Dementia in Alzheimer's Disease: Diagnosis

Criteria for the clinical diagnosis of Alzheimer's Disease NINCDS / ADRDA (according to McKhann et al., 1984)

1. A clinical diagnosis of a possible Alzheimer's disease can be established with:
   • presence of a dementia syndrome in the absence of other neurological, psychiatric or systemic diseases capable of causing dementia, but with atypical origin, clinical manifestations or course;
   • the presence of a second systemic or neurologic disease that can cause dementia, but can not be considered a cause of dementia in this case;
   • gradually progressing severe violation of one cognitive function in the absence of other causes identified in scientific studies
2. The criteria for the clinical diagnosis of a probable Alzheimer's disease are as follows:
   • the dementia, established according to the clinical examination, the results of the Brief Study of Mental Status (Mini-Mental Test) or similar tests and confirmed with a neuropsychological study; violation in two or more cognitive areas;
   • progressive deterioration of memory and other cognitive functions;
   • absence of disturbances of consciousness;
   • beginning of the disease between the ages of 40 and 90, more often after 65 years;
   • absence of systemic disorders or other brain diseases that could lead to progressive memory impairment and other cognitive functions
3. The diagnosis of a probable Alzheimer's disease is confirmed by the following symptoms:
   • progressive violation of specific cognitive functions, such as speech (aphasia), motor skills (apraxia), perception (agnosia);
   • violations of daily activities and behavioral changes;
   • weighed family history of the disease, especially with pathomorphological confirmation of the diagnosis;
   • The results of additional research methods:
   • no changes in cerebrospinal fluid in a standard study;
   • no changes or nonspecific changes (for example, enhanced copper-wave activity) on the EEG,
   • the presence of cerebral atrophy on CG with a tendency to progress in repeated studies
4. Criteria for the diagnosis of a reliable Alzheimer's disease:
   • clinical criteria for probable Alzheimer's disease and histopathologic confirmation from biopsy or autopsy data

[1], [2], [3], [4], [5], [6]

Criteria for diagnosis of dementia of the Alzheimer's type DSM-IV

A. Development of a multiple cognitive defect, manifested by the following two signs:

1. Memory impairment (a violation of the ability to remember a new one or reproduce previously learned information)
2. One (or several) of the following cognitive disorders:
   • aphasia
   • apraxia (impaired ability to perform actions, despite the preservation of elementary motor functions)
   • agnosia (a violation of the ability to recognize or identify objects, despite the preservation of elementary sensory functions)
   • disorder of regulatory (executive - executive) functions (including planning, organization, phased implementation, abstraction)

B. Each of the cognitive abnormalities specified in criteria A1 and A2 causes significant impairment in social or occupational life and represents a significant reduction in relation to the previous level of functioning

B. The flow is characterized by a gradual onset and a steady increase in cognitive impairment

D. Cognitive defects prescribed by criteria A1 and A2 are not caused by any of the following diseases:

• another central nervous system disease that causes progressive memory impairment and other cognitive functions (eg, cerebrovascular disease, Parkinson's disease, Gingington's disease, subdural hematoma, normotensive hydrocephalus, brain tumor)
• systemic diseases that can be the cause of dementia (hypothyroidism, vitamin B12 deficiency, folic acid or nicotinic acid, pschercalcemia, neurosyphilis, HIV infection)
• states caused by the administration of substances

D. Cognitive defect does not develop exclusively during delirium

E. The condition can not be better explained by the presence of another disorder related to axis I (eg, major depressive disorder, schizophrenia).

Despite the large number of diseases that can lead to the development of dementia, the differential diagnosis is facilitated by the fact that approximately 80-90% of all dementias are related to degenerative or vascular forms. Vascular variants of dementia occupy about 10-15% of all dementias and are represented by "multi-infarct dementia" and Binswanger's disease. The main cause of both forms is hypertension; second place - atherosclerosis; further - cardiogenic cerebral embolism (most often with non-valvular atrial fibrillation), etc. It is not surprising that both forms sometimes combine in one patient. Multi-infarct dementia is manifested by multiple foci of discharge (cortical, subcortical, mixed) of brain tissue on MRI, Binswanger's disease by diffuse changes in white matter. The latter on MRI are referred to as leykoareozis (leykoareoz). Leukoareosis is manifested in CT or MRI (in the T2-weighted images mode) spotted or diffuse lowering of the density of white matter in the periventricular region and the semiovalicular center.

[7], [8]