Chronic Subdural Hematoma
A chronic subdural hematoma is an old blood collection that accumulates slowly over weeks to months between the dura and arachnoid membranes covering the brain. It is most common in older adults and people on blood thinners; most cases are successfully treated with burr-hole drainage.
Última actualización: 2026-06-07
Definition
A chronic subdural hematoma (cSDH) is a blood collection, usually older than 21 days, that accumulates slowly in the subdural space between the dura mater and the arachnoid membrane. The initial small bleed organizes over time, and a vascularized capsule (membrane) forms around it. Repeated small bleeds from this capsule cause the collection to enlarge slowly over weeks to months. In a portion of cases the hematoma is bilateral.
Causes and Risk Factors
Chronic subdural hematoma usually develops in older adults after a minor or unremembered head injury. Brain atrophy leaves the bridging veins stretched and fragile, so even slight strain can cause bleeding. Important risk factors include advanced age, use of blood thinners (anticoagulants/antiplatelets), alcohol use, clotting disorders, and a previously placed cerebrospinal fluid shunt.
Symptoms
Symptoms usually begin insidiously and progress over days to weeks. Common features include headache, confusion and forgetfulness, weakness on one side of the body (hemiparesis), balance and gait disturbance, speech difficulty, and sometimes seizures. The picture can mimic other neurological diseases, occasionally presenting with progressive dementia, gait disturbance, and urinary incontinence. Chronic subdural hematoma should therefore be considered in older adults with new neurological symptoms.
Diagnosis
The first investigation is usually a brain computed tomography (CT). A chronic subdural hematoma typically appears as a crescent-shaped collection following the brain surface and may be hypodense (dark) or mixed density depending on its age. Internal septations and membranes indicate encapsulation. MRI is valuable for hematomas that are isodense to brain or whose age needs to be determined; FLAIR and susceptibility-weighted sequences help distinguish the collection and microbleeds.
Treatment
For symptomatic chronic subdural hematomas or those causing mass effect, the standard treatment is surgical drainage through a burr hole (a small opening in the skull); a temporary drain may be placed in the subdural space. Twist-drill drainage, or craniotomy for calcified or heavily septated hematomas, is preferred in selected cases. Small, asymptomatic collections may regress spontaneously in some patients and can be followed closely. Blood thinners are reviewed and may be temporarily stopped, with their effect reversed when needed; the timing of restarting therapy is individualized by the physician.
Recurrence and Middle Meningeal Artery Embolization
Re-accumulation of the hematoma (recurrence) can occur in a proportion of cases; bilateral location, septation, clotting disorders, and use of blood thinners raise the recurrence risk. Recurrences may be re-drained. In recent years, middle meningeal artery embolization has been used—either alone or in addition to surgery—as an option to reduce recurrence by decreasing the blood supply to the hematoma capsule.
Prognosis
Chronic subdural hematoma has a far better course than acute subdural hematoma, and surgical drainage generally yields favorable results; symptoms such as gait disturbance and confusion can improve rapidly. Nonetheless, outcomes vary with the patient's age, general condition, comorbidities, and whether recurrence occurs. Outcomes are individual and none can be guaranteed.
Referencias
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:1083-1086.
- Winn HR, ed. Youmans Neurological Surgery. 6th ed. Saunders; 2011:535-543.
- Kolias AG, et al. Chronic subdural haematoma: modern management and emerging therapies. Nat Rev Neurol. 2014.
- Link TW, et al. Middle Meningeal Artery Embolization for Chronic Subdural Hematoma. Neurosurgery. 2019.
Este artículo es informativo y no sustituye un examen médico. Las decisiones de diagnóstico y tratamiento son individuales.