Association of Visual Impairment in Neuromyelitis Optica Spectrum Disorder With Visual Network Reorganization

Abstract

This cross-sectional study examines adaptive visual network connectivity changes in neuromyelitis optica spectrum disorder.

Key Points

Question

Is visual impairment in neuromyelitis optica spectrum disorder associated with adaptive functional network reorganization?

Findings

In this cross-sectional study of 31 patients with aquaporin-4 antibody–positive neuromyelitis optica spectrum disorder, a selective and pronounced increase of visual network functional connectivity was observed. This increased connectivity was associated with impaired visual function and retinal damage and was more pronounced in patients with a history of optic neuritis.

Meaning

Visual impairment and anterior visual system damage are associated with a selective reorganization of functional visual networks in neuromyelitis optica spectrum disorder.

Abstract

Importance

Severe visual impairment is one of the major symptoms in neuromyelitis optica spectrum disorder (NMOSD), but functional network reorganization induced by the diminished sensory input has not been investigated thus far.

Objective

To examine adaptive visual network connectivity changes in NMOSD.

Design, Setting, and Participants

In this cross-sectional study, data were collected from May 1, 2013, through February 31, 2016, from 31 patients with aquaporin-4 antibody–positive NMOSD and 31 age- and sex-matched healthy control individuals at the

Department of Neurology and NeuroCure Clinical Research Center at Charité–Universitätsmedizin Berlin, Berlin, Germany.

Main Outcomes and Measures

Visual function (high-contrast visual acuity and contrast sensitivity), optical coherence tomography (peripapillary retinal nerve fiber layer and ganglion cell layer thickness), and resting-state functional magnetic resonance imaging (functional connectivity of large-scale brain networks).

Results

Thirty-one patients with NMOSD (mean [SD] age, 48.2 [13.9] years; 28 women and 3 men) and 31 healthy controls (mean [SD] age, 47.2 [15.3] years; 28 women and 3 men) participated in the study. Patients had a selective and pronounced increase of functional connectivity in the primary and secondary visual networks. Increased primary visual network connectivity correlated with reduced high-contrast visual acuity ( r = −0.39, P = .006), reduced low-contrast sensitivity ( r = −0.33, P = .03), and more severe retinal damage measured by optical coherence tomography ( r = −0.4, P = .01). Furthermore, visual functional connectivity was significantly higher in patients with a history of optic neuritis compared with patients without optic neuritis (mean [SD] regression coefficients, 50.0 [4.3] vs 34.6 [5.6]; P = .04).

Conclusions and Relevance

Impaired visual function and retinal damage are associated with selective reorganization of the visual network in NMOSD. These findings advance the understanding of visual system dysfunction in NMOSD and, more generally, provide insight into pathophysiologic responses of the visual system to impaired visual input.