Subdural Haematoma in the Elderly

Definition and pathogenesis. A collection of blood in the subdural space caused by tearing of the bridging cortical veins. Cerebral atrophy in old age stretches these veins and widens the subdural space, so a trivial or entirely unremembered head injury is sufficient. Classified as acute (<3 days, hyperdense), subacute (3 days–3 weeks, isodense) and chronic (>3 weeks, hypodense).

Risk factors. Age over 65, brain atrophy, recurrent falls, alcohol excess, anticoagulants and antiplatelet drugs, previous subdural haematoma, epilepsy, coagulopathy, chronic liver disease, haemodialysis, and CSF over-drainage after shunting.

Clinical presentation — “the great imitator”. Fluctuating consciousness, headache, gradual cognitive decline mimicking dementia, personality change, gait disturbance and falls, hemiparesis, dysphasia, or simply delirium and unexplained functional decline. A history of trauma is absent in up to half of cases, so a high index of suspicion is essential.

Diagnosis. Non-contrast CT head is the first-line investigation. Beware the isodense subacute phase and bilateral collections, where midline shift may be absent — look instead for effaced sulci, compressed ventricles and loss of grey–white differentiation. MRI is more sensitive when CT is equivocal. Check INR, coagulation profile and platelet count.

Management. Reverse anticoagulation urgently — vitamin K with 4-factor prothrombin complex concentrate for warfarin, idarucizumab for dabigatran, and andexanet alfa or PCC for factor Xa inhibitors. Surgery: burr-hole drainage with a subdural drain for symptomatic chronic SDH (the drain reduces recurrence), and craniotomy for acute or organised clot. Small, asymptomatic collections may be managed conservatively with serial imaging.

Complications and prognosis. Recurrence in 10–30%; seizures, infection, tension pneumocephalus, venous thromboembolism and prolonged rehabilitation. Outcome depends more on the GCS at presentation and premorbid frailty than on the size of the clot. Restarting anticoagulation must be individualised — usually about 4 weeks, earlier if there is a mechanical valve.

Middle meningeal artery embolisation (MMAE). Three randomised trials published together in the New England Journal of Medicine on 20 November 2024 — EMBOLISE (n=400), STEM (n=310) and MAGIC-MT (n=722) — showed that adjunctive MMAE significantly reduces recurrence or progression of chronic subdural haematoma requiring reoperation, without increasing disability. MMAE devascularises the inflammatory neomembranes that drive re-bleeding, and is now an established adjunct to surgery — especially valuable in older, anticoagulated, high-surgical-risk patients.