This document compares and contrasts multiple sclerosis (MS) and acute disseminated encephalomyelitis (ADEM). It notes that MS is a relapsing demyelinating disease that typically affects adults aged 20-40 and presents with multiple ovoid lesions in characteristic areas like the corpus callosum and brainstem. In contrast, ADEM typically affects younger patients and presents with more diffuse, asymmetrical lesions that often involve the cortex and deep gray matter. While MS and ADEM can have similar presentations, ADEM lesions tend to be larger and enhancement is usually simultaneous, whereas MS often shows new non-enhancing lesions over time.

1. MS VS ADEM
• Maj Satyendra
• Ref
– BMJ
– Radiopaedia
– Radiologyassistant.nl
– 31 Aug 13

2. • Multiple sclerosis
relapsing demyelinating
disease
• disseminated in space
and time
• adolescence and sixth
decade, peak at 35
years
• monophasic
• acute inflammation and
demyelination
• 1-2 weeks after viral
infection or vaccination

4. • Plaques -ovoid in shape
and perivenular in
distribution.
• Typical for MS- corpus
callosum, U-fibers,
temporal lobes,
brainstem, cerebellum
and spinal cord.
• Coronal PD image of a
brain specimen with MS
involvement

5. • involvement of U-fibers
in MS.
• RIGHT: U-fibers are not involved
in patient with hypertension.
• Juxtacortical lesions are
specific for MS.
• adjacent to the cortex
and must touch the
cortex.

6. • Typical findings for MS
• Multiple lesions adjacent
to the ventricles (red
arrow).
• Ovoid lesions
perpendicular to the
ventricles (yellow arrow).
• Multiple lesions in
brainstem and
cerebellum.

7. • Typical spinal cord lesions
in MS are relatively small
and peripherally located.
• cervical cord
• less than 2 vertebral
segments
• A spinal cord lesion with
lesion in the cerebellum
or brainstem is very
suggestive of MS.

8. • Dawson fingers
• result of inflammation
around penetrating
venules.

9. • Enhancement is another
typical finding in MS.
• enhancement present
one month after the
occurrence of a lesion.
• Simultaneous enhancing
and non-enhancing
lesions -radiological
counterpart of the clinical
dissemination in time and
space.

10. • Juxtacortical lesions
• located in the U-fibers
are also very specific for
MS.

11. • dissemination in time.
• LEFT: Single lesion on
T2WI
• RIGHT: Two new lesions
at 3 month follow-up.

12. ADEM
• Diffuse and relatively
asymmetrical lesions
• enhance simultaneously
• preferential involvement of
the cortical gray matter and
the deep gray matter of the
basal ganglia and thalami.
• axial FLAIR and T2W-images of
a young patient with ADEM
• extensive involvement of the
cortical and gray matter,
thalamus.

13. • ADEM can involve the
spinal cord, U-fibers
and corpus callosum
and sometimes show
enhancement.
• lesions are often large
and in a younger age
group

14. • Grey matterof the basal
ganglia often involved

15. • Lesions are usually
bilateral but
asymmetrical.

16. OPEN RING
• sign for demyelination
• Ring component :
represent advancing
front of demyelination
• open part of the ring
usually point towards
the grey matter

17. ADEM
• Complete recovery
within one month (50-
60%)
• Sequelae (most
commonly seizures)
(20-30%)