Symptoms of ischemic stroke

Symptoms of ischemic stroke are diverse and depend on the location and volume of the lesion of the brain. The most frequent localization of the focus of the cerebral infarction is carotid (80-85%), less often - vertebrobasilar basin (15-20%).

Infarcts in the pool of blood supply of the middle cerebral artery

The peculiarity of the blood supply pool of the middle cerebral artery is the presence of a pronounced system of collateral circulation. With occlusion of the proximal part of the middle cerebral artery (segment Ml), a subcortical infarction may occur, while the cortical area of the blood supply remains unaffected if there is sufficient blood flow through the meningeal anastomoses. In the absence of these collaterals, an extensive heart attack can occur in the area of blood supply to the middle cerebral artery.

In case of a heart attack in the area of blood supply to the superficial branches of the middle cerebral artery, the deviation of the head and eyeballs may sharply arise in the direction of the affected hemisphere, with the development of total aphasia and ipsilateral ideomotor apraxia in the defeat of the dominant hemisphere. When the subdominant hemisphere is affected, contralateral disregard for space, anosognosia, aproposia, dysarthria develops.

Infarctions of the brain in the upper branches of the middle cerebral artery are clinically manifested by contralateral hemiparesis (mainly of the upper limbs and face) and contralateral hemianesthesia with the same preferential localization in the absence of visual field defects. With extensive foci of lesions, friendly outflow of eyeballs and fixation of gaze towards the affected hemisphere can appear. When the dominant hemisphere is affected, Broca's motor aphasia develops. Oral apraxia and the ideomotor apraxia of the ipsilateral limb are also common. Infarcts of the subdominant hemisphere lead to the development of spatial one-sided ignoring and emotional disturbances. With occlusion of the lower branches of the middle cerebral artery, motor disorders, sensory agrarians and asteroognosis can develop. Often, visual field defects are detected: contralateral homonymous hemianopsia or (more often) upper quadrant hemianopsia. Defeats of the dominant hemisphere lead to the development of aphasia Wernicke with a violation of understanding speech and retelling, paraphasic semantic errors. Infarction in the subdominant hemisphere leads to the development of contralateral disregard with sensory predominance, anosognosia.

For infarction in the pool of blood supply of striatocapsular arteries, pronounced hemiparesis (or hemiparesis and hemiipesthesia) or hemiplegia with or without dysarthria are characteristic. Depending on the size and location of the lesion, the paresis mainly extends to the face and upper limb or to the entire contralateral half of the body. With a large striatocapsular infarction, typical manifestations of occlusion of the middle cerebral artery or its pial branches can develop (for example, aphasia, ignoring and homonymous lateral hemianopsia).

Lacunar infarction is characterized by the development in the blood supply of one of the single perforating arteries (single striatocapsular arteries). It is possible to develop lacunar syndromes, in particular isolated hemiparesis, hemihyesthesia, atactic hemiparesis or hemiparesis in combination with hemi-hemesthesia. The presence of any, even transient, signs of a deficiency in higher cortical functions (aphasia, agnosia, hemianopsia, etc.) makes it possible to reliably differentiate striatocapsular and lacunar infarcts.

Infarcts in the basin of the blood supply to the anterior cerebral artery

Infarcts in the pool of blood supply to the anterior cerebral artery are encountered 20 times less infarcts in the area of blood supply to the middle cerebral artery. The most common clinical manifestation are motor disabilities, with occlusion of the cortical branches, in most cases, a motor deficiency in the foot and the entire lower limb develops and a less pronounced paresis of the upper limb with extensive facial and linguistic damage. Sensory disorders are usually mild, and sometimes completely absent. Incontinence is also possible.

Infarcts in the pool of blood supply of the posterior cerebral artery

With occlusion of the posterior cerebral artery, infarcts of the occipital and medio-partal regions of the temporal lobe develop. The most common symptoms are visual field defects (contralateral homonymous hemianopsia). Photopsy and visual hallucinations may also be present, especially when the subdominant hemisphere is affected. Occlusion of the proximal segment of the posterior cerebral artery (P1) can lead to the development of cerebral and thalamus brain infarctions, because these areas are supplied with blood from some of the branches of the posterior cerebral artery (thalamosubthalamic, thalamocolloid and posterior choroid arteries).

Infarcts in the vertebrobasilar blood supply

Occlusion of a single perforating branch of the basilar artery leads to the development of a limited cerebral infarction, especially in the bridge and midbrain. Infarctions of the brainstem are accompanied by symptoms of cranial nerve damage on the ipsilateral side and motor or sensory impairments on the opposite side of the body (so-called alternating brainstem lesions). The occlusion of the vertebral artery or its main penetrating branches departing from the distal sections may lead to the development of lateral medullary syndrome (Wallenberg syndrome). The blood supply of the lateral medullary region is also variable and can be carried out by small branches of the posterior cerebellar, anterior lower cerebellar and basilar arteries.

Classification of ischemic stroke

Ischemic stroke is a clinical syndrome of acute cerebral vascular injury, it can be the outcome of various diseases of the cardiovascular system. Depending on the pathogenetic mechanism of development of acute focal cerebral ischemia, several pathogenetic variants of ischemic stroke are isolated. The most widespread classification is TOAST (Trial of Org 10172 in Acute Stroke Treatment), it distinguishes the following options for ischemic stroke:

• atherothrombotic - due to atherosclerosis of large arteries, which leads to their stenosis or occlusion; when fragmentation of an atherosclerotic plaque or thrombus develops arterio-arterial embolism, also included in this variant of a stroke;
• cardioembolic - the most frequent causes of embolic infarction are arrhythmia (flutter and atrial fibrillation), valvular heart disease (mitral), myocardial infarction, especially the prescription up to 3 months;
• lacunar - due to occlusion of small-sized arteries, their lesion is usually associated with the presence of arterial hypertension or diabetes mellitus;
• ischemic, associated with other, more rare causes: non-atherosclerotic vasculopathies, hypercoagulable blood, hematological diseases, hemodynamic mechanism of development of focal cerebral ischemia, stratification of the arterial wall;
• ischemic of unknown origin. To it carry strokes with the unidentified reason or with presence of two and more possible or probable reasons when it is impossible to put the definitive diagnosis.

The severity of the lesion as a special option is allocated a small stroke, the neurologic symptomatology present with it regresses during the first 21 days of the disease.

In the acute period of stroke, according to clinical criteria, light, moderate and severe ischemic stroke is isolated.

Depending on the dynamics of neurological disorders, a stroke in development ("stroke in progress" - with an increase in the severity of neurologic symptoms) and a completed stroke (with the stabilization or reverse development of neurological disorders) are distinguished.

There are different approaches to the periodization of ischemic stroke. Taking into account epidemiological indicators and modern ideas about the applicability of thrombolytic drugs for ischemic stroke, the following periods of ischemic stroke can be distinguished:

• the most acute period is the first 3 days, of which the first 3 hours are defined as a therapeutic window (the possibility of using thrombolytic drugs for systemic administration); with regression of symptoms in the first 24 h diagnosed transient ischemic attack;
• acute period - up to 28 days. Previously, this period was determined up to 21 days; accordingly, as a criterion for diagnosing a minor stroke, there is still a regression of symptoms until the 21st day of the disease;
• early recovery period - up to 6 months;
• late recovery period - up to 2 years;
• the period of residual phenomena is after 2 years.

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