Silent progression of brain atrophy in aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder

Abstract

ObjectiveTo investigate longitudinal brain atrophy in patients with neuromyelitis optica spectrum disorder (NMOSD).MethodsWe investigated the longitudinal brain atrophy rate in patients with aquaporin-4 antibody-positive NMOSD (AQP4+NMOSD) and those with multiple sclerosis (MS) in a retrospective cohort study. Brain volume was calculated with statistical parametric mapping-12.ResultsWe enrolled 36 patients with AQP4+NMOSD and 60 with MS. Patients with NMOSD were older and had a higher Kurtzke’s expanded disability status scale score at baseline MRI compared with those with MS. Disease duration, annual relapse rate and intervals from the last attack and from disease-modifying drugs initiation were not significantly different between the two groups. Lower normalised lesion volume and higher normalised white matter volume were found in patients with NMOSD compared with those with MS at baseline MRI. However, the annualised atrophy rate of normalised brain volume was similar between the NMOSD (median 0.47; IQR 0.75; p=0.49) and MS (median 0.46; IQR 0.84) groups. After adjustment of age and the presence of clinical relapse, no differences of the annualised atrophy rate of normalised brain volume also were found for NMOSD and MS. Patients with AQP4+NMOSD with long cord lesion showed higher annualised atrophy rate of normalised grey matter volume compared with those without long cord lesion.ConclusionsSilent progression of brain atrophy was present in patients with AQP4+NMOSD, as shown in patients with MS, even in the clinically inactive age-matched cases. Subclinical dying back degeneration may explain the brain atrophy in patients with AQP4 +NMOSD.

Frequency of new asymptomatic MRI lesions during attacks and follow-up of patients with NMOSD in a real-world setting

“…30 First myelitis attack can be associated with asymptomatic spinal cord MRI lesions in seropositive NMOSD patients (STM rather than LETM), but these silent lesions have also been described in patients with ON in the absence of prior myelitis. 31 In this study, we found that one-quarter of patients experienced asymptomatic STM lesion during the relapsefree period. In addition to this, spinal cord atrophy and reductions of mean upper cervical cord area have been reported in seropositive NMOSD, even in the absence of a clinical history of relapses or previous spinal cord MRI lesions.…”

Dorsal medulla surface texture: Differentiating neuromyelitis optica spectrum disorder from multiple sclerosis

“…Volumetric data related to the study of NMOSD have contributed to our understanding of the impact of the disease on cortical gray matter, 15 deep gray matter, 16,17 hippocampal, 18,19 brainstem, 20 and whole brain volume measures. 21 The incorporation of texture adds an alternative form of information to volume change alone. This approach also enables the identification of early spatial pattern changes within Central to the pathophysiology of NMOSD are AQP4-IgG antibodies that bind selectively to the mercurial-insensitive 22 water sensitive transporting proteins.…”

“…Volumetric data related to the study of NMOSD have contributed to our understanding of the impact of the disease on cortical gray matter, 15 deep gray matter, 16,17 hippocampal, 18,19 brainstem, 20 and whole brain volume measures 21 . The incorporation of texture adds an alternative form of information to volume change alone.…”

Glial Fibrillary Acidic Protein in Blood as a Disease Biomarker of Neuromyelitis Optica Spectrum Disorders

“…However, recent optical coherent tomography and visual evoked potential studies suggested subclinical neurodegeneration in NMOSD patients ( 101 , 102 ). More recently, silent progression of brain atrophy was documented in NMOSD patients, even in clinically inactive patients ( 103 ). Additional studies on blood GFAP levels further support the concept of ongoing subclinical neurodegeneration in NMOSD.…”

“…The value of NfL may be more pronounced elsewhere. Given that NfL is a neuronal structural component, serum NfL might be a better biomarker for monitoring the degree of neurodegeneration of NMOSD ( 101 – 103 ) and associated cognitive impairment ( 113 ) than serum GFAP. This possibility should be elucidated in future studies.…”