Cognitive rehabilitation of hemianopia

Cognitive rehabilitation of hemianopia through multisensory stimulation

AvDesk is a multisensory telerehabilitation device, realized in collaboration with IRCCS Stella Maris. For more than 10 years we have been working on a compensatory rehabilitation treatment that has shown excellent results both in subjects with hemianopia and in those with neglect.Our device offers a cognitive rehabilitation treatment and can 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, most frequently due to vascular dementia, primary visual cortexes, areas designated for processing visual information.

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

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

What are the causes of hemianopia?

The main causes of this problem are:

• thrombosis;
• stroke (recover our cycle of encounters “Cerebral stroke: let’s make it clear“);
• aneurysms;
• compressions of the optic pathways;
• brain tumors;
• cerebral ischemias.

Treatment of cognitive rehabilitation

Through the stimulation of the multisensory neurons (audio/visual type) we are able to train eye movements in the direction in which the patient has shown campimetric deficits and/or neglect. The subject must demonstrate that he has perceived the target light (red light), by interacting with a button and directing the eyes towards the origin of the sound.

The neurorehabilitative process is aimed at increasing in the patient the saccharide movement, 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. This results in a progressive reinforcement of compensatory functions (such as the implementation of appropriate eye-care strategies).

The multisensory neurons, are especially active in the first years of life and then yield to a sort of “lethargy”, respond better to a multisensory stimulus (auditory and visual). This kind of neurons are located in the upper colliculum, an area which, even in the case of injuries such as a cerebral stroke, remain untouched.

Hemianopia: multisensory rehabilitation

In the webinars that were organize during the year, Dr. Tinelli, child neuropsychiatrist and Head of the Laboratory of Vision at IRCCS Stella Maris, presented the applicability of the multisensory approach also in children with hemianopia due to acquired and non-congenital lesions. Subjects with congenital lesion have a spontaneous reorganization due to the great brain plasticity present at birth. Conversely, children with acquired injury, show a different behavior, similar to that of adults: difficulties in tasks of visual exploration, reading, recognition of persons, etc.

In a study carried out a few years ago, some hemianoptic children with congenital and acquired lesions were subjected to a battery of visual exploration in which they had to identify a target. In subjects with congenital lesion, both in the ipsilesional side and in the counter-lesional one (that of the campimetric deficit), reaction times were similar; this was not the case in children with acquired lesions, where the reaction time in the hemianoptic side is twice that of the healthy side.

Developments in research

Later studies have made it clear that in children with congenital lesions and hemianopia, blindsight or blind visiondevelops, unlike what happens in children with acquired injury. Psychophysical forced choice techniques have been used to demonstrate this.

At this point in the study, the main challenge was finding out how to help hemianoptic children with acquired lesions. Rehabilitation treatment based on the stimulation of multisensory neurons has been successfully applied. The duration of treatment is relatively short (2-3 weeks), as it is possible to achieve excellent results, in children and adults alike.

The basic principles underlying this type of rehabilitation could allow us to widen the application opportunities of this treatment to other types of visual and cognitive deficits.

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