Rehemorrhage of brainstem cavernous malformations: a benchmark approach to individualized risk and severity assessment.

OBJECTIVE: Brainstem cavernous malformations (BSCMs) represent a unique subgroup of cavernous malformations with more hemorrhagic presentation and technical challenges. This study aimed to provide individualized assessment of the rehemorrhage clustering risk of BSCMs after the first symptomatic hemorrhage and to identify patients at higher risk of neurological deterioration after new hemorrhage, which would help in clinical decision-making. METHODS: A total of 123 consecutive BSCM patients with symptomatic hemorrhage were identified between 2015 and 2022, with untreated follow-up > 12 months or subsequent hemorrhage during the untreated follow-up. Nomograms were proposed to individualize the assessment of subsequent hemorrhage risk and neurological status (determined by the modified Rankin Scale [mRS] score) after future hemorrhage. The least absolute shrinkage and selector operation (LASSO) regression was used for feature screening. The calibration curve and concordance index (C-index) were used to assess the internal calibration and discrimination performance of the nomograms. Cross-validation was further performed to validate the accuracy of the nomograms. RESULTS: Prior hemorrhage times (adjusted OR [aOR] 6.78 per ictus increase) and Zabramski type I or V (OR 11.04) were associated with rehemorrhage within 1 year. A lower mRS score after previous hemorrhage (aOR 0.38 for a shift to a higher mRS score), Zabramski type I or V (OR 3.41), medulla or midbrain location (aOR 2.77), and multiple cerebral cavernous malformations (aOR 11.76) were associated with worsened neurological status at subsequent hemorrhage. The nomograms showed good accuracy and discrimination, with a C-index of 0.80 for predicting subsequent hemorrhage within 1 year and 0.71 for predicting neurological status after subsequent hemorrhage, which were maintained in cross-validation. CONCLUSIONS: An individualized approach to risk and severity assessment of BSCM rehemorrhage was feasible with clinical and imaging features.

Comparative studies of the diagnosis and treatment of cerebral cavernous malformations in adults: systematic review.

BACKGROUND: Cerebral cavernous malformation (CCM) management decisions are usually made after CCM diagnosis is suspected or definitively diagnosed on axial imaging by indirectly comparing a surgeon's estimate of operative morbidity and mortality against published estimates of CCM untreated clinical course. METHODS: We used comprehensive electronic strategies to search OVID Medline and EMBASE for original studies published before 2011 of ≥20 adults with CCM that (a) evaluated diagnostic test accuracy, or (b) compared treatment with microsurgery or stereotactic radiosurgery against conservative management in a concurrent or historical control group and reported clinical outcome(s). We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group's approach to identify level 1 or level 2 studies according to the Oxford Centre for Evidence-Based Medicine's 2011 criteria. RESULTS: We found one eligible diagnostic test accuracy study of 72 patients with brain masses accompanied by vasogenic edema and substantial amounts of blood, which found that hyperintense perilesional signal on T1-weighted magnetic resonance imaging could differentiate CCM from other causes with excellent specificity (98 %) and reasonable sensitivity (62 %). We found five potentially eligible observational studies of adults with a CCM that had already bled, but none met level 2 criteria for a "dramatic" effect (the conventionally calculated probability of the two groups of observations coming from the same population should be less than 0.01 and a rate ratio greater than 10). We found 11 potentially eligible observational studies of adults with CCM and epilepsy, but nine studies did not demonstrate dramatic effects and the remaining two studies showed dramatic effects, but they were at high risk of bias. CONCLUSIONS: To address the absence of level 1 or 2 evidence to support CCM treatment decisions, there is a need for large studies of CCM treatment with a concurrent control group, ideally with randomized treatment allocation.

Post-operative remnants of brainstem cavernomas: incidence, risk factors and management.

INTRODUCTION: The risk of leaving a remnant after surgery for a cavernous malformation in the brainstem is generally not stressed enough, even though such remnants appear to have a high risk of re-bleeding. At least 40% of known cavernoma remnants after surgery have further bleeding episodes. A retrospective analysis of 30 patients with brainstem cavernoma who underwent surgery is presented, focusing on incidence, risk factors and management of post-surgical residuals. The sites were, medulla in three patients, pons-medulla in four, pons in 16, pons-midbrain in four and midbrain in three. All 30 patients came to our clinical observation with at least one episode of acute-onset neurological deficit and all were operated in the sub-acute phase. Only one patient had a worse stable outcome than the pre-surgical state, and 29 did better or were stable. All patients had a brain MRI scan within 72 h after surgery to confirm that complete removal had been achieved. In three, although the surgical cavity and its border appeared clean at the end of surgery, with no lesion remaining, post-operative MRI detected a residuum. These three patients were re-operated, but one had a further bleed prior to excision. MATERIALS AND METHODS: In our series, the surgical finding of a multi-lobular cavernoma (as opposed to the more frequent finding of a discrete lesion with a thick capsule), with a thin wall and satellite nodules separated by a thin layer of apparently intact white matter, was common (seven patients). This group included the three patients with evidence of residuum on post-operative MRI. In our experience, the surgical finding of a multi-lobular cavernoma carries a higher risk of residuum and post-surgical re-bleeding. CONCLUSION: Immediate post-operative brain MRI scans are therefore strongly recommended for their detection, especially in this group of patients, and if a residual is detected early re-intervention is less risky than the natural history.