Horizontal nystagmus and multiple sclerosis using 3-Tesla magnetic resonance imaging

Area of Science:

• Neuroscience
• Ophthalmology
• Radiology

Background:

• Nystagmus in multiple sclerosis (MS) is typically linked to brainstem lesions.
• However, lesions in other brain regions can also cause nystagmus.
• High-field 3-Tesla MRI (3TMRI) improves the detection of these non-brainstem lesions.

Purpose of the Study:

• To investigate the distribution of structural lesions and tract disruption in MS patients experiencing horizontal nystagmus.
• Utilize 3TMRI and diffusion tensor imaging (DTI) for detailed analysis.

Main Methods:

• Twenty-four MS patients with horizontal nystagmus underwent 3TMRI brain scans.
• Eighteen of these patients also had DTI for tractography analysis.
• Lesion locations and tract integrity (fractional anisotropy - FA) were assessed.

Main Results:

• 194 lesions were identified across 20 regions of the neural integrator circuit, with 140 in the cortex and 54 in the brainstem.
• Most patients had lesions in both cortical and brainstem areas.
• Seventy-two percent of patients showed tract disruption (FA < 0.2), with significantly lower FA in bidirectional nystagmus.

Conclusions:

• Horizontal nystagmus in MS is associated with lesions in cortical eye fields and their descending pathways, in addition to potential brainstem involvement.
• Advanced tractography techniques are crucial for pinpointing the exact sites responsible for nystagmus in MS.