Neurovascular pathology: Stroke

Stroke, which is the first cause of dependence in adults in our environment, and the second of mortality (the first in women), is defined as a sudden alteration of central nervous system blood circulation, which can be of two main types:

  • Ischemia: Decrease in the arrival of blood to a specific area of ​​the central nervous system, usually due to the interposition of a thrombus (clot that forms locally) or embolus (clot or other physical element that is generated in another location and circulates through the torrent blood to occlude a brain vessel). This in turn can be:
    • Transitory, when the emergency physiological systems “respond” in time, restoring blood flow and resolving the symptoms spontaneously and without leaving permanent brain damage. It is the so-called transient ischemic attack (TIA), and it is a real opportunity to study what happened to avoid a recurrence of the ischemia that could be irreversible in the near future.
    • Definitive, when the situation lasts long enough to produce an irreversible injury, that is, an infarction, which represents the “death” of the affected nervous tissue.
  • Hemorrhage: Rupture of a vessel located in the central nervous system, with the consequent “spilling” of blood on that tissue.

 

It usually appears with typical symptoms, such as a sudden deviation of of the mouth, a sudden difficulty in speaking or moving a part of the body, or an acute visual loss affecting one eye or part of the visual field. But on other occasions, the symptoms are less common, which increases the diagnostic difficulty and can delay their recognition and then their prevention or treatment.

In all cases, early attention is the key to reduce the sequelae, which can otherwise be severe. An adequate prevention can minimize the risk of suffering a first stroke or a recurrent stroke. It should be taken into account that, if some people are lucky enough to come out with little or no sequelae from a first cerebrovascular event, the probability of succeeding in a second event is very low. The neurologist expert in stroke plays a differentiating role in the prevention of this pathology, as it optimizes the prevention strategy after detecting the mechanisms by which a stroke can occur (or has occurred) in a certain person and reducing the probability of a fatal event. When, unfortunately, these sequelae have not been avoided, we must resort to the appropriate pharmacological and therapeutic resources to minimize them (highlighting here the rehabilitation therapies, occupational therapy and speech therapy).

Beyond stroke, understood as a recognizable clinical event due to the aforementioned symptoms, the detection of little “silent” vascular brain lesions is also frequent, that is, chronic ones, which have never given clear symptoms, but which are detected by chance in some brain imaging test that is indicated for some circumstantial reason (for example, to rule out traumatic injuries after an accident). Those colloquially called “microinfarcts” are included in this group. Although its impact is usually less than that of a stroke, its accumulation can cause certain problems, for example, memory disturbances, difficulties in dealing with daily life or at work, or loss of motor skills, in people who suffer them. It is here where, once again, clarifying its origin and acting to stop its appearance are key to prevent the progression of these problems or even the eventual occurrence of a stroke in the near future.

Videos

Common carotid artery by echography
Vertebral artery source by ecography
Willis polygon by echography
V2 segment of vertebral artery by echography