Effect of body temperature on visual evoked potential delay and visual perception in multiple sclerosis

Area of Science:

• Neuroscience
• Ophthalmology
• Clinical Neurology

Background:

• Multiple sclerosis (MS) is a demyelinating disease affecting the central nervous system.
• Temperature modulation is explored as a potential method to assess neurological function in MS.
• Evoked potentials are electrophysiological measures used to evaluate sensory pathway integrity.

Purpose of the Study:

• To investigate the effect of body temperature changes on evoked potentials in multiple sclerosis patients.
• To compare the reliability of evoked potentials with other clinical assessments for monitoring demyelination.

Main Methods:

• Seven multiple sclerosis patients underwent controlled cooling and heating.
• Evoked potential delay was measured under different temperature conditions.
• Control experiments were conducted on healthy subjects.
• Perceptual delay, visual acuity, and modulation transfer function (MTF) were also assessed in one patient.

Main Results:

• Evoked potential delay changed in only 5 out of 11 experiments in MS patients.
• Heating degraded perceptual delay, visual acuity, and MTF in one patient, but improved double-flash resolution.
• Control subjects established temperature-related limits for evoked potential delay.

Conclusions:

• The medium frequency flicker evoked potential test shows limited reliability in monitoring MS demyelination.
• Double-flash campimetry and perceptual delay campimetry appear more reliable for tracking disease progression.
• The objectivity of evoked potential testing may offer advantages in specific clinical scenarios.