Primary Angiitis of the Central Nervous System Presenting with Microhemorrhages on Gradient Echo Imaging (P07.042)

Objective: To highlight the utility of magnetic resonance gradient echo (MR GRE) in the early diagnosis of primary angiitis of the central nervous system (PACNS) through a case report. Background PACNS is a rare form of vasculitis. The presenting symptoms of PACNS are often nonspecific, including encephalopathy, headaches, stroke, seizures, and cranial nerve palsies. Currently, biopsy is the gold standard for diagnosing PACNS. The sensitivity and specificity of less invasive testing, including conventional MRI, magnetic resonance angiography (MRA), CSF analysis, and four vessel angiography, are not as robust. Design/Methods: Case-report and literature review. Results: : A 52 year old gentleman presented for workup of episodic vertigo, dysphasia, and headaches. MRI brain revealed confluent subcortical T2 signal hyperintensities in the right frontotemporal and left temporal regions, corresponding small punctuate and linear zones of contrast enhancement, and a subacute left cerebellar hemorrhage. His MR GRE imaging revealed subcortical microhemorrhages and a left cerebellar hemorrhage. Serologic workup revealed normal CBC, electrolytes, INR, sedimentation rate, lactate dehydrogenase, angiotensin-converting enzyme level, myeloperoxidase, proteinase, antiphospholipid, and paraneoplastic antibodies. CSF examination revealed prominent lymphocytosis and negative cytology. MRA and conventional angiography were unrevealing. A cortical biopsy revealed chronic perivascular lymphocytic inflammation with focal granulomatous features and negative beta amyloid stain suggestive of PACNS. The patient was treated with a five day course of intravenous methylprednisolone (1 gram daily), followed by an oral prednisone taper. He reported no further episodes of vertigo or semantic paraphasia following initiation of steroids. Conclusions: Our case demonstrates the utility of GRE in the early diagnosis of PACNS. The presence of cortical and/or subcortical signal hypointensities on GRE (consistent with petechial hemorrhages) can help to distinguish PACNS from many of its mimickers. Such an imaging modality may be useful for promptly establishing the diagnosis and treating with immunosuppression, which is needed to avoid significant morbidity and mortality. Disclosure: Dr. Toledano has nothing to disclose. Dr. Smith has nothing to disclose. Dr. Dhamija has nothing to disclose. Dr. Jones has nothing to disclose. Dr. Moseley has nothing to disclose.