The need for an extensive neuropsychological assessment for a reliable diagnosis of mild cognitive impairment in patients with Parkinson's disease

Eye tracking metrics to screen and assess cognitive impairment in patients with neurological disorders

PURPOSE OF REVIEW

Eye tracking is a powerful method to investigate the relationship between behavior and neural mechanisms. In recent years, eye movement analysis has been used in patients with neurological disorders to assess cognitive function. In this review, we explore the latest eye tracking researches in neurological disorders that are commonly associated with cognitive deficits, specifically, amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), and epilepsy. We focus on the application of ocular measures in these disorders, with the goal of understanding how eye tracking technology can be used in the clinical setting.

FINDINGS

Eye tracking tasks (especially saccadic tasks) are often used as an adjunct to traditional scales for cognitive assessment. Eye tracking data confirmed that executive dysfunction is common in PD and ALS, whereas AD and MS are characterized by attention deficits. Research in evaluating cognitive function in epilepsy using eye tracking is still in its early stages, but this approach has shown advantages as a sensitive quantitative method with high temporal and spatial resolution. Eye tracking technology can facilitate the assessment of cognitive impairment with higher temporal resolution and finer granularity than traditional cognitive assessment. Oculomotor data collected during cognitive tasks can provide insight into biological processes. Eye tracking provides a nonverbal and less cognitively demanding method of measuring disease progression in cognitively impaired patients.

Clinical utility of the INECO Frontal Screening for detecting Mild Cognitive Impairment in Parkinson's disease

Cognitive deficits in Parkinson's disease typically affect executive functions. Recently, the concept of Mild Cognitive Impairment (MCI) has been related to PD (PD-MCI). PD-MCI is considered a transition phase to Parkinson's disease Dementia. Therefore, it is important to identify PD-MCI in a reliable way.

OBJECTIVE

To evaluate the sensitivity and specificity of the INECO Frontal Screening (IFS) in detecting cognitive deficits in PD-MCI. Additionally, we compare the IFS and the Addenbrook Cognitive Examination Revised (ACE-R) between three groups; PD-MCI, MCI, and controls.

METHODS

The IFS and ACE-R were administered to 36 patients with PD-MCI, 31 with MCI (amnestic-multidomain subtype) and 92 healthy controls. Sensitivity and specificity were determined using ROC analysis. The groups were compared using one-way analysis of variance.

RESULTS

The IFS had adequate accuracy in differentiating patients with PD-MCI from healthy controls (AUC=0.77, sensitivity=0.82, specificity=0.77), and good accuracy in differentiating PD-MCI from MCI patients (AUC=0.80, sensitivity=0.82, specificity=0.61). However the IFS had low accuracy in differentiating MCI patients from healthy controls (AUC=0.47, sensitivity=0.52, specificity=0.41). On the ACE-R, the PD-MCI group had low performance in Fluency and Language. Only patients with PD-MCI had difficulties on the IFS, specifically in inhibitory control and visual working memory. This dysexecutive profile explains the sensitivity and specificity values found in the IFS.

CONCLUSION

The present study results suggest that the IFS is a suitable screening tool for exploring cognitive dysfunction in PD-MCI, especially in those patients with a dysexecutive profile.