Assessment of Eye Movements in Stroke Patients and Closed-loop Intervention

This study is divided into two parts concerning the diagnostic and treatment of visuospatial deficits in patients affected by unilateral stroke. Eye movements indices during free viewing of natural scenes will be correlated to the standard neuropsychological evaluation, describing the cognitive, motor and functional spectrum of patient status. Moreover, functional and structural neuroimaging will be exploited to identify neural correlates of patient eye movements characteristics. Ultimately, a subsample of randomly assigned participants, at the IRCCS San Camillo, will undergo a novel visual exploration training, in addition to the standard rehabilitation. This protocol consists of natural scene exploration guided by an auditory biofeedback system which tracks online parsed fixations. Concretely, the training maneuvers exploration toward salient regions of the presented image, as indicated by a normative sample. Changes in free viewing behavior, neuropsychological assessment and neuroimaging will be discussed compared to an active control group and a healthy sample.

• Visual exploration training (Behavioral): Visual exploration of natural scenes guided by closed-loop auditory biofeedback through eye-tracking
• Standard neuropsychological rehabilitation (Behavioral): Standard rehabilitation delivered at the IRCCS San Camillo hospital

Primary outcomes

• Change pre-post rehabilitation in eye movements patterns during free viewing [At day 0 and day 30 (i.e., end of the rehabilitation)]: Eye movements patterns described by fixations, saccades and blinks related features summarized by principal component analysis (PCA)
• Change pre-post rehabilitation in Behavioral Inattention Test score [At day 0 and day 30 (i.e., end of the rehabilitation)]: Neuropsychological test assessing visuospatial deficits
• Change pre-post rehabilitation in Trail Making Test score [At day 0 and day 30 (i.e., end of the rehabilitation)]: Neuropsychological test assessing visuospatial abilities, scored as the time to complete the task
• Change pre-post rehabilitation in Posner Test reaction times [At day 0 and day 30 (i.e., end of the rehabilitation)]: Neuropsychological test assessing visuospatial abilities, scored with the measured reaction times
• Change pre-post rehabilitation in Attention Matrices Test [At day 0 and day 30 (i.e., end of the rehabilitation)]: Neuropsychological test assessing visuospatial deficits
• Change pre-post rehabilitation in Brief Visuospatial Memory Test Revised [At day 0 and day 30 (i.e., end of the rehabilitation)]: Neuropsychological test assessing visuospatial memory
• Change pre-post rehabilitation in Bells Test [At day 0 and day 30 (i.e., end of the rehabilitation)]: Neuropsychological test assessing visuospatial deficits
• Change pre-post rehabilitation in Apple Test score [At day 0 and day 30 (i.e., end of the rehabilitation)]: Neuropsychological test assessing visuospatial deficits
• Change pre-post rehabilitation in Comb and Razor Test [At day 0 and day 30 (i.e., end of the rehabilitation)]: Neuropsychological test assessing functional activities to investigate spatial attention deficits
• Change pre-post rehabilitation in Mental Number Interval Bisection [At day 0 and day 30 (i.e., end of the rehabilitation)]: Neuropsychological test investigating spatial biases in the mental number line
• Change pre-post rehabilitation in Anosognosia [At day 0 and day 30 (i.e., end of the rehabilitation)]: Neuropsychological test investigating deficits awareness
• Change pre-post rehabilitation in Load Test [At day 0 and day 30 (i.e., end of the rehabilitation)]: Neuropsychological test assessing spatial attentional deficits with cognitive load as a moderator
• Change pre-post rehabilitation in the Catherine-Bergego Scale score [At day 0 and day 30 (i.e., end of the rehabilitation)]: Test assessing activities of daily living involving spatial attention

Secondary outcomes

• Change pre-post rehabilitation in structural and functional connectivity [At day 0 and day 30 (i.e., end of the rehabilitation)]: Structural and functional MRI connectivity maps

Sex: All, ages: 18 Years to any, accepts healthy volunteers

Inclusion Criteria:

* Vigilant
* First unifocal ischemic or hemorragic stroke
* Presence of maximum two lacunae, clinically silent, smaller than 15 mm. in the structural MRI
* Evident symptoms in the visual, attentive, memory, motor or language domain supported by the radiological exam

Exclusion Criteria:

* Previous stroke history, visible at the radiological exam
* Multifocal deficit
* Incapacity to remain vigilant during the required assessments
* Claustrophobia and/or metallic objects which could prevent MRI acquisition
* Presence of other neurological, psychiatric or medical conditions which may undermine interpretation of behavioral and neuroimaging results

• Pollock A, Hazelton C, Henderson CA, Angilley J, Dhillon B, Langhorne P, Livingstone K, Munro FA, Orr H, Rowe FJ, Shahani U. Interventions for disorders of eye movement in patients with stroke. Cochrane Database Syst Rev. 2011 Oct 5;2011(10):CD008389. doi: 10.1002/14651858.CD008389.pub2. PMID 21975780

• Marco Zorzi, Principal investigator, San Camillo IRCCS, Venice, Italy