imaging in neurology - demyelinating diseases

DR. Rahi Kiran.B
SR Neurology
GMC, KOTA

1. IMAGING IN NEUROLOGY DEMYELINATING DISEASES Dr. Rahi Kiran.B DM Resident Dept. of Neurology GMC Kota

2. Normal myelination does not reach maturity until 2 years  myelination progresses from central to peripheral caudal to rostral dorsal to ventral sensory then motor As myelination progresses myelin deposition causes an increase in T1 signal that completes at 1 year of age - adult T1 myelination pattern Between 1-2 years of age the drawing out of water from myelinating areas results in a decrease in T2 signal - adult myelination pattern achieved by 3 years

3. A D B E F C

4. Multiple Sclerosis A - FLAIR best for periventricular and juxtacortical lesions. B - T2 images are often best for viewing infratentorial lesions. C- Homogenous uptake of contrast. D - Black hole sign On MRI T1W E- dawsons fingers F- Open-ring pattern, specific for demyelinating lesions.

5. Multiple Sclerosis

6. Multiple Sclerosis Over 95% CDMS have positive findings on MRI linear, round, or ovoid lesions surrounding the medullary veins that radiate centripetally away from the lateral ventricles One of the earliest findings is alternating areas of linear hyperintensity along the ependyma on sagittal FLAIR - " ependymal 'dot-dash'" sign Spinal cord lesions can be found in 50% to 90% of CDMS The most common site - cervical cord. Typical MS lesions – do not extend beyond 2 vertebral segments, tend to involve the posterior and lateral regions, occupy less than half the area of the cord on axial images. triangle-shaped hyperintensities . at the callososeptal interface and a "dot-dash" appearance . along the ventricle.

7. multiple foci of punctate and ring enhancement in the cerebral white matter. Note "target" appearance Before steroids after steroids

8. " Tumefactive " MS. T1WI – large hypointense lesions in both cerebral Hemispheres with significant perilesional edema T2WI-very hyperintense and surrounded by a thin hypointense rim and perilesional edema Hypointense rims of the lesion show striking but Incomplete ring enhancement DWI shows that the enhancing rims restrict moderately Rims demonstrate low ADC values The presence of T2 hypointense rim and open-ring enhancement are potentially suggestive of demyelination .

9. MS: DIFFERENTIAL DIAGNOSIS MULTIFOCAL T2/FLAIR HYPERINTENSITIES ADEM-history of viral prodrome or recent vaccination Hypoxic-ischemic lesions- small-vessel disorders- cortical infarcts, border zone, or watershed lesions, lacunes Lyme disease-Cranial nerve enhancement is more common than in MS. Vascular-preferentially involves the basal ganglia and spares the callososeptal interface Susac syndrome-preferentially involve the middle of the corpus callosum , not the callososeptal interface. MASS-LIKE ("TUMEFACTIVE") LESION(S) Neoplasm ○ Glioblastoma multiforme ○ Metastases • PML/PML-IRIS ○ HIV/AIDS ○ Natalizumab -treated MS • Medication-related- Enbrel

10. MS: DIFFERENTIAL DIAGNOSIS Brainstem - symmetrical and central peripheral

11. Multiple Sclerosis Variants-Marburg disease Axial FLAIR- Large heterogeneously hyperintense lesion in the right parietal WM with a smaller lesion on the left Axial T1 C+- multiple bilateral incomplete ring-enhancing lesions in the deep and periventricular WM. T1 C+ -through ventricles shows the necrotic, cavitating , acutely enhancing right parietal " tumefactive " mass Coronal T1C+ -shows extension around the left ventricle

12. Multiple Sclerosis Variants-Marburg disease acute, severe fulminant MS Multifocal > solitary disease ○ Characterized by coalescent white matter plaques - Brain , spinal cord Lesions characterized by massive inflammation, necrosis • diffusely disseminated disease ○ Large cavitating lesions ○ Incomplete ("open") enhancing rim ○ Multiple other patchy enhancing foci

13. monophasic with a low rate of recurrence Signs of increased ICP, aphasia, and behavioral symptoms are typical. CSF is usually normal no history to suggest acute disseminated encephalomyelitis (ADEM) Approximately 15% of cases progress to MS. Solitary unilateral masses are present in two-thirds Differential Diagnosis- Tumefactive " MS, Pyogenic abscess, neoplasm, metastasis and glioblastoma multiforme . Multiple Sclerosis Variants- Schilder Disease

14. Multiple Sclerosis Variants- Balo Concentric Sclerosis Acute lesions- hyperintense on FLAIR, restrict on DWI, show concentric "onion bulb" enhancement Follow-up scans show alternating rings of iso - and hyperintensity on T1 and T2WI, no enhancement

15. • Concentric rings of demyelination /myelin preservation ○ Resemble tree trunk or onion bulb ○ Solitary > multifocal • "Whirlpool" hyperintense concentric rings on T2WI ○ Minimal mass effect, edema • Actively demyelinating layers enhance Multiple Sclerosis Variants- Balo Concentric Sclerosis

16. Chronic Relapsing Inflammatory Optic Neuropathy (CRION) Young middle age female with recurrent sequential optic neuritis(Steroid responsive) T2 - high-signal intensity foci - left optic nerve T1C+ enhancement DWI - expanded left optic nerve with bright signal

17. Chronic Relapsing Inflammatory Optic Neuropathy (CRION) Relapsing ON without known involvement in other areas of the CNS. unilateral relapsing optic neuritis, sequential relapses of both optic nerves, and simultaneous, bilateral optic neuritis. Characteristic features – Middle age female history of optic neuritis with at least one relapse, objective loss of visual function NMO IgG negative contrast enhancement of the affected optic nerve on MRI Response to steroid treatment followed by relapse with dose reduction Compared to inflammatory ON – Severity less, response more

18. ADEM FLAIR-bilateral white matter lesions with a "fluffy" appearance and "fuzzy" margins T1 C+ -enhance intensely but heterogeneously DWI shows acute diffusion restriction in the lesions

19. ADEM numerous, large, same stage , include white(asymmetric)  and gray matter (symmetric-thalamus and basal ganglia ),do not always show gadolinium enhancement, also show good resolution compared with MS lesions. Spinal cord lesions 10-30% >50%

20. Acute Hemorrhagic Leukoencephalitis Axial FLAIR- splenium and genu of the corpus Callosum , bifrontal focal hemispheric white matter lesions , subtle confluent hyperintensity in the occipital subcortical white matter DWI shows restricted diffusion in the corpus callosum splenium GRE - punctate hypointensities in the corpus callosum with subtle "blooming" in the subcortical WM SWI-Innumerable bilaterally symmetric punctate and linear "blooming" hypointensities are seen throughout the WM with striking sparing of cortical gray matter.

21. Mortality is 60-80%.

22. Petechial microhemorrhages similar to those seen in AHLE Diffuse vascular injury, disseminated intravascular coagulopathy , Fat emboli, thrombotic thrombocytopenic purpura , sepsis, vasculitis , hemorrhagic viral fevers, malaria, and rickettsial diseases.

23. A-Axial T2 WI - showing swelling and bright T2 B- Axial CE MRI -no evident post-contrast enhancement. C- Axial - DWI ADC -bilateral symmetrical parenchymal areas of bright signal in DWI and low values in ADC

24. acute necrotizing encephalopathy (ANE) young children, is often associated with influenza, results from a para - or postinfectious cytokine storm. Strikingly symmetric thalamic necrosis with bilateral T2/FLAIR hyperintensities and bithalamic hemorrhages is common

25. T2 FLAIR- medulla, hypothalamus,optic chiasma , midbrain, internal capsule, periventricular white matter, corpus callosum , T2 hyperintense C1-5 with patchy enhance ment Neuromyelitis Optica Spectrum Disorder

26. Neuromyelitis Optica Spectrum Disorder NMO- IgG , is 90% specific and 70-75% sensitive .. 10-25% of NMOSD patients are seronegative -The F:M ratio - 1:1 one or both optic nerves are involved together with the spinal cord- most commonly cervical Brain - cluster around the third and fourth ventricles and the dorsal midbrain/aqueduct of Sylvius . 15-20% of patients with NMOSD are over age 60 at onset (85- 90%) are relapsing, 30% of NMOSD are initially misdiagnosed with MS. NMO- IgG seropositivity is detected in 3-5% of patients with CIS brain is more involved in MS, whereas multisegmental contiguous spinal cord disease is typical of NMOSD

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28. MS- multiple lesions most often the cervical cord usually less than 2 vertebral segments relatively small and peripherally located NMO- more than 3 vertebral segments swelling of the cord. often involve most of the cord.

29. Susac Syndrome T2WI - hyperintense foci, the middle of the corpus callosum genu and thalamus Axial T1 C+ shows that the corpus callosum genu lesion enhances. Enhancing lesions in the left temporal lobe, left thalamus,pons

30. Susac Syndrome SICRET (Small Infarcts of Cochlear, Retinal, and Encephalic Tissue)

31. CLIPPERS Sagittal FLAIR - multiple punctate hyperintensities "peppering" the pons , Medulla extending into the upper cervical spinal cord T1 C+ - punctate and curvilinear foci of enhancement, extension into the cerebellum and superior cerebellar peduncle DWI - scattered foci of restricted diffusion Axial T2 SWI shows multiple hemorrhagic foci in the pons .

32. CLIPPERS C hronic L ymphocytic I nflammation with P ontine P erivascular E nhancement R esponsive to S teroids. onset is is 40-50 years, minor male predominance subacute brainstem symptoms such as gait ataxia, diplopia , facial paresthesias , and nystagmus differential diagnosis - autoimmune encephalitis , Bickerstaff brainstem encephalitis , vasculitis , intravascular lymphoma , lymphomatoid granulomatosis , neuro - Behçet , neurosarcoidosis , CNS histiocytosis , multiple sclerosis, and NMOSD. Dramatic response to glucocorticosteroids (GCSs) supports relapses are common therapy failure is a strong indication for an alternative diagnosis.

33. Osmotic demyelination syndrome T1 C+ ( Gd ): no enhancement trident shaped appearance FLAIR:  hyperintense DWI:  hyperintense

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