Grading brainstem involvement in multiple sclerosis - by means of electro-oculography

Area of Science:

• Neurology
• Ophthalmology
• Neuroscience

Background:

• Internuclear ophthalmoplegia (INO) is a common brainstem disorder in multiple sclerosis (MS).
• Monitoring MS progression and brainstem involvement is crucial for treatment and rehabilitation.
• Electro-oculography (EOG) offers a potential method for assessing INO in MS.

Purpose of the Study:

• To evaluate the utility of electro-oculography (EOG) in grading the course of multiple sclerosis (MS).
• To assess brainstem involvement in MS patients by analyzing INO through EOG findings.
• To establish a grading system for medial longitudinal fasciculi (MLF) lesions based on EOG parameters.

Main Methods:

• Selected 130 clinically defined multiple sclerosis (MS) patients (78 males, 52 females; mean age 43.5 years).
• Assessed saccadic eye movements, spontaneous nystagmus, vestibular (VOR), visuo-vestibular (VVOR), and optokinetic nystagmus (OKN).
• Identified slowing of the adducting eye as an indicator of interocular pathway lesions.

Main Results:

• The visuo-vestibular reflex (VVOR) test demonstrated the highest sensitivity in detecting abnormalities.
• Randomized saccades were the least sensitive test, but impairment always correlated with abnormalities in other tests.
• A grading scale for MLF involvement was proposed, ranging from isolated VVOR abnormalities to impaired randomized saccades.

Conclusions:

• Electro-oculography (EOG) findings can effectively monitor the progression of multiple sclerosis (MS).
• A grading system for brainstem involvement, specifically MLF lesions, can be established using EOG.
• This grading system is valuable for therapeutic trials and rehabilitation strategies in MS management.