Dyscirculatory encephalopathy - Diagnosis

Diagnosis of cerebrovascular insufficiency

To diagnose chronic cerebral circulatory insufficiency, it is necessary to establish a connection between clinical manifestations and pathology of cerebral vessels. For the correct interpretation of the detected changes, careful collection of anamnesis with an assessment of the previous course of the disease and dynamic observation of patients are very important. It is necessary to keep in mind the inverse relationship between the severity of complaints and neurological symptoms and the parallelism of clinical and paraclinical signs during the progression of cerebral vascular insufficiency.

It is advisable to use clinical tests and scales taking into account the most common clinical manifestations of this pathology (assessment of balance and gait, identification of emotional and personality disorders, neuropsychological testing).

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Anamnesis

When collecting anamnesis from patients suffering from certain vascular diseases, attention should be paid to the progression of cognitive disorders, emotional and personal changes, focal neurological symptoms with the gradual formation of expanded syndromes. Identification of these data in patients at risk of developing cerebrovascular accident or who have already suffered a stroke and transient ischemic attacks, with a high degree of probability allows us to suspect chronic cerebrovascular insufficiency, especially in elderly people.

From the anamnesis, it is important to note the presence of ischemic heart disease, myocardial infarction, angina pectoris, atherosclerosis of the peripheral arteries of the extremities, arterial hypertension with damage to target organs (heart, kidneys, brain, retina), changes in the valve apparatus of the heart chambers, heart rhythm disturbances, diabetes mellitus and other diseases.

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Physical examination

Conducting a physical examination allows us to identify pathology of the cardiovascular system. It is necessary to determine the integrity and symmetry of pulsation in the main and peripheral vessels of the extremities and head, as well as the frequency and rhythm of pulse fluctuations. Blood pressure should be measured on all 4 extremities. It is necessary to auscultate the heart and abdominal aorta to detect murmurs and heart rhythm disturbances, as well as the main arteries of the head (vessels of the neck), which allows us to determine the noise above these vessels, indicating the presence of a stenotic process.

Atherosclerotic stenoses usually develop in the initial sections of the internal carotid artery and in the area of the bifurcation of the common carotid artery. Such localization of stenoses allows one to hear systolic noise during auscultation of the neck vessels. If there is noise above the vessel, the patient should be referred for duplex scanning of the main arteries of the head.

Laboratory research

The main direction of laboratory research is to clarify the causes of chronic cerebral circulatory failure and its pathogenetic mechanisms. A clinical blood test is examined, reflecting the content of platelets, erythrocytes, hemoglobin, hematocrit, leukocytes with an expanded leukocyte formula. The rheological properties of blood, lipid spectrum, blood coagulation system, and glucose content in the blood are studied. If necessary, additional tests are carried out to exclude specific vasculitis, etc.

Instrumental research

The task of instrumental methods is to clarify the level and degree of damage to the vessels and brain matter, as well as to identify background diseases. These tasks are solved using repeated ECG recordings, ophthalmoscopy, echocardiography (as indicated), cervical spondylography (if pathology in the vertebrobasilar system is suspected), ultrasound examination methods (ultrasound Dopplerography of the main arteries of the head, duplex and triplex scanning of extra- and intracranial vessels).

Structural assessment of the brain matter and cerebrospinal fluid pathways is performed using imaging methods (MRI). To identify rare etiologic factors, noninvasive angiography is performed, which allows identifying vascular anomalies and determining the state of collateral circulation.

An important place is given to ultrasound examination methods, which allow to detect both cerebral blood flow disorders and structural changes in the vascular wall, which can cause stenosis. Stenoses are usually divided into hemodynamically significant and insignificant. If a decrease in perfusion pressure occurs distal to the stenotic process, this indicates a critical or hemodynamically significant narrowing of the vessel, developing with a decrease in the lumen of the artery by 70-75%. In the presence of unstable plaques, which are often detected in concomitant diabetes mellitus, an occlusion of the lumen of the vessel by less than 70% will be hemodynamically significant. This is due to the fact that with an unstable plaque, arterio-arterial embolism and hemorrhages into the plaque with an increase in its volume and an increase in the degree of stenosis are possible.

Patients with such plaques, as well as with hemodynamically significant stenoses, should be referred for consultation to a vascular surgeon to decide on the issue of surgical restoration of blood flow in the main arteries of the head.

We should not forget about asymptomatic ischemic cerebrovascular accidents, which are detected only when using additional examination methods in patients without complaints and clinical manifestations. This form of chronic cerebrovascular insufficiency is characterized by atherosclerotic lesions of the main arteries of the head (with plaques, stenosis), "silent" cerebral infarctions, diffuse or lacunar changes in the white matter of the brain and atrophy of brain tissue in individuals with vascular lesions.

It is believed that chronic cerebral circulatory failure exists in 80% of patients with stenotic lesions of the main arteries of the head. Obviously, this indicator can reach an absolute value if adequate clinical and instrumental examination is carried out to identify signs of chronic cerebral ischemia.

Considering that chronic cerebrovascular insufficiency primarily affects the white matter of the brain, preference is given to MRI rather than CT. MRI in patients with chronic cerebrovascular insufficiency reveals diffuse changes in the white matter, cerebral atrophy, and focal changes in the brain.

MRIs show periventricular leukoaraiosis (rarefaction, decreased tissue density), reflecting ischemia of the white matter of the brain; internal and external hydrocephalus (dilation of the ventricles and subarachnoid space), caused by atrophy of the brain tissue. Small cysts (lacunae), large cysts, as well as gliosis, may be detected, indicating previous cerebral infarctions, including clinically "silent" ones.

It should be noted that all of the listed signs are not considered specific; it is incorrect to diagnose cerebrovascular insufficiency only based on imaging examination methods.

Differential diagnostics of cerebrovascular insufficiency

The above-mentioned complaints, characteristic of the initial stages of chronic cerebral circulatory insufficiency, can also arise in oncological processes, various somatic diseases, be a reflection of the prodromal period or asthenic “tail” of infectious diseases, be part of the symptom complex of borderline mental disorders (neuroses, psychopathy) or endogenous mental processes (schizophrenia, depression).

Signs of encephalopathy in the form of diffuse multifocal brain damage are also considered non-specific. Encephalopathies are usually defined by the main etiopathogenetic sign (post-hypoxic, post-traumatic, toxic, infectious-allergic, paraneoplastic, dysmetabolic, etc.). Dyscirculatory encephalopathy most often has to be differentiated from dysmetabolic, including degenerative processes.

Dysmetabolic encephalopathy caused by disorders of brain metabolism can be either primary, arising as a result of a congenital or acquired metabolic defect in neurons (leukodystrophy, degenerative processes, etc.), or secondary, when disorders of brain metabolism develop against the background of an extracerebral process. The following variants of secondary metabolic (or dysmetabolic) encephalopathy are distinguished: hepatic, renal, respiratory, diabetic, encephalopathy with severe multiple organ failure.

Differential diagnostics of cerebrovascular insufficiency with various neurodegenerative diseases, which usually involve cognitive impairment and focal neurological manifestations, pose great difficulties. These diseases include multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration, Parkinson's disease, diffuse Lewy body disease, frontotemporal dementia, and Alzheimer's disease. Differentiating between Alzheimer's disease and cerebrovascular insufficiency is often far from a simple task: cerebrovascular insufficiency often initiates subclinical Alzheimer's disease. In more than 20% of cases, dementia in the elderly is of a mixed type (vascular-degenerative).

Dyscirculatory encephalopathy must be differentiated from such nosological forms as brain tumor (primary or metastatic), normotensive hydrocephalus manifested by ataxia, cognitive disorders, impaired control over pelvic functions, idiopathic dysbasia with impaired walking software and stability.

It is necessary to keep in mind the presence of pseudodementia (the dementia syndrome disappears against the background of treatment of the underlying disease). As a rule, this term is applied to patients with severe endogenous depression, when not only the mood worsens, but also motor and intellectual activity weakens. It is this fact that gave grounds to include a time factor in the diagnosis of dementia (the persistence of symptoms for more than 6 months), since the symptoms of depression are relieved by this time. Probably, this term can also be applied to other diseases with reversible cognitive disorders, in particular, in secondary dysmetabolic encephalopathy.

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