27 May 2020 Author : Pedro Silva Carvalho Dementia is a medical and social problem with increasing importance. It occurs in all ages but is more relevant in the more advanced age groups. About 1% of the population over 65 years of age is affected and this figure more than doubles every 5 years. In a 2017 report by the Organization for Economic Cooperation and Development (OECD), on the prevalence of dementia, Portugal is referred to as the fourth country with the more cases per 1000 inhabitants. The average for OECD countries is 14.8 cases of dementia per 1000 inhabitants, so in Portugal it is estimated in 19.9 cases. According to this report, there would be 205 000 people with dementia in Portugal at that time, a figure estimated to be 322 000 by 2037. How do dementias present? Overall, the common feature in dementias is memory failure (cognitive dysfunction), which causes a progressive functional decline. However, memory failures can have causes other than dementia and some are even reversible. In the case of dementias, there are specific changes. Dementia is a syndrome (a set of symptoms) that can be caused or characterized by multiple cognitive deficits. These include memory failure and at least one of the following symptoms: Aphasia: disturbance in the formulation and understanding of language; Apraxia: loss of ability to perform precise movements and gestures that would lead to a given objective, despite the will to do it and the physical capacity to perform it; Agnosia: loss or deterioration of the ability to recognize or identify objects, although the sensory function is intact, or inhibition of the execution function. Over time, in dementia, social and occupational functions are also affected. Symptoms and early signs of dementia are often subtle and vague and may not be immediately obvious. In addition to frequent and progressive memory failure, the most common are personality changes, apathy and isolation, loss of ability to perform daily tasks and confusion. Some dementias may have a hereditary relationship, but most do not. What are the diseases in which there are memory failures? Several diseases or clinical conditions can be associated with memory problems. The most frequent are: Degenerative brain diseases, such as Alzheimer dementia, Lewy body dementia, Parkinson dementia and frontotemporal dementia; Vascular dementia; Alcohol-related dementia (Korsakoff syndrome); Intracranial tumors; Normal pressure hydrocephalus; Huntington disease; Drugs chronic intoxication; Mixed diseases, for example liver failure, pernicious anemia, hypothyroidism, neurosyphilis, Cushing disease, Creutzfeldt Jakob disease, multiple sclerosis, epilepsy, among others; Traumatic brain injury; AIDS (acquired immunodeficiency syndrome) dementia complex; Pseudodementia (depressive conditions with cognitive impairment); Anxiety disorders; Vitamin deficit. These different clinical conditions can occur simultaneously. The memory failures associated with depressive conditions, some vitamin and hormonal deficiencies, infectious processes, drug overdose, brain tumors, among others, are in most cases reversible, that is, if the symptoms are treated, they usually disappear. What are the most common dementias? Alzheimer dementia Alzheimer dementia accounts for about 60% of all cases. It installs gradually, over years, during which a degenerative process that affects the brain occurs. The connections between brain cells are damaged, and nerve cells are reduced in size and number, forming neurofibrillary tangles inside and senile plaques in the outer space between them. The cells end up dying, affecting the various brain areas, and functions or capacities are lost, namely memory. Vascular dementia Vascular dementia is the second most common type of dementia. It is related to changes in blood circulation in the brain. There are several types. It usually occurs when there are several previous risk factors such as hypertension, hypercholesterolemia, diabetes, among others. Vascular dementia may have a presentation like Alzheimer disease, although with deterioration with retrospectively identifiable time frames. In some people there is a combined picture of these two types: vascular dementia and Alzheimer. Parkinson disease Parkinson disease is a progressive disorder of the central nervous system, characterized by tremor, stiffness in the limbs and joints, changes in speech and difficulty in initiating movements. In advanced stages of the disease, dementia can occur in some patients. Lewy body dementia Lewy body dementia is caused by the degeneration and death of brain cells, where abnormal spherical structures (Lewy bodies) develop. Visual hallucinations, stiffness or tremors often occur, with rapid oscillations. It is sometimes difficult to distinguish from Parkinson dementia. Hypersensitivity to antipsychotics and benzodiazepines often occurs. Frontotemporal dementia Frontotemporal dementia is the name given to a group of dementias in which there is a degeneration of one or both frontal or temporal brain lobes. It includes fronto-temporal dementia, semantic dementia, non-fluent progressive aphasia, and Pick disease. In a high number of cases there is a family history of the disease. Frontotemporal dementia is one of the dementias with the earliest onset. It may have a less relevant start in what concerns memory and more relevant in behavior. Dementia caused by alcohol (Korsakoff syndrome) Excessive alcohol consumption, particularly if associated with a diet low in vitamin B1 (thiamine) can lead to irreversible brain damage. The most vulnerable brain regions are those involved in memory, organization, planning, social skills, insight, and balance. The approach includes suspending / reducing alcohol consumption and taking vitamin B1 (thiamine). Behavioral and psychological symptoms of dementia The behavioral and psychological symptoms of dementia include a set of changes with high prevalence in the clinical evolution of dementia, about 75% of patients. These changes justify in many cases the intervention of psychogeriatrics or psychiatry and are related to a more unfavorable clinical evolution in terms of survival, burden on the caregiver and incidence of institutionalization, among other factors. The spectrum of neuropsychiatric manifestations in patients with dementia can be divided into three groups: Affective syndrome; Psychotic syndrome; Other neuropsychiatric disorders. The most frequent signs are apathy, depression, agitation, and aggression. The medical diagnosis of conditions with the aforementioned symptoms, fundamentally memory failures, should be carried out when the first signs or symptoms appear, in order to guarantee an early and correct treatment. Early treatment allows a better clinical management of the case, and suffering reduction for both patient and caregivers. If symptoms are caused by dementia, early diagnosis provides earlier access to support, information, and medication. In most dementia cases, the goal of treatment is to delay the process and improve behavioral and psychological symptoms, since they have no cure. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
