Open AccessEarly and extensive spinal white matter involvement in neuromyelitis optica
Author(s) -
Hayashida Shotaro,
Masaki Katsuhisa,
Yonekawa Tomomi,
Suzuki Satoshi O.,
Hiwatashi Akio,
Matsushita Takuya,
Watanabe Mitsuru,
Yamasaki Ryo,
Suenaga Toshihiko,
Iwaki Toru,
Murai Hiroyuki,
Kira Jun-ichi
Publication year - 2017
Publication title -
brain pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.986
H-Index - 132
eISSN - 1750-3639
pISSN - 1015-6305
DOI - 10.1111/bpa.12386
Subject(s) - neuromyelitis optica , white matter , spinal cord , medicine , multiple sclerosis , aquaporin 4 , pathology , magnetic resonance imaging , radiology , immunology , psychiatry
Objectives Studies of longitudinally extensive spinal cord lesions (LESCLs) in neuromyelitis optica (NMO) have focused on gray matter, where the relevant antigen, aquaporin‐4 (AQP4), is abundant. Because spinal white matter pathology in NMO is not well characterized, we aimed to clarify spinal white matter pathology of LESCLs in NMO. Methods We analyzed 50 spinal cord lesions from eleven autopsied NMO/NMO spectrum disorder (NMOSD) cases. We also evaluated LESCLs with three or fewer spinal cord attacks by 3‐tesla MRI in 15 AQP4 antibody‐positive NMO/NMOSD patients and in 15 AQP4 antibody‐negative multiple sclerosis (MS) patients. Results Pathological analysis revealed seven cases of AQP4 loss and four predominantly demyelinating cases. Forty‐four lesions from AQP4 loss cases involved significantly more frequently posterior columns (PC) and lateral columns (LC) than anterior columns (AC) (59.1%, 63.6%, and 34.1%, respectively). The posterior horn (PH), central portion (CP), and anterior horn (AH) were similarly affected (38.6%, 36.4% and 31.8%, respectively). Isolated perivascular inflammatory lesions with selective loss of astrocyte endfoot proteins, AQP4 and connexin 43, were present only in white matter and were more frequent in PC and LC than in AC (22.7%, 29.5% and 2.3%, P corr = 0.020, and P corr = 0.004, respectively). MRI indicated LESCLs more frequently affected PC and LC than AC in anti‐AQP4 antibody‐seropositive NMO/NMOSD (86.7%, 60.0% and 20.0%, P corr = 0.005, and P corr = 0.043, respectively) and AQP4 antibody‐seronegative MS patients (86.7%, 73.3% and 33.3%, P corr = 0.063, and P corr = 0.043, respectively). PH, CP and AH were involved in 93.3%, 86.7% and 73.3% of seropositive patients, respectively, and in 53.3%, 60.0% and 40.0% of seronegative patients, respectively. Conclusions NMO frequently and extensively affects spinal white matter in addition to central gray matter, especially in PC and LC, where isolated perivascular lesions with astrocyte endfoot protein loss may emerge. Spinal white matter involvement may also appear in early NMO, similar to cerebral white matter lesions.