Minimal hepatic encephalopathy is associated to alterations in eye movements

Area of Science:

• Neuroscience
• Gastroenterology
• Ophthalmology

Background:

• Minimal hepatic encephalopathy (MHE) diagnosis relies on the Psychometric Hepatic Encephalopathy Score (PHES) but lacks sensitivity for early detection.
• Saccadic eye movement assessment is a promising method for identifying early cognitive changes in various neurological conditions.

Purpose of the Study:

• To investigate saccadic eye movement alterations in MHE patients.
• To determine the relationship between these eye movement changes and cognitive deficits.
• To evaluate the utility of eye movement analysis as a tool for early MHE diagnosis.

Main Methods:

• 118 cirrhotic patients (32 with MHE, 86 without MHE) and 35 controls underwent PHES, Stroop test, and a comprehensive eye movement test battery using the OSCANN system.
• Analysis included visual saccades, antisaccades, memory-guided saccades, fixation, and smooth pursuit, examining 177 distinct eye movement parameters.

Main Results:

• MHE patients exhibited significant alterations in 56 out of 177 eye movement parameters compared to non-MHE patients.
• Impaired saccadic eye movements, including longer latencies and reduced accuracy, were observed in MHE patients.
• These eye movement deficits correlated significantly with impairments in mental processing speed and attention.

Conclusions:

• Eye movement analysis, particularly antisaccades and memory-guided saccades, shows potential for discriminating between MHE and non-MHE patients.
• This method offers a rapid, reliable, objective, and reproducible approach for the early diagnosis of minimal hepatic encephalopathy.