Spatial tuning function of pattern visual evoked potentials in multiple sclerosis patients without optic neuritis...

Area of Science:

• Neuroscience
• Ophthalmology
• Neurology

Background:

• Multiple sclerosis (MS) is a demyelinating disease affecting the central nervous system.
• Optic neuritis is a common initial symptom of MS, but visual pathway dysfunction can occur without a history of optic neuritis.
• Assessing visual evoked responses (VERs) can reveal subclinical visual pathway damage.

Purpose of the Study:

• To investigate the amplitude and latency-check size function of pattern visual evoked responses (pVERs) in multiple sclerosis (MS) patients without a history of optic neuritis.
• To compare pVERs between MS patients and healthy controls.

Main Methods:

• Thirty-six MS patients and 21 control subjects participated in the study.
• Pattern visual evoked responses were recorded using five different check sizes (2°, 1°, 30', 15', and 7').
• Analysis focused on P100 amplitude and latency, inter-ocular differences, and the amplitude-check size function.

Main Results:

• MS patients exhibited significantly reduced P100 amplitudes and delayed P100 latencies across all tested check sizes compared to controls (p < 0.05).
• Inter-ocular amplitude and latency differences were significantly greater in MS patients.
• The amplitude-check size function showed a more pronounced flattening in large checks for MS patients, particularly those with reduced P100 amplitudes.

Conclusions:

• Subclinical visual pathway dysfunction, characterized by reduced P100 amplitudes and delayed P100 latencies, is present in MS patients even without a history of optic neuritis.
• The amplitude-check size function is altered in MS patients, with larger check sizes revealing more significant abnormalities.
• pVERs, especially the amplitude-check size function, can serve as a sensitive tool for detecting visual pathway involvement in MS.