Acinetopsia (motion blindness): types, symptoms, causes and treatment

This disorder causes us to be unable to appreciate movement in what we see.

When we observe the environment, our eyes perform a large number of movements to capture each and every detail and movement that compose it. Our brain then composes a harmonious image of everything around us, including moving objects and people.

Our eyes work like a video camera that produces thousands of frames of our surroundings, while our brain projects the "movie" in our mind. However, what happens when this function is disturbed? In these cases, acinetopsia appears.a disorder by which the person presents difficulties to perceive the movement.

What is acinetopsia?

Akinetopsia, also known as akinetopsia or motion blindness, is a neurological disorder affecting the sense of sight.consists of a disorder of a neurological nature that affects the sense of sight. Specifically, akinetopsia causes, in those who suffer from it, an inability to perceive movement through sight.

This condition, first described around 1991 by the British neurologist Semir Zeki, causes the affected person to be unable to perceive movement through vision.. The patient cannot see either the movement of his own body or that of other people or objects.

However, akinetopsia is not an "all or nothing" condition. The condition can be of varying degrees of severity. From the mildest, in which the person perceives movement as if it were a sequence of images or a movie in which the frames pass in slow motion; to the most severe, in which the patient experiences a total inability to perceive movement.

In this disorder, the person can only perceive other subjects, objects or him/herself in one particular place and then suddenly in another. Or at most, he perceives a kind of blurred trail behind the moving object.

Although all other sensory functions and abilities remain intact, people with akinesthesia also have their visuomotor skills disturbed.. Since they do not perceive their own movements well, tasks such as walking and moving, or reaching for objects can be really complicated.

Types of Akinetopsia and Symptoms

As mentioned above, akinetopsia can present in different degrees of involvement. These degrees constitute the different typologies of this disorder, which vary both in the severity of the symptoms and in the level of blindness it causes in the person.

There are two different types of acinetopsia. They are as follows.

1. Fine or discrete akinetopsia

This first type of akinetopsia, known as fine or discrete, is the one that presents a milder symptomatology and, therefore, less incapacitating for the person. However, sufferers also report experiencing enormous discomfort.

In mild akinetopsia, the person perceives the movement as if visualizing a reel. as if visualizing a reel in which the frames pass at a much slower speed.. Another example would be a multiple exposure photograph, in which the person can perceive the motion trail of both objects and people, including the patient himself.

At the moment, it is not known what abnormality in the functioning of the organism causes this disorder. However, experts point to the idea that an abnormal functioning of the mechanisms that allow us to maintain visual stability in eye movements may cause this type of akinetopsia.

2. Macroscopic achinetopsia

Also known as gross achinetopsia, this type of motion blindness is extremely rare and of very low incidence among the population. and of very low incidence among the population.

In contrast to fine acinetopsia, in macroscopic acinetopsia the person is completely unable to perceive movement in its entirety. This means that the person can only see a static world in which the object or person is in one place for an instant and then in a different place.

The few people who suffer from it, tend to suffer from numerous problems to perform their daily tasks normally.. Daily activities such as maintaining a conversation are highly complicated since the patient is unable to perceive changes in the movement of facial expressions. Likewise, daily routines, such as crossing the street, become very dangerous, since it is not possible to perceive the movement of cars.

In order to compensate for these difficulties, people with akinetopsia train their hearing. In this way, using their sense of hearing, they can, for example, calculate the distance of moving objects.

What are the causes?

The origin of acinetopsia lies in an abnormal functioning or interruption of activity in the area of the cortex located in the central area of the lobe. in the central area of the temporal lobe. Structural alterations in this area of the brain can transform the processes of comprehension of sensory information. In the case of this rare disorder, it is the processes that deal with visual information that are compromised.

There are several reasons why this brain region may be affected. From brain injuries, to the consumption of certain antidepressants or hallucinogens, or some diseases such as Alzheimer's disease.

1. Brain lesions

One of the causes of this disorder can be a lesion provoked in the posterior area of the visual cortex.Although it is really complicated, since a lesion of this type is susceptible to generate many more sensory deficits.

2. Antidepressant medication

The administration of very high doses of some antidepressants can cause visual problems such as akinetopsia. However, this tends to disappear when the treatment is eliminated or the dose is readjusted.

3. Hallucinogenic substances

Regular or recurrent use of certain hallucinogenic substances can cause sensory disturbances of all kinds. can cause sensory disturbances of all kinds, including the less severe version of acinetopsiaincluding the less severe version of acinetopsia, fine acinetopsia.

4. Migraine aura

Aura is a visual phenomenon that accompanies migraine headaches. It tends to appear moments before the onset of pain and is manifested by visual symptoms such as spots in space, flashes or fine acinetopsia.

5. Alzheimer's disease

Although they do not appear very frequently, acinetopsia, present in varying degrees, may accompany memory disturbances in Alzheimer's patients.

Is there a treatment?

For the time being, there are no pre-established guidelines for the treatment of akinetopsia. In cases where this is caused by the administration of psychotropic drugs, discontinuation of their use should eliminate the symptoms of this disorder.

However, brain surgery, although risky, is an option, brain surgery, although risky, is an option to attempt to eliminate to try to eliminate acinetopsia in those cases in which a brain lesion is underlying.