Fahr Syndrome in Acute Trauma and Neuro oncology Settings: Two Illustrative Cases and A Narrative Review

Background: Fahr syndrome denotes acquired, typically bilateral and symmetrical intracranial calcifications with predilection for the basal ganglia, subcortical white matter, and cerebellum. Primary Familial Brain Calcification, formerly called Fahr disease, refers to genetic forms, whereas Fahr syndrome usually describes secondary calcifications in the context of disturbances of calcium phosphate homeostasis, mitochondrial disease, chronic kidney disease, infections, or other systemic conditions. The radiologic appearance can be mistaken for acute hemorrhage or traumatic injury in emergency settings, which may trigger inappropriate escalation of care. Objective: To describe two illustrative cases that presented in acute care environments, one in a trauma context and one in neuro oncology, and to propose a pragmatic imaging and laboratory approach that helps clinicians distinguish calcification from blood products and identify likely etiologies of secondary calcification. Methods and overview: We present structured case narratives focusing on imaging sequences, Hounsfield unit sampling, and clinical decision points, integrated with a concise narrative review to offer a stepwise diagnostic strategy suitable for emergency departments and neurosurgical services. Findings: In both cases, systematic Hounsfield unit sampling with values of 150 HU or higher together with persistence on bone windows supported the interpretation of mineralized tissue rather than acute blood. In the trauma case, this averted an unnecessary escalation toward surgical intervention. In the neuro oncology case, recognition of calcifications coexisting with hemorrhagic metastases allowed appropriate oncologic coordination and symptom control without emergency neurosurgery. Conclusions: A structured head CT review that combines targeted Hounsfield unit sampling with deliberate use of bone windows, followed by focused laboratory testing of calcium, phosphate, magnesium, parathyroid hormone, and renal function, improves diagnostic precision in patients with suspected Fahr type calcifications and helps avoid unnecessary procedures.