BACKGROUND Cerebral amyloid angiopathy-related inflammation (CAA-ri) is an acknowledged syndrome of reversible encephalopathy, also known as cerebral ß-related angiitis. It is characterized by brisk progressive higher mental dysfunctions, headaches, seizures/epilepsy, and behavioral changes, and is highly responsive to immunosuppressive medications. To quickly and properly determine patients' management plans and prognoses, doctors are left with only CAA-ri-associated behavioral changes and seizures, in addition to a high index of suspicion of the correct diagnosis. CASE REPORT A 67-year-old woman was presented to the emergency room (ER) with behavioral changes and seizures. Upon screening, the patient was found to have radiological evidence of asymmetrical cortical-subcortical white-matter lesions accompanied by multiple cerebral microbleeds in the background of the negative screening for infectious/neoplastic and paraneoplastic processes. After undergoing a brain biopsy, the diagnosis was confirmed to be amyloid deposition within the inflammatory vessel walls. The patient showed a dramatic improvement after methylprednisolone pulse therapy, plasma exchange, and rituximab maintenance. CONCLUSIONS We encourage and support brain biopsies to confirm highly suspicious CAA-ri atypical cases to initiate early treatment and achieve the best outcome without any further delays.