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

The Imaging of Multiple Sclerosis* Utility of MRI* Differential of White Matter Lesions* Future direction of neuroradiology

Jessica Floyd, M4

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

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

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

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

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

WHAT DOES IT LOOK LIKE?

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

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

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

T2 Lesions- FLAIR

Dawson’s Fingers- Sagital FLAIR

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

T2 lesions & T1 Holes

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

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’s Dz Typically unilateral Inflammatory edema temporary cord

expansion Ddx- Tumor (bx)

Gadolinum enhancment with active BBBB Post mortem path studies show greater

demyelination than assumed with conventional t2 imaging

35 yo female- acute onset Quadriparesis

Spinal Lesions- Gad-enhancement

Brain Atrophy

Significant Clinical Implications Correlates with clinical disability Predictive of later progressive

disability Many standard therapies slow

progression of atrophy over time

Callosal Atrophy

Diagnosis

Ensuring MS is of high suspicion, consider prevalence and a priori probability

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

Normal Aging & Fazeka’s

Virchow Robin Spaces

Vascular vs Multiple Sclerosis

Vascular disease vs Multiple Sclerosis

66 yo Male T2 HyperintensitiesNone being OvoidFew Periventricular LesionsNo Juxtacortical lesions

Vascular vs. Multiple Sclerosis

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

Diagnostic Criteria

Dissemination in TIME- 3 months

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

42 yo woman with MS, no Sx

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

Diffusion Tensor Imaging

Diffusion Tensor Imaging

o3-D water diffusion oMean Diffusivity- overall diffusionoFractional anisotropy- amount of elongatedness of diffusionoColorized primary eigenvector maps- illustrate different directions of the primary fiber tracto RED = L-Ro GREEN = Up-Downo BLUE = In-Out of page

Gad- enhancement T1 & T2

Dawson’s fingers – T1 & T2

FLAIR & T-1 black hole

Confluent Lesions & Atrophy

Progressive Multifocal Leukoencephalopathy

Sarcoidosis

Acute Disseminated Encephalomyelitis