en Vascular Neurosurgery Case report <p><strong>Background and Aim:</strong> Spontaneous acute subdural hematoma (ASDH) without trauma is a rare and often misdiagnosed manifestation of ruptured intracranial aneurysms. While most aneurysmal bleeds result in subarachnoid hemorrhage, middle cerebral artery (MCA) aneurysms can, in exceptional cases, rupture directly into the subdural space.<br> <strong>Case Presentation</strong>: We report the case of a 48-year-old female patient who presented with sudden-onset headache, altered sensorium, and left-sided ASDH without any history of trauma. Computed tomography angiography (CTA) revealed a saccular aneurysm at the M4 segment. The patient underwent emergency craniotomy with hematoma evacuation and microsurgical clipping of the aneurysm. Postoperative recovery was favorable with gradual neurological improvement Aneurysmal ASDH accounts for a small fraction of non-traumatic subdural bleeds. Distal MCA branches, lying close to the subdural compartment, can rupture in a manner that bypasses the subarachnoid space entirely. Timely vascular imaging is essential to avoid misdiagnosis and guide definitive treatment.</p> <p><strong>Conclusion</strong>: In patients presenting with non-traumatic ASDH, especially in the absence of external injury or contusions, underlying vascular lesions such as MCA aneurysms should be considered. Early CTA or digital subtraction angiography (DSA) plays a critical role in diagnosis and surgical planning, improving outcomes in this rare yet neurosurgically critical condition.</p> Middle cerebral artery aneurysm, spontaneous subdural hematoma, non-traumatic subdural hemorrhage, Vascular imaging in SDH, CT angiography in SDH 0 0 http://irjns.org/browse.php?a_code=A-10-1428-1&slc_lang=en&sid=1 Ram Parajiya parajiya_ram@yahoo.in 100319475328460013116 0009-0005-1306-987X No Department of Neurosurgery, Jawaharlal Nehru Medical College, Belagavi, India. Abhishek Patil drabhishekpatil87@gmail.com 100319475328460013117 100319475328460013117 Yes Department of Anesthesiology, Jawaharlal Nehru Medical College, Belagavi, India Purvashree Deshmukh purvashreedeshmukh@gmail.com 100319475328460013118 100319475328460013118 No Department of Anesthesiology, Jawaharlal Nehru Medical College, Belagavi, India Pradeep Goudar pradeepsgoudar6543@icloud.com 100319475328460013119 100319475328460013119 No Department of Radiology, Jawaharlal Nehru Medical College, Belagavi, India.