Nonaneurysmal perimesencephalic subarachnoid hemorrhage on noncontrast head CT: An accuracy, inter-rater, and intra-rater reliability study.

BACKGROUND AND PURPOSE: To evaluate the reliability and accuracy of nonaneurysmal perimesencephalic subarachnoid hemorrhage (NAPSAH) on Noncontrast Head CT (NCCT) between numerous raters. MATERIALS AND METHODS: 45 NCCT of adult patients with SAH who also had a catheter angiography (CA) were independently evaluated by 48 diverse raters; 45 raters performed a second assessment one month later. For each case, raters were asked: 1) whether they judged the bleeding pattern to be perimesencephalic; 2) whether there was blood anterior to brainstem; 3) complete filling of the anterior interhemispheric fissure (AIF); 4) extension to the lateral part of the sylvian fissure (LSF); 5) frank intraventricular hemorrhage; 6) whether in the hypothetical presence of a negative CT angiogram they would still recommend CA. An automatic NAPSAH diagnosis was also generated by combining responses to questions 2-5. Reliability was estimated using Gwet's AC1 (κG), and the relationship between the NCCT diagnosis of NAPSAH and the recommendation to perform CA using Cramer's V test. Multi-rater accuracy of NCCT in predicting negative CA was explored. RESULTS: Inter-rater reliability for the presence of NAPSAH was moderate (κG = 0.58; 95%CI: 0.47, 0.69), but improved to substantial when automatically generated (κG = 0.70; 95%CI: 0.59, 0.81). The most reliable criteria were the absence of AIF filling (κG = 0.79) and extension to LSF (κG = 0.79). Mean intra-rater reliability was substantial (κG = 0.65). NAPSAH weakly correlated with CA decision (V = 0.50). Mean sensitivity and specificity were 58% (95%CI: 44%, 71%) and 83 % (95%CI: 72 %, 94%), respectively. CONCLUSION: NAPSAH remains a diagnosis of exclusion. The NCCT diagnosis was moderately reliable and its impact on clinical decisions modest.

Endovascular Management of Brain Arteriovenous Malformations.

Due to the risk of cerebral hemorrhage, and its related morbidity-mortality, brain arteriovenous malformations (bAVMs) are a rare and potentially life-threatening disease. Despite this, there is only one randomized controlled trial on bAVM management, A Randomized trial of Unruptured Brain Arteriovenous malformations (ARUBA). The results of the ARUBA trial favor a noninterventional approach in the case of an unruptured bAVM; however, implementation of these findings is challenging in daily practice. Instead, management of bAVM relies on multidisciplinary discussions that lead to patient-specific strategies based on patient preferences, local expertise, and experience in referral centers. Considering the diverse patterns of presentation and numerous treatment modalities, implementing standardized guidelines in this context proves challenging, notwithstanding the recommendations or expert opinions offered. Endovascular treatment (EVT) of bAVM can be curative, or can serve as an adjunct treatment prior to surgery or radiosurgery ("pre-EVT"). EVT practice is in constant evolution (i.e., venous approach, combination with surgery during the same anesthesia, etc.). Liquid embolic agents such as ethylene vinyl alcohol (EVOH) copolymer and cyanoacrylates (CYA), and their method of injection to increase bAVM occlusion have also benefited from technical evolutions such as the use of adjunctive flow arrest techniques (mini balloons, pressure cooker technique, and multiple catheters). Further research is necessary to evaluate the advantages and disadvantages of EVT for bAVM.

Clipping Versus Coiling for Ruptured MCA Aneurysms Associated with Intracerebral Hematoma Requiring Surgical Evacuation.

BACKGROUND: Ruptured middle cerebral artery aneurysm (MCAa) can lead to intracerebral hematoma, and surgical evacuation can be performed in these cases. MCAa can be treated by clipping or before by endovascular therapy (EVT). Our objective was to compare the impact on the functional outcome of MCAa in patients with intracerebral hematoma requiring evacuation. METHODS: This is a multicenter, retrospective, cohort study with nine French neurosurgical units from January 1, 2013, to December 31, 2020. All participants were adult patients who required evacuation of an intracerebral hematoma. We looked for risk factors for poor outcomes by comparing the baseline characteristics and treatments performed by using the 6-month modified Rankin scale score. Poor outcomes were defined by an modified Rankin scale score of 3-6. RESULTS: A total of 162 patients were included. A total of 129 (79.6%) patients were treated by microsurgery, and 33 (20.4%) patients were treated by EVT. In multivariate analysis, factors associated with poor outcomes included hematoma volume, realization of a decompressive craniectomy, occurrence of procedure-related symptomatic cerebral ischemia, occurrence of delayed cerebral ischemia, and EVT. In the propensity score matching analysis (n = 33 per group), poor outcomes were observed in 30% of the patients in the clipping group versus 76% in the EVT group (P < 0.001). These differences may have been related to a longer delay between hospital admission and hematoma evacuation in the EVT group. CONCLUSIONS: In the specific subgroup of ruptured MCAa with intracerebral hematoma that requires surgical evacuation, clipping with concomitant hematoma evacuation could provide better functional outcomes than EVT followed by surgical evacuation.

Angiographic results of surgical or endovascular treatment of intracranial aneurysms: a systematic review and inter-observer reliability study.

PURPOSE: Results of surgical or endovascular treatment of intracranial aneurysms are often assessed using angiography. A reliable method to report results irrespective of treatment modality is needed to enable comparisons. Our goals were to systematically review existing classification systems, and to propose a 3-point classification applicable to both treatments and assess its reliability. METHODS: We conducted two systematic reviews on classification systems of angiographic results after clipping or coiling to select a simple 3-category scale that could apply to both treatments. We then circulated an electronic portfolio of angiograms of clipped (n=30) or coiled (n=30) aneurysms, and asked raters to evaluate the degree of occlusion using this scale. Raters were also asked to choose an appropriate follow-up management for each patient based on the degree of occlusion. Agreement was assessed using Krippendorff's α statistics (αK), and relationship between occlusion grade and clinical management was analyzed using Fisher's exact and Cramer's V tests. RESULTS: The systematic reviews found 70 different grading scales with heterogeneous reliability (kappa values from 0.12 to 1.00). The 60-patient portfolio was independently evaluated by 19 raters of diverse backgrounds (neurosurgery, radiology, and neurology) and experience. There was substantial agreement (αK=0.76, 95%CI, 0.67-0.83) between raters, regardless of background, experience, or treatment used. Intra-rater agreement ranged from moderate to almost perfect. A strong relationship was found between angiographic grades and management decisions (Cramer's V: 0.80±0.12). CONCLUSION: A simple 3-point scale demonstrated sufficient reliability to be used in reporting aneurysm treatments or in evaluating treatment results in comparative randomized trials.

Comparing N-hexyl cyanoacrylate (Magic Glue) and N-butyl cyanoacrylate (NBCA) for neurovascular embolization using the pressure cooker technique: An experimental study in swine.

BACKGROUND: The pressure cooker (PC) technique uses a second microcatheter to produce a proximal occlusion to prevent the reflux of liquid embolic agent (LEA) injected through a more distal microcatheter, and can be used to treat arteriovenous malformations and dural arteriovenous fistulae. The liquid embolic Magic Glue (MG) (N-hexyl cyanoacrylate (NHCA)) has been introduced as an alternative to N-butyl cyanoacrylate (NBCA). Our goals were to compare the extent of embolization of rete mirabile with or without the PC technique using NBCA or MG, and to compare the proximal occlusions obtained with MG or NBCA while using the PC technique in a renal arterial model. METHODS: Rete mirabile were embolized with (n = 4) and without (n = 4) the PC technique, using MG (n = 4) or NBCA (n = 4). A renal arterial model was then used to study the characteristics of the MG plug (n = 10) used for the PC technique, and resistance to catheter withdrawal as compared to NBCA (n = 4). Specimens were analyzed macro- and microscopically and compared to angiographic results. RESULTS: Extent of rete embolization with CYA agents was not significantly greater when using the PC technique. Results were similar with both types of cyanoacrylate (p = 0.657). The force necessary to withdraw the microcatheter was less with MG than with NBCA (p = 0.035). CONCLUSION: MG was similar to NBCA in extent of rete embolization. Less traction force was necessary to withdraw trapped non-detachable microcatheters using MG compared to NBCA.

Arteriovenous malformations of the posterior fossa: a systematic review.

BACKGROUND: Posterior fossa arteriovenous malformations (pfAVMs) can be challenging lesions to manage. AVMs in this location may have distinct features compared with supratentorial AVMs. Our aim was to systematically review the literature on the presenting characteristics of pfAVMs and compare clinical and angiographic outcomes after the various types of treatment employed. METHODS: The review was conducted according to the Cochrane Collaboration guidelines. Electronic databases from 1900 to March 2018 were searched and complemented by hand-searching and cross-referencing. Articles were categorized into (i) AVM studies that included those in the posterior fossa, (ii) those that focused exclusively on pfAVM, and (iii) those that further specified a cerebellar or brainstem location of the AVM. RESULTS: Seventy-seven articles with 4512 pfAVM patients were retained for analyses. Compared with historical supratentorial controls, pfAVMs were reported to more frequently present with rupture, to more commonly have associated arterial aneurysms, and to more frequently lead to poor clinical and angiographic outcomes. The quality of the literature and lack of standardization of outcome reporting precluded performing a meta-analysis on the results of the various different treatment modalities. CONCLUSIONS: Posterior fossa AVMs may have some distinct features compared with supratentorial AVMs. The available reports on pfAVMs are not sufficiently standardized to provide reliable guidance for patient management decisions. This goal will require future studies to be multicentric and to focus on standardized, repeatable clinical and angiographic outcomes.

Innate immunity activation in the early brain injury period following subarachnoid hemorrhage.

BACKGROUND: Aneurysmal subarachnoid hemorrhage (SAH) is a catastrophic disease with devastating consequences, including a high mortality rate and severe disabilities among survivors. Inflammation is induced following SAH, but the exact role and phenotype of innate immune cells remain poorly characterized. We investigated the inflammatory components of the early brain injury in an animal model and in SAH patients. METHOD: SAH was induced through injection of blood in the subarachnoid space of C57Bl/6 J wild-type mice. Prospective blood collections were obtained at 12 h, days 1, 2, and 7 to evaluate the systemic inflammatory consequences of SAH by flow cytometry and enzyme-linked immunosorbent-assay (ELISA). Brains were collected, enzymatically digested, or fixed to characterize infiltrating inflammatory cells and neuronal death using flow cytometry and immunofluorescence. Phenotypic evaluation was performed at day 7 using the holding time and footprint tests. We then compared the identified inflammatory proteins to the profiles obtained from the plasma of 13 human SAH patients. RESULTS: Following SAH, systemic IL-6 levels increased rapidly, whereas IL-10 levels were reduced. Neutrophils were increased both in the brain and in the blood reflecting local and peripheral inflammation following SAH. More intracerebral pro-inflammatory monocytes were found at early time points. Astrocyte and microglia activation were also increased, and mice had severe motor deficits, which were associated with an increase in the percentage of caspase-3-positive apoptotic neurons. Similarly, we found that IL-6 levels in patients were rapidly increased following SAH. ICAM-1, bFGF, IL-7, IL-12p40, and MCP-4 variations over time were different between SAH patients with good versus bad outcomes. Moreover, high levels of Flt-1 and VEGF at admission were associated with worse outcomes. CONCLUSION: SAH induces an early intracerebral infiltration and peripheral activation of innate immune cells. Furthermore, microglia and astrocytic activation are present at later time points. Our human and mouse data illustrate that SAH is a systemic inflammatory disease and that immune cells represent potential therapeutic targets to help this population of patients in need of new treatments.

Clipping of a PICA aneurysm located on the contralateral side of its parent vertebral artery in front of the brainstem: how I do it.

BACKGROUND: Vertebro-PICA aneurysms may be challenging because of their relationship with the brainstem and the lower cranial nerves, especially when the vertebral artery is tortuous and the aneurysm is located in front of the brainstem, contralaterally to the parent vertebral artery. We describe the surgical technique for safe approach. METHOD: Cadaveric dissection performed by the authors, provided comprehensive understanding of relevant anatomy. Intraoperative photos and videos show clipping of the aneurysm using a combined midline and far-lateral suboccipital craniotomy with a para-condylar extension. The literature reviews potential complications. CONCLUSION: This combined approach allows safe clipping of such PICA aneurysms.

[Meningeal melanoma arising from a preexisting meningeal melanocytoma: A clinical, pathological and cytogenetic study about one case]. / Transformation d'un mélanocytome méningé en mélanome : étude clinique, histopathologique et cytogénétique.

Meningeal melanocytic tumors are rare. We report an exceptional case of transformation of a meningeal melanocytoma in a malignant melanoma. The course of the disease extents from 61-years to 85-years and ends with the death of the patient. Besides histopathological and immunohistochemical data, we also report the array CGH study of the melanocytoma and melanoma components suggesting the malignant transformation from whole chromosome gains in the melanocytoma to additional segmental aberrations in the malignant melanoma. Beyond the rarity of this tumor subtype, this case report highlights the potential interest of molecular analyses for diagnostic and prognostic purposes in the field of meningeal melanocytic tumors.

A new time-resolved 3D angiographic technique (4D DSA): Description, and assessment of its reliability in Spetzler-Martin grading of cerebral arteriovenous malformations.

BACKGROUND AND PURPOSE: The Spetzler and Martin (SM) cerebral arteriovenous malformation (AVM) classification is a widely used 5-tier classification. This common language allows specialists to exchange about AVMs and must be reliably characterized by the imaging methods. We presented an agreement study on a new method of digital subtracted 3D rotational angiography resolved in time (four-dimensional DSA: 4D DSA) compared to the gold standard (two-dimensional DSA: 2D DSA) in AVM grading using the SM classification. METHODS: Ten patients with AVMs were included during one year, they had an angiographic exploration with both 4D DSA and 2D DSA. Three readers assessed the SM classification. One reader conducted a second reading. The inter-, intra-observer and intermodality agreements were calculated by Kappas. Dose to patient was reported. RESULTS: Considering the SM grade, the inter-observer agreement between 4D DSA and 2D DSA was equivalent (κ=0.45 and 0.46), and calculated as substantial κ=0.76 between the 2 methods. The agreement between 4D DSA and 2D DSA was calculated as moderate κ=0.46 assessing the size of the nidus, slight κ=0.18 analyzing the drainage and almost perfect κ=0.95 depicting the localization. 4D DSA performed during a standard initial angiographic assessment of AVM represented approximately 6% of the total dose. CONCLUSION: The addition of this new technique 4D DSA could be performed regularly in addition to the 2D DSA if available, to assess SM grading, with an acceptable exposure to ionizing radiation.

Surgical clipping or endovascular coiling for unruptured intracranial aneurysms: a pragmatic randomised trial.

BACKGROUND: Unruptured intracranial aneurysms (UIAs) are increasingly diagnosed and are commonly treated using endovascular treatment or microsurgical clipping. The safety and efficacy of treatments have not been compared in a randomised trial. How to treat patients with UIAs suitable for both options remains unknown. METHODS: We randomly allocated clipping or coiling to patients with one or more 3-25 mm UIAs judged treatable both ways. The primary outcome was treatment failure, defined as: initial failure of aneurysm treatment, intracranial haemorrhage or residual aneurysm on 1-year imaging. Secondary outcomes included neurological deficits following treatment, hospitalisation >5 days, overall morbidity and mortality and angiographic results at 1 year. RESULTS: The trial was designed to include 260 patients. An analysis was performed for slow accrual: 136 patients were enrolled from 2010 through 2016 and 134 patients were treated. The 1-year primary outcome, available for 104 patients, was reached in 5/48 (10.4% (4.5%-22.2%)) patients allocated surgical clipping, and 10/56 (17.9% (10.0%-29.8%)) patients allocated endovascular coiling (OR: 0.54 (0.13-1.90), p=0.40). Morbidity and mortality (modified Rankin Scale>2) at 1 year occurred in 2/48 (4.2% (1.2%-14.0%)) and 2/56 (3.6% (1.0%-12.1%)) patients allocated clipping and coiling, respectively. New neurological deficits (15/65 vs 6/69; OR: 3.12 (1.05-10.57), p=0.031), and hospitalisations beyond 5 days (30/65 vs 6/69; OR: 8.85 (3.22-28.59), p=0.0001) were more frequent after clipping. CONCLUSION: Surgical clipping or endovascular coiling of UIAs did not show differences in morbidity at 1 year. Trial continuation and additional randomised evidence will be necessary to establish the supposed superior efficacy of clipping.

Chronic subdural haematomas in elderly population. Neurosurgical aspects and focus on the single-burr hole technique performed under assisted local anaesthesia.

OBJECTIVE: Chronic subdural haematomas (CSDH) is a common pathology that usually affects the elderly population. The incidence of CSDH has recently been increasing with the expansion of the aging population. The objective of our study was to evaluate the outcome following surgical drainage of CSDH in elderly patients. MATERIALS AND METHODS: We performed a retrospective analysis of 455 consecutive patients with CSDHs over a 5-year period. Among them, all 121 patients older than 80-year old were included in the study. Clinical status, comorbidities, type of surgical technique and outcome were analyzed. Outcome at last follow-up was measured using the Markwalder grading score and the Glasgow outcome scale. RESULTS: Patients ranged from 80- to 94-year old with a median age of 84 years (range 80-94). Ninety-eight percent of patients were surgically treated by a small burr hole under assisted local anaesthesia. About 69.2% of patients improved post-operatively. The mortality rate was 6.8%. CONCLUSION: CSDH is a common pathology in the elderly population. Patients with CSDHs often have comorbodities that need to be considered in deciding whether surgical treatment is indicated. When surgery is elected, small craniostomy techniques performed under assisted local anesthesia is safe and should be favored in this frail population.

The Treatment of Brain Arteriovenous Malformation Study (TOBAS): A preliminary inter- and intra-rater agreement study on patient management.

OBJECT: The best management of brain arteriovenous malformation (bAVM) patients remains unknown. Randomized allocation may be more readily accepted when there is uncertainty and disagreement regarding the management of potential participants. In planning for a trial, we aimed to assess variability and agreement among physicians managing bAVM patients. METHODS: A portfolio composed of 35 patients was sent to 47 clinicians of various specialties managing bAVM patients. For each patient, physicians were asked their best management decision (surgery/embolization/radiosurgery/conservative), their confidence level, and whether they would include the patient in a randomized trial comparing conservative and curative management. Seven physicians, who had access to all images of each patient, independently responded twice, to assess inter and intra-rater agreement using kappa statistics. RESULTS: The inter-rater agreement (30 raters, including 16 neuroradiologists) for best management decision was only "fair" (κ [95%CI]=0.210[0.157; 0.295]). Agreement remained below 'substantial' (κ<.6) between physicians of the same specialty, and when no distinctions were made between various treatments (when responses were dichotomized as conservative versus curative). With access to all images the inter-rater agreement remained fair. The intra-rater agreement reached "substantial" only for the dichotomized decisions. Responding clinicians were willing to include 54.4% of patients (mainly unruptured bAVMs) in a randomized trial. CONCLUSION: There is a lack of agreement among clinicians involved in the management of bAVM patients. In this study a substantial proportion of clinicians were willing to offer randomized allocation of management options to a substantial number of patients.

Comparison of injection/dissection and injection/corrosion methods: example of vertebral veins in the transverse canal.

PURPOSE: In order to contribute some new elements to the discussion on the organization of the vertebral veins inside the transverse canal, we compared two dissection techniques: injection/dissection and injection/corrosion. The aim of this study was to compare these two techniques to study the vertebral veins, and also to emphasize the importance of preserving specimens in anatomical museums. METHODS: Using the injection/dissection technique, latex was injected into ten specimens, then the transverse canal was opened to expose the vertebral veins and their anastomoses. Using the injection/corrosion technique, altufix was injected into eight specimens that were afterwards plunged in sulfuric acid and washed daily until complete corrosion was obtained. RESULTS: Both techniques showed concordant results. The vertebral veins were plexuous, located ventro-laterally to the artery and received constant metamerical branches at each level. The injection/dissection technique conserved the anatomical relationships allowing metamerical analysis of the vertebral veins. The injection/corrosion technique, however, failed to conserve these relationships but provided a precise visualization of smaller anastomosis. CONCLUSIONS: By analyzing different aspects of the vertebral veins anatomy in the transverse canal, the two techniques complete each other. This study emphasizes the importance of preserving the anatomical preparations: in addition to the historical and cultural value of these preparations, they contain precious information that furthers our anatomical knowledge.

Connectivity within the primary motor cortex: a DTI tractography study.

PURPOSE: Because of the motor function of the precentral area, the connections of the primary motor cortex by white matter fiber bundles have been widely studied in diffusion tensor imaging (DTI). Nevertheless, the connections within the primary motor cortex have yet to be explored. We have studied the connectivity between the different regions of the precentral gyrus in a population of subjects. METHODS: Based on T1 magnetic resonance imaging (MRI) and on individual sulco-gyral anatomy, we defined a parcellation of the right and the left precentral gyri in 20 healthy subjects (10 right-handers; 10 left-handers). This parcellation gave us the opportunity to study MRI tracks reconstructed by tractography within the precentral gyrus and to compare these connections across subjects. We also performed a classical dissection of post-mortem brain tissue to isolate this pattern of connectivity. RESULTS: We showed MRI tracks connecting the different parts of the same precentral gyrus. This result was reproducible and was found in the left and right hemispheres of the 20 subjects. A quantitative description of the bilateral distribution of the MRI tracks was performed, based on statistical analysis and asymmetry indices, to compare asymmetry and handedness. CONCLUSIONS: To the best of our knowledge, this pattern of connectivity has never before been detailed in the literature. Its functional meaning remains to be determined, which requires further study.

Corticospinal tract asymmetry and handedness in right- and left-handers by diffusion tensor tractography.

PURPOSE: Cerebral hemispheres represent both structural and functional asymmetry, which differs among right- and left-handers. The left hemisphere is specialised for language and task execution of the right hand in right-handers. We studied the corticospinal tract in right- and left-handers by diffusion tensor imaging and tractography. The present study aimed at revealing a morphological difference resulting from a region of interest (ROI) obtained by functional MRI (fMRI). METHODS: Twenty-five healthy participants (right-handed: 15, left-handed: 10) were enrolled in our assessment of morphological, functional and diffusion tensor MRI. Assessment of brain fibre reconstruction (tractography) was done using a deterministic algorithm. Fractional anisotropy (FA) and mean diffusivity (MD) were studied on the tractography traces of the reference slices. RESULTS: We observed a significant difference in number of leftward fibres based on laterality. The significant difference in regard to FA and MD was based on the slices obtained at different levels and the laterality index. We found left-hand asymmetry and right-hand asymmetry, respectively, for the MD and FA. CONCLUSIONS: Our study showed the presence of hemispheric asymmetry based on laterality index in right- and left-handers. These results are inconsistent with some studies and consistent with others. The reported difference in hemispheric asymmetry could be related to dexterity (manual skill).

Contribution of embryology in the understanding of cervical venous system anatomy within and around the transverse foramen: a review of the classical literature.

Anatomic arrangement of venous system within the transverse foramen is a controversial topic among authors. Precise knowledge of this arrangement is necessary in imaging where vertebral artery dissection is suspected, as well as in surgical approaches of cervical spine. This knowledge objective cannot be achieved without a prerequisite knowledge of primitive venous system. We present here an update on the development of the transverse foramen venous system through a literature review. Our review of the classical literature aimed at synthesis of available related embryological knowledge and relating this synthesis to cervical vertebrae anatomy. Our findings with regard to different primitive descriptions were consistent and often complementary across the studies. The description has varied from a single vertebral vein to a single vein divided at certain areas, or even to a confluence of venous plexus. In this manner, the embryonic knowledge for instance on venous system can help us to better understand the segmental development of vertebral veins and their plexus arrangement. Furthermore, the cranial-caudal embryology, in particular of the nervous system, conveys the initial plexiform arrangement of vertebral veins, which ends into a single venous trunk joining the subclavian vein.

Indications for surgical evacuation of cerebellar intracerebral hemorrhage: consensus guidelines from the French Society of Neurosurgery (SFNC) and the French Society of Vascular Neurology (SFNV).

BACKGROUND: Cerebellar intracerebral hemorrhage (ICH) is associated with poor functional prognosis and high mortality. Surgical evacuation has been proposed to improve outcome. The purpose of this review was to determine the benefit of surgical evacuation of cerebellar ICH and to establish guidelines for when it should be performed. METHOD: The writing committee comprised 9 members of the SFNV and the SFNC. Recommendations were established based on a literature review using the PICO questions. The American Heart Association (AHA) classification was used to define recommendation level. In case of insufficient evidence, expert opinions were provided. RESULTS: Levels of evidence were low to moderate, precluding definitive recommendations. Based on available data, surgical hematoma evacuation is not recommended to improve functional outcome (Class III; Level B NR). However, based on subgroup analysis, surgical evacuation may be considered in strictly selected patients (Class IIb; Level C-EO): hematoma volume 15-25 cm3, GCS 6-10, and no oral anticoagulation or antiplatelet therapy. Moreover, surgical evacuation is recommended to decrease risk of death (Class IIa; Level B NR) in patients with a hematoma volume >15 cm3 and GCS score <10. CONCLUSION: These guidelines were based on observational studies, limiting the level of evidence. However, except for strictly selected patients, surgical evacuation of cerebellar ICH was not associated with improved functional outcome, limiting indications. Data from RCTs are needed in this field.