs of Dementia. There are several causes of dementia attributed to the damage to the parts of the brain responsible for decision making, language learning, and memory.

According to statistics, around 5%-8% of people over 65 years of age suffer from some form of dementia. Almost half of the population above 80 have some dementia.

Alzheimer's disease is the most common cause of progressive dementia. Depending upon the cause, some Dementia symptoms are reversible and improve with treatment, but many diseases which cause dementia aren’t treatable.

Dementia can be split into two groups.

Cortical Dementias: The cause of cortical dementia is damage to the cerebral cortex, the outer region of the brain that plays a critical role in memory and language processing leading to severe memory loss and loss of the ability to understand language. Examples include Alzheimer's and Creutzfeldt-Jakob disease.

Subcortical Dementias: It is caused by damage in the parts of the brain beneath the cortex. Forgetfulness and language problems are not a feature of subcortical dementia; instead, the ability to start activities and thinking speed. This type is caused by Huntington's disease, Parkinson's disease, and HIV.

There are some types of dementia that affect both parts of the brain. For example, Lewy Body dementia is both cortical and subcortical, characterized by abnormal balloon-like protein clumps in the brain. Common signs and symptoms include visual hallucinations (seeing things that aren't there), difficulty in focusing and attention. 

The most common causes of dementia include:

Degenerative Neurological Diseases 

• Alzheimer's disease is the most common disorder of dementia. The causes of Alzheimer's disease are related to mutations of three genes, which can be passed down to the next generation. One of the genes that increase risk is Apolipoprotein E4 (APOE).
• Parkinson's disease eventually leads to dementia.
• Huntington's disease is caused by genetic mutation around 30-40, wasting away specific nerve cells in your brain and spinal cord, leading to a severe decline in cognitive skills.
• Some types of multiple sclerosis. This type of dementia gets worse over the period.

Vascular disorders

The disorders that cause damage to the blood vessels supplying the brain also result in dementia.

This includes traumatic brain injuries like automobile accidents, falls, concussions, central nervous system infections (e.g., meningitis, HIV, Creutzfeldt-Jakob disease), long-term drug or alcohol abuse, and fluid build-up in the brain like in certain types of hydrocephalus.

Reversible Causes of Dementia

These include the causes that can be reversed with treatment. They include:

• Infections and immune disorders:e.g., IV-associated neurocognitive disorders (HAND), Multiple sclerosis
• Metabolic problems and endocrine abnormalities:e.g., low blood sugar (hypoglycemia)
• Decrease or increase in sodium or calcium
• Vitamin B-12 deficiency.
• Nutritional deficiencies:e.g., dehydration (not drinking enough fluids),
• Vitamin B-1(standard in chronic alcohol use), B-6 and B-12, and vitamin E deficiencies.
• Copper deficiency.
• Brain tumors
• Subdural hematomas: bleeding beneath the brain’s outer covering common in the elderly after a fall.
• Side effects of medicines.
• Normal-pressure hydrocephalus: is caused by enlarged ventricles in the brain, resulting in walking problems, urinary difficulty, and memory loss.

Risk factors that can't be changed:

1. Age: Age is a significant risk factor. Many people above 65 years start to experience some form of dementia. But it can be found in young people also.

2. Family history: A positive family history of dementia puts you at greater risk of developing the condition. People with a family history may never develop symptoms, and many people without a family history do. Genetic mutations responsible for the development of dementia can be determined with tests.

3. Down syndrome: it is mainly found in people with downs syndrome by middle-age.

Modifiable risk factors:

• Diet and exercise: Lack of exercise increases the risk of dementia. There is a greater incidence of dementia in people who eat an unhealthy diet than those who follow a balanced diet rich in produce, whole grains, nuts, and seeds.
• Excessive alcohol use: A large amount of alcohol consumption is associated with brain changes.
• Cardiovascular risk factors: Hypertension(high blood pressure), high cholesterol, atherosclerosis (fat deposition in arteries) can damage brain cells.
• Diabetes: Poor control of blood sugar levels may lead to brain blood vessel damages.
• Smoking.
• Depression.
• Sleep disturbances.
• Vitamin and nutritional deficiencies: Low levels of Vitamin D, B-6, B-12, and folate increase the risk of dementia.
• Medications that can worsen memory: Over-the-counter sleep aids containing diphenhydramine and oxybutynin (Ditropan XL) used to treat urinary urgency.
• Air pollution.

Signs to watch for:

• Short-term memory problems, including forgetfulness and repeating the same question repeatedly.
• Communication problems like loss of words.
• Getting lost: Difficulty with visual and spatial abilities, such as getting lost while driving.
• Difficulty in fulfilling complex but familiar tasks, like fixing a meal or paying bills.
• Personality changes, like depression, agitation, paranoia (delusions), and mood swings.
• Difficulty with coordination and motor functions.
• Confusion and disorientation.

Diagnosis of dementia and determining the type is challenging. The cause of dementia must be recognized by the pattern of loss of skills and function. With the help of available Biomarkers, a more accurate diagnosis of Alzheimer's disease can be made.

No single test can diagnose dementia; several tests are performed to pinpoint the problem. Medical history and symptoms followed by a physical examination are also very important.

Cognitive and Neuropsychological Tests: are performed to evaluate your memory, problem-solving, orientation, visual perception, attention, movement, reasoning, sense of judgment,  language skills, and engagement.

Imaging: PET scans, CT or MRI scans of the brain can check for evidence of stroke, bleeding, tumor or hydrocephalus.

Laboratory Tests:

Include;

Vitamin B-12 levels, Thyroid levels

Spinal fluid test for infections, inflammations, or markers of degenerative changes.

Psychiatric evaluation: A psychiatrist can detect the presence of depression or any other psychiatric illness as a cause of your symptoms.

Most types of dementia can't be cured. Treatment aims to manage symptoms and improve quality of life.

• Cholinesterase Inhibitors: These medications work by increasing levels of a chemical messenger, acetylcholine, which is involved in memory and judgment. They include; donepezil (Aricept), rivastigmine (Exelon), and galantamine (Razadyne). 
• Memantine: Memantine (Namenda) is directed at another chemical messenger called glutamate involved in learning and memory processes. Dizziness is a common side effect. 
• Psychosocial: therapies, exercise, balanced diet, and palliative care.

The prognosis of dementia is variable. Some people may live longer, while others live for ten years after diagnosis. Patients need great care. The family members need to be well aware of the symptoms and act accordingly to prevent complications. If not treated well, the prognosis is poor.

To cope with the disease, the following lifestyle changes must be adopted,

• A person is advised to take a healthy balanced diet with vitamins, minerals, amino acids, antioxidants, etc.
• Regular exercise
• Mind stimulating exercises like games, puzzles, reading.
• Quit smoking and excess alcohol.
• Good sleep hygiene and a regular sleep-wake schedule should be followed.
• Psychological therapies: a person should undergo cognitive behavioral therapy or psychotherapy to control the symptoms of anxiety and depression.

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 16, 2023.

References

What Is Dementia? Symptoms, Types, and Diagnosis | National Institute on Aging (nih.gov)

https://www.nia.nih.gov/health/what-is-dementia

Dementia prevention, intervention, and care: 2020 report of the Lancet Commission - The Lancet

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30367-6/fulltext?inf_contact_key=779905f3c1735bf89533cbb79fb3e8eaf651f238aa2edbb9c8b7cff03e0b16a0