P- 91 CHANGES IN EARLY VISUAL PERCEPTION IN PATIENTS WITH MINIMAL HEPATIC ENCEPHALOPATHY

Introduction and Objectives

Minimal Hepatic Encephalopathy (MHE) is characterized by very subtle cognitive changes that are diagnosed with the Psychometric hepatic encephalopathy score (PHES) and critical flickering frequency (CFF). Patients with MHE are slower in attention tests evaluated with visual cognitive evocative potentials, which are late indicators. However, it is unknown whether there is also slowness in automatic responses of early visual perception, such as those of stationary visual potential P100. This study aimed to detect early visual changes in patients with minimal hepatic encephalopathy

Materials and Methods

Cirrhotic patients who went to the Liver Clinic of the Gastroenterology Service of the Mexican General Hospital "Eduardo Liceaga" were included. The PHES, CFF test was applied and the electroencephalogram (EEG) was recorded while repeated visual stimuli were presented to obtain the stationary visual potential P100.

Results

89 patients with hepatic cirrhosis participated in 54 women (60.7%) with 53 ± 7.9 years of age and 8.3 ± 3.4 years of schooling. Fifty-seven patients (64.0%) and 64 FCP-positive (71.9%) were PHES-positive. MHE (PHES and CFF positive) was detected in 53 patients (59.6%). 29 MHE patients and 10 patients with cirrhosis agreed to do the perceptual tests. P100 latency of the visual potential was quantified lower in patients with MHD 113 ± 9 milliseconds than in cirrhotic 94 ± 14 milliseconds.

Conclusions

Patients with MHE showed slowness in early perceptual processes that preceded cognitive processes.