Demyelinating Diseases

Question 1

Characteristic MRI findings in acute demyelinating lesions?

Answer 1

Open ring sign (enhancement feature)

Question 2

Multiple Sclerosis:
-Age
-Sex

Answer 2

-30-40 y/o
-slight Female predominance

Question 3

Multiple Sclerosis:
-Adjuvant therapy

Answer 3

Plasma exchange (PLEX)
-ring-enhancing lesions &/or mass effect associated with beneficial response to PLEX

Question 4

Balo Sclerosis:
-MR findings

Answer 4

Concentric globe appearance with alternating bands of myelin loss and preservation

*Diagnosis requires correlation with MRI

Question 5

MS - Relapsing Remitting:
-Clinical
-Histologic
-Ancillary

Answer 5

-Intermittent dysfunction and recovery; Progressive debility

-Plaques with inflammation, myelin loss and relative axonal sparing
*Inactive plaques lack macrophages

-CSF oligoclonal bands

Question 6

MS - Acute (Marburg Type):
-Clinical
-Histologic
-Ancillary

Answer 6

-Monophasic, rapidly progressive with marked disability

-Active inflammation, Edema, Astrocytosis, Myelin loss, Axonopathy

*Confluent and large areas of FLAIR and T2 hyperintensity

Question 7

MS - Tumefactive:
-Clinical
-Histologic
-Ancillary

Answer 7

-Single white matter mass lesion (suspicious for glioma)

-Active inflammation, Edema, Astrocytosis, Myelin loss, Axonapathy

*Open rim T1 contrast enhancement

Question 8

Neuromyelitis Optica (NMO):
-Clinical
-Histologic
-Ancillary

Answer 8

-Rapid progressive; Visual symptoms with spinal cord sensory loss, weakness

-Myelin and Axon loss; mixed inflammation (lymphs, eos, neuts); Hyalinzed vessels w/ superimposed ischemic necrosis

-NMO-IgG Ab against Aquaporin-4

*T2 & T1 enhancing signal > 3 spinal cord segments

Question 9

Acute Disseminated Encephalomyelitis:
-Clinical
-Histologic
-Ancillary

Answer 9

-Monophasic demyelinative disease in kids and adults; Follows inciting event; Self-limited

-Perivenous lymphocytic cuff, Myelin loss, Axonal preservation

*Numerous, minute T2 hyperintense cerebral white matter lesions

Question 10

Acute Hemorrhagic Leukoencephalitis:
-Clinical
-Histologic
-Ancillary

Answer 10

-Abrupt onset CNS dysfunction; Fatal (frequently); Follows inciting event

-Perivenous lymphocytic cuff, Myelin loss, Axonal preservation with ANGIONECROSIS

*Focal hemorrhages and Marked Cerebral white matter edema

Question 11

Progressive Multifocal Leukoencephalopathy:
-Clinical
-Histologic
-Ancillary

Answer 11

-3-6 month course of visual, sensory, motor and personality symptoms in immunocompromised patient

-Enlarged Oligo nuclei w/ Viral particles; Enlarged atypical astrocytic nuclei

• JC Virus by IHC, CSF PCR and ISH

Question 12

Subacute Sclerosing Panencephalitis:
-Clinical
-Histologic
-Ancillary

Answer 12

-Kids following Measles infection; Progressive global encephalopathic disease

-Perivascular lymphcyte cuffing, microglial proliferation, Intranuclear inclusions in Neurons & Oligos

*CSF measles titer, IHC or ISH for measles virus in tissue

Question 13

HIV Leukoencephalopathy:
-Clinical
-Histologic
-Ancillary

Answer 13

-Cognitive complaints and apathy

-Areas of myelin pallor, microglial nodules, macrophages and Multi-Nucleated Giant Cells

-IHC for gp120; CSF HIV PCR (high viral burden and negative PML)

Question 14

Binswanger Disease (Subcortical Arteriosclerotic Encephalopathy):
-Clinical
-Histologic
-Ancillary

Answer 14

-Hypertensive patients; Progressive loss of executive function, psychosis, urinary incontinence, mild memory loss

-Patchy myelin loss and white matter infarct; arteriolosclerosis and hemorrhages

*Lacunar infarcts in BG and Thalamus; Ventricular dilation

Question 15

CADASIL (Cerebral Autosomal Dominant Arteriopathy w/ Subcortical Infarcts & Leukoencephalopathy):
-Clinical
-Histologic
-Ancillary

Answer 15

-Hereditary; Slowly Progressive; Migraines, Psychiatric & Cognitive Defects

-Diffuse small artery damage with Smooth Muscle Degeneration; Deposition of PAS-Positive Granular Osmiophilic Material (GOM)

-NOTCH3 Gene mutation testing; IHC for protein product

*Frontal/Temporal lobes & Deep Gray nuclei; Cystic infarcts & enlarged Perivascular spaces

Question 16

Fat Embolism:
-Clinical
-Histologic
-Ancillary

Answer 16

-Rapidly progressive confusion, seizures, delirium, and Coma; hours to days after traumatic injury or metabolic insults

-Embolic occlusion of mall vessels by Fat Droplets - petechial hemorrhage and focal ischemic damage in cerebral white matter

-Oil Red O reactive intravascular fat in frozen sections of brain; Fat in urine, blood & sputum; Emboli in retinal vasculature on funduscopic exam

*CT may only show Edema;; MRI: patchy areas of variable T1 intesity and areas of high T2 intensity