Overview on the Causes of Dementia

Dementia epitomizes itself in a variety of ways and is caused by a variety of factors. Although much progress has been made in dementia research, scientists still do not have a complete understanding of the disease’s causes. Here’s what we could grasp so far about the causes and risk factors for various types of dementia.

Alzheimer’s Disease

Alzheimer’s disease (AD) is thought to be responsible for 60 to 80 percent of all dementia cases, according to the Alzheimer’s Association. The specific causation of Alzheimer’s disease is unknown. However, various theories exist.

An accumulation of abnormal material in the brain

Amyloid plaques and neurofibrillary tangles, two abnormal structures in the brain, are frequent in Alzheimer’s disease. The buildup could be a contributing factor, but experts aren’t sure if the findings are due to the disease or not.

Amyloid plaques are clumps of beta-amyloid, a naturally occurring protein fragment in the brain. When these beta-amyloid proteins cluster together, plaques form, disrupting nerve cell transmission and causing brain inflammation. The hippocampus, the memory-related portion of the brain, has an abundance of these plaques in people with Alzheimer’s disease. In Alzheimer’s disease, the transfer of short-term memories to long-term memories is frequently disturbed. Find out about the additional signs and symptoms of Alzheimer’s disease.

Fibrous tangles of an aberrant protein called tau are known as neurofibrillary tangles. Tau is a fiber-like protein that helps the brain’s microtubules stay in place. Nutrients, chemicals, and information are transported via microtubules to other cells. The fibers of tau become twisted up together when they are harmed, presumably owing to a genetic mutation. The microtubules become unstable and dissolve as a result of this. This effect has the potential to bring the entire neuron transport system down.

Mutations in the Human Genome

Some people get Alzheimer’s disease as early as their early 30s or 40s. This is known as Alzheimer’s disease with young-onset. Three known gene mutations are thought to play a role in the production of amyloid plaques in early-onset AD. The more frequent kind of Alzheimer’s disease, often known as late-onset Alzheimer’s disease, is not affected by these three gene abnormalities.

Inclusions

Alzheimer’s disease and other dementias are linked to aberrant brain formations known as inclusions. Various aberrant proteins make up these formations. It’s unclear whether or not these structures cause or are caused by the disease.

Lewy Body Dementia

Lewy body dementia is a type of degenerative dementia that affects many people. This condition is characterized by abnormal brain structures known as Lewy bodies. They’re situated in the cortex, the brain’s outer layer. The cortex is in charge of language processing, perception, production, and comprehension.

Lewy bodies can also be found in the substantia nigra and numerous areas of the brain stem. Nerve cells in this area release important neurotransmitters that aid with movement and coordination.

People with Parkinson’s disease have a lot of Lewy bodies in their brains.

Vascular Disease Dementia

The brain demands an endless supply of oxygen from the bloodstream to function properly. Brain cells cannot operate correctly without oxygen. Brain cells can perish if the oxygen supply is disrupted for a long time. Vascular dementia can be caused by any disorder that impairs proper blood flow to the brain.

Vascular dementia comes in a variety of forms. Each has its own set of causes and symptoms. Multi-infarct dementia (MID), for example, is caused by a series of minor strokes in the brain. When a stroke ensues in the left hemisphere of the brain and the hippocampus is involved, dementia is more likely.

Vascular dementia does not affect everyone who has had a stroke.

Frontal Lobe Dementia

A set of disorders known as frontal lobe dementia causes major alterations in behavior and linguistic abilities. Frontotemporal dementia is another name for it.

All of these ailments are caused by the degeneration of brain cells in the frontal and temporal lobes. Behind the eyes and above the ears are the frontal and temporal lobes of the brain. Personality, judgment, emotion, and language are all controlled by these areas.

Amyloid plaques are uncommon in frontal lobe dementia, whereas neurofibrillary tangles are common. It can run in families, implying that genetics may play a role in the disease’s development.

Pick’s disease is a genetically based frontal lobe dementia. Pick bodies, which are aberrant formations formed largely of the protein tau, are seen inside the neurons of people with this condition. Pick bodies to clog up brain cells, causing them to swell and eventually die. This causes the frontotemporal regions of the brain to shrink, or atrophy, as a result.

There is no specific treatment for frontal lobe dementia at this time.

Conditions that may be Reversible

Dementia and dementia-like symptoms can be treated for a variety of reasons. If identified early enough and treated properly, they may be reversible. The following are some examples of reversible conditions:

Deficiencies in Vitamins and Minerals

Chronic alcoholism generally results in thiamine (vitamin B-1) deficiency, which can substantially damage mental capacities, particularly recollections of recent events.

Severe vitamin B-6 deficiency can lead to pellagra, a multisystem disorder that can include dementia.

In some situations, vitamin B-12 deficiency has been connected to dementia.

Poisoning

Dementia symptoms can be triggered by exposure to lead, other heavy metals, or other harmful substances. Counting on the stringency of the brain damage, these symptoms may or may not go away following treatment.

Even after they have stopped abusing substances like alcohol and recreational drugs, people who have overused these substances can develop dementia. Substance-induced persistent dementia is the name for this condition.

Endocrine Disorders and Metabolic issues

Thyroid disorders can cause apathy, depression, or dementia-like symptoms.

Lack of sugar in the bloodstream or Hypoglycemia can lead to confusion and personality changes.

Mental changes might be triggered by too little or too much sodium or calcium.

Some people’s capacity to absorb vitamin B-12 is limited. Pernicious anemia is a disorder that can induce personality changes, irritability, and depression.

Effects of Medications

Prescription drugs can sometimes cause delirium, which is a type of side effect that looks like dementia. These dementia-like symptoms might emerge as a result of a single medicine or as a result of drug interactions. They may grow gradually over time or appear suddenly.

Illegal drug use can also cause delirium, which resembles dementia.

Problems with the Heart and Lungs

To carry out its usual tasks, the brain requires a lot of oxygen. Conditions that restrict the brain from receiving adequate oxygen, such as chronic lung illness or heart difficulties, can starve brain cells and cause delirium-like symptoms.

Infections

Due to other side effects of the body’s battle to overcome the infection or fever, many illnesses can induce neurological symptoms such as confusion or delirium.

Infections affecting the brain or the membrane that protects it, such as meningitis and encephalitis, can cause disorientation, impaired judgment, and memory loss.

Syphilis, if left untreated, can harm the nervous system and lead to dementia.

Lyme illness might cause memory or thinking problems in certain people.

Dementia can occur in those who have severe stages of AIDS. People with weakened immune systems, such as those suffering from leukemia or AIDS, are at risk of developing a disease known as progressive multifocal leukoencephalopathy (PML). PML is caused by the JC virus, a common human polyomavirus. It causes the myelin sheath that protects nerve cells to be damaged or destroyed. PML can cause mental confusion, difficulties thinking or communicating, and other issues.

Other Reasons

Hematomas in the Subdural Space

Dementia-like symptoms and impairments in mental function can be caused by bleeding between the brain’s surface and its outer covering (the dura) or subdural hematomas.

Anoxia

When the brain is deprived of oxygen, anoxia develops. It can be caused by a variety of issues. These are some of them:

• attack on the heart
• surgery on the heart
• Asthma attack
• Inhalation of smoke or carbon monoxide
• strangulation
• an anesthetic overdose

The time it takes for you to recover is determined by how long you were without oxygen.

Tumors of the Brain

Brain tumors can cause harm to the tissue in your brain as well as pressure inside your skull. This can make it difficult for your brain to work normally. Dementia can be caused by damage to or disruption of the brain’s processes.

Stroke

When the movement of blood to the brain is impeded, a stroke occurs. This can nearly increase your chances of having some types of dementia, including vascular dementia. Age, sex, and family history are all factors that increase your chances of developing dementia after a stroke.

Accidental Brain Damage

Any large impact on your skull can result in traumatic brain injury. Proteins in your brain, including beta-amyloid and tau proteins, can behave improperly as a result of these injuries, causing injury to your brain. This has the prospect of leading to dementia.

One of the most common traumatic brain injuries is falling down and hurting your head at home. Another serious cause of dementia is hitting your head in a car accident, particularly against the windshield. If you’ve had a severe brain injury, you’re five times more likely to acquire dementia.

People who have had several traumatic brain injuries are at an even higher risk of getting dementia. They’re in danger of developing chronic traumatic encephalopathy, which is a form of dementia.

TBIs are classified into three categories based on the severity of the injury:

Mild: These cause you to lose consciousness for less than half an hour or don’t cause you to lose consciousness at all. Disorientation, headaches, dizziness, or the difficulty to speak clearly only last a few weeks or months at most. A mild traumatic brain injury has a minimal risk of producing dementia.

Moderate: These can cause you to lose consciousness for up to a half-hour. Many of the same symptoms of a minor injury appear, but they can continue for months or even years and be considerably more severe. A mild brain injury has a substantially higher chance of producing dementia.

Severe: These can make you lose consciousness for up to 24 hours. The severe brain damage might have terrible symptoms.

Dementia in Other Forms

Dementia can also be caused by the following conditions:

When numerous illnesses contribute to your dementia, it is referred to as mixed dementia. In a case of mixed dementia, Alzheimer’s disease, Lewy body disorders, and vascular problems may all be present.

Huntington’s disease is a genetic disorder that causes nerve cells in the spine and brain to die. If you have dementia, you may begin to notice symptoms of cognitive impairment after the age of 30.

Parkinson’s disease: Parkinson’s disease damages your nerves, which can lead to dementia.

Creutzfeldt-Jakob disease is a brain disease that is thought to be caused by abnormalities with brain proteins or interaction with diseased brain or nerve tissue. Symptoms usually don’t develop until after you’ve reached the age of 60.

A medley of risk factors, such as family lifestyle decisions and history, are frequently responsible for many illnesses. Huntington’s disease is only passed down through families, and it cannot be contracted if you do not have the necessary genes.

Dementia-related Risk Factors

Some dementia risk factors are uncontrollable, such as:

• Your age, as after the age of 65, your risk increases.
• As you become older, your memory starts to deteriorate.
• Down syndrome (a genetic condition that causes dementia at an early age)
• Because a family history of dementia can raise your risk of having dementia, your genes are important.

Other risk factors may react to treatment or lifestyle modifications. These are some of them:

• consuming a large amount of alcohol
• heavy smokers
• Obesity or a poor diet might cause heart problems.
• Diabetes, especially if you aren’t being treated for it or if it isn’t under control.
• Depression, especially when it strikes later in life and you have no prior history of mental health issues, maybe devastating.