Contributions
Abstract: P718
Type: Poster Sessions
Abstract Category: Clinical aspects of MS - Neuro-ophthalmology
Background: We have previously shown that functional modification in the visual cortex of clinically isolated optic neuritis (CIS-ON) patients may occur to compensate for the damage sustained by the affected optic nerve.
Objective: The current study was designed to further our understanding of what happens within the visual cortex following ON, utilizing graph theory analysis methods. We also expanded our study to include neuromyelitis optica spectrum disorder (NMOSD) patients to test whether the effects are connected to disease or to disability.
Methods: Eighty-eight subjects, including 18 CIS-ON, 21 CIS without ON (CIS-nON), and 23 NMOSD, as well as 26 healthy controls (HC) underwent resting state functional MRI (RS-fMRI). Visual networks were constructed through inter-regional temporal correlations of RS-fMRI time-courses, comprising 50 visual regions (25 per hemisphere).
Results: preliminary results show no significant differences between hemispheres in any of the groups. Both hemispheres show that the HC visual networks were significantly more connected and had higher global efficiency than those of the patient groups, particularly those of the CIS-nON group. No significant differences were found between the NMOSD and CIS-ON groups, and both were more connected and showed higher global efficiency than the CIS-nON group.
Conclusions: the significant difference between the HC and CIS-nON groups suggests that the patients exhibit reduced connectivity, possibly in the entire brain, irrelevant of the affected system. The relative rise in connectivity within the visual system observed in the ON groups compared to CIS-nON suggests attempted cortical compensation. The observation that NMOSD patients appear to exhibit the same compensatory rise in connectivity within the visual system as observed in the CIS-ON group posits that disability rather than disease type serves as a trigger for the compensatory process.
Disclosure: YB and NL were funded by the National Multiple Sclerosis Society (research grant 5128-A) and the Applebaum Foundation. FP serves on the scientific advisory board for Novartis; received speaker honoraria and travel funding from Bayer, Novartis, Biogen Idec, Teva, Sanofi-Aventis/Genzyme, Merck Serono, Alexion, Chugai, MedImmune, and Shire; is an academic editor for PLoS ONE; is an associate editor for Neurology® Neuroimmunology & Neuroinflammation; consulted for SanofiGenzyme, Biogen Idec, MedImmune, Shire, and Alexion; and received research support from Bayer, Novartis, Biogen Idec, Teva, Sanofi-Aventis/Genzyme, Alexion, Merck Serono, German Research Council, Werth Stiftung of the City of Cologne, German Ministry of Education and Research, Arthur Arnstein Stiftung Berlin, EU FP7 Framework Program, Arthur Arnstein Foundation Berlin, Guthy Jackson Charitable Foundation, and National Multiple Sclerosis of the USA.
Abstract: P718
Type: Poster Sessions
Abstract Category: Clinical aspects of MS - Neuro-ophthalmology
Background: We have previously shown that functional modification in the visual cortex of clinically isolated optic neuritis (CIS-ON) patients may occur to compensate for the damage sustained by the affected optic nerve.
Objective: The current study was designed to further our understanding of what happens within the visual cortex following ON, utilizing graph theory analysis methods. We also expanded our study to include neuromyelitis optica spectrum disorder (NMOSD) patients to test whether the effects are connected to disease or to disability.
Methods: Eighty-eight subjects, including 18 CIS-ON, 21 CIS without ON (CIS-nON), and 23 NMOSD, as well as 26 healthy controls (HC) underwent resting state functional MRI (RS-fMRI). Visual networks were constructed through inter-regional temporal correlations of RS-fMRI time-courses, comprising 50 visual regions (25 per hemisphere).
Results: preliminary results show no significant differences between hemispheres in any of the groups. Both hemispheres show that the HC visual networks were significantly more connected and had higher global efficiency than those of the patient groups, particularly those of the CIS-nON group. No significant differences were found between the NMOSD and CIS-ON groups, and both were more connected and showed higher global efficiency than the CIS-nON group.
Conclusions: the significant difference between the HC and CIS-nON groups suggests that the patients exhibit reduced connectivity, possibly in the entire brain, irrelevant of the affected system. The relative rise in connectivity within the visual system observed in the ON groups compared to CIS-nON suggests attempted cortical compensation. The observation that NMOSD patients appear to exhibit the same compensatory rise in connectivity within the visual system as observed in the CIS-ON group posits that disability rather than disease type serves as a trigger for the compensatory process.
Disclosure: YB and NL were funded by the National Multiple Sclerosis Society (research grant 5128-A) and the Applebaum Foundation. FP serves on the scientific advisory board for Novartis; received speaker honoraria and travel funding from Bayer, Novartis, Biogen Idec, Teva, Sanofi-Aventis/Genzyme, Merck Serono, Alexion, Chugai, MedImmune, and Shire; is an academic editor for PLoS ONE; is an associate editor for Neurology® Neuroimmunology & Neuroinflammation; consulted for SanofiGenzyme, Biogen Idec, MedImmune, Shire, and Alexion; and received research support from Bayer, Novartis, Biogen Idec, Teva, Sanofi-Aventis/Genzyme, Alexion, Merck Serono, German Research Council, Werth Stiftung of the City of Cologne, German Ministry of Education and Research, Arthur Arnstein Stiftung Berlin, EU FP7 Framework Program, Arthur Arnstein Foundation Berlin, Guthy Jackson Charitable Foundation, and National Multiple Sclerosis of the USA.