Hemianopsia: Types, Symptoms, Causes And Treatment
Hemianopsia is one of the neurological disorders that show us to what extent vision is a complex functioning process Normally we believe that what we see enters through the eyes in the form of light and is represented in the brain as a unit, after our nervous system has been responsible for unifying the information received in “raw” format.
However, the sense of sight works from a process that is not limited to collecting data and uniting them, but rather has a much more active role than it seems: it composes images that are not actually the same as what they capture. the eyes.
In reality, the simple fact of having a pair of these sensory organs already makes this necessarily so, and hemianopsia helps us understand this Let’s see it.
As far as we know, vision is one of the most important senses we have, but it is also true that it can fail in many different ways. Hemianopsia is one of them.
As its name suggests, hemianopsia has to do with the hemispheres, or rather, the hemibodies, which are the sides of our body divided by a vertical axis (that is, the left or right sides) in regards to our nervous system. Specifically, hemianopsia is blindness in relation to one side of the visual field
In other words, it is not that we do not see through one eye and as a consequence our visual field narrows in the horizontal sense as one of its sides is reduced; is that in one of the two eyes, or in both, one of the two halves of the visual field has ceased to exist
Hemianopia may seem unusual and is not as easy to understand as conventional blindness, but in reality it is still a neurological disease that affects vision. Therefore, all its associated symptoms have to do with this type of problem: orientation problems, confusion due to not finding a space, person or object feeling of not knowing where you are, etc.
It is also possible that these symptoms are mixed with those of the accident or illness that in turn caused the hemianopsia, which, as we will see, can be caused by very varied phenomena.
In any case, these symptoms also depend on the type of hemianopsia in question, since this alteration appears in different ways.
Guys
The main types of hemianopia obey a first fundamental classification: unilateral and bilateral hemianopia In the first case, the alteration only affects one of the eyes, while in the second, it manifests itself in vision that depends on both eyes.
In turn, bilateral hemianopia It can be homonymous, if the affected side in both eyes is the same, or heteronymous if in each eye the affected side is different: in one it affects the right, and in the other, the left.
Causes
Typically, hemianopsia is caused by lesions caused by trauma, stroke and tumors all of which structurally affect the nervous system.
However, in some cases it may be due to transient phenomena such as substance use or migraines with aura, which can lead to temporary hemianopsia, with very rapid remission of symptoms.
The parts of the nervous system that are usually behind hemianopia are the optic chiasm or the last sections of the optic pathways on their route to the thalamus: the optic tracts.
It is possible to confuse hemianopsia with hemineglect, a neurological disorder that also has to do with the hemibodies.
The main difference between the two is that In hemineglect, not only vision is affected but the experimentation of all the senses.
The second important difference is that in hemineglect the problem is not technically in the vision itself, but rather in attention. Sensory data reaches the brain, but they are not processed as if they were relevant: they are “discarded”. For this reason, it has been seen that there is a kind of very meager notion of what happens in the ignored hemibody, although this information does not pass to consciousness and the person believes they have not realized anything, as has been seen in experiments.
Treatment
In the case of transient hemianopia, the intervention is limited to ensuring the well-being of the person until the effects wear off. Treatments aimed at intervening in non-transitory hemianopsia They are of the neurological rehabilitation type assuming that complete recovery may not occur.
