This Week in Neurosurgery — May 28, 2026

Welcome to This Week in Neurosurgery. This week we're covering 10 notable papers spanning neuro-oncology, spine surgery, and endovascular techniques. We'll also touch on new developments in liquid biopsies and take a critical look at some foundational concepts in our field. Let's dive in.

Neuro-Oncology: Local Control and Liquid Biopsies First up, in neuro-oncology, we have several papers exploring local treatment strategies and the evolving role of molecular diagnostics.

Starting with local control, a prospective phase II trial in the *Journal of neuro-oncology* evaluated intraoperative radiotherapy, or IORT, immediately following resection of newly diagnosed brain metastases [1]. In this single-arm study of 35 patients, a dose of 30 Gray was delivered to the resection cavity. The primary endpoint was local control, which was excellent at 94.3%. Overall survival was also notable, with a median of 43.6 months. However, distant brain control was only 57.1%, and radionecrosis, though predominantly low-grade, occurred in 20% of patients. The authors conclude that IORT is a feasible alternative to postoperative stereotactic radiosurgery in select patients, offering the advantage of immediate, single-session treatment.

Also on the topic of focused radiation, a study in *Neurosurgery* compared stereotactic radiosurgery to reoperation for small, surgically accessible recurrent glioblastomas [5]. This retrospective study is important because it highlights a critical selection bias. Initially, it appeared that radiosurgery led to better survival. However, the investigators noted that patients selected for radiosurgery had significantly smaller tumors to begin with. To correct for this, they performed a propensity-score matched analysis, comparing 23 patients in each group with similar tumor volumes and performance status. In this matched comparison, post-recurrence survival was similar between radiosurgery and reoperation, at 19.2 months versus 15.1 months, respectively. The key difference was in safety: the complication rate was substantially lower in the radiosurgery group, at just over 4 percent, compared to 26 percent in the reoperation group. The takeaway is that for carefully selected patients with small recurrent glioblastomas, radiosurgery provides comparable survival to a second surgery but with significantly fewer complications.

Shifting from treatment to diagnostics, two papers in the *Journal of neuro-oncology* highlight the potential of liquid biopsies. The first demonstrates that analyzing circulating tumor DNA from cerebrospinal fluid can be a powerful tool for glioma patients [10]. In a cohort of 43 patients, investigators were able to detect mutations in 60% of CSF samples. They successfully identified key diagnostic markers like IDH1 mutations, TERT promoter mutations, and EGFR amplifications. Critically, this CSF-based analysis allowed for the molecular reclassification of three patients according to the latest WHO criteria, changing their diagnosis without an additional tissue biopsy. The main limitation was technical, as detection often failed in samples with very low DNA yield.

Complementing this, another study in the same journal developed a liquid biopsy-based genomic risk score to predict neurologic death in over 300 patients with non-small cell lung cancer [7]. By analyzing mutations in the blood, they created a scoring system that could stratify patients into low, moderate, and high-risk groups for neurologic death. Patients in the high-risk group had a nearly four-fold increased hazard of neurologic death compared to the low-risk group. In the subgroup of patients who already had brain metastases, the cumulative incidence of neurologic death was over 52% in the high-risk group versus zero in the low-risk group. This suggests a feasible, non-invasive way to identify patients who might benefit from more aggressive CNS-directed surveillance or therapy.

Spine and Pediatric Decompression Turning to the spine and pediatric neurosurgery, two papers address long-standing questions about surgical timing and technique.

A systematic review and meta-analysis in the *Journal of clinical neuroscience* asked if the timing of decompression affects outcomes after a complete traumatic spinal cord injury [3]. Analyzing 12 studies with over 600 patients, the authors found that early surgery, defined as within 24 hours, significantly improved the chances of neurological recovery. Patients undergoing early decompression were 1.66 times more likely to improve by at least two AIS grades. When an even more dramatic recovery was considered—improving by at least three AIS grades to ambulatory function—the benefit was even larger. However, a crucial subgroup analysis revealed this benefit was driven entirely by patients with cervical spine injuries. For complete thoracolumbar injuries, the timing of surgery did not show a significant effect on recovery. This provides strong evidence to prioritize urgent decompression for complete cervical spinal cord injuries.

Meanwhile, a major trial in *The New England Journal of Medicine* tackled a contentious issue in pediatric neurosurgery: whether to perform a duraplasty during posterior fossa decompression for Chiari I malformation with syringomyelia [4]. In this multicenter, cluster-randomized trial, 162 children underwent either decompression with duraplasty or decompression alone. The primary outcome was the rate of surgical complications within six months. The results were not statistically significant, with a complication rate of 14% in the duraplasty group versus 6% in the bone-only group. Looking at secondary outcomes, the picture was mixed. Duraplasty led to greater syrinx reduction and a much lower rate of repeat decompression—3% versus 14%. However, rates of clinical improvement and changes in quality of life were similar between the two groups. The authors conclude that because the primary outcome was not met, larger trials are needed to clarify the relative benefits and risks of each approach.

Endovascular Insights and Post-Stroke Prediction In vascular neurosurgery, a large study in the *Journal of Neurosurgery* provides valuable data on the resolution of chronic subdural hematomas after middle meningeal artery embolization, or MMAE [9]. Based on real-world data from over 1700 patients, the study found that hematoma thickness decreases in a predictable exponential decay pattern. The estimated time to a 50% reduction in thickness was 1.8 months, and to an 80% reduction, 8.9 months. This timeline is critical, as the study also showed a direct link between the speed and extent of resolution and functional outcomes. Patients who achieved at least a 73% reduction in hematoma size within 90 days were significantly more likely to have a good functional outcome. This study provides quantitative benchmarks to guide patient expectations and evaluate treatment response after MMAE.

On the acute side of vascular neurology, a study in *World Neurosurgery* used machine learning to predict outcomes after endovascular thrombectomy for stroke [8]. Recognizing that many patients have poor outcomes despite successful recanalization, the researchers developed a model incorporating post-procedural transcranial Doppler, or TCD, data. Among 176 patients, the most influential predictors of a poor 3-month outcome were TCD-derived hemodynamic measures, specifically the mean flow velocity index and the peak systolic velocity ratio, along with older age and smoking status. This work underscores that restoring flow is only part of the battle; the quality of post-reperfusion cerebral hemodynamics is a key determinant of recovery.

Re-examining Foundational Concepts Finally, two papers this week prompt us to step back and think critically about the language we use and the fundamental biology of our patients.

A review article in *Neurosurgery* takes a critical look at our use of the terms "eloquent" and "noneloquent" cortex [6]. The authors argue this binary framework is an outdated relic that fails to capture the brain's complex, network-based nature. They point out that evidence has grown for over a century that so-called "silent" areas have important functions. They propose moving toward a more nuanced framework that considers network essentiality, neuroplastic potential, and the degree of certainty about a region's function. This has direct implications for how we counsel patients about surgical risks.

And in the journal *Nature*, a massive basic science study integrated over 11,000 transcriptomes from mice, rats, macaques, and humans to identify universal hallmarks of aging and mortality [2]. They discovered conserved gene expression signatures related to inflammation, mitochondrial function, and chromatin modification that track with chronological age and predict time to death across species. While not immediately applicable at the bedside, this work provides a foundational molecular framework for understanding aging, which is the single biggest risk factor for many of the pathologies we treat, and for developing future interventions.

If you only have time for one paper this week, make it the systematic review and meta-analysis on decompression timing for complete traumatic spinal cord injury in the *Journal of clinical neuroscience* [3]. It provides strong, actionable evidence that surgery within 24 hours significantly improves the chances of neurological recovery, but specifically for patients with cervical-level injuries.

Here are the key takeaways from this week in Neurosurgery.

First, for patients with complete traumatic cervical spinal cord injuries, surgical decompression within 24 hours is critical and significantly improves the odds of neurological recovery [3].

Second, in pediatric Chiari I with syrinx, adding a duraplasty to posterior fossa decompression does not have a clear benefit over bone-only decompression in terms of complications, though it may reduce the syrinx more effectively and lower the need for reoperation. The evidence remains uncertain [4].

Third, for small, surgically accessible recurrent glioblastomas, stereotactic radiosurgery offers similar survival to re-operation but with a significantly lower complication rate, making it a strong salvage treatment option in select patients [5].

Fourth, middle meningeal artery embolization for chronic subdural hematoma leads to a predictable, exponential decay in hematoma size, with faster and more complete resolution by 90 days associated with better long-term functional outcomes [9].

Finally, the field of liquid biopsy is advancing rapidly, with CSF ctDNA showing promise for reclassifying gliomas based on molecular markers [10] and blood-based genomic scores helping to predict neurologic death in cancer patients [7].

That's your roundup for This Week in Neurosurgery. The full transcript and references are available on the episode page in your AudioScholar library. This is an AI-curated summary — for clinical decisions, always consult primary sources and current guidelines. See you next week.