Abstract Details

Title Hippocampal Regional Vulnerability to Damage Differs Between MS and Neuromyelitis Optica

Topic Multiple Sclerosis

Presentation(s) P1 - Poster Session 1 (12:00 PM-1:00 PM)

Poster/Presentation
Number 9-010

Objective To characterize regional hippocampal volumetric alterations in multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) and to estimate correlations between regional hippocampal volumetric alterations and MRI measures of inflammation and hippocampal disconnection.

Background Hippocampal involvement is known to occur in MS, where hippocampal subfields have different susceptibility to damage and there is in-vivo evidence of dentate gyrus (DG) hypertrophy as a possible response to the inflammatory environment. Less is known about other inflammatory diseases like NMOSD.

Design/Methods Twenty-eight seropositive NMOSD patients, 24 age- and disease duration-matched relapsing-remitting MS and 20 healthy controls (HC) underwent a 3.0T MRI. From the 3D-T1-weighted sequence manual hippocampal segmentation was performed. Brain T2 and T1 lesion volumes (LV) were also assessed. From diffusion weighted sequences, a probabilistic tractography was run to reconstruct and assess eventual microstructural damage of the major hippocampal connections: the fornix, the uncinate fasciculus (UF) and the cingulum.

Results

Compared to HC, NMOSD patients had similar global hippocampal volumes. the subregional analysis showed only mild atrophy in the Cornus Ammonis (CA) 1 subfield. Compared to HC, MS patients had significant hippocampal atrophy (p<0.001), especially in the CA1 and Subiculum. Evidence of DG hypertrophy was found in MS (right p<0.05, left p<0.001), but not in NMOSD. Hippocampal anatomical connections were damaged in MS (p<0.001) and preserved in NMOSD. No correlation was found between regional hippocampal atrophy, brain T2 and T1 LVs and measures of hippocampal disconnection in NMOSD patients. In MS patients, hippocampal volume abnormalities were significantly related to brain T2 and T1 LVs and to damage of the cingulum and UF (r=-0.8, p=0.01).

Conclusions The preferential susceptibility to damage of the CA1 is a common feature in neuroinflammatory diseases but DG hypertrophy is a peculiar finding of MS, suggesting that other factors, in addition to inflammation, contribute to this process.

Authors/Disclosures
Laura Cacciaguerra, MD, PhD (Mayo Clinic) PRESENTER	Dr. Cacciaguerra has nothing to disclose.
Gianna Carla Riccitelli (San Raffaele)	No disclosure on file
Marta Radaelli (Hsr)	Marta Radaelli has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Merck Serono. Marta Radaelli has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen. Marta Radaelli has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Novartis. Marta Radaelli has received personal compensation in the range of $0-$499 for serving on a Speakers Bureau for Sanofi-Genzyme.
Elisabetta Pagani	Elisabetta Pagani has nothing to disclose.
Massimo Filippi, MD, FAAN (Ospedale San Raffaele, Neuroimaging Research Unit)	Dr. Filippi has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Alexion, Almirall, Biogen, Merck, Novartis, Roche, Sanofi. Dr. Filippi has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alexion, Biogen, Bristol-Myers Squibb, Merck, Novartis, Roche, Sanofi, Sanofi-Aventis, Sanofi-Genzyme, Takeda. Dr. Filippi has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Bayer, Biogen, Celgene, Chiesi Italia SpA, Eli Lilly, Genzyme, Janssen, Merck-Serono, Neopharmed Gentili, Novartis, Novo Nordisk, Roche, Sanofi, Takeda, and TEVA. Dr. Filippi has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Springer Nature. The institution of Dr. Filippi has received research support from Biogen Idec, Merck-Serono, Novartis, Roche, the Italian Ministry of Health, the Italian Ministry of University and Research, and Fondazione Italiana Sclerosi Multipla.
Maria A. Rocca (Neuroimaging Research Unit)	Maria Assunta Rocca has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen, Bristol Myers Squibb, Eli Lilly, Janssen, Roche. Maria Assunta Rocca has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for AstraZaneca, Biogen, Bristol Myers Squibb, Bromatech, Celgene, Genzyme, Horizon Therapeutics Italy, Merck Serono SpA, Novartis, Roche, Sanofi and Teva. The institution of Maria Assunta Rocca has received research support from MS Society of Canada, the Italian Ministry of Health, the Italian Ministry of University and Research, and Fondazione Italiana Sclerosi Multipla.