Microstroke: What It Is, Causes, and How to Distinguish It from a Mini-Stroke

Your arm grows heavy and stops obeying you, your speech becomes tangled, half of your face seems to slide downward — and ten minutes later everything passes. Such short episodes are called a microstroke, or mini-stroke, and the trap is that the person returns to their activities without ever learning that they were on the brink. We explain where it comes from and why it cannot be left unexamined.

What a microstroke is

A microstroke is a temporary disruption of blood supply to an area of the brain. One of the arteries carrying oxygen-rich blood becomes blocked, and the tissue stops receiving oxygen for several minutes. Symptoms appear suddenly. It differs from a "major" stroke in that blood flow restores on its own and brain tissue does not die.

Duration — from several minutes to several hours, with everything fully resolving within 24 hours; in most cases the episode lasts one to two hours.

• face — a drooping corner of the mouth on one side, the person cannot smile;
• arms — weakness or numbness in one arm, inability to raise and hold both;
• speech — slurred, unclear, or lost while consciousness is clear;
• vision — temporary loss of vision or loss of part of the visual field;
• sensation and balance — numbness or tingling in half of the body, dizziness, loss of coordination.

Microstroke and transient ischemic attack: what the difference is

There is no difference in essence: microstroke, mini-stroke, "small stroke" are everyday names for one condition that doctors call a transient ischemic attack, TIA. The confusion stems from the old definition: previously, TIA was considered any episode of neurological impairment that ended in less than a day. The definition was changed after it was found that in some people with symptoms shorter than a day, diffusion-weighted MRI reveals small infarcts. If the damage is irreversible, the episode is considered a stroke.

Causes of microstroke

Most often, the vessel lumen is blocked by a thrombus that formed elsewhere in the body and traveled with the blood to the brain arteries; less often — trauma or narrowing of the vessel. The typical underlying ground is atherosclerosis of the carotid and vertebral arteries.

The main risk factor is elevated blood pressure. Next come atrial fibrillation and other heart diseases, diabetes mellitus, high cholesterol, smoking, alcohol abuse, excess weight, blood clotting disorders, and prior TIA or stroke. The risk is higher in men, in people over 55, and in those whose relatives have had a stroke.

Silent stroke: can it go unnoticed

It is difficult to estimate how often transient ischemic attacks occur: patients often do not attach importance to temporary symptoms and do not see a doctor. But this does not mean that TIA is insignificant.

Why a microstroke is dangerous

The episode itself does not destroy the brain: TIA does not cause lasting brain damage. The danger lies elsewhere — it is a warning. In 30–50% of people who have had a TIA, a stroke develops within five years. Some strokes occur in the following days and weeks: in some — within three months, and half of these — in the first 48 hours after the attack. Attacks may recur.

How it is diagnosed and when urgent help is needed

In the first hours, it is impossible to distinguish a microstroke from a stroke: they look the same, and the earlier treatment is started, the more effective it is. A person with such symptoms is examined in a hospital, even if everything has passed by the time the team arrives; referral to a specialist is made within 24 hours of symptom onset. If the episode occurred in the last 48 hours, hospitalization is likely in order to find the cause and observe.

The doctor takes a history, measures blood pressure, listens to the heart and neck vessels — when the carotid artery is narrowed, a murmur of abnormal blood flow is heard. Next — CT or MRI of the head, angiography, echocardiography, ultrasound of the carotid arteries, ECG and rhythm monitoring, examinations to detect diabetes, high cholesterol, and other risk factors. If similar episodes have occurred before and you did not seek care, an urgent visit to a doctor is needed.

A microstroke is a reason to call 103 or 112 immediately: a drooping corner of the mouth, inability to raise and hold both arms, slurred speech, sudden loss of vision, weakness or numbness in half of the body, severe dizziness. You should call even if the symptoms have disappeared while you were waiting for the team: evaluation in a hospital is still needed.

This material is for reference and does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer