Eye-tracking controlled cognitive function tests in patients with amyotrophic lateral sclerosis: a controlled proof-of-principle study

Abstract

Amyotrophic lateral sclerosis (ALS) primarily affects motor and speech abilities. In addition, cognitive functions are impaired in a subset of patients. There is a need to establish an eye movement-based method of neuropsychological assessment suitable for severely physically impaired patients with ALS. Forty-eight ALS patients and thirty-two healthy controls matched for age, sex and education performed a hand and speech motor-free version of the Raven's coloured progressive matrices (CPM) and the D2-test which had been especially adapted for eye-tracking control. Data were compared to a classical motor-dependent paper-pencil version. The association of parameters of the eye-tracking and the paper-pencil version of the tests and the differences between and within groups were studied. Subjects presented similar results in the eye-tracking and the corresponding paper-pencil versions of the CPM and D2-test: a correlation between performance accuracy for the CPM was observed for ALS patients (p < 0.001) and controls (p < 0.001) and in the D2-test for controls (p = 0.048), whereas this correlation did not reach statistical significance for ALS patients (p = 0.096). ALS patients performed worse in the CPM than controls in the eye-tracking (p = 0.053) and the paper-pencil version (p = 0.042). Most importantly, eye-tracking versions of the CPM (p < 0.001) and the D2-test (p = 0.024) reliably distinguished between more and less cognitively impaired patients. Eye-tracking-based neuropsychological testing is a promising approach for assessing cognitive deficits in patients who are unable to speak or write such as patients with severe ALS.

A first approach to a neuropsychological screening tool using eye-tracking for bedside cognitive testing based on the Edinburgh Cognitive and Behavioural ALS Screen

“…This study shows the feasibility and reliability of a mobile eye-tracking screening tool based on the ECAS which can be easily administered even at the patient's bedside in a time frame of usually less than one hour. As in previous studies with healthy subjects (15,24,25) and ALS patients (16), there was a strong association between performance in both modalities of cognitive testing (oculomotor and paper-and-pencil) with satisfying correlations between scores in all relevant domains of both versions of the ECAS in the healthy control and in the patient sample.…”

“…A pseudo-randomized study design similar to the one previously reported by Keller et al. 2015 (16) was used: To avoid sequence effects, patients and HC were each subdivided into two age-gender-and education-matched groups. One group completed the German paper-and-pencil ECAS version (23) according to standard procedures first, followed by the eye-tracking based version, whereas the other group did vice versa.…”

Functional reorganization during cognitive function tasks in patients with amyotrophic lateral sclerosis

“…This study shows the feasibility and reliability of a mobile eye-tracking screening tool based on the ECAS which can be easily administered even at the patient's bedside in a time frame of usually less than one hour. As in previous studies with healthy subjects (15,24,25) and ALS patients (16), there was a strong association between performance in both modalities of cognitive testing (oculomotor and paper-andpencil) with satisfying correlations between scores in all relevant domains of both versions of the ECAS in the healthy control and in the patient sample.…”

“…Even though oculomotor impairments may occur in some patients in the course of ALS (12)(13)(14), for many patients it still has the potential to be a valuable tool in the detection of cognitive deficits. Previous studies have already proven the applicability of this approach for ALS patients (15)(16)(17)(18), using different tasks of executive functioning and devices which require a stationary testing environment. Yet, a mobile version of a cognitive screening tool specifically designed for bedside use in ALS patients is still lacking.…”

Classification of user performance in the Ruff Figural Fluency Test based on eye-tracking features

“…Keller et al [15] developed a neuropsychological assessment method for patients with Amyotrophic lateral sclerosis (ALS) based on eye movement. The participants (forty-eight ALS patients and thirty-two healthy controls) were tested by two tests (D2-test and Raven's coloured progressive matrices) adapted for eyetracking control.…”