Critical spinal cord lesions associate with secondary progressive motor impairment in long-standing MS: A population-based case-control study

MR Imaging Features of Critical Spinal Demyelinating Lesions Associated with Progressive Motor Impairment

BACKGROUND AND PURPOSE

Progressive MS is typically heralded by a myelopathic pattern of asymmetric progressive motor weakness. Focal individual "critical" demyelinating spinal cord lesions anatomically associated with progressive motor impairment may be a compelling explanation for this clinical presentation as described in progressive solitary sclerosis (single CNS demyelinating lesion), progressive demyelination with highly restricted MR imaging lesion burden (2-5 total CNS demyelinating lesions; progressive paucisclerotic MS), and progressive, exclusively unilateral hemi- or monoparetic MS (>5 CNS demyelinating progressive unilateral hemi- or monoparetic MS [PUHMS] lesions). Critical demyelinating lesions appear strikingly similar across these cohorts, and we describe their specific spinal cord MR imaging characteristics.

MATERIALS AND METHODS

We performed a retrospective, observational MR imaging study comparing spinal cord critical demyelinating lesions anatomically associated with progressive motor impairment with any additional "noncritical" (not anatomically associated with progressive motor impairment) spinal cord demyelinating lesions. All spinal cord MR images (302 cervical and 91 thoracic) were reviewed by an experienced neuroradiologist with final radiologic assessment on the most recent MR imaging. Anatomic association with clinical progressive motor impairment was confirmed independently by MS subspecialists.

RESULTS

Ninety-one individuals (PUHMS, 37 [41%], progressive paucisclerosis 35 [38%], progressive solitary sclerosis 19 [21%]) with 91 critical and 98 noncritical spinal cord MR imaging demyelinating lesions were evaluated. MR imaging characteristics that favored critical spinal cord demyelinating lesions over noncritical lesions included moderate-to-severe, focal, lesion-associated spinal cord atrophy: 41/91 (45%) versus 0/98 (0%) (OR, 161.91; 9.43 to >999.9); lateral column axial location (OR, 10.43; 3.88-28.07); central region (OR, 3.23; 1.78-5.88); ventral column (OR, 2.98; 1.55-5.72); and larger lesion size of the axial width (OR, 2.01;1.49-2.72), transverse axial size (OR, 1.66; 1.36-2.01), or lesion area (OR, 1.14; 1.08-1.2). Multiple regression analysis revealed focal atrophy and lateral axial location as having the strongest association with critical demyelinating lesions.

CONCLUSIONS

Focal, lesion-associated atrophy, lateral column axial location, and larger lesion size are spinal cord MR imaging characteristics of critical demyelinating lesions. The presence of critical demyelinating lesions should be sought as these features may be associated with the development of progressive motor impairment in MS.

Plasma glial fibrillary acidic protein levels correlate with paramagnetic rim lesions in people with radiologically isolated syndrome

BACKGROUND

There are no specific, evidence-based recommendations for the management of individuals with radiologically isolated syndrome. Imaging and blood biomarkers may have prognostic utility.

OBJECTIVE

To determine whether plasma neurofilament light protein (NfL) or glial fibrillary acidic protein (GFAP) levels in people with radiologically isolated syndrome correlate with imaging measures that have been shown to be associated with negative clinical outcomes in people with multiple sclerosis.

METHODS

Cross-sectional analysis of people with radiologically isolated syndrome. Participants underwent magnetic resonance imaging (MRI) of the brain and cervical spinal cord, and plasma was collected. Plasma NfL and GFAP levels were measured with a single-molecule array, and correlations with MRI measures were assessed, including the number of: T1-black holes, white-matter lesions demonstrating the central vein sign, paramagnetic rim lesions, cervical spinal cord lesions and infratentorial lesions.

RESULTS

Plasma GFAP levels, but not NfL levels, showed correlations with the number of T1-black holes, white matter lesions demonstrating the central vein sign and paramagnetic rim lesions (all p < 0.05).

CONCLUSION

We found correlations between plasma GFAP levels and imaging measures associated with poor clinical outcomes and chronic inflammation in individuals with radiologically isolated syndrome. Plasma GFAP may have prognostic utility in clinical trials and clinical practice.

Myelitis features and outcomes in CNS demyelinating disorders: Comparison between multiple sclerosis, MOGAD, and AQP4-IgG-positive NMOSD

Inflammatory myelopathies can manifest with a combination of motor, sensory and autonomic dysfunction of variable severity. Depending on the underlying etiology, the episodes of myelitis can recur, often leading to irreversible spinal cord damage and major long-term disability. Three main demyelinating disorders of the central nervous system, namely multiple sclerosis (MS), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders (AQP4+NMOSD) and myelin oligodendrocyte glycoprotein-IgG associated disease (MOGAD), can induce spinal cord inflammation through different pathogenic mechanisms, resulting in a more or less profound disruption of spinal cord integrity. This ultimately translates into distinctive clinical-MRI features, as well as distinct patterns of disability accrual, with a step-wise worsening of neurological function in MOGAD and AQP4+NMOSD, and progressive disability accrual in MS. Early recognition of the specific etiologies of demyelinating myelitis and initiation of the appropriate treatment is crucial to improve outcome. In this review article we summarize and compare the clinical and imaging features of spinal cord involvement in these three demyelinating disorders, both during the acute phase and over time, and outline the current knowledge on the expected patterns of disability accrual and outcomes. We also discuss the potential implications of these observations for patient management and counseling.

Oligoclonal M bands and cervical spinal cord lesions predict early secondary progressive multiple sclerosis

Objective

To determine baseline cerebrospinal fluid and magnetic resonance imaging (MRI) variables at the onset of a clinically isolated syndrome (CIS) suggestive of multiple sclerosis (MS) that predict evolution to secondary progressive MS (SPMS).

Methods

276 CIS patients with a minimum follow-up of 10 years were studied. Baseline presence of oligoclonal IgG and IgM bands (OCGB and OCMB respectively); number of brain T2 lesions (B-T2L), brain gadolinium enhancement lesions (brain-GEL), cervical spinal cord T2 lesions (cSC-T2L); and fulfillment of 2017 McDonald criteria among other variables were collected.

Results

14 patients ended up with a non-MS condition. 138/276 CIS patients fulfilled 2017 McDonald criteria. Mean age was 32.4 years, 185 female. 227 received treatment, 95 as CIS. After a mean follow-up of 12 years, 36 patients developed SPMS. Conversion to SPMS was associated with OCGB (p = 0.02), OCMB (p = 0.0001); ≥ 9 B-T2L (p = 0.03), brain-GEL (p = 0.03), and cSC-T2L (p = 0.03). However, after adjusting for sex, age, BT2L, brain-GEL, SC-T2, and OCMB status, only OCMB (HR 4.4, 1.9–10.6) and cSC-T2L (HR 2.2, 1.0–6.2) suggested an independent association with risk of conversion to SPMS. Patients with both risk factors had a HR of 6.12 (2.8–12.9).

Discussion

OCMB and SC-T2 lesions are potential independent predictors of conversion to SPMS.

Visual imaging as a predictor of neurodegeneration in experimental autoimmune demyelination and multiple sclerosis

Thalamic volume is associated with clinical disability in multiple sclerosis (MS) and is vulnerable to secondary neurodegeneration due to its extensive connectivity throughout the central nervous system (CNS). Using a model of autoimmune demyelination that exhibits CNS-infiltrating immune cells in both spinal cord white matter and optic nerve, we sought to evaluate neurodegenerative changes due to lesions affecting the spino- and retino-thalamic pathways. We found comparable axonal loss in spinal cord white matter and optic nerve during the acute phase of disease consistent with synaptic loss, but not neuronal cell body loss in the thalamic nuclei that receive input from these discrete pathways. Loss of spinal cord neurons or retinal ganglion cells retrograde to their respective axons was not observed until the chronic phase of disease, where optical coherence tomography (OCT) documented reduced inner retinal thickness. In patients with relapsing-remitting MS without a history of optic neuritis, OCT measures of inner retinal volume correlated with retino-thalamic (lateral geniculate nucleus) and spino-thalamic (ventral posterior nucleus) volume as well as neuroperformance measures. These data suggest retinal imaging may serve as an important noninvasive predictor of neurodegeneration in MS.

Multiple sclerosis lesions and atrophy in the spinal cord: Distribution across vertebral levels and correlation with disability

BACKGROUND

The vast majority of magnetic resonance imaging (MRI) studies on multiple sclerosis (MS) covered the spinal cord (SC), if at all, incompletely.

OBJECTIVE

To assess SC involvement in MS, as detectable by whole SC MRI, with regard to distribution across vertebral levels and relation to clinical phenotypes and disability.

METHODS

We investigated SC MRI with sagittal and axial coverage. Analyzed were brain and SC MRI scans of 17 healthy controls (HC) and of 370 patients with either clinically isolated syndrome (CIS, 27), relapsing remitting MS (RRMS, 303) or progressive MS (PMS, 40). Across vertebral levels, cross-sectional areas were semiautomatically segmented, and lesions manually delineated.

RESULTS

The frequency of SC lesions was highest at the level C3-4. The volume of SC lesions increased from CIS to RRMS, and from RRMS to PMS whereas lesion distribution across SC levels did not differ. SC atrophy was demonstrated in RRMS and, to a higher degree, in PMS; apart from an accentuation at the level C3-4, it was evenly distributed across SC levels. SC lesions and atrophy volume were not correlated with each other and were independently associated with disability.

CONCLUSION

SC lesions and atrophy already exist at the stage of RRMS in the whole SC with an accentuation in the cervical enlargement; SC lesions and atrophy are more pronounced in the stage of PMS. Both contribute to the clinical picture but are largely independent.

Comparison of MRI Lesion Evolution in Different Central Nervous System Demyelinating Disorders

BACKGROUND AND OBJECTIVE

There are few studies that compare lesion evolution across different CNS demyelinating diseases, yet knowledge of this may be important for diagnosis and understanding differences in disease pathogenesis. We sought to compare MRI T2-lesion evolution in myelin-oligodendrocyte-glycoprotein-IgG-associated disorder (MOGAD), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG-NMOSD), and multiple sclerosis (MS).

METHODS

In this descriptive study, we retrospectively identified Mayo Clinic patients with MOGAD, AQP4-IgG-NMOSD, or MS and: 1) brain or myelitis attack; 2) available attack MRI within 6 weeks; and 3) follow-up MRI beyond 6 months without interval relapses in that region. Two neurologists identified the symptomatic or largest T2-lesion for each patient (index lesion). MRIs were then independently reviewed by two neuroradiologists blinded to diagnosis to determine resolution of T2-lesions by consensus. The index T2-lesion area was manually outlined acutely and at follow-up to assess variation in size.

RESULTS

We included 156 patients (MOGAD, 38; AQP4-IgG-NMOSD, 51; MS, 67) with 172 attacks (brain, 81; myelitis, 91). The age (median [range]) differed between MOGAD (25 [2-74]), AQP4-IgG-NMOSD (53 [10-78]) and MS (37 [16-61]) (p<0.01) and female sex predominated in the AQP4-IgG-NMOSD (41/51 [80%]) and MS (51/67 [76%]) groups but not among those with MOGAD (17/38 [45%]). Complete resolution of the index T2-lesion was more frequent in MOGAD (brain, 13/18[72%]; spine, 22/28[79%]) than AQP4-IgG-NMOSD (brain, 3/21[14%]; spine, 0/34[0%]) and MS (brain, 7/42[17%]; spine, 0/29[0%]), p<0.001. Resolution of all T2-Lesions occurred most often in MOGAD (brain, 7/18[39%]; spine, 22/28[79%]) than AQP4-IgG-NMOSD (brain, 2/21[10%]; spine, 0/34[0%]), and MS (brain, 2/42[5%]; spine, 0/29[0%]), p< 0.01. There was a larger median (range) reduction in T2-lesion area in mm² on follow-up axial brain MRI with MOGAD (213[55-873]) than AQP4-IgG-NMOSD (104[0.7-597]) (p=0.02) and MS, 36[0-506]) (p< 0.001) and the reductions in size on sagittal spine MRI follow-up in MOGAD (262[0-888]) and AQP4-IgG-NMOSD (309[0-1885]) were similar (p=0.4) and greater than MS (23[0-152]) (p<0.001).

CONCLUSIONS

The MRI T2-lesions in MOGAD resolve completely more often than AQP4-IgG-NMOSD and MS. This has implications for diagnosis, monitoring disease activity, and clinical trial design, while also providing insight into pathogenesis of central nervous system demyelinating diseases.