What is dementia and the Types of dementia?

Dementia is the leading cause of long-term disability in the elderly, affecting 2% of people aged 65-70 years and 20% of those over 80. It usually begins with minor memory disturbances.

Dementia is a chronic deterioration of at the least three higher functions (start, and finally often alter all intellectual functions). Acquired (the main difference with mental retardation, like this, usually occurs from childhood), and a level of ordinary consciousness and attention (unlike delirium, in which there is a decrease in the level of consciousness).

In other words, it is a progressive loss of memory and other cognitive functions, preserving the level of consciousness, but with obvious maladjustment of the individual to their environment. The diagnosis is usually given when the patient presents a set of signs and symptoms that respond to these alterations for about three months.

Dementias compromise the intellectual faculties of those affected, such as language, memory, and visuospatial skill, as well as their emotional capacity and personality. The mild cognitive impairment can often precede Dementia, progressing around 10% annually from mild situation to the establishment of Dementia.

The most common form of Dementia is Alzheimer’s disease, which makes up about 70% of all dementias.

Dementia is an age-related disorder. It affects 2% of people aged 65-70 years and 20% of those over 80 years. It is the main cause of long-term disability in the elderly, a significant public health problem, taking into account the increase in life expectancy in developed societies. This has made its prevalence higher than in the past since the elderly population exceeded in figures half a century ago. More than 47 million people in the world have Dementia, with an increase of more than 7 million new cases per year. By 2050, this figure is estimated to exceed 130 million.

Regarding gender, it seems that Alzheimer’s disease is slightly more linked to the female sex, while other types of Dementia, such as vascular, is somewhat more frequent in men.

Its treatment in most cases lies in the control of symptoms and cognitive and behavioral therapies since there is currently no curative therapy or well-established prevention of most types of Dementia.

Types of Dementia

Alzheimer disease

It is the most common cause of Dementia in the West. The onset of symptoms usually occurs after the age of 65. However, in some patients, it can occur before the age of 40 (in which case it is generally associated with hereditary forms of the disease, which can happen in 25% of cases).

At first, the clinic is limited to specific memory lapses. Later, an alteration of recent memory (ability to store new information and retrieve it after some time) and learning capacity is established. 

Fronto-temporal Dementia (Pick’s disease)

It is a degenerative disorder characterized by abnormal substances, known as Pick’s bodies and cells, inside some neurons that are located in the frontal and temporal lobes.

It usually affects patients in the middle ages of life; thus, it is one of the most frequent dementias in patients between 45 and 65.

It is usually Dementia that progresses slowly, and the main clinical alteration is in the sphere of the personality; the most striking symptoms are:

  • Difficulties in social relationships, leading to isolation.
  • Compulsive and inappropriate behavior in various environments.
  • Alterations in the control of emotions.
  • Loss of executive abilities.
  • Language impairment from the early stages of the disease, which may be the first noticeable symptom.
  • Impaired ability to read and write, as well as decreased vocabulary.
  • Sudden mood changes.
  • Muscular stiffness.
  • As the disease progresses, apathy is the symptom that dominates in the clinic.
  • Recent memory disturbances and learning ability are common.

The diagnosis is based on the patient’s symptoms since compulsive behavior, and emotional disturbances are evident from the disease’s beginning. Tests that can be performed are magnetic resonance imaging of the brain, electroencephalography (EEG), the examination of cerebrospinal fluid, computed tomography of the head, etc.

There is no known cure for this disease, which completely incapacitates the patient. In its treatment, antidepressants and antipsychotics are used to control the emotional ups and downs of the patient and those drugs that help alleviate other associated disorders such as nutritional and thyroid problems, depression, infections, anemia, etc.

Among the symptoms of Dementia with Lewy bodies, we found:

  • Slowly progressive cognitive decline. Cognitive fluctuations are a typical feature of this disease and are mainly based on attention and alertness.
  • Visual hallucinations are also characteristic and sleep disturbances (in the muscle relaxation phase, these patients tend to be very active).
  • Alterations in mood and behavior (sadness, depression, anger, lack of initiative).
  • There may be tremors, and other symptoms such as muscle weakness and stiffness and an unsteady gait, sometimes making the differential diagnosis of Parkinson’s disease difficult.

The diagnosis includes physical and neurological examinations that evaluate the patient’s functional and expressive capacity, memory, and other abilities, in addition to performing tests such as CT or MRI. However, the definitive diagnosis is only obtained after the death of the patient by performing an autopsy.