Chronic subdural haematoma in older adults: slow bleeding after a minor knock

Cambridge University Hospitals describes a cSDH as a collection of old blood that forms between the skull and the dura, the membrane covering the brain, originating from damage to the veins supplying that membrane. Because the skull is rigid, as the haematoma expands it presses on the brain, and the bigger it is, the more likely it is to affect the brain. It can occur on one or both sides.

The leaflet says the cause is not fully understood. A common idea is that a head injury causes a bleed that the body fails to reabsorb and instead seals within a membrane that slowly draws in fluid, and it notes this process can occur over weeks to months. It says the brain shrinks with age, so the subdural space is larger and the crossing blood vessels are stretched and more likely to tear with even minor injuries.

Cambridge lists patients taking blood-thinning medication, older patients, those unsteady on their feet with an increased likelihood of falling, those with liver disease or clotting disorders, and those who drink alcohol to excess. The NHS similarly flags a blood clotting disorder or taking blood-thinning medicine, alcohol before the injury, and previous brain surgery as reasons to go to A&E after a head injury.

For older people this means that a fall or knock, even apparently trivial, in someone taking an anticoagulant or antiplatelet tablet deserves assessment, and that anyone on these medicines should tell the doctor about any head knock in the past weeks to months.

The NHS lists a bad headache that does not get better after painkillers, feeling and being sick, confusion and memory problems, personality change such as unusual aggression, drowsiness, slurred speech and swallowing problems, vision problems, loss of balance and falls, weakness or paralysis on one side, seizures and loss of consciousness. Cambridge says most cSDH are small and cause no symptoms, but some slowly expand and cause arm or leg weakness, a facial droop or difficulty communicating, occasionally a sudden seizure, and other symptoms including headache, confusion, drowsiness, dizziness, new unsteadiness, nausea and collapse. Different combinations may come and change over time.

Cambridge makes an important point: confusion often leads to the brain scan that finds a cSDH but on its own is rarely caused by it, whereas arm or leg weakness, speech difficulty or headaches are better indicators that the cSDH is causing a problem. Because the picture can look like stroke, dementia or delirium in an older person, a brain scan is needed to tell the difference. Sudden weakness, facial droop or speech trouble should always be treated as a possible stroke and 999 called.

The NHS says go to A&E after a head injury if you have been knocked out but have now woken up, have vomited since the injury, have a headache that does not go away with painkillers, a change in behaviour, memory problems, been drinking alcohol or taking drugs before the injury, have a blood clotting disorder or take blood-thinning medicine, or have had brain surgery. It says to call 999 if someone has hit their head and has been knocked out and not woken, has difficulty staying awake, a fit, problems with vision or hearing, clear fluid from the ears or nose, numbness or weakness in part of the body, problems with walking, balance, understanding, speaking or writing, or a head wound with something inside it. It says not to drive to A&E.

Cambridge says a cSDH is diagnosed with a CT or MRI brain scan, along with blood tests, particularly if the person takes blood thinners, plus a full history and examination. Once diagnosed, the hospital doctor discusses the case with a neurosurgical team, who advise on a treatment plan; the person may be admitted locally for observation or transferred to a neurosurgical centre by ambulance, sometimes quickly. If someone cannot understand the information to make a decision, the neurosurgical team treats them in their best interests, where possible discussing with the next of kin.

Cambridge says treatment is either surgery or conservative management; if the cSDH is small or incidental and not causing significant problems, monitoring with follow-up and possibly repeat scans may be chosen, with medicines to treat other conditions or to reverse blood thinners, and a warning to attend A&E if symptoms appear or worsen. If surgery is chosen, it happens within a few days. The anaesthetist reviews the person; most commonly it is under general anaesthetic, occasionally local anaesthetic with light sedation, and the leaflet says the risks of problems such as heart attacks, chest infections or DVT increase in older people or those with other health conditions.

The NHS says most people with a haematoma need surgery: either a small section of the skull is cut open and then sealed, or small burr holes are drilled and the haematoma is sucked out. A small haematoma causing only mild symptoms may be monitored and given no treatment or given medicines to reduce brain swelling. Decisions about stopping or restarting blood thinners are made by the specialists; never stop an anticoagulant on your own.

The NHS says subdural haematomas can be very serious injuries, and even with the best care there is a high risk of death; people with serious ones can be left with long-term problems with walking, talking and thinking, and seizures. It says a full recovery may not be possible, but physiotherapy, occupational therapy and speech and language therapy (for speaking, eating and swallowing) can help. It suggests talking to others affected by brain injury, and the care team may know of local groups. Falls prevention, a review of medicines and home safety are sensible parts of recovery for older adults.