The term dementia (synonyms: Senile dementia; arteriosclerotic dementia; dementia; dementia senilis; dementia in brain atrophy; cognition disorder; presbyophrenia; senile dementia; ICD-10-GM F00 – ICD-10-GM F03 (see below); ICD-10-GM G31.82: Lewy body disease) refers to the loss of formerly acquired intellectual skills, which can have various causes. Since the majority of persons suffering from dementia are over 65 years of age, it is also colloquially referred to as senile dementia. In addition to memory, impaired functions include language, arithmetic and judgment. As a rule, dementia is preceded by a mild cognitive impairment (MCI). Main groups of dementia considering the ICD-10-GM:
- Alzheimer-type dementia (DAT) (50-70-(80) %; ICD-10-GM F00.-) – most common cause of dementia in the Western world; see also Alzheimer’s disease.
- Vascular dementia (VD; 15-25-(35) %; ICD-10-GM F01.-) – result of infarction (Latin: infarcere, “to clog”) of the brain secondary to vascular disease (vascular disease), including cerebrovascular hypertension (brain vascular hypertension); is in turn subdivided into:
- Multi-infarct dementia (ICD-10-GM F01.1): begins gradually, after several transient ischemic episodes (TIA; sudden disturbance of blood flow to the brain, resulting in neurologic disturbances that resolve within 24 hours) that cause an accumulation of infarcts in brain tissue
- Subcortical vascular dementia (ICD-10-GM F01.2): arteriosclerotic encephalopathy/arteriosclerosis-related brain disease (SAE; Binswanger’s disease; F01.2): cases with a history of hypertension (high blood pressure) and ischemic foci (tissue sections of the brain that occur as a result of reduced blood flow (ischemia)) in the medullary camp of the hemispheres
- Dementia in diseases classified elsewhere (ICD-10-GM F02.-).
- Unspecified dementia (ICD-10-GM F03).
- Other forms of dementia:
- Dementia in primary Parkinson’s disease (PDD) (<10%; ICD-10-GM G20.-): a dementia that develops during the course of Parkinson’s disease.
- Circumscribed brain atrophy, frontotemporal dementia (ICD-10-GM G31.0, FTD; synonyms: Pick’s disease; Pick’s disease; about 10%; ICD-10-GM F02.0.- ) – progressive dementia with onset in middle age (40-60 years of age), characterized by early, slowly progressive personality change and loss of social skills (loss of social control). The disease is followed by impairment of intellect, memory, and language functions with apathy, euphoria, and occasionally extrapyramidal phenomena. Dementia usually progresses far more rapidly in FTD than in Alzheimer-type dementia.
- Dementia of Lewy disease (Lewy body dementia, LBD) (0.5-15-(30)%; ICD-10-GM G31.82) – associated with hallucinations; central feature of LBD is dementia associated with functional limitations in daily living. Memory function is relatively well preserved at disease onset. Attention deficits, impairment of executive and visuoperceptual functions are common; this form often occurs with Parkinson’s disease
- Mixed dementia – combination of the presence of Alzheimer’s pathology and other pathological changes that together cause dementia.
Furthermore, one can distinguish between:
- Primary dementia – dementia is a disease in its own right.
- Secondary dementia – the dementia is a consequence of another (neurological) disease
In addition, dementia syndrome can occur in a variety of diseases. Sex ratio: dementia of the Alzheimer’s type: men to women is 1: 3 (in the group over 85 years). Vascular dementia: men to women is 2: 1. Peak incidence: The disease occurs predominantly in older age (> 75 years). Early-onset (present) dementia is defined as onset before the age of 65.
Approximately 20% of people with dementia before the age of 65 have frontotemporal dementia.The prevalence (disease frequency) for dementia of the Alzheimer’s type is 5% in the group over 70 years of age (in the western world). In the over 85 age group, the prevalence is 20-40%. The prevalence for vascular dementia is 1.5% of the population (in Germany).In the 85+ age group, the prevalence is approximately 14%.The prevalence for Lewy body dementia is reported to be highly variable with 0-5% in the general population and 0-30.5% within dementia patients. The incidence of dementia continues to increase due to aging trends. In the hospital, the specialties with the highest prevalence of dementia are internal medicine and trauma surgery. The incidence (frequency of new cases) for vascular dementia is approximately 6-28 cases per 1,000 inhabitants per year (in Germany). Course and prognosis: All neurodegenerative dementias (Alzheimer’s dementia, frontotemporal dementia, Levy body dementia, Parkinson’s dementia) are progressive diseases with courses over several years. They are accompanied by a decline in cognitive performance, a loss of everyday competence and a breakdown of personality, and end in a need for care and a reduced life expectancy. None of the diseases is curable. In the context of vascular dementia, gradual progressions with long phases without progression and even phases of slight improvement are possible. Note: In early onset (presence) dementia, the diagnosis latency is about four and a half years! Comorbidities: Malnutrition is the most important comorbidity of dementia. Furthermore, dementia is increasingly associated with hypertension (36%), depression (21%), musculoskeletal diseases (18%), carcinoma (17%), heart failure (15%), diabetes mellitus (14%), coronary heart disease (CHD; coronary artery disease) (12%), apoplexy (stroke) (5%), and chronic obstructive pulmonary disease (COPD) (4%). Another comorbidity is depressive disorder.
