Magnetic resonance imaging at baseline and follow-up to differentiate between pediatric monophasic acquired CNS demyelination and MS
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Updated: Nov 26, 2025
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Magnus Spangsberg Boesen1, Morten Blinkenberg2, Alfred Peter Born3
1Department of Pediatrics, Rigshospitalet, University of Copenhagen, Denmark; Department of Neurology, Herlev Hospital, Denmark.
Background:
It is essential to distinguish acute disseminated encephalomyelitis (ADEM) from MS early. Our aim was to determine MRI features at baseline and follow-up to distinguish pediatric ADEM from MS stratified according to age at onset.
Methods:
Using hospital ICD-10 codes for acquired demyelinating syndromes from a nationwide register and subsequent chart review, we identified 52 children (<18 years) with ADEM and 66 children with MS. We undertook a retrospective analysis of MRI scans at onset and at follow-up. The MRI rater was a senior neuroradiologist blinded to clinical characteristics.
Results:
At baseline, children with ADEM had more diffuse poorly demarcated lesions, particularly in the basal ganglia/thalamus (p = 0.001) and cerebellar peduncles (p < 0.0001). Further, longitudinal extensive transverse myelitis was strongly associated with ADEM (p<0.0001). Children with ADEM had fewer contrast-enhancing lesions (p = 0.0004), occipital lesions (p = 0.01), optic nerve lesions (p = 0.01), periventricular lesions, well-defined lesions only (p<0.0001), and fewer fulfilled dissemination in time according to the McDonald 2017 criteria (p = 0.005). On baseline MRI, dissemination in space and time was fulfilled in 17% of children with ADEM and in 34% of children with MS (p = 0.06), and 60% of children with ADEM fulfilled the criterion for dissemination in space. The mean time from baseline MRI to follow-up MRI was 1.0 year for children with ADEM and 2.1 years for children with MS. On follow-up MRI, 85% of children with ADEM had partial or complete T2 lesion resolution, but in the 58% without complete resolution lesions were predominantly frontal. Only 47% of children with MS had partial or complete T2 lesion resolution, and therefore more MRI features differed between children with ADEM and MS on follow-up. MRI had the greatest distinguishing value after age 11 years because MS is exceptional in the first decade of life.
Conclusion:
Age at onset and the timing of MRI in relation to disease onset are critical in the interpretation of MRI to distinguish between ADEM and MS.
Insights
Differentiating acute disseminated encephalomyelitis (ADEM) from multiple sclerosis (MS) in children is crucial. MRI features at baseline and follow-up, along with age at onset, help distinguish these conditions.
Area of Science:
- Pediatric Neurology
- Neuroimaging
- Demyelinating Diseases
Background:
- Early differentiation between acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) is clinically essential in pediatric patients.
- Magnetic Resonance Imaging (MRI) plays a pivotal role in diagnosing and differentiating these neurological conditions.
- Age at onset is a significant factor influencing the presentation and diagnosis of demyelinating diseases in children.
Purpose of the Study:
- To identify specific MRI characteristics at baseline and follow-up that can reliably distinguish pediatric ADEM from MS.
- To stratify the diagnostic value of MRI findings based on the age of the child at disease onset.
Main Methods:
- Retrospective analysis of MRI scans from 52 children with ADEM and 66 children with MS, identified via a nationwide register.
- MRI interpretation was performed by a senior neuroradiologist blinded to clinical data.
- Scans were analyzed at disease onset (baseline) and during follow-up (mean 1.0 year for ADEM, 2.1 years for MS).
Main Results:
- Baseline MRI showed ADEM lesions were more diffuse, poorly demarcated, and prevalent in basal ganglia/thalamus and cerebellar peduncles compared to MS.
- Longitudinal extensive transverse myelitis was strongly associated with ADEM. ADEM cases had fewer contrast-enhancing lesions and occipital/optic nerve involvement.
- Follow-up MRI revealed significant T2 lesion resolution in ADEM (85%) versus MS (47%), with lesion location differing. MRI distinction improved after age 11.
Conclusions:
- MRI findings at baseline and follow-up, particularly lesion characteristics and evolution, are key to differentiating pediatric ADEM from MS.
- The timing of MRI relative to disease onset and the child's age are critical factors influencing diagnostic accuracy.
- Age-stratified analysis highlights that MRI is most valuable for distinguishing ADEM from MS after 11 years of age.
