Cognitive rehabilitation of hemianopsia

Cognitive rehabilitation of hemianopia through multisensory stimulation

AvDesk® is a multisensory telerehabilitation device, the result of a collaboration with IRCCS Stella Maris. For more than 10 years we have been working on a compensatory rehabilitation treatment that seems to have excellent results both in subjects with hemianopia and in those with neglect.Our device offers a cognitive rehabilitation and is able to enhance visual skills through audiovisual stimuli.

What is hemianopia and what are the symptoms?

This problem arises as a result of injuries related to traumatic events, more frequently due to vascular dementia, to the primary visual cortices, areas designated for processing visual information.

The number of patients with hemianopia following a stroke is astonishing: 25,000 new cases (60% of the total).

The therapy is designed to rehabilitate patients, children and adults, who have a visual field deficit resulting from neurological diseases.

What are the causes of hemianopia?

Here are the main causes of this problem are:
  • thrombosis;
  • stroke (recover our cycle of meetings "Brain stroke: let's clarify“);
  • aneurysms;
  • compressions of the optic pathways;
  • brain tumors;
  • cerebral ischemias.

Cognitive rehabilitation treatment

Through the stimulation of the multisensory neurons (audio / visual type) the eye movements are trained in the direction in which the patient has the field deficit and / or neglect. The subject must demonstrate that he has perceived the luminous target (red light), interacting with a button and directing the eyes towards the source of the sound.

The neurorehabilitative process is aimed at increasing the saccadic movement in the patient, that is the response time to audiovisual stimuli. This type of approach exploits the mechanisms of neural plasticity, naturally present in the brain, and integration of multisensory elements. In this way, a progressive reinforcement of the compensatory functions is obtained (such as the implementation of appropriate oculomotor strategies).

The multisensory neurons, particularly active in the first years of life and then succumbing to a sort of "lethargy", respond better to a multisensory stimulus (auditory and visual). This type of audiovisual neurons are located in the superior colliculus, an area which, even in the case of injuries such as a cerebral stroke, remains preserved from damage.

Hemianopia: multisensory rehabilitation

In the webinars we organize throughout the year, Dr. Tinelli, child neuropsychiatrist and Head of the Vision Laboratory at IRCCS Stella Maris, presented the applicability of the multisensory approach even in children with hemianopia due to acquired and non-congenital lesions. Subjects with congenital lesion have a spontaneous reorganization due to the large brain plasticity present at birth; conversely, children with an acquired lesion approach a type of behavior more similar to that of adults: difficulty in tasks of visual exploration, reading, recognition of people, etc.

In a study a few years ago, some hemianoptic children with congenital and acquired lesions were subjected to a battery of tests of visual exploration with the aim of identifying a target. In subjects with congenital lesion, both in the ipsilesional and in the contralesional side (that of the fieldimetric deficit), the reaction times are similar; this does not happen in children with acquired lesion where the reaction times on the hemianoptic side are double those of the healthy side.

Research developments

Subsequent studies have made it possible to understand that in children with congenital lesions and hemianopia develops the blindsight or blind vision, unlike what happens in children with an acquired lesion. Techniques were used to demonstrate this forced choice psychophysical type.

At this point in the study, the main challenge was figuring out how to help hemianoptic children with acquired injuries. The rehabilitation treatment based on the stimulation of multisensory neurons was thus successfully applied. The duration of the treatment is short (2-3 weeks), so often with a good initial motivation it is possible to obtain excellent results even in children.

The founding principles underlying this type of rehabilitation are such as to widen the applicative opportunities of this treatment to other types of visual and cognitive deficits.

Retrieve the intervention of Dr. Tinelli on the cognitive rehabilitation of hemianopia presented during our first webinar "Neurovisual rehabilitation and brain plasticity: a look at the potential of telemedicine“.