Background

To predict the clinical course of myelin oligodendrocyte glycoprotein (MOG)-antibody (Ab)-associated disease (MOGAD) is essential to guide treatment recommendations.

Objectives

We aimed to 1) compare clinical features and disease course, and 2) to evaluate the association of MOG-Ab dynamics and relapses, between children and adults with MOGAD.

Methods

Retrospective study evaluating clinical features of 98 children and 266 adults with MOGAD, between January 2014 and September 2019. To analyse relapses over the whole disease course, a Cox regression analysis for recurrent time-to-event data was performed, introducing treatment as time-dependent covariate. To evaluate dynamics, delta mean fluorescence intensity ratio signal (ΔMFIratio) of MOG-Ab was measured in patients with a minimum time elapsed between two samples of 4 months.

Results

Median age at onset of symptoms was 10.9 (interquartile range 5.4-14.3) years in children and 36.2 (27.7-47.6) in adults. Isolated optic neuritis was the most frequent clinical presentation both in children (40.8%) and adults (55.9%), p=0.013, and acute disseminated encephalomyelitis syndrome was more frequent in children (36.7% vs. 5.6%; p<0.001). Compared to adults, children displayed a better recovery (EDSS ≥3.0 at last follow-up reached only by 10 of 97 [10.3%] vs. 66/247 [26.7%], p<0.001).

In the multivariate analysis, adults were at higher risk of relapse than children (Hazard ratio 1.41, 95%Confidence interval [CI] 1.12-1.78; p=0.003). Among the 124 participants evaluated for MOG-Ab dynamics, 36.3% became seronegative, 60.5% decrease and 3.2% increase the ΔMFIratio. At two years, 64.2% (95%CI 40.9-86.5) of non-relapsing children became MOG-Ab negative compared to 14.1% (95%CI 4.7-38.3) of relapsing ones, log-rank p<0.001, with no differences observed between non-relapsing and relapsing adults, log-rank p=0.280.

Conclusions

MOGAD differs in its clinical presentation at onset, showing a progressive shift in the clinical features across age-groups. Compared to children, adults have a higher risk of relapses and a worse functional recovery. Finally, children with monophasic disease became MOG-Ab negative earlier than relapsing ones, but not in adults. Considering these differences, management and treatment guidelines should be considered independently in children and adults.

Background

Multiple sclerosis (MS) is a chronic, immune-mediated demyelinating disease of the central nervous system. Up to 90% of MS patients have spinal cord hyperintensities seen on MRI. The spinal cord is one of four anatomical locations integrated into the 2017 McDonald diagnostic criteria, allowing spatial dissemination.

Objectives

The main objective of this study is to describe a group of MS patients with disappearing of initial spinal cord lesions.

Methods

We performed a retrospective study of MS patients followed in Montpellier University Hospital between 2015 and 2019. All the patients with an acute partial transverse myelitis and no spinal cord lesion identified on follow­-up MRI were recorded. MRI sequences were: Sagittal T1 TSE; Sagittal T1 TSE gado; Sagittal T2; Sagittal T2 TSE; T2 AX; Sagittal T2 STIR.

Results

Among 2700 MS patients, 8 cases had initial spinal cord lesions, not found on serial MRI. Clinical features of these patients were: sex ratio F/M – 4:1; mean age of onset 32,8 (±17,3) years. At last clinical evaluation (duration of follow-up: 60,7 ±55,3 months) mean EDSS was 0.75 (±0,89). All the patients had cervical or dorsal acute partial transverse myelitis with dorsal and lateral localizations. On the control MRI, spinal cord hyperintensities were no longer present using sagittal and axial STIR and T2 sequences.

Conclusions

This study shows that spinal cord lesions can disappear over time. These features could be explained by transient demyelination, oedema without any demyelination. Since MR sequences were identical in all MS patients, false negative could be unlikely.