Background: Most of Multiple Sclerosis (MS) patients without previous optic neuritis (ON) show

In eyes without ON, VEPs were more frequently abnormal than OCT, while the two techniques showed similar sensitivity in eyes previously affected by ON. The correlation of VEPs and OCT measures with disability prompts further exploration of the two techniques as potential markers of disease burden.

Resting-state (RS) functional magnetic resonance imaging (fMRI) is a relatively novel tool which explores connectivity between functionally linked, but anatomically separated, brain regions. The use of this technique has allowed the identification, at rest, of the main brain functional networks without requiring subjects to perform specific active tasks. Methodologically, several approaches can be applied for the analysis of RS fMRI, including seed-based, independent component analysis-based and/or cluster-based methods. The most consistently described RS network is the so-called "default mode network". Using RS fMRI, several studies have identified functional connectivity abnormalities in migraine patients, mainly located at the level of the pain-processing network. RS functional connectivity is generally increased in pain-processing network, whereas is decreased in pain modulatory circuits. Significant abnormalities of RS functional connectivity occur also in affective networks, the default mode network and the executive control network. These results provide a strong characterization of migraine as a brain dysfunction affecting intrinsic connectivity of brain networks, possibly reflecting the impact of long lasting pain on brain function.

NEDA is associated with a relatively preserved RNFL over 2 years. A greater neuroretinal loss was detected even in patients with clinical evidence of disease activity independently from changes in brain MRI lesions, prompting further validation of OCT as an additional tool in MS monitoring.

Background: Neuroretinal atrophy is associated with whole-brain atrophy and disease activity in multiple sclerosis (MS). Recent findings support that subclinical visual pathway involvement might also occur in neuromyelitis optica spectrum disorders (NMOSDs). Objective: The objective of this study is to assess retinal thinning in MS and NMOSD and its association with disease activity. Methods: In total, 27 NMOSD and 54 propensity-score-matched MS patients underwent optical coherence tomography, visual acuity, and visual-evoked potentials at 2.4 years apart, in addition to routine clinical and magnetic resonance imaging (MRI) assessment. We excluded eyes with acute optic neuritis. Results: In NMOSD, we detected peripapillary retinal nerve fiber layer (pRNFL) thinning in patients with disease activity during follow-up (−0.494 µm/year), but not in stable patients (−0.012 µm/year). Macular ganglion cell-inner plexiform layer (GCIPL) thinning occurred instead in all patients (−0.279 µm/year). Relapsing–remitting multiple sclerosis (RRMS) meeting NEDA-3 criteria had no pRNFL or GCIPL thinning during follow-up. Active-disease RRMS and progressive MS, both active and stable, displayed pRNFL (−0.724, −0.586, −0.556 µm/year, respectively) and GCIPL loss. Conclusion: In MS, neuroretinal atrophy was associated with disease activity but occurred in progressive MS even when achieving NEDA-3 criteria. In NMOSD, pRNFL thinning was associated with non-ocular relapses due to a spreading of inflammatory activity. GCIPL thinning was found in all patients, supporting a primary retinal pathology targeting AQP4-rich structures.