Following chronic subdural hematoma (cSDH) surgery, patients had higher risk for mortality and long-term cognitive and functional impairment lasting up to 10 years, a new cohort study showed.

In a population-matched study, 10-year survival among patients surgically treated for cSDH was 55.5% compared with 73.5% in matched control individuals from the general population.

Despite global quality of life (QOL) being preserved among long-term survivors, patients reported persistent impairments across multiple domains, including cognitive and role functioning, with reduced social functioning observed in men.

“From a clinical standpoint, our results emphasize the need for long-term continuity of care beyond hospital discharge with sustained engagement of primary physicians,” the investigators led by Thomas Petutschnigg, MD, Department of Neurosurgery and Stroke Research Center in Bern, Switzerland, wrote.

“Comprehensive postoperative follow-up beyond routine timepoints — including cognitive and frailty screening, neurorehabilitation or geriatric rehabilitation, and social reintegration programs — should be considered,” the researchers added.

The study was published online on April 13 in JAMA Neurology.

Filling a Research Gap

Although prior studies have reported higher mortality after cSDH surgery, including 1-year mortality rates of up to 24%, most available data are limited to short-term follow-up.

Long-term data beyond 5 years remain scarce, and it’s unclear whether excess mortality persists over the long term.

The current analysis included 359 patients with cSDH (mean age, 73.4 years; women, 32.6%) who were previously enrolled in a single-center clinical trial in Switzerland between 2012 and 2016. All patients underwent surgical treatment with routine postoperative imaging follow-up as part of the original study protocol.

Long-term mortality was obtained through a nationwide registry and compared with outcomes in 919,625 age-, sex-, and birth month-matched individuals from the Swiss general population.

Health-related quality of life (HRQOL) was assessed 10 years after surgery using a validated questionnaire administered to consenting survivors. Outcomes included cognitive, physical, role, emotional, and social functioning, as well as global QOL.

Responses were obtained from 147 of 202 eligible survivors, and results were compared with age- and sex-adjusted European reference values.

At baseline, patients had a median Glasgow Coma Scale score of 15 (15-15) and a low median National Institutes of Health Stroke Scale score of 2 (0-3). Most patients (91.9%) were living independently prior to hospitalization. Cardiovascular comorbidities were common, including arterial hypertension (55.0%), coronary artery disease (27.4%), and cardiac arrhythmias (25.4%).

Long-term survival data were available for all patients through December 31, 2023. Over a mean follow-up of 9.55 years, 153 patients died, with a median age at death of 85.2 years.

Twofold Increased Mortality Risk

Overall mortality was significantly higher among patients with cSDH than among matched control individuals, with more than double the risk for death over follow-up (hazard ratio [HR], 2.02; 95% CI, 1.73-2.37; P < .001). The survival gap progressively widened over time.

At year 1, survival was 92.8% in the cSDH group vs 98.8% in control individuals, with an absolute difference of 6 percentage points.

At 5 years, survival declined to 76.6% vs 88.2% in control individuals, with an absolute difference of 11.6 percentage points.

At 10 years, 55.5% of patients with cSDH remained alive compared with 73.5% of matched control individuals, which represents an 18-percentage-point absolute difference.

When assessing HRQOL measures, compared with control individuals, men reported significantly lower scores for physical functioning (75.9 vs 83.22; P < .001) and reduced social functioning (84.3 vs 90.00; P = .02).

Women also showed significantly lower role functioning (69.0 vs 80.91; P = .02) and cognitive functioning (70.2 vs 86.50; P < .001). In contrast, emotional functioning and overall QOL were similar to those of control individuals.

Given patients’ generally independent baseline status and low early postoperative mortality, the investigators cautioned that the observed mortality difference may underestimate true long-term risk in the general cSDH population.

However, “This strengthens the validity of our findings and underscores that patients with cSDH remain at elevated risk of death well beyond the perioperative period,” the investigators wrote.

Study limitations included its single-center design, potential selection bias, loss to follow-up among long-term survivors, and reliance on non-Swiss normative HRQOL data.

Notable Long-Term Disability Burden

In an accompanying editorial, David J. Robinson, MD, MS, of the University of Cincinnati College of Medicine in Cincinnati, and Jared Knopman, MD, of NewYork-Presbyterian Hospital/Weill Cornell Medical Center in New York City, agreed with the researchers that the long-term disability burden observed in these patients was notable given they were relatively healthy at baseline, with most living independently at home.

“While this is not representative of the premorbid disability observed in the overall cSDH population, it could argue for a more direct causal role of the cSDH in the long-term cognitive and physical impairments observed,” they wrote.

Previous research has suggested cSDH itself may contribute to brain and functional decline potentially driven by “neuroinflammation or other neurodegenerative processes either initiated or enhanced by the hemorrhage.”

The editorialists cautioned that the findings come with several key caveats. These include the use of a HRQOL survey originally developed for oncology patients, which may not fully capture the complexity of brain injury-related disability, as well as the lack of a comprehensive multimorbidity measure such as the Charleston Comorbidity Index, and a lack of comorbidity data on control individuals.

“As a result, this study still cannot definitively address the extent to which the cSDH or its management contributed to these outcomes, making it unclear how best to mitigate the observed long-term impairments,” they wrote.

The editorialists called for additional clinical trials to better define optimal treatment strategies for cSDH, and an emphasis on long-term function and other patient-centered outcomes.

Disclosure information for study authors is available in the original study publication. Robinson and Knopman reported having no relevant financial disclosures.