Non-Aneurysmal Subarachnoid Hemorrhage in a Patient With Type 1 Diabetes Mellitus: A Case Report

Non-aneurysmal subarachnoid hemorrhage (NASAH) is defined as bleeding into the subarachnoid space without an identifiable aneurysm. In patients with long-standing diabetes mellitus (DM), chronic microvascular damage may contribute to vascular fragility and hemorrhage. Emerging evidence suggests a possible association between NASAH and diabetes, particularly through microangiopathic mechanisms. We report the case of a 40-year-old female patient with a 14-year history of poorly controlled Type 1 DM (T1DM) who presented with sudden-onset severe occipital headache, neck stiffness, and vomiting. On examination, she was neurologically intact with a Glasgow Coma Scale score of 15/15, with mild nuchal rigidity. Non-contrast head CT revealed diffuse subarachnoid hemorrhage. CT angiography showed no aneurysm or vascular malformation, confirming NASAH. She was managed conservatively with nimodipine, analgesics, and supportive care, with good clinical recovery and no residual deficits. This case highlights NASAH as a potential microvascular complication of long-standing T1DM. Early recognition and appropriate imaging are essential for diagnosis, particularly in resource-limited settings, and can lead to favourable outcomes.