Development of chronic subdural haematoma from mild head injury: A case report and review of current Malaysian guidelines on traumatic brain injury.

Delayed chronic subdural haematoma (cSDH) is a common but potentially serious complication following traumatic brain injury (TBI). Mild TBIs are commonly managed by primary care providers (PCPs), particularly in large, resource-limited settings such as Malaysia, where access to tertiary neurosurgical services may be delayed. Early identification of red-flag signs and symptoms and timely referrals are crucial to prevent clinical deterioration. We describe the case of a 66-year-old man who sustained mild head injury following a vasovagal syncope. His initial brain CT revealed evidence of a small traumatic subarachnoid haemorrhage over the left precentral sulcus, with resolution on an interval scan 24 hours later. He was discharged home without follow-up. Eleven weeks later, he developed bilateral lower-limb weakness and unsteady gait, which prompted an urgent referral by his general practitioner. Repeat CT revealed bilateral acute-on-chronic subdural haematomas, with mass effect requiring emergency burr-hole drainage. The patient showed excellent post-operative improvement and was discharged home on day 4, with no clinical or radiological recurrence on subsequent follow-up. This case highlights the risk of delayed cSDH in patients following mild TBI, even in those discharged with a normal CT scan. PCPs play a pivotal role in recognising high-risk patients, ensuring structured follow-up and facilitating timely specialist referral. We advocate for updating the Malaysian head injury guidelines to incorporate routine follow-up protocols for at-risk patients, modelled after international standards.