Palmetto Health Richland August 2008

1. Palmetto Health Richland August 2008 • 35 yo AAF presents with confusion, agnosia, apraxia, right-sided lower extremity paresis • Symptoms first noticed 2 hours ago • CT scan- no blood • MRI- single hyperintense lesion in the left periventricular white matter • Started IV steroids, ran a panel of CSF & blood studies • 3 days later- Symptoms resolved • Diagnosed with Multiple Sclerosis

2. Jessica Floyd, M4 The Imaging of Multiple Sclerosis* Utility of MRI * Differential of White Matter Lesions* Future direction of neuroradiology

3. What is Multiple Sclerosis? • Chronic Inflammatory demyelinating disease of the CNS • 2nd-3rd decade of life (“belongs to the climax of life”) • 2:1 Female predominance • 250-350,000 people with MS in the US • Cyclical inflammatory reactions followed by remission of symptoms and variable recovery • Relapsing-Remitting- 80% • Primary Progressive- 20%; closer incidence M:F • Secondary Progressive

4. Charcot’s description • First described by Charcot in 1835 • Patient history, physical exam, autopsy • Salpetriere (1865)  to the United States • Blood vessel at the center of each lesion • Preserved axis cyllinder • Atrophy of the medullary sheath • Types: • Cephalic • Spinal • Mixed: cerebrospinal

5. Broad Symptom Complex • Sensory disturbances • Unilateral optic neuritis • Diplopia- Internuclearopthalmoplegia • Nystagmus • Lhermitte’s sign • Limb weakness • Clumsiness • Gait ataxia • Neurogenic bladder • Bowel symptoms

6. Symptoms • Fatigue • Worse in the afternoon • Physiologic increases in temperature • Post Partum worsening of Symptoms ~ 4wk • Uhthoff’s symptom- hot shower, hot bath • Pseudoexacerbations with fever

7. Symptoms • Highly suggestive of MS: • Paroxysmal pain, paresthesias • Trigeminal neuralgia • Episodic clumsiness, nysarthria • Tonic limb posturing • Less common: • Prominent cortical signs • Aphasia, apraxia, recurrent seizures, visual field loss, early dementia • Extrapyramidal phenomena • Chorea, rigidity

8. WHAT DOES IT LOOK LIKE?

9. Brain Lesions • Most sensitive modality is MRI • Sensitive to inflammation • Sensitive to demyelination • CT is a poor tool unless very severe destruction • Callosal atrophy • Whole brain atrophy

10. T2 Lesions • Inflammation (water) & Demyelination (loss of fat)  Hyperintensities on T2 weighted images • Confirm with FLAIR images • Round, Ovoid • Vary in size. Few mm Few cm • Periventricular region, corpus callosum • Perivascular distribution, penetrating venules • Dawson’s fingers • Juxtacortical Lesions, U-fibers

11. T2 Lesions • Temporal Lobe • Brainstem- peripherally • Deep Gray Matter- BG, Thalamus (LC) • Cerebellum • Spinal Cord • Recurrent Lesions in Same Area CONFLUENT lesions • MC anterior & posterior to lateral ventricle • Vasogenic edema = “fuzzy extension” of T2 signal • LARGE DIFFERENTIAL FOR T2 Hyperintensities

12. T2 Lesions- FLAIR

13. Dawson’s Fingers- Sagital FLAIR

14. T1 Holes • SEVERE Tissue Injury  T1 dark signals • Rarely seen in the spinal cord or post fossa • Stronger correlation with demyelination & axonal loss than T2 hyperintensities • Evolution of enhancing lesions  T1 Holes associated with more progressive disease

15. T2 lesions & T1 Holes

16. Gadolinium-Enhancing Lesions • Indicates breakdown of the blood-brain barrier • Very active inflammation • Pattern of enhancement • Homogenous • Ring reactivation of an old lesion • Heterogeneous • Enhancement duration varies- days, weeks • 5% pts have >3 months of single lesion enhancement

18. Spinal Cord Lesions • Round, Ovoid on T2 • Limited to 1-2 spinal cord segments • 80% involve half of cord cross sectional area • Ddx- ITM, Devic’sDz • Typically unilateral • Inflammatory edema temporary cord expansion • Ddx- Tumor (bx) • Gadolinumenhancment with active BBBB • Post mortem path studies show greater demyelination than assumed with conventional t2 imaging

19. 35 yo female- acute onset Quadriparesis

20. Spinal Lesions- Gad-enhancement

21. Brain Atrophy • Significant Clinical Implications • Correlates with clinical disability • Predictive of later progressive disability • Many standard therapies slow progression of atrophy over time

22. Callosal Atrophy

23. Diagnosis • Ensuring MS is of high suspicion, consider prevalence and a priori probability

25. How suspicious are you? • Imaging is only one part of the story, clinical picture • Incidental Finding versus Manifesting Clinically • Normal Aging or Virchow Robin Spaces • Vascular disease • Infarction • Multi-infarct Dementia • Hypertensive encephalopathy • Sarcoidosis- ACE level, pulmonary Sx, CXR • SLE- discoid/malar rash, other organ involvment • Lyme Disease- CN7 palsy, rash, influenza-like illness • HIV- test, immunocompromised • Progressive Multifocal Leukoencephalopathy- immunocompromised • Largest differential concerns Vascular versus MS

26. Normal Aging & Fazeka’s

27. Virchow Robin Spaces

28. Vascular vs Multiple Sclerosis

29. Vascular disease vs Multiple Sclerosis 66 yo Male T2 Hyperintensities None being Ovoid Few Periventricular Lesions No Juxtacortical lesions

30. Vascular vs. Multiple Sclerosis

31. Criteria for Diagnosis of MS • Since MRI revolutionized the diagnosis of MS, needed specific criteria • Crux of the Dx is demonstrating attacks of neurologic dysfunction are separated in space and time • Clinical criteria* pt hx, PE findings, • Laboratory Criteria* oligoclonal bands, IgG index • MRI * 2001 McDonald Criteria, 2005 revised

34. Diagnostic Criteria

35. Dissemination in TIME- 3 months

36. One episode, treat or not to treat? • Cannot diagnose MS on MRI alone- need the clinical exam & history • However, MRI can now show us what even a vigorous clinical exam cannot • Revolutionizing treatment treat earlier • Mild cognitive deficits discovered earlier

37. 42 yo woman with MS, no Sx

38. Coming in the future… • MR Spectroscopy- N-acetyl aspartate, Lactate • Diffusion Tensor Imaging • Able to pick up on lesions not yet detectable on MRI • Ability to give you information on precisely how damaged the lesion is compared to other lesions

39. Diffusion Tensor Imaging

40. Diffusion Tensor Imaging • 3-D water diffusion • Mean Diffusivity- overall diffusion • Fractional anisotropy- amount of elongatedness of diffusion • Colorized primary eigenvector maps- illustrate different directions of the primary fiber tract • RED = L-R • GREEN = Up-Down • BLUE = In-Out of page

41. Gad- enhancement T1 & T2

42. Dawson’s fingers – T1 & T2

43. FLAIR & T-1 black hole

44. Confluent Lesions & Atrophy

45. Progressive Multifocal Leukoencephalopathy

46. Sarcoidosis

47. Acute Disseminated Encephalomyelitis