Neuroradiology–Neuropathology Conference University of North Carolina Hospitals Michael Solle MD, Neuroradiology Thomas W. Bouldin MD, Neuropathology February, 2011

Case 1 History 48-year-old woman with history of end-stage renal disease secondary to lupus, on hemodialysis, who presented with new acute onset of left lower extremity weakness and difficulty walking after dialysis.

Imaging MRI of the thoracic spine Hyperintense signal within the spinal cord extending from T3–T6. This could possibly relate to vasculitis from patient’s lupus. T2 hypointense/T1 iso- to hyper-intense mass within the spinal canal of the upper thoracic spine with associated cord displacement. This is concerning for an epidural hematoma. Bilateral pleural effusions.

Surgery T2 through T5 laminectomy for the evacuation of an intradural hematoma. Preoperative Diagnosis: T3–T5 extramedullary hematoma. Postoperative Diagnosis: T3–T5 subdural hematoma. Pathology: acute blood clot.

Review of spinal lesions Location is key Intramedullary Extramedullary, intradural Extradural Identifying the CSF containing space, the dura and the epidural fat help to localize the abnormality.

Case 2 History 30-year-old previously healthy man with three weeks of episodic right-sided numbness and tingling along with a complete right homonymous hemianopsia and difficulty naming objects.

Additional history In 2009 intermittent tinnitus had become a loud humming that would sometimes become so loud that he could not understand what was said to him. In early 2010, was seen by an ophthalmologist, who noted retinal vasculitis. In the interval between visits he underwent a cochlear implant without a magnet in order to facilitate continued MRI screening. The implant improved his hearing significantly in his right ear; he remains essentially deaf in his left ear.

Surgery Image-guided left occipital craniotomy for open biopsy of enhancing left occipital lobe lesion.

 Biopsy of occipital lesion revealed nonspecific brain necrosis () and reactive gliosis in surrounding brain. The histologic changes are compatible with an infarct.

Biopsy also revealed atypical lymphoid infiltrates around blood vessels in area of brain necrosis. The significance of these lymphoid infiltrates is not known.

Name that Eponym? Consisting of classic clinical triad of subacute encephalopathy visual loss secondary to branch retinal artery occlusion sensorineural hearing loss  Answer: Susac’s Syndrome Caused by microangiopathy involving the brain, cochlea, and retina

Susac’s Syndrome Headache, often severe and sometimes migrainous, is an almost constant complaint may be the major presenting feature of the encephalopathy cognitive changes, confusion, and memory and psychiatric disturbances MR often interpreted as "typical" for MS or ADEM In unexplained encephalopathy, a neuro- ophthalmologist or retinal specialist should perform a dilated funduscopic examination… Susac’s Syndrome John O. Susac, Guest Editorialist, Winter Haven, FL http://www.ajnr.org/cgi/content/full/25/3/351

Susac’s syndrome (continued) Clinical course is usually self-limited, variable. 2–4 years as short as 6 months or as long as 5 years  Some patients recover with little residual disease; others are profoundly impaired. cognitive deficits gait disturbance hearing loss Vision is not usually seriously impaired. Susac’s Syndrome John O. Susac, Guest Editorialist, Winter Haven, FL http://www.ajnr.org/cgi/content/full/25/3/351

Susac’s syndrome (continued) Pathogenesis is unknown. Difficult to evaluate the results of treatment: IV methylprednisolone followed by oral steroids in conjunction with cyclophosphamide or immunoglobulin Some respond to monotherapy with steroids, cyclophosphamide, or immunoglobulin.  Anticoagulation has no role. Susac’s Syndrome John O. Susac, Guest Editorialist, Winter Haven, FL http://www.ajnr.org/cgi/content/full/25/3/351

Case 3 History 20-year-old woman with 2–3 year history of complex partial seizures.

Biopsy of cortical lesion revealed a proliferation of oligodendrocyte-like cells in a myxoid background. A neuron (arrow) appears to “float” within the myxoid matrix.

DNET (DNT) Dysembryoplastic neuroepithelial tumor, WHO grade I Cortical location; temporal, frontal lobe Commonly present with complex partial seizures Slow growing—may remodel/scallop inner table of skull Variable enhancement May have microcystic appearance

Case 4 History 40-year-old woman with hypertension was transferred from an outside hospital ED because of cerebellar infarcts.

Surgery Suboccipital/posterior fossa craniectomy for excision of left cerebellar infarct and duraplasty. Placement of a right frontal external ventricular drain.

Pathology Purkinje cells (arrow) with eosinophilic cytoplasm and pyknotic nuclei (red neurons) Widespread nuclear pyknosis in neurons of the internal granular layer Only a few inflammatory cells The histologic changes are consistent with an acute cerebellar infarct.

Cerebellar Infarction PICA > superior cerebellar > AICA Etiology often: dissection of the vertebral arteries (particularly in younger patients) basilar artery disease (in older patients). Cerebellar infarcts may lead rapidly to death caused by compression of the brain stem acute obstructive hydrocephalus from compression of 4th ventricle Herniations Upward cerebellar herniation (seen as effacement of quadrigeminal plate cistern) Downward herniation of cerebellar tonsils may also occur. Emergency resection of involved cerebellum and/or a ventriculostomy may be required as a life-saving measure.

Case 5 History 20-year-old man who began to notice significant dysequilibrium on movement, which interfered with his playing of baseball. He noticed that he was not able to track a baseball while moving nor to swing a bat and hit the ball. He had previously been very good at this.

Surgery Large vestibular schwannoma with multiple large vessels contained within it was densely adherent along the brainstem to blood vessels. Facial nerve was dissected in its entirety and stimulated at 0.1 milliamps at the completion of the case. There is a small residual pancake-like tumor along brainstem, densely adherent to several large vessels.

Pathology Spindle cell tumor with some nuclear palisading (Verocay bodies). Compact Antoni type A tissue (upper left of photo) and loose Antoni type B tissue (lower right of photo) are present. The histologic features are consistent with a schwannoma.

Vestibular schwannoma AKA, “acoustic” schwannoma Benign tumor arising from Schwann cells of the vestibulocochlear nerve Large tumors Avidly enhancing mass, with expansion of the porus acusticus, and an "ice cream on cone“ appearance when the mass is both within the CPA and IAC Small tumors High-resolution T2 MR: small low signal “filling defect" in high signal CSF Most common presentation is an adult with unilateral sensorineural hearing loss If bilateral, consider NF-2 as underlying diagnosis Important to comment on involvement of cochlear aperture

DDx of cerebellopontine angle mass Vestibular schwannoma Most common CPA mass Epidermoid cyst mimic rare cystic schwannoma, no enhancement FLAIR/CISS/DWI to differentiate from arachnoid cyst Arachnoid cyst follows CSF on all MR sequences; no enhancement Meningioma dural tail; eccentric to porus acusticus without widening it Facial nerve schwannoma Look for labyrinthine segment "tail" to differentiate Metastasis Lymphoma Aneurysm