DEMENTIA

Dementia, commonly referred to as senility, can be defined as the loss of intellectual functions to an extent that disrupts daily life activities. The term dementia comes from the Greek word de-mense, meaning the loss of mind. It is a word used to describe the loss or deterioration of the mind and cognitive functions over time. Dementia is not the name of a single disease, but rather a general term given to all diseases that involve impairment of memory and similar mental abilities.
Leaving aside cases of cognitive decline seen in childhood, dementia in adults is generally a disease that emerges in the older age group. Due to this characteristic, for years, the slowing of cognitive activity and intellectual decline seen in a person in the older age group has been attributed to the physiological ageing process of the brain (senility). However, clinical observations and supporting studies have revealed that dementia is distinct from the physiological ageing process. Indeed, the mere observation that there are individuals in our immediate surroundings who are over eighty or ninety years old but retain normal cognitive function supports the view that ageing alone does not cause dementia.

In reality, dementia is a clinical condition resulting from various pathological processes. In a sense, as with epilepsy, the term dementia merely describes a clinical presentation. However, there are significant differences in the prevalence of dementia depending on its aetiological causes. Today, as a result of increased human lifespan, there has been a marked increase in the proportion of the elderly population, and the number of patients with dementia has increased accordingly. This situation has accelerated research into dementia, and neuropathological studies have revealed a new fact. When the brains of individuals over the age of sixty-five, both with and without dementia, were examined histopathologically, findings specific to Alzheimer’s disease, which was clinically and pathologically defined separately in 1907, were detected in 50% of patients with dementia. In up to 15% of cases, the cause of dementia was found to be related to vascular disorders. This condition is called vascular dementia. In a group comprising 14 to 25 per cent of autopsy cases, Alzheimer’s disease and vascular findings were found together, and this condition is called mixed dementia.

As can be seen from these figures, Alzheimer’s disease accounts for half of the causes of dementia in the elderly. When dementia associated with other neurodegenerative diseases (e.g. Lewy body dementia, Parkinson’s disease, etc.) is included, this proportion rises to 99%. Dementia caused by toxic, metabolic, and endocrine factors, brain tumours, and other neurological diseases constitutes a very small group among the causes of dementia.
An increase in the incidence of many diseases affecting the brain, particularly Alzheimer’s disease, has been observed. Identifying the causes, eliminating them, and developing new treatment options will make ageing more pleasant.