Alzheimer’s Disease

As Alzheimer’s disease (synonyms: Alzheimer’s dementia (AD); Alzheimer’s disease; Alzheimer’s sclerosis; Alzheimer’s syndrome; Alzheimer’s disease; amyloid deposits; dementia in Alzheimer’s disease; dementia of the Alzheimer type; plaques and neurofibrils; SDAT; senile dementia of the Alzheimer type; Alzheimer’s disease; ICD-10-GM G30.-: Alzheimer’s disease) is a primary degenerative brain disease associated with progressive dementia.

According to ICD-10-GM criteria, dementia in Alzheimer’s disease is defined as follows:

  • ICD-10 definition: Alzheimer’s disease is a primary degenerative cerebral disease of unknown etiology with characteristic neuropathologic and neurochemical features. It usually begins insidiously and develops slowly but steadily over a period of several years.
  • ICD-10-GM F00.0* : Dementia in Alzheimer’s disease, with early onset (type 2), ICD-10-GM G30.0* : Alzheimer’s disease with early onset: dementia in Alzheimer’s disease with onset before age 65. The course shows a comparatively rapid deterioration, there are clear and multiple disturbances of higher cortical functions.
  • ICD-10-GM F00.1* : Dementia in Alzheimer’s disease, with late onset (type 1), ICD-10-GM G30.1* : Alzheimer’s disease with late onset: dementia in Alzheimer’s disease with onset after age 65, usually in the late 70s or after, with slow progression and with memory impairment as the main feature.
  • ICD-10-GM F00.2* : Dementia in Alzheimer’s disease, atypical or mixed form, ICD-10-GM G30.8* : Other Alzheimer’s disease: mixed dementia subsumes patients with mixed Alzheimer’s disease and vascular dementia.
  • ICD-10-GM F00.9* : Dementia in Alzheimer’s disease, unspecified, ICD-10-GM G30.9* : Alzheimer’s disease, unspecified

The disease accounts for close to three quarters of all dementias, making it the most common form of dementia in old age.

A familial clustering of the disease is possible.

According to the current American guideline for diagnosis, Alzheimer’s disease can be defined as follows:

  1. Preclinical stage
  2. Stage of mild cognitive decline.
  3. Stage of dementia

See also under Classification.

A committee assembled by the National Institute on Aging (NIA) and the Alzheimer’s Association (AA) in “Alzheimer’s and Dementia” is turning away from symptomatology and wants to use biomarkers for the diagnosis of Alzheimer’s disease (AD) as decisive criteria in research in the future (see laboratory diagnostics below).

Sex ratio: males to females is 1: 1-2.

Frequency peak: Mostly the disease starts after the age of 65 (Late Onset Alzheimer’s disease (LOAD)), rather rarely the early form of the disease occurs before the age of 65 (Early onset Alzheimer’s disease (EOAD)).

The prevalence of the disease is about 2% in the group of people under 65, 3% in the group of people aged 70, 6% in the group of people aged 75, and 20% of people aged 85 are affected (in Germany). As the average age of the German population continues to rise, the number of Alzheimer’s patients will inevitably increase in the future.

Course and prognosis: Alzheimer’s disease usually develops gradually but steadily over a period of several years. The course of the disease varies greatly in terms of the type and intensity of symptoms. Alzheimer’s disease is not curable. It takes an average of eight years from the onset of the disease until the death of the affected person.