Visual evoked potentials in normal subjects and patients with multiple sclerosis

Area of Science:

• Neuroscience
• Ophthalmology
• Clinical Neurology

Background:

• Multiple Sclerosis (MS) is a demyelinating disease affecting the central nervous system.
• Visual evoked potentials (VEPs) are non-invasive electrophysiological tests measuring visual pathway function.
• Pattern-reversal checkerboard stimulation is a standard VEP technique.

Purpose of the Study:

• To evaluate the diagnostic utility of VEPs in patients with suspected or confirmed multiple sclerosis.
• To establish normative VEP data across a wide age range (10-69 years) and sexes.
• To determine the sensitivity of VEPs in detecting MS-related visual pathway dysfunction.

Main Methods:

• VEPs were recorded using checkerboard pattern-reversal stimulation in 70 healthy subjects and 100 MS patients.
• Analysis focused on latency, inter-eye latency difference, and amplitude ratios of the major positive component.
• Normative data were stratified by sex and age groups to define abnormality criteria.

Main Results:

• Abnormal VEP findings were observed in 85% of all MS patients, with higher rates in definite MS (100%) and those with optic neuritis history (98%).
• VEP abnormalities correlated with symptom duration and were present in all patients with visual acuity below 0.67.
• Age and sex influenced VEP parameters, with longer latencies and smaller amplitudes in older males.

Conclusions:

• VEPs are highly sensitive in diagnosing multiple sclerosis, particularly in cases with optic neuritis.
• Utilizing sex- and age-specific normative values enhances diagnostic accuracy without increasing false positives.
• VEP testing is a valuable tool for detecting subclinical visual pathway involvement in MS.