A Study of Taste- and Olfactory-Evoked Potentials in Patients With Visual Impairment: Taste, Smell, and Vision

N/ANot Yet RecruitingNCT07707219

Centre Hospitalier Universitaire Dijon50 enrolled

Overview

Visual impairment, whether central or peripheral, may influence the plasticity of other sensory modalities, such as taste and smell. Taste-evoked potentials (TEPs) and smell-evoked potentials (SEPs)-methods for analyzing brain activity in response to taste and smell stimuli-allow for the objective assessment of these interactions. This approach has already demonstrated its value in the study of cognitive disorders. This study aims to demonstrate an enhancement of taste and smell capabilities that could compensate for specific visual impairments, particularly in situations involving food choices.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

Conditions

Central Visual Impairment Peripherical Visual Impairment Macular Retinal Dystrophy Peripherical Macular Dystrophy

Interventions

Taste and smell evaluationOTHER

Determination of taste and smell ability scores using standardized methods (ETOC and Taste Strips)

Recording of evoked potentials (EP)OTHER

A recording of gustatory evoked potentials (GEP) and olfactory evoked potentials (OEP) in response to stimuli consisting of sucrose solution, vanillin, and a combination of the two.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 60 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Adult: ≥ 18 years and ≤ 60 years * Individual who has given oral consent * Individual who has been fasting (no food, drink, or tobacco) for at least 1 hour prior to PEG and PEO measurement * No cognitive complaints and normal neurological examination. * Group of patients with visual impairment: A. Central: documented bilateral macular dystrophy (e.g., Stargardt disease, Best disease) with confirmed central scotoma (CV 24.2, 10.2, or 30.2). B. Peripheral: documented bilateral peripheral retinal dystrophy with confirmed peripheral involvement (CV 30-2 or 24-2). • Control group: a person with normal vision and no known ophthalmological abnormalities (normal visual acuity and fundus examination) who is precisely matched by sex and smoking status (former smoker who has quit vs. nonsmoker), and approximately matched by age (± 5 years) to a visually impaired participant included in the study. Exclusion Criteria: For this group: patients with visual impairments: * Individuals who are not enrolled in or eligible for a social security program * Individuals subject to a legal protective measure (guardianship, conservatorship) * Individuals subject to judicial safeguard measures * Adults who are legally incapacitated or unable to give informed consent * Documented COVID-19 infection within the 6 months prior to enrollment * Active smokers (≥1 cigarette per day) or users of any other inhaled substances (water pipe, cannabis, etc.) * Participants following a sugar-free diet * Participants with diabetes, of any type * Participants taking medication (ongoing during the study) that interferes with taste perception • Pregnant or breastfeeding women * Individuals with neurodegenerative diseases (Parkinson's, Alzheimer's) * Individuals with braids, dreadlocks, or any other hairstyle that prevents electrodes from being placed in sufficiently precise locations on the scalp. * Overweight subjects with a BMI ≥ 35 kg/m²

Outcomes

Primary Outcomes

Average latency of PEG (Taste-Evoked Potentials) peaks

Measurement of the mean latency of taste-evoked potential peaks in visually impaired patients versus control subjects following purely gustatory stimulation (sucrose).

Time frame: At the baseline

Average amplitude of PEG (Taste-Evoked Potentials) peaks

Measurement of the mean amplitude of taste-evoked potential peaks in visually impaired patients versus control subjects following purely gustatory stimulation (sucrose).