A recent Neurosurgery digest,
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Study Type: Experimental animal study (rat model)

Key Question: Does maximum ICP in the early phase of experimental SAH correlate with neurological outcome and SAH severity, and can it serve as a reliable severity classifier?

Key Findings:

• Maximum ICP strongly correlated with neurological score, SAH grade, and 24-hour mortality across four groups (sham; mild <50 mmHg; moderate 50–149 mmHg; severe ≥150 mmHg)
• Higher maximum ICP was associated with greater cortical and hippocampal neuronal damage, apoptosis, and oxidative stress on histology at 24 hours
• Moderate ICP group (50–149 mmHg) identified as the most reproducible and clinically translatable tier for SAH research

Clinical Relevance: Establishes ICP monitoring as a valid severity-stratification tool in preclinical SAH models, which has implications for interpreting translational research underpinning future ICP-targeted therapies relevant to UK neurocritical care practice.

Limitations: Findings are confined to a rodent model and may not translate directly to human SAH pathophysiology or ICP dynamics.

Study Type: Retrospective cohort study

Key Question: Does neurosurgical intervention improve mortality and functional outcomes in patients aged ≥80 years with CT-confirmed traumatic brain injury?

Key Findings:

• Neurosurgical intervention reduced 30-day mortality (HR 0.46, 95% CI 0.28–0.76) but conferred no survival benefit at one year (HR 0.84, 95% CI 0.63–1.12)
• Favourable 6-month outcome (GOS 4–5) was similar between surgical (29%) and conservatively managed (34%) patients; preinjury dependency, age, ASA class, and injury severity were the strongest predictors of poor outcome
• Delayed trephination for chronic subdural haematoma carried only 5% mortality, whereas acute craniotomy was associated with significantly worse outcomes

Clinical Relevance: This challenges routine surgical escalation in octogenarians with TBI, supporting a goals-of-care and functional-baseline approach to neurosurgical decision-making — directly relevant to MDT practice across UK major trauma centres.

Limitations: Single-centre retrospective design limits generalisability and introduces selection bias in surgical case allocation.

Study Type: Retrospective two-centre cohort study

Key Question: Do younger and elderly GBM patients differ in molecular genetics (via NGS) and survival outcomes?

Key Findings:

• Elderly patients (≥65 years) had significantly shorter median OS (11.0 vs 18.0 months; p=0.001); multivariate analysis confirmed age as independent adverse prognostic factor (HR 1.961, p=0.002)
• MGMT methylation was more prevalent in elderly patients (p=0.009) and independently protective (HR 0.513, p=0.004); GTR and Stupp protocol completion also independently improved survival
• No NGS-derived mutation (including ATRX, MET, CDK6 amplification) reached statistical significance between age groups after correction for multiple testing

Clinical Relevance: Supports continued MGMT methylation testing across all age groups in NHS GBM pathways, as elderly patients may particularly benefit from temozolomide-based regimens despite lower Stupp protocol completion rates.

Limitations: Small sample (n=124) limits statistical power to detect molecular differences between age groups, and non-significant NGS trends should be interpreted cautiously.

Study Type: Prospective cohort study

Key Question: Does dominant-hemisphere petroclival meningioma resection via the extradural subtemporal approach cause distinct postoperative cognitive changes, and what are the corresponding neuroimaging correlates?

Key Findings:

• Dominant-side resection caused significant short-term cognitive decline across multiple domains (MMSE Δ−6.4, MoCA Δ−5.1, SDMT Δ−17.8); non-dominant-side resection did not
• rs-fMRI identified reduced spontaneous activity in left thalamus, middle temporal gyrus, and middle frontal gyrus, with attenuated cerebello-cortical and cerebello-subcortical functional connectivity in cognitively impaired patients
• Cognitive deficits and neuroimaging changes largely resolved by three months postoperatively

Clinical Relevance: For UK neurosurgeons managing skull base meningiomas, this highlights the need for structured preoperative counselling and postoperative cognitive monitoring in dominant-hemisphere cases, and supports three-month neuropsychological follow-up as a minimum standard.

Limitations: Very small sample (n=23, recruited over six months), limiting statistical power and generalisability.

Study Type: Retrospective validation study (single-centre, n=50)

Key Question: Can an agentic AI framework reliably replicate expert decision-making and surgical trajectory planning for spontaneous intracerebral haemorrhage?

Key Findings:

• AI treatment recommendations agreed with expert consensus in 82% of cases (41/50; κ=0.71), with discrepancies concentrated in borderline surgical candidates
• Automated trajectory planning generated feasible minimally invasive corridors in all 50 cases; median angular deviation from expert-defined trajectories was 7.6° (IQR 5.1–9.8°)
• AI-generated trajectories demonstrated equal or superior safety margins to expert planning in the majority of evacuation candidates

Clinical Relevance: This framework could reduce operator-dependent variability in ICH surgical planning, relevant to UK centres managing high case volumes with variable subspecialty expertise across regional neurosurgical networks.

Limitations: Small retrospective single-centre dataset of 50 cases limits generalisability, and prospective clinical validation with patient outcome data is absent.

Study Type: Single-arm meta-analysis (29 studies; n=2,943)

Key Question: What are the pooled postoperative visual field outcomes following endoscopic endonasal transsphenoidal surgery (EETS) for pituitary macroadenomas?

Key Findings:

• Visual field improvement achieved in 79% of patients (95% CI: 73–84%); complete normalisation in 41% (95% CI: 29–53%)
• Visual field deterioration was rare at 1% (95% CI: 0–1%); 19% remained unchanged
• Pooled CSF leak rate was 7% (95% CI: 4–10%)

Clinical Relevance: These figures provide benchmark outcome rates directly applicable to preoperative counselling for pituitary macroadenoma patients in UK neurosurgical practice, where EETS is now the standard approach.

Limitations: Significant heterogeneity in visual field testing methodology and follow-up timing across included studies limits the validity of pooled estimates as standardised recovery benchmarks.

Study Type: Case series with retrospective institutional database review

Key Question: Do genetic factors contribute to pineal cyst formation, and is there evidence for hereditary predisposition?

Key Findings:

• Monozygotic male triplets each harboured morphologically identical 14 mm pineal cysts despite differing clinical presentations
• Whole-exome sequencing identified a germline *HERC2* nonsense variant and a somatic *INO80E* frameshift mutation in cyst tissue, suggesting a possible two-hit oncogenic model
• Institutional database review (n=243) revealed familial clustering in four unrelated families, with identical cyst sizes in three of four families — all affected relatives were first-degree

Clinical Relevance: Incidental pineal cysts are frequently encountered in UK neurosurgical practice; evidence of hereditary clustering may prompt clinician awareness when taking family histories, though current surveillance protocols remain unaffected.

Limitations: Causality cannot be established from a single case and small retrospective database review; ascertainment bias is likely.

Study Type: Technical case report / operative "how I do it" description

Key Question: What surgical approach and technique achieves safe gross total resection of lateral-type posterior fossa ependymoma in a young child?

Key Findings:

• Single case of a 2-year-old presenting with torticollis and vomiting, harbouring a cerebellopontine angle ependymoma
• Gross total resection was achieved following pre-operative external ventricular drain insertion to manage hydrocephalus
• Authors assert GTR as the primary determinant of prognosis in this tumour subtype

Clinical Relevance: Lateral-type posterior fossa ependymomas are rare and technically demanding; this operative description may inform surgical planning for paediatric neurosurgeons managing similar cases at UK specialist centres.

Limitations: Single-case technical report with no outcome data, follow-up, or comparative series — no generalisable conclusions can be drawn regarding efficacy or safety.