Cerebral amyloid angiopathy-related inflammation (CAAri) is characterized by perivascular inflammation related to the abnormal deposition of beta-amyloid in the leptomeninges and cerebral blood vessels. We present two atypical presentations of this inflammatory vasculopathy.  

Case 1: A 68-year-old woman presented with two weeks of memory loss and was found to have an enhancing right frontal hemorrhagic lesion with convexity subarachnoid hemorrhages. Patient underwent resection of the mass. Steroids were initiated but rapidly discontinued due to adverse effects. Two years later, she presented with aphasia, hallucinations, and memory concerns. She was found to have recurrent right frontal hemorrhage with new curvilinear enhancement throughout stable superficial siderosis. Pathology from the resection was reviewed, showing beta-amyloid deposition within the parenchymal vessels with perivascular inflammation. She was started on mycophenolate mofetil for concern for CAAri. After 3 months of treatment, she reported improvement with her MOCA increasing from 12 to 23 out of 30.
Case 2: A 74-year-old man presented with one week of headache after an episode of left upper extremity ataxia. MRI showed right-sided leptomeningeal enhancement with underlying gyral edema. Lumbar puncture was significant for mixed pleocytosis of 135 cells with elevated protein of 87. He was treated with IV acyclovir and later oral prednisone with clinical and radiographic improvement after the latter. One year after the initial presentation, the patient had recurrence of leptomeningitis. Leptomeningeal biopsy demonstrated beta-amyloid deposition throughout the leptomeningeal and cortical vessels with nonspecific perivascular macrophages indicative of chronic inflammation. He was initiated on mycophenolate mofetil.

Both patients were treated for alternative diagnoses prior to diagnosis via biopsy (hemorrhagic tumor, VZV meningitis). CAAri can be distinguished from non-inflammatory CAA by the presence of headache, neuropsychiatric symptoms, and seizure. CAAri is often treatable with immunotherapy, and therefore a high level of suspicion for the condition must be maintained.