multiple sclreosis

1. Dr. Sunil Kumar Sharma
Senior Resident
Dept. of Neurology
GMC Kota

2. Introduction
⚫Demyelinating diseases comprise of diseases of central
and peripheral nervous system in which disruption of
myelin is a dominant feature.
⚫Diseases affecting central nervous system (CNS) myelin
can be classified on the basis of whether a primary
biochemical abnormality of myelin exists(dysmyelinating)
or whether some other process damages the myelin or
oligodendroglial cells (demyelinating).

3. • Cell Body
• Dendrites
• Axons
– Presynaptic
terminals
– Bundles of
axons form
nerves

4. Myelin sheath
⚫Gray matter primarily contains neurons and their
processes & the white matter is composed
predominantly of myelinated bundles of axons
⚫The oligodendroglial cell membrane is the source of
the myelin sheath, which is a tightly wrapped,
multilayered membrane which ensheathes axons

5. Myelin sheath
Cholesterol, galactocerebroside,
sphingomyelin, and phospholipids
are the lipids found in fully formed
white matter and account for the
stability and strength . Transmission electron micrograph of
a myelinated axon, myelin sheath,
which is a tightly wrapped,
multilayered membrane

6. Classification of diseases of
myelin

8. Acute disseminated
encephalomyelitis (ADEM)
⚫Best diagnostic clue: Multifocal WM/basal ganglia
lesions 7-14 days following infection/vaccination
⚫Location: May involve both brain and spinal cord;
predominantly WM but alsogray matter (GM)

9. MRI Findings
⚫T2WI: T2 abnormalities betterseen with FLAIR
FLAIR
⚫Multifocal punctate to large flocculent FLAIR
hyperintensities
⚫Bilateral butasymmetric Involveperipheral WM/GM
junction
⚫Can involve brain stemand posteriorfossa
⚫Do not usually involve callososeptal interface
⚫Tumefactive, mass-like lesions possible, yetwith less
masseffect than expected forsize

10. ADEM…
DWI
⚫Variably restricted diffusion in acute lesions
⚫Apparent diffusion coefficient (ADC): Increased In
ADEM Due to extracellular water within
demyelination

11. T1 C+
⚫Punctate, ring, incompletering, peripheral
enhancement
⚫Cranial nerve(s) mayenhance
MRS
⚫N-acetylaspartate (NAA) low within regions of
prolonged T2
⚫Other metabolites usually normal
Best imaging tool-Contrast-enhanced MRI

15. Acutedisseminated
encephalomyelitis.
A: SagittalT2-weighted image
demonstrates high signal
intensityof the majorityof
the spinal cord with mild
expansion in the
cervicothoracic region.
B: Axial T2-weighted image
of the cervical cord
demonstrates involvement of
both grayand white matter.

16. Inflammatory Demyelinating
Pseudotumor
⚫Clinical Features- Demyelinating diseases
occasionally present as solitary, focal, or ill-defined
space-occupying lesions in the brain that closely
mimica neoplasm both clinicallyand radiologically.
⚫These lesionscan be found in all age groups but
mostly in the third to fifth decades .
⚫The clinical features are similar to those of
postinfectious/postvaccinal encephalomyelitis, i.e. an
acute onset of symptoms and dramatic response to
steroids.

17. ⚫In contrast toclassic MS, there is no predilection for
the periventricularwhite matter, optic nerves, or
brainstem.
⚫If thediagnosisof demyelination is considered, biopsy
can perhaps be delayed and patients can be imaged
after treatment with steroids to look for regression of
MR findings

18. Inflammatory demyelinating
pseudotumor-
Axial FLAIR images demonstrate ill-
defined high signal intensity within
the right frontoparietal white matter
(A)and effacementof adjacentgyri
and extensionalong the lengthof the
corticospinal tract,
(B)the posterior limbof the internal
capsule, and
(C)the cerebral peduncle.
Postcontrastaxial T1-weighted image
(D)shows ill-defined minimal
enhancement. These findings mimic
theappearanceof a large infiltrative
neoplasm.
Biopsy confirmed the presenceof
demyelination.

19. Multiple sclerosis (MS)
MR Findings
TlWI
⚫Acute: Iso-/mildly hypointense
⚫Chronic: Hypointensecenter, hyperintense rim
⚫Variableatrophy; mostly lossof WM
T2WI
⚫High convexity "sand-like“( < 2 mm diameter) Virchow-
Robin spaces in recent-onset MS
⚫Hypointense basal ganglia 10-20% chronic MS

20. Multiple sclerosis (MS)…
FLAIR
⚫Bilateral, asymmetric linear/ovoid FLAIR
hyperintensities
⚫Perivenularextension; "Dawson finger“ Along path
of deep medullary veins
⚫Hyperintensities becomeconfluent with severity
DWI
⚫Acute lesions-Concentric ring pattern on
diffusion-weighted images with hyperintense rim

21. MS…
Tl C+
⚫Transient enhancement during active
demyelination (> 90% disappear within 6 months)
⚫Nodular (68%)
⚫Ring (23%)
⚫Semilunar, incomplete, "horseshoe-shaped" (9%)

22. MS…
MRS
⚫ NAA (NAA/Cr), Choline (Cho/Cr)
⚫MRS abnormalities found in NAWM
NAA in
⚫Only secondary progressive MS shows
normal appearing gray matter (NAGM)
⚫May allowearly distinction between relapsing-
remitting & secondary-progressive

23. MR diagnosis of MS requires
⚫ ≥3 discrete lesions ≥5 mm
⚫Lesions in characteristic location
⚫MS compatible clinical history
Nuclear Medicine Findings
⚫PET: Glucose utilization correlates with
NAA in lesions and NAWM
Imaging Recommendations
⚫Best imaging tool: MRI
⚫Protocol advice: Contrast-enhanced MR with
sagittal FLAIR

28. Extensivecervical spinal cord lesions with multiple
sclerosis.
A: Sagittal T2-weighted imageshows extensive irregular
high signal within thecord substance.
B: Axial T2-weighted imageshows the typical peripheral
location of the multiplesclerosis plaque.

29. C: A patientwith multiplesclerosis shows an ill-defined lesion on
T2-weighted imageextending from thedorsal medulla to C2.
D: Postcontrast T1-weighted imagedemonstrates minimal
peripheral enhancement.

30. Differential Diagnoses for MS
ADEM
⚫Viral prodrome, monophasic illness
⚫Assymetrical
⚫CC not involved
Autoimmune-mediated Vasculitis
⚫Enhancing lesions spare callososeptal interface
⚫"Beaded" angiogram appearance

31. Lyme disease
⚫Can be identical to MS (skin rash common)
Susacsyndrome
⚫Clinical presentation, course different from MS
⚫Classic triad of Encephalopathy ,Branch retinal
artery occlusions & Hearing loss.
⚫Self-limited (2-4 yduration, then stabilizes),
⚫Monophasic
⚫Multifocal supratentorial WM lesions
⚫Always involves CC

32. DDs. Of MS

33. Acute hemorrhagic
leukoencephalitis (Hurst disease)
⚫Acute hemorrhagic leukoencephalitis (Hurst disease)
is considered a hyperacuteor fulminant form of ADEM
⚫
⚫This entity is typicallyseen in young
⚫Patients havean abruptonsetof fever, neck stiffness,
and progressive neurologic deficits often leading to
comaand death within 1 to 5 days.

34. Acute hemorrhagic
leukoencephalitis (Hurst disease)…
⚫reported afterviral respiratory infections, sepsis,
ulcerativecolitisand asthma, and as a manifestationof
drug toxicity .
⚫CSF -elevationof IgG and the presenceof MBP.
⚫clinical recoveryare reported after theadministration
of high-dose steroids

35. Acute hemorrhagic
leukoencephalitis (Hurst disease)
Extensive abnormal signal
involving the
supraventricular white matter
is present, with acute
hemorrhage presentas foci of
marked hypointensity within
thewhite matter lesions.

36. PML
⚫PML is caused by reactivation of a latent infection bya
papovavirus (JC virus).
⚫Mostcasesof PML todayoccuras a complicationof AIDS,
and approx. 5% of all patients with AIDS ultimately
develop PML
⚫The non-AIDS population typically harborsan underlying
disease affecting immunocompetence, such as leukemia,
lymphoma, sarcoidosis, tuberculosis, or malignancy, or
has received immunosuppressivetherapy

37. PML…

38. HIV encephalopathy
⚫HIV encephalopathy, also known as AIDS dementia
complex, HIV dementia, and hiv-associated dementia
complex is a progressivedementing illnessof AIDS.
⚫Occurs in patientswith advanced immunosuppression.
⚫The mostcommon finding on imaging is atrophyof the
brain.

39. HIV encephalopathy…
⚫In earlystagesof thedisease, small areas of high signal
intensityare seen on the t2-weighted sequences in the
periventricularwhite matterthat lack masseffector
edema
⚫Bilateral symmetric increased signal intensityon the
T2-weighted sequences has been described in the
basal ganglia (caudate and putamen) and thalamus
and mayalso involve the brainstem

40. Human immunodeficiency
virus encephalopathy in a
patient with acquired
immunodeficiency
syndrome showing diffuse
white matter involvement.
A–D: FLAIR images
progressing inferiorly to
superiorly demonstrate
diffuse white mattersignal
abnormality.

41. Human immunodeficiencyvirusencephalopathywith
characteristic involvement of the basal ganglia.
A: Axial FLAIR imagedemonstrates bilateral symmetric
increased signal intensitywithin the basal gangliaand external
capsules.
B: Axial postcontrast T1-weighted imagedemonstrates no
evidence of enhancement.

42. Neuromyelitis Optica
⚫Neuromyelitis optica (Devic type) is a syndrome of
acute onset of optic neuritis and transverse myelitis
(LETM) thatdevelopatapproximately the same time
⚫ Classically, NMO patients have relapsesconsisting of
optic neuritisand myelitis
⚫The targetof the NMO antibody is the Aquaporin-4
(AQP4).

44. Central Pontine and Extrapontine
Myelinolysis (Osmotic Demyelination)
⚫Central pontine myelinolysis describes demyelination
usually isolated to the central pons; however,
extrapontine sitesof demyelination are not uncommon.
⚫It is commonly found in association with alcoholism,
chronic nutritional deficiency, and manyothersystemic
disorders with electrolyte abnormalities including
chronic pulmonary disease, liver and kidney diseases,
diabetes mellitus, livertransplant, and neoplasia.

45. ⚫The term “osmoticdemyelination syndrome” has been
proposed because of the common association with
rapidlycorrected hyponatremia.
⚫The symptomsof central pontine myelinolysis include
spastic quadriparesis, pseudobulbar palsy, changing
levelsof consciousness, and coma .
⚫A significant proportion of patients progress todeath,
which may be preceded by a state of pseudocoma
(locked-in syndrome).

46. Central pontine myelinolysis.
A: T2-weighted axial imageshows characteristic high signal
intensity within the midpons, with a surrounding rim of
normal-appearing pontine parenchyma and sparing of the
corticospinal tracts.
B: Sagittal T1-weighted imagedemonstrates a low-signal lesion
within the pons.

48. Marchiafava-Bignami Disease
⚫Marchiafava-Bignami disease is a rare condition in
whichdemyelination and necrosis primarily affect the
corpus callosum and sometimes also involve
extracallosal regions.
⚫It is almost exclusively found in male alcoholics and
was originally described in Italian people who drank
red wine .
⚫In more recent years, it has been described in poorly
nourished nondrinkers

49. Marchiafava-Bignami Disease…
Sagittal T1-weighted image
(A) demonstrates small
areas of low signal intensity
in the genu, body, and
splenium of the CC

50. Subacute Combined Degeneration
of the Spinal Cord
⚫Vitamin B12 (cobalamin) deficiency mayaffect the CNS
or peripheral nervous system but most commonly
involvesthespinal cord.
⚫ Subacutecombined degeneration (SCD) refers to
vitamin B12 deficiency with demyelination and
vacuolation found in the posteriorand lateral columns
of the spinal cord

51. Subacutecombined degeneration of thespinal cord
(B12 deficiency).
A: Sagittal T2-weighted image demonstrates a long
segmentof high signal intensitywithin thedorsal aspect
of thecervical spinal cord.
B: Axial T2-weighted imageshows high signal intensity
within thedorsal columns.

52. Hypertensive Encephalopathy (Reversible
Posterior Leukoencephalopathy)
⚫Hypertensiveencephalopathy is aclinical entity that it is
important to recognize early because the clinical and
imaging findings are usuallyreversible.
⚫Acuteelevationof blood pressure (several hours todays
before the onset of symptoms) is the most common
precipitant
⚫The syndrome can also be seen with renal
decompensation, preeclampsia/eclampsia, fluid retention,
and treatmentwith immunosuppressivedrugs .
⚫Cyclosporine ,tacrolimus, FK506, L-asparaginase,
cisplatin, and mouse monoclonal antibody (OKT3)

54. Thank You

55. References
⚫Magnetic Resonance Imaging of the Brain and Spine,
4th ed, 2009, ScottW. Atlas
⚫Bradley ; neurology in clinical practice 7’thedition
⚫Osborn Diagnostic Imaging Brain 2004