Anton’s syndrome: symptoms, causes and treatment

This strange syndrome appears in people who believe they can see in spite of having cortical blindness.

Of all the senses oriented to the perception of the outside world, vision is the one that is most developed in human beings.

Our visual capacity allows us to detect and process very detailed information about the world around us, giving us the ability to perceive a great deal of information about the stimuli around us. However, sight is a sense that can be lost or not possessed at all: there are a large number of disorders that can cause a person to be born without the ability to see or to lose a large part or even all of his or her visual capacity.

In those people who were born with the ability to see but who abruptly lose it after a brain injury, sometimes a strange condition arises in which, despite not being able to perceive the environment visually, they are convinced that they do. This is Anton's syndromeabout which we are going to speak throughout this article.

Anton syndrome: main characteristics

It receives the name of syndrome of Anton a medical condition characterized by the presence of anosognosia or lack of awareness of the presence of disturbances that occurs in people who have completely lost their vision at the objective level after having suffered a brain injury that destroyed their vision. after having suffered a brain injury that destroys the cortical areas responsible for processing this type of information.

This is a type of visual agnosia, i.e. a lack of recognition of the visual information that the subject receives, although in this case it is due to the non-recognition of non-vision.

Symptoms

The person suffering from this condition is not dissimulating or pretending, but actually is unable to detect that he/she cannot see and acts as if he/she possesses the ability to perceive the environment through his/her eyes. In this situation the subject confabulates visually, i.e. mentally and unconsciously generates the content they would see, sometimes using information from their other senses, which can sometimes appear to have some accuracy. Even if they usually stumble often due to their lack of vision, the denial of blindness is usually continuous and persistent, although in confrontation with visual stimuli they usually give inaccurate responses.

Although their visual organs are functional, the visual cortex, which allows the processing and perception of visual information, is destroyed or disconnected, so that vision is not possible (a condition known as cortical blindness). Anton's syndrome is usually is usually accompanied by some impairment of cognitive functions, which occur comorbidlyThe syndrome is usually accompanied by some compromise of cognitive functions, which occur comorbidly but are not part of the syndrome itself, such as memory problems.

Since they are not able to perceive that they do not see and because they move normally as a result, they often stumble and sometimes even have accidents that can endanger their physical integrity.

In addition to this the mixture of blindness and denial of this implies that dysfunctionalities arise. in spheres such as social, academic (it is not uncommon for them to claim to be able to read and write despite not really being able to do so) or work (in which their performance will usually be obviously reduced and, depending on the type of employment, they may even commit negligence due to their problems).

Causes

As a general rule, the causes of the appearance of Anton's syndrome are to be found in the presence of a brain lesion. This lesion must produce a destruction or disconnection of the visual areas of the occipital lobe at bilateral level, that is to say, affecting the occipital region of both cerebral hemispheres. This lesion is the origin of the cortical blindness that prevents them from seeing.

The reason for the appearance of anosognosia is not so clear, although it is common to find that the injury suffered has also generated damage or alterations in the occipitotemporal regions that would serve as an area of association.

The causes for the appearance of the lesion may be multiple, the most common being the presence of cerebrovascular accidents (either by ischemia or hemorrhage). (either by ischemia or hemorrhage).

In addition, other possible causes of its appearance are cranioencephalic trauma, the presence of infections or compression caused by brain tumors. Arterial hypertension, smoking or Diabetes are risk factors for vascular problems that may affect in this sense.

Treatment

Anton's syndrome is a complex disorder whose treatment is complex and usually requires the joint work of a multidisciplinary team that takes into account the different needs and particularities of the case in question.

To begin with, it is necessary to understand that cortical blindness is usually chronic, although in some cases there can be some improvement if abilities such as light perception are preserved and/or if the cause of the blindness is partially reversible (this is very rare, but sometimes the reabsorption of a hemorrhage or the treatment of certain infections that cause blindness may lead to some improvement).

At the medical level, efforts will be made to treat the cause and the brain injury as best as possible, which may or may not include surgery. However, this would be to treat the cause itself and not so much Anton's syndrome, which can be understood as a complication of it.

Regardless of this, treatment will require intervention at the level of making the subject aware of his or her current situation and the existence of visual problems. In this regard, it may be necessary to to restructure their beliefs by proposing behavioral experiments.. This is a first step that may be essential for the patient to adhere to rehabilitation programs and neurological or functional stimulation, so that the patient can learn mechanisms to reduce the difficulties that his condition generates.

Psychoeducation is of paramount importanceThe psychoeducation is essential, especially for the affected person, but also for his or her close environment, which is usually the reason why the patient comes for consultation and is usually more concerned than the subject himself (who, after all, believes that he or she can see perfectly well).

Bibliographical references:

• Belloch, A., Baños, R. and Perpiñá, C. (2008) Psychopathology of perception and imagination. In A. Belloch, B. Sandín and F. Ramos (Eds.) Manual de Psicopatología (2nd edition). Vol I. Madrid: McGraw Hill Interamericana.
• Donoso, A. (2002). Anosognosia in brain diseases. Rev.chil.neuro-psychiatr., 40 (2).
• Kaufman, D. (2008). Clinical neurology for psychiatrists. Sixth edition. Elsevier.
• Misra, M.; Rath, S. & Mohanty, A.B.(1989). Anton syndrome and cortical blindness due to bilateral occipital infarction. Indian Journal of Ophthalmology, 37 (4): 196.
• Prigatano, G. (2010). The study of anosognosia. Oxford University Press.