Home Neurology Dementia


Verified By Apollo General Physician June 12, 2019 2605 0


The word ‘dementia’ describes a set of symptoms that include memory loss and difficulties with thinking, problem-solving or language. Changes in mood and behavior are also associated with dementia. The symptoms experienced in dementia depend on the parts of the brain damaged and the underlying conditions that are resulting in dementia.

There are various types of dementia. Alzheimer’s is the most common type, constituting to 50 – 70% of the cases. Other types include vascular dementia, Lewy body dementia, frontotemporal dementia, normal pressure hydrocephalus, Parkinson’s disease, syphilis, Creutzfeldt–Jakob disease, etc. A person may experience more than a single type of dementia.  Dementia occurs when the brain is damaged due to a series of damages.

According to a study, dementia occurs in about 10% of the people at some point in their lives. As age progresses, there could be a significant increase in the risk of developing the disorder. In people between the ages 65 – 74, dementia occurs in about 3% of them, 19% people aged between 75 – 84 years and about half of the population aging over 85 years are seen suffering from some form of dementia. Therefore, dementia is considered to be one of the most common causes of disability among the old. The number of deaths caused due to dementia has increased significantly, doubling up in number between the years 1990 and 2013. Dementia was seen to occur most commonly in low and middle-income countries. Some studies also suggest that the prevalence rates are slightly higher in women than in men at ages 65 and above. Even though dementia commonly affects older people, it is not considered as a normal part of aging.

The severity of dementia could be categorized based on the level of disability caused due to the neurological disorders.

The four main stages of dementia classified based on their severity are

  • Mild Cognitive Impairment: Though this stage does not necessarily signify dementia, it has symptoms that could possibly progress into the disorder. This is characterized by general forgetfulness. This occurs as age advances and is not considered as dementia in all cases. This stage progresses into dementia in certain cases alone.
  • Mild Dementia: This is a stage where a person experiences symptoms of dementia and cognitive impairments that could affect daily life. Memory loss, confusion, personality changes, getting lost, difficulty in planning and executing tasks are some of the common symptoms seen in individuals with mild dementia.
  • Moderate Dementia: This stage of dementia is more challenging, making the affected individual need more help. Symptoms of moderate dementia are similar to that of mild dementia but are intense and stronger. A patient with moderate dementia is likely to have sleep disturbances and could display agitation and suspicion. They could require help in performing simple routine activities like dressing up, combing hair, etc.
  • Severe Dementia: Symptoms of dementia are the worst in this stage. The affected individual may have a problem with communication, speech, etc. Tasks such as sitting up, holding up the head could become impossible. A person may also have loss of bladder control. Full-time care is required for patients with severe dementia.


Dementia could affect as the age of a person progresses. However, in most cases, an underlying health condition could be a reason for the development of dementia. Damage to the brain cells due to age or other brain disorders often leads to dementia.

The common causes of dementia are:

Alzheimer’s disease (AD) – This is considered to be the most common cause of dementia. This disease results in damage of the brain cells by abnormal proteins. The symptoms of AD are problems with day to day memory. These include finding difficulty to find the right words, solving problems, perceiving things in three dimensions, etc.

Vascular Dementia (VD) – This is the second most common cause of dementia. This is caused due to the damage or death of brain cells as the oxygen supply to the brain is reduced because of the blockage or narrowing of blood vessels. Symptoms of VD can occur suddenly, following a major stroke or can develop over time due to a series of minor strokes. This dementia could also occur due to a disease known as subcortical vascular dementia that affects the small blood vessels deep in the brain. Symptoms of VD could be similar to that of AD.

Mixed Dementia – It is possible for an individual with dementia to experience more than a single type of dementia at one point. Such a condition is termed as mixed dementia. The symptoms of such dementia could also be a mix of the types of symptoms for each of dementia experienced by the person. Patients with vascular dementia could experience Alzheimer’s disease as well.

Dementia with Lewy Bodies – This type is caused by the formation of tiny abnormal structures, called the Lewy bodies, inside the brain cells. They alter the chemistry of the brain and could result in the death of brain cells. Hallucinations, improper judging of distances, varied alertness through the day, etc. are some of the symptoms of this type of dementia. This type of dementia is closely related to Parkinson’s disease and so could display the same symptoms.

Frontotemporal Dementia – This type of dementia is caused due to the damage to the front and side parts of the brain. An abnormal protein forms clumps inside the brain cells, causing the cells to die. Based on the part of the brain damaged, the person may display varied symptoms. Personality and behavioral changes could be the most obvious signs.

Apart from these common causes of dementia, there are some rare causes that lead to the development of the disorder. These rare causes constitute to about 5% of all dementia cases. Dementia caused by rare causes is common in individuals younger than 65 years of age. Such causes include:

In very rare cases, people with Parkinson’s disease, Huntington’s disease and Down’s syndrome could develop dementia if the primary health issues get worse.


The symptoms of dementia vary from stage to stage. Commonly affected areas of the brain in dementia include memory, visual-spatial, language, attention and problem-solving. On the Mini-Mental State Examination (MMSE), a person scoring between 27 to 30 is considered normal. This falls to lower numbers as the disease advance. A person having dementia might not display signs and symptoms immediately. As the disorder itself progresses with time, its symptoms also come to light much later after the process begins.  The symptoms show up gradually and get worse over time.

Other common behavioral and psychological symptoms found in people suffering from dementia include:

  • Abnormal motor behavior
  • Agitation
  • Anxiety
  • Apathy
  • Changes in sleep and appetite
  • Delusion
  • Depression
  • Disinhibition
  • Elated mood
  • Insomnia
  • Impulsive behavior
  • Irritability

Problems affecting people with dementia include:

  • Tremors
  • Trouble balancing
  • Speech and language difficulty
  • Problems with memory
  • Trouble eating or swallowing
  • Restlessness
  • Visual problems
  • Sudden expression of anger
  • Psychosis

Based on the stage of dementia, the symptoms displayed by the affected person could vary. While some symptoms become intense as the stages advance, some of them are seen only upon the onset of a new stage.

Symptoms of dementia for each of the stages are as follows

Mild cognitive impairment (MCI)

As discussed earlier, not all MCI leads to dementia. However, studies show that about 70% of all MCI cases turn into dementia at some point. An in-depth neuropsychological testing is required to diagnose MCI.

A person with MCI experiences –

  • Issues with memory
  • Trouble finding words (anomia)
  • No indication of dementia
  • No trouble performing daily activities

Mild Dementia

Individuals with mild dementia usually score between 20 and 25 on the MMSE. Symptoms of mild dementia are noticeable and can hinder a person’s ability to perform daily activities. Symptoms depend on the type of dementia a person is suffering from. Common symptoms include –

  • Forgetting regular things (taking pills, doing laundry)
  • Memory difficulty
  • Anomia
  • Trouble executing plans
  • Inability to handle finances independently (first noticeable symptom in most cases)
  • Getting lost in new places
  • Personality changes
  • Social withdrawal
  •  Abnormal
  • Difficulties at work

Moderate Dementia

In this stage of dementia, the symptoms seen in the mild stage are worsened. Individuals with moderate dementia could score between 6 and 17 on the MMSE. Besides showing intense mild-dementia symptoms, a person with moderate dementia could show the following symptoms as well –

  • Impaired social judgment
  • Impaired problem-solving ability
  • Losing new information quickly
  • Inability to function in new places
  • Inability to perform simple chores
  • Require assistance with personal care and hygiene
  • Require reminders for simple tasks

Severe Dementia

By this stage, a patient with dementia would not be able to do most of the chores without assistance. In this stage, the affected individual requires care and supervision constantly. In the absence of assistance, the patient would not be able to recognize common dangers and may fall prey to it. Symptoms of late dementia or severe dementia include –

  • Bladder incontinence
  • Inability to swallow
  • Brain tumor
  • Loss of appetite
  • Inability to recognize familiar people
  • Altered sleeping habits
  • Insomnia

Risk Factors

The risk factors for dementia can be broadly categorized into two types:

Modifiable Risk Factors: These risk factors include those that could be changed or altered by the individual. Factors such as consumption of alcoholic beverages, weight management, etc. could be considered as modifiable risk factors.

Fixed Risk Factors: Factors that have no hand of the individual over the set risk are called fixed risk factors. They include age, gender, genetics, ethnicity etc.

In general, the following are the risk factors for dementia:


This is considered a major risk factor for dementia. As age increases, the risk of dementia increases significantly. At least one person in 20 people suffering from dementia would have developed the disorder under 65 years of age. A person over 64 years of age has doubled risk of developing Alzheimer’s disease or vascular dementia.

The factors that contribute to the risks that come with age are –

  • High blood pressure
  • Increased risk of cardiovascular diseases
  • Changes in nerve cells and DNA cell structures
  • Loss of sex-hormones
  • Weakened immune systems


Women were seen to have a slightly higher risk of developing dementia compared to men. This is mostly seen in case of Alzheimer’s disease. However, when it comes to vascular dementia, men are at a higher risk than women.


Certain ethnic communities are at a higher risk of dementia compared to Europeans. South Asian people or those from India and Pakistan are more vulnerable to dementia. Similarly, African origin individuals are more prone to dementia.


Though it is not proven that genes are directly responsible for causing dementia in a person, it is understood that they could be responsible for an elevated risk for the disorder. In certain cases where the person is exposed to a risk of inheriting Alzheimer’s from familial genes, the risk of developing dementia could also increase considerably.

Medical Conditions

Conditions like cardiovascular diseases which damage the heart, arteries or blood circulation significantly increase a person’s chance of developing dementia. Other conditions like type-2 diabetes, high blood pressure, high blood cholesterol levels and obesity in mid-life or later life are factors that increase the risk of developing dementia. Most of the medical conditions are avoidable through lifestyle modifications. Diseases like Parkinson’s, multiple sclerosis and HIV have also been identified as risk factors for dementia.

Psychological Conditions

Dementia is seen to be prevalent in people who have experienced periods of depression in mid-life or later life. The onset of depression in a person for the first time when he/she is about 60 years old could be an early symptom of dementia.

Lifestyle Factors

Developing a healthy lifestyle is the core of being healthy. Several studies showed that the risk of dementia is the lowest in people who have healthy behaviors in mid-life.

Smoking, consumption of excess alcohol, unhealthy diet, obesity and physical inactivity has been associated with increased risk for dementia.

Regular exercise, maintaining appropriate body weight, cutting down on excess alcohol, quitting smoking, maintaining a healthy diet are certain factors that could considerably lower the risk of developing dementia.


Diagnosis of dementia cannot be done by any single test. Often, to confirm dementia, a wide screening process is needed to carefully understand the patient’s behavior and symptoms, considering the health and medical history of the patient. The symptoms of dementia are so close to other brain conditions that diagnosing dementia becomes considerably difficult.

In order to begin the screening process for dementia, it is required that the symptoms persist for at least six months. Often, delirium is confused with dementia as the symptoms appear to be similar. But delirium is limited to shorter duration/episodes, unlike dementia which is constantly present. Due to this difference, one can understand whether the symptoms indicate dementia or delirium. Dementia has a typically long and slow onset of symptoms, unlike delirium.

To diagnose dementia, cognitive tests, imaging tests and laboratory tests would be done.

Cognitive testing

While there are many brief tests with a duration of about 5 to 15 minutes which are used to screen dementia, the mini mental state examination (MMSE) is considered to be the best. The MMSE is a useful tool to help diagnose dementia. Other tests used under cognitive testing include abbreviated mental test score (AMTS), modified mini-mental state examination (3MS), cognitive abilities screening instrument (CASI), Montreal cognitive assessment (MOCA), trail-marking test and clock drawing test. Detection of mild cognitive impairment is better with MOCA than with MMSE.

Sometimes, a simple questionnaire could also be used to analyze a person’s cognitive functioning. Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) is the best-known questionnaire used in such diagnosis. Others include The Alzheimer‘s Disease Caregiver Questionnaire, General Practitioner Assessment of Cognition, etc.

Laboratory testing

Laboratory tests are usually done to rule out other possible health issues that could be the cause of the impairment. Some routine tests that could be ordered include complete blood count, vitamin b12, folic acid, thyroid stimulating hormone (TSH), c-reactive protein, electrolyte, calcium, liver enzymes and renal function tests. Sometimes, an underlying infection or a vitamin deficiency could be the cause of confusion and disorientation in elderly patients.


When a person suffering from dementia does not show any evident neurological problems (such as paralysis), a CT scan or an MRI scan will not be able to pick up diffuse metabolic changes associated with dementia. However, these scans could help in detecting normal pressure hydrocephalus, which is a potentially reversible cause of dementia. SPECT and PET- serve as the most useful tools in assessing long-standing cognitive dysfunction.


Sometimes, treating dementia is all about treating the underlying cause. These causes could be nutritional, hormonal, the presence of tumor and drug-related dementia. In most cases, these causes are reversible. Dementia-like Alzheimer’s can be managed with the improvement of cognitive and behavioral symptoms in combination with medications and/or psychotherapy.

Following are a few treatment procedures followed to address dementia:

  • Psychotherapy – This involves addressing problematic behaviors like aggression or socially inappropriate conduct. This also involves designing strategies for the patient to complete simple and routine daily activities like dressing up, into simpler steps to help avoid confusion and agitation.
  • Environmental Modifications – This involves modification of the patient’s surroundings to promote and comfort and decrease agitation. Such modifications include removal of hazardous substances from the vicinity of the patient (knives, blades, chemicals, tools, etc.), using child-proof latches, using bed rails, bathroom safety rails, lowering hot water temperature, disabling the stove, and others to prevent accidents.
  • Medication – In order to treat the behavioral problems in dementia, the use of antipsychotic medications has proven to be effective, especially in reducing persistent aggression with a risk of self-harm. This treatment, however, is meant to be short-term. To treat restlessness and agitation, anti-anxiety medications can be used. Medication given to a patient with dementia should be administered very cautiously and in the lowest effective doses, in order to minimize side-effects.

In most cases, dementia will not be cured completely. Treatment of dementia, in these cases, is done to manage the symptoms and enhance the patient’s stable functioning.


The prevention of dementia is a global health priority and therefore requires a global response. Dementia is said to be effectively prevented by reducing risk factors such as diabetes, high blood pressure, obesity, smoking, physical inactivity and depression. According to a study, more than a third dementia case are theoretically preventable.

The following are a few effective techniques for the prevention of dementia:

  • Mental Activity – It is important to carry out intellectual activities to keep the mind in shape in later years. Activities like reading, learning new languages, playing board games, playing a musical instrument can delay the onset or slow down the progression of disease in Alzheimer’s and vascular dementia.
  • Physical Activity – Maintenance of blood-cholesterol levels, healthy body weight and blood pressure, lower the risk of developing dementia. An active lifestyle can lower the risk up to half. This is because physical activity could give rise to new neurons in the brain. Exercising could boost brain-derived neurotropic factor (BDNF) levels by 2 – 3 times.
  • Diet – An unhealthy diet could lead to obesity, which is said to increase the risk of any dementia, particularly, Alzheimer’s. Nuts and vegetables are proven to be beneficial in the prevention of dementia due to their high content of polyunsaturated fats. On the contrary, non-fish meat could increase the risk due to the presence of saturated fat in high content. Vitamin B3 also shows to prevent dementia as people with high levels of vitamn B3 were found to have the lowest risk of the disease. Hence, dementia patients are also given 100 to 300 mg of vitamin B3 per day. Alcohol consumption increases the risk of dementia.
  • Depression – Preventing depression can potentially prevent dementia as the clinical presentation of both the disorders is relatively equal. There is no evidence of whether depression is a cause or symptom of dementia or not, but a few studies suggest that depression increases the risk of dementia. Depression, if present in a person, is best treated in mid-life in order to prevent dementia in later stages.
  • Sleep Pattern – Avoiding sleeping longer than 9 hours per day could prevent the development of dementia. However, lack of sleep is also associated with an increased risk for dementia. Therefore, a moderate amount of sleep helps in prevention of the disease.
  • Medication – Medications like antihypertensives, anti-diabetics, steroid hormones, NSAIDs have been shown to prevent dementia owing to their mechanisms of action.


What diseases increase the risk of developing dementia?

The following diseases can increase the risk of dementia –

Can head injuries increase the risk of developing dementia?

Few studies show that a serious head injury or trauma could increase the risk of developing Alzheimer’s or other forms of dementia.

What is the difference between Alzheimer’s and dementia?

Alzheimer’s refers to one particular form of dementia. Dementia is an umbrella term that covers various diseases related to memory loss. Confusion, mood and behavioral changes.

Does forgetfulness always indicate dementia?

On common grounds, normal and healthy individuals tend to forget simple things. This could include forgetting where they have kept the keys, forgetting to get a particular work done, etc. This does not always indicate dementia. Dementia or memory problem is a much serious issue where a person forgets things occasionally. If forgetfulness interferes with everyday life and starts to appear troublesome, it may be an indication of some form of dementia.

Am I more vulnerable to dementia if one of my parents has it?

Not always is dementia inherited. The genes inherited from parents will have a small effect on the risk of dementia. However, this could be modifiable by making simple lifestyle adjustments and developing healthy living habits. Taking the following precautions can considerably reduce your risk of developing dementia –

  • Quit smoking
  • Exercise regularly
  • Maintain a healthy body weight
  • Minimize alcohol intake
  • Maintain healthy cholesterol levels
  • Control high blood pressure
  • Eat a balanced diet
  • Be active

What foods help in lowering the risk of dementia?

Foods that contain high omega-3 fatty acids, like oily fish, lower the risk of dementia. Turmeric and superfoods like berries, red wine is also believed to lower the risk.

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