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OBJECTIVE Anatomical taxonomy is a practical tool to successfully guide clinical decision-making for patients with brain arteriovenous malformations and brainstem cavernous malformations (CMs). Deep cerebral CMs are complex, difficult to access, and highly variable in size, shape, and position. The authors propose a novel taxonomic system for deep CMs in the thalamus based on clinical presentation (syndromes) and anatomical location (identified on MRI). METHODS The taxonomic system was developed and applied to an extensive 2-surgeon experience from 2001 through 2019. Deep CMs involving the thalamus were identified. These CMs were subtyped on the basis of the predominant surface presentation identified on preoperative MRI. Six subtypes among 75 thalamic CMs were defined: anterior (7/75, 9%), medial (22/75, 29%), lateral (10/75, 13%), choroidal (9/75, 12%), pulvinar (19/75, 25%), and geniculate (8/75, 11%). Neurological outcomes were assessed using modified Rankin Scale (mRS) scores. A postoperative score ≤ 2 was defined as a favorable outcome and > 2 as a poor outcome. Clinical and surgical characteristics and neurological outcomes were compared among subtypes. RESULTS Seventy-five patients underwent resection of thalamic CMs and had clinical and radiological data available. Their mean age was 40.9 (SD 15.2) years. Each thalamic CM subtype was associated with a recognizable constellation of neurological symptoms. The common symptoms were severe or worsening headaches (30/75, 40%), hemiparesis (27/75, 36%), hemianesthesia (21/75, 28%), blurred vision (14/75, 19%), and hydrocephalus (9/75, 12%). The thalamic CM subtype determined the selection of surgical approach. A single approach was associated with each subtype for most patients. The main exception to this paradigm was that in the surgeons’ early experience, pulvinar CMs were resected through a superior parietal lobule–transatrial approach (4/19, 21%), which later evolved to the paramedian supracerebellar-infratentorial approach (12/19, 63%). Relative outcomes implied by mRS scores were unchanged or improved in most patients (61/66, 92%) postoperatively. CONCLUSIONS This study confirms the authors’ hypothesis that this taxonomy for thalamic CMs can meaningfully guide the selection of surgical approach and resection strategy. The proposed taxonomy can increase diagnostic acumen at the patient bedside, help identify optimal surgical approaches, enhance the clarity of clinical communications and publications, and improve patient outcomes.

OBJECTIVE Giant cerebral cavernous malformations (GCCMs) are rare vascular malformations. Unlike for tumors and aneurysms, there is no clear definition of a "giant" cavernous malformation (CM). As a result of variable definitions, working descriptions and outcome data of patients with GCCM are unclear. A new definition of GCCM related to surgical outcomes is needed. METHODS An institutional database was searched for all patients who underwent resection of CMs > 1 cm in diameter. Patient information, surgical technique, and clinical and radiographic outcomes were assessed. A systematic review was performed to augment an earlier published review. RESULTS In the authors’ institutional cohort of 183 patients with a large CM, 179 with preoperative and postoperative modified Rankin Scale (mRS) scores were analyzed. A maximum CM diameter of ≥ 3 cm was associated with greater risk of severe postoperative decline (≥ 2-point increase in mRS score). After adjustment for age and deep versus superficial location, size ≥ 3 cm was strongly predictive of severe postoperative decline (OR 4.5, 95% CI 1.2–16.9). A model with CM size and deep versus superficial location was developed to predict severe postoperative decline (area under the receiver operating characteristic curve 0.79). Thirteen more patients with GCCMs have been reported in the literature since the most recent systematic review, including some patients who were treated earlier and not discussed in the previous review. CONCLUSIONS The authors propose that cerebral CMs with a diameter ≥ 3 cm be defined as GCCMs on the basis of the inflection point for functional and neurological outcomes. This definition is in line with the definitions for other giant lesions. It is less exclusive than earlier definitions but captures the rarity of these lesions (approximately 1% incidence) and variation in outcomes. GCCMs remain operable with potentially favorable outcomes. The term "giant" is not meant to deter or contraindicate surgery.

OBJECTIVE Part 2 of this 2-part series on pontine cavernomas presents the taxonomy for subtypes 4–6: inferior peduncular (IP) (subtype 4), rhomboid (5), and supraolivary (6). (Subtypes 1–3 are presented in Part 1.) The authors have proposed a novel taxonomy for pontine cavernous malformations based on clinical presentation (syndromes) and anatomical location (MRI findings). METHODS The details of taxonomy development are described fully in Part 1 of this series. In brief, pontine lesions (323 of 601 [53.7%] total lesions) were subtyped on the basis of predominant surface presentation identified on preoperative MRI. Neurological outcomes were assessed according to the modified Rankin Scale, with score ≤ 2 defined as favorable. RESULTS The 323 pontine brainstem cavernous malformations were classified into 6 distinct subtypes: basilar (6 [1.9%]), peritrigeminal (53 [16.4%]), middle peduncular (100 [31.0%]), IP (47 [14.6%]), rhomboid (80 [24.8%]), and supraolivary (37 [11.5%]). Subtypes 4–6 are the subject of the current report. IP lesions are located in the inferolateral pons and are associated with acute vestibular syndrome. Rhomboid lesions present to the fourth ventricle floor and are associated with disconjugate eye movements. Larger lesions may cause ipsilateral facial weakness. Supraolivary lesions present to the surface at the ventral pontine underbelly. Ipsilateral abducens palsy is a strong localizing sign for this subtype. A single surgical approach and strategy were preferred for subtypes 4–6: for IP cavernomas, the suboccipital craniotomy and telovelar approach predominated; for rhomboid lesions, the suboccipital craniotomy and transventricular approach were preferred; and for supraolivary malformations, the far lateral craniotomy and transpontomedullary sulcus approach were preferred. Favorable outcomes were observed in 132 of 150 (88%) patients with follow-up. There were no significant differences in outcomes between subtypes. CONCLUSIONS The neurological symptoms and signs associated with a hemorrhagic pontine subtype can help define that subtype clinically with key localizing signs. The proposed taxonomy for pontine cavernous malformation subtypes 4–6 meaningfully guides surgical strategy and may improve patient outcomes.

OBJECTIVE Safe entry zones (SEZs) enable safe tissue transgression to lesions beneath the brainstem surface. However, evidence for the safety of SEZs is scarce and is based on anatomical studies, case reports, and small series. METHODS A cohort of 154 patients who underwent microsurgical brainstem cavernous malformation (BSCM) treatment during a 23-year period and who had preoperative MR images and intraoperative photographs or videos was retrospectively examined. This study assessed the safety of SEZs for access to deep BSCMs, preoperative MRI to predict BSCM surface proximity, and the relationships between BSCM subtype, surgical approach, and SEZs. Lesions were characterized as exophytic, superficial, or deep on the basis of preoperative MRI and intraoperative inspection. Outcomes were scored as good (modified Rankin Scale [mRS] score ≤ 2) or poor (mRS score > 2) and relative outcomes as stable/improved or worse relative to baseline (± 1 point). RESULTS Resections included 34 (22%) in the midbrain, 102 (66%) in the pons, and 18 (12%) in the medulla. Of those, 23 (15%) were exophytic, 57 (37%) were superficial, and 74 (48%) were deep. Established SEZs were used for 97% (n = 72) of deep lesions; the preferred SEZ associated with its subtype was used for 91% (n = 67). MR images accurately depicted exophytic BSCMs that did not require SEZ approaches (sensitivity, 96%) but overestimated the proximity of lesions superficial to brainstem surfaces (specificity, 67%), resulting in unanticipated SEZ use. Final neurological outcomes were good in 80% of patients with follow-up data (119/149), and relative outcomes were stable/improved in 93% (139/149). Outcomes for patients with brainstem transgression through an SEZ did not differ from outcomes for patients with superficial or exophytic lesions that did not require SEZ use (final mRS score ≤ 2 in 72% of all patients with deep lesions vs 82% of all patients with superficial or exophytic lesions [p = 0.10]). Among patients with follow-up, the rates of permanent new cranial nerve deficits in patients with deep BSCMs and superficial or exophytic BSCMs were 21% and 20%, respectively (p = 0.81), with no significant change in overall cranial nerve deficit (0 and −1, p = 0.65). CONCLUSIONS Neurological outcomes for patients with deep BSCMs were equivalent to those for superficial or exophytic BSCMs, validating the safety of SEZs for deep BSCMs. Preoperative T1-weighted MR images overestimated the lesion’s surface proximity, necessitating detailed knowledge of SEZs and readiness to use them in cases of radiological-microsurgical discordance. Most patients achieved favorable outcomes despite the transgression of eloquent brainstem tissue in and around SEZs.

OBJECTIVE Brainstem cavernous malformations (BSCMs) are complex, difficult to access, and highly variable in size, shape, and position. The authors have proposed a novel taxonomy for pontine cavernous malformations (CMs) based upon clinical presentation (syndromes) and anatomical location (findings on MRI). METHODS The proposed taxonomy was applied to a 30-year (1990–2019), 2-surgeon experience. Of 601 patients who underwent microsurgical resection of BSCMs, 551 with appropriate data were classified on the basis of BSCM location: midbrain (151 [27%]), pons (323 [59%]), and medulla (77 [14%]). Pontine lesions were then subtyped on the basis of their predominant surface presentation identified on preoperative MRI. Neurological outcomes were assessed according to the modified Rankin Scale, with a score ≤ 2 defined as favorable. RESULTS The 323 pontine BSCMs were classified into 6 distinct subtypes: basilar (6 [1.9%]), peritrigeminal (53 [16.4%]), middle peduncular (MP) (100 [31.0%]), inferior peduncular (47 [14.6%]), rhomboid (80 [24.8%]), and supraolivary (37 [11.5%]). Part 1 of this 2-part series describes the taxonomic basis for the first 3 of these 6 subtypes of pontine CM. Basilar lesions are located in the anteromedial pons and associated with contralateral hemiparesis. Peritrigeminal lesions are located in the anterolateral pons and are associated with hemiparesis and sensory changes. Patients with MP lesions presented with mild anterior inferior cerebellar artery syndrome with contralateral hemisensory loss, ipsilateral ataxia, and ipsilateral facial numbness without cranial neuropathies. A single surgical approach and strategy were preferred for each subtype: for basilar lesions, the pterional craniotomy and anterior transpetrous approach was preferred; for peritrigeminal lesions, extended retrosigmoid craniotomy and transcerebellopontine angle approach; and for MP lesions, extended retrosigmoid craniotomy and trans–middle cerebellar peduncle approach. Favorable outcomes were observed in 123 of 143 (86%) patients with follow-up data. There were no significant differences in outcomes between the 3 subtypes or any other subtypes. CONCLUSIONS The neurological symptoms and key localizing signs associated with a hemorrhagic pontine subtype can help to define that subtype clinically. The proposed taxonomy for pontine CMs meaningfully guides surgical strategy and may improve patient outcomes.

OBJECTIVE Vertebrobasilar dissecting (VBD) aneurysms are rare, and patients with these aneurysms often present with thromboembolic infarcts or subarachnoid hemorrhage (SAH). The morphological nature of VBD aneurysms often precludes conventional clip reconstruction or coil placement and encourages parent artery exclusion or endovascular stenting. Treatment considerations include aneurysm location along the vertebral artery (VA), the involvement of the posterior inferior cerebellar artery (PICA), and collateral blood flow. Outcomes after endovascular treatment have been well described in the neurosurgical literature, but microsurgical outcomes have not been detailed. Patient outcomes from a large, single-surgeon, consecutive series of microsurgically managed VBD aneurysms are presented, and 3 illustrative case examples are provided. METHODS The medical records of patients with dissecting aneurysms affecting the intracranial VA (V4), basilar artery, and PICA that were treated microsurgically over a 19-year period were reviewed. Patient demographics, aneurysm characteristics, surgical procedures, and clinical outcomes (according to modified Rankin Scale [mRS] scores at last follow-up) were analyzed. RESULTS Forty-two patients with 42 VBD aneurysms were identified. Twenty-six aneurysms (62%) involved the PICA, 14 (33%) were distinct from the PICA origin on the V4 segment of the VA, and 2 (5%) were located at the vertebrobasilar junction. Thirty-four patients (81%) presented with SAH with a mean Hunt and Hess grade of 3.2 at presentation. Six (14%) of the 42 patients had been previously treated using endovascular techniques. Nineteen aneurysms (45%) underwent clip wrapping, 17 (40%) were treated with bypass trapping, and 6 (14%) underwent parent artery sacrifice. The complete aneurysm obliteration rate was 95% (n = 40), and the surgical complication rate was 7% (n = 3). The 8 patients with unruptured VBD aneurysms were significantly more likely to be discharged home (n = 6, 75%) compared with 34 patients with ruptured aneurysms (n = 9, 27%; p = 0.01). Good outcomes (mRS score ≤ 2) were observed in 20 patients (48%). Eight patients (19%) died. CONCLUSIONS These data demonstrate that patients with VBD aneurysms often present after a rupture in poor neurological condition, but favorable results can be achieved with open microsurgical repair in almost half of such cases. Microsurgery remains a viable treatment option, with the choice between bypass trapping and clip wrapping largely dictated by the specific location of the aneurysm and its relationship to the PICA.

OBJECTIVE The Barrow Ruptured Aneurysm Trial (BRAT) was a single-center trial that compared endovascular coiling to microsurgical clipping in patients treated for aneurysmal subarachnoid hemorrhage (aSAH). However, because patients in the BRAT were treated more than 15 years ago, and because there have been advances since then—particularly in endovascular techniques—the relevance of the BRAT today remains controversial. Some hypothesize that these technical advances may reduce retreatment rates for endovascular intervention. In this study, the authors analyzed data for the post-BRAT (PBRAT) era to compare microsurgical clipping with endovascular embolization (coiling and flow diverters) in the two time periods and to examine how the results of the original BRAT have influenced the practice of neurosurgeons at the study institution. METHODS In this retrospective cohort study, the authors evaluated patients with saccular aSAHs who were treated at a single quaternary center from August 1, 2007, to July 31, 2019. The saccular aSAH diagnoses were confirmed by cerebrovascular experts. Patients were separated into two cohorts for comparison on the basis of having undergone microsurgery or endovascular intervention. The primary outcome analyzed for comparison was poor neurological outcome, defined as a modified Rankin Scale (mRS) score > 2. The secondary outcomes that were compared included retreatment rates for both therapies. RESULTS Of the 1014 patients with aSAH during the study period, 798 (79%) were confirmed to have saccular aneurysms. Neurological outcomes at ≥ 1-year follow-up did not differ between patients treated with microsurgery (n = 451) and those who received endovascular (n = 347) treatment (p = 0.51). The number of retreatments was significantly higher among patients treated endovascularly (32/347, 9%) than among patients treated microsurgically (6/451, 1%) (p < 0.001). The retreatment rate after endovascular treatment was lower in the PBRAT era (9%) than in the BRAT (18%). CONCLUSIONS Similar to results from the BRAT, results from the PBRAT era showed equivalent neurological outcomes and increased rates of retreatment among patients undergoing endovascular embolization compared with those undergoing microsurgery. However, the rate of retreatment after endovascular intervention was much lower in the PBRAT era than in the BRAT.

OBJECTIVE Anatomical taxonomy is a practical tool that has successfully guided clinical decision-making for patients with brain arteriovenous malformations. Brainstem cavernous malformations (BSCMs) are similarly complex lesions that are difficult to access and highly variable in size, shape, and position. The authors propose a novel taxonomy for midbrain cavernous malformations based on clinical presentation (syndromes) and anatomical location (identified with MRI). METHODS The taxonomy system was developed and applied to an extensive 2-surgeon experience over a 30-year period (1990–2019). Of 551 patients with appropriate data who underwent microsurgical resection of BSCMs, 151 (27.4%) had midbrain lesions. These lesions were further subtyped on the basis of predominant surface presentation identified on preoperative MRI. Five distinct subtypes of midbrain BSCMs were defined: interpeduncular (7 lesions [4.6%]), peduncular (37 [24.5%]), tegmental (73 [48.3%]), quadrigeminal (27 [17.9%]), and periaqueductal (7 [4.6%]). Neurological outcomes were assessed using modified Rankin Scale (mRS) scores. A postoperative score ≤ 2 was defined as a favorable outcome; a score > 2 was defined as a poor outcome. Clinical and surgical characteristics and neurological outcomes were compared among subtypes. RESULTS Each midbrain BSCM subtype was associated with a recognizable constellation of neurological symptoms. Patients with interpeduncular lesions commonly presented with ipsilateral oculomotor nerve palsy and contralateral cerebellar ataxia or dyscoordination. Peduncular lesions were associated with contralateral hemiparesis and ipsilateral oculomotor nerve palsy. Patients with tegmental lesions were the most likely to present with contralateral sensory deficits, whereas those with quadrigeminal lesions commonly presented with the features of Parinaud syndrome. Periaqueductal lesions were the most likely to cause obstructive hydrocephalus. A single surgical approach was preferred (> 90% of cases) for each midbrain subtype: interpeduncular (transsylvian-interpeduncular approach [7/7 lesions]), peduncular (transsylvian-transpeduncular [24/37]), tegmental (lateral supracerebellar-infratentorial [73/73]), quadrigeminal (midline or paramedian supracerebellar-infratentorial [27/27]), and periaqueductal (transcallosal-transchoroidal fissure [6/7]). Favorable outcomes (mRS score ≤ 2) were observed in most patients (110/136 [80.9%]) with follow-up data. No significant differences in outcomes were observed between subtypes (p = 0.92). CONCLUSIONS The study confirmed the authors’ hypothesis that taxonomy for midbrain BSCMs can meaningfully guide the selection of surgical approach and resection strategy. The proposed taxonomy can increase diagnostic acumen at the patient bedside, help identify optimal surgical approaches, enhance the consistency of clinical communications and publications, and improve patient outcomes.

OBJECTIVE Ophthalmic artery (OA) aneurysms are surgically challenging lesions that are now mostly treated using endovascular procedures. However, in specialized tertiary care centers with experienced neurosurgeons, controversy remains regarding the optimal treatment of these lesions. This study used propensity adjustment to compare microsurgical and endovascular treatment of unruptured OA aneurysms in experienced tertiary and quaternary settings. METHODS The authors retrospectively reviewed the medical records of all patients who underwent microsurgical treatment of an unruptured OA aneurysm at the University of California, San Francisco, from 1997 to 2017 and either microsurgical or endovascular treatment at Barrow Neurological Institute from 2011 to 2019. Patients were categorized into two cohorts for comparison: those who underwent open microsurgical clipping, and those who underwent endovascular flow diversion or coil embolization. Outcomes included neurological or visual outcomes, residual or recurrent aneurysms, retreatment, and severe complications. RESULTS A total of 345 procedures were analyzed: 247 open microsurgical clipping procedures (72%) and 98 endovascular procedures (28%). Of the 98 endovascular procedures, 16 (16%) were treated with primary coil embolization and 82 (84%) with flow diversion. After propensity adjustment, microsurgical treatment was associated with higher odds of a visual deficit (OR 8.5, 95% CI 1.1–64.9, p = 0.04) but lower odds of residual aneurysm (OR 0.06, 95% CI 0.01–0.28, p < 0.001) or retreatment (OR 0.12, 95% CI 0.02–0.58, p = 0.008) than endovascular therapy. No difference was found between the two cohorts with regard to worse modified Rankin Scale score, modified Rankin Scale score greater than 2, or severe complications. CONCLUSIONS Compared with endovascular therapy, microsurgical clipping of unruptured OA aneurysms is associated with a higher rate of visual deficits but a lower rate of residual and recurrent aneurysms. In centers experienced with both open microsurgical and endovascular treatment of these lesions, the treatment choice should be based on patient preference and aneurysm morphology.

The anterior and posterior communicating arteries are natural connections between arteries that enable different adjacent circulations to redistribute blood flow instantly in response to changing supply and demand. An analogous communication does not exist in the middle cerebral circulation. A middle communicating artery (MCoA) can be created microsurgically between separate middle cerebral artery (MCA) trunks, enabling flow to redistribute in response to changing supply and demand. The MCoA would draw blood flow from an adjacent circulation such as the external carotid circulation. The MCoA requires the application of fourth-generation techniques to reconstruct bi- and trifurcations after occluding complex MCA trunk aneurysms. In this report, the authors describe two recent cases of complex MCA bi- and trifurcation aneurysms in which the occluded efferent trunks were revascularized by creating an MCoA. The first MCoA was created with a “double-barrel” superficial temporal artery–M2 segment bypass and end-to-end reimplantation of the middle and inferior MCA trunks. The second MCoA was created with an external carotid artery–radial artery graft–M2 segment interpositional bypass and end-to-side reimplantation of the inferior trunk onto the superior trunk. Both aneurysms were occluded, and both patients experienced good outcomes. This report introduces the concept of the MCoA and demonstrates two variations. Angioarchitectural and technical elements include the donation of flow from an adjacent circulation, a communicating bypass, the application of fourth-generation bypass techniques, and a minimized ischemia time. The MCoA construct is ideally suited for rebuilding bi- and trifurcated anatomy after trapping or distally occluding complex MCA aneurysms.

BACKGROUND Coccidioidomycosis is a primarily self-limiting fungal disease endemic to the western United States and South America. However, severe disseminated infection can occur. The authors report a severe case of coccidioidal meningitis that appeared to be a subarachnoid hemorrhage (SAH) on initial inspection. OBSERVATIONS A man in his early 40s was diagnosed with coccidioidal pneumonia after presenting with pulmonary symptoms. After meningeal spread characterized by declining mental status and hydrocephalus, coccidioidal meningitis was diagnosed. The uniquely difficult aspect of this case was the deceptive appearance of SAH due to the presence of multiple aneurysms and blood draining from the patient’s external ventricular drain. LESSONS Coccidioidal infection likely led to the formation of multiple intracranial aneurysms in this patient. Although few reports exist of coccidioidal meningitis progressing to aneurysm formation, patients should be closely monitored for this complication because outcomes are poor. The presence of basal cistern hyperdensities from a coccidioidal infection mimicking SAH makes interpreting imaging difficult. Surgical management of SAH can be considered safe and viable, especially when the index of suspicion is high, such as in the presence of multiple aneurysms. Even if it is unclear whether aneurysmal rupture has occurred, prompt treatment is advisable.

A man in his 60s presented with severe ophthalmoparesis and loss of visual acuity in his right eye. He was found to have a giant aneurysm of the cavernous internal carotid artery (ICA). Treatment with a flow diverter was recommended. The aneurysm caused matricidal outflow restriction of the ICA. Microwire and microcatheter access through the aneurysm was challenging, requiring multiple wires, stentriever reduction, and more. Eventually, a construct of 3 Pipeline embolization devices was created across the aneurysm. Troubleshooting access across giant aneurysms is an important part of treatment. Informed consent was obtained for the procedure and for publication. The video can be found here: https://stream.cadmore.media/r10.3171/2022.7.FOCVID2258

A variety of pathogenic mechanisms have been described in the formation, maturation, and rupture of brain arteriovenous malformations (bAVMs). While the understanding of bAVMs has largely been formulated based on animal models of rare hereditary diseases in which AVMs form, a new era of “omics” has permitted large-scale examinations of contributory genetic variations in human sporadic bAVMs. New findings regarding the pathogenesis of bAVMs implicate changes to endothelial and mural cells that result in increased angiogenesis, proinflammatory recruitment, and breakdown of vascular barrier properties that may result in hemorrhage; a greater diversity of cell populations that compose the bAVM microenvironment may also be implicated and complicate traditional models. Genomic sequencing of human bAVMs has uncovered inherited, de novo, and somatic activating mutations, such as KRAS, which contribute to the pathogenesis of bAVMs. New droplet-based, single-cell sequencing technologies have generated atlases of cell-specific molecular derangements. Herein, the authors review emerging genomic and transcriptomic findings underlying pathologic cell transformations in bAVMs derived from human tissues. The application of multiple sequencing modalities to bAVM tissues is a natural next step for researchers, although the potential therapeutic benefits or clinical applications remain unknown.

OBJECTIVE Good functional outcomes after aneurysmal subarachnoid hemorrhage (aSAH) are often dependent on early detection and treatment of cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI). There is growing evidence that continuous monitoring with cranial electroencephalography (cEEG) can predict CVS and DCI. Therefore, the authors sought to assess the value of continuous cEEG monitoring for the detection of CVS and DCI in aSAH. METHODS The cerebrovascular database of a quaternary center was reviewed for patients with aSAH and cEEG monitoring between January 1, 2017, and July 31, 2019. Demographic data, cardiovascular risk factors, Glasgow Coma Scale score at admission, aneurysm characteristics, and outcomes were abstracted from the medical record. Patient data were retrospectively analyzed for DCI and angiographically assessed CVS. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and odds ratio for cEEG, transcranial Doppler ultrasonography (TCDS), CTA, and DSA in detecting DCI and angiographic CVS were calculated. A systematic literature review was conducted in accordance with PRISMA guidelines querying the PubMed, Cochrane Controlled Trials Register, Web of Science, and Embase databases. RESULTS A total of 77 patients (mean age 60 years [SD 15 years]; female sex, n = 54) were included in the study. Continuous cEEG monitoring detected DCI and angiographically assessed CVS with specificities of 82.9% (95% CI 66.4%–93.4%) and 94.4% (95% CI 72.7%–99.9%), respectively. The sensitivities were 11.1% (95% CI 3.1%–26.1%) for DCI (n = 71) and 18.8% (95% CI 7.2%–36.4%) for angiographically assessed CVS (n = 50). Furthermore, TCDS detected angiographically determined CVS with a sensitivity of 87.5% (95% CI 71.0%–96.5%) and specificity of 25.0% (95% CI 7.3%–52.4%). In patients with DCI, TCDS detected vasospasm with a sensitivity of 85.7% (95% CI 69.7%–95.2%) and a specificity of 18.8% (95% CI 7.2%–36.4%). DSA detected vasospasm with a sensitivity of 73.9% (95% CI 51.6%–89.8%) and a specificity of 47.8% (95% CI 26.8%–69.4%). CONCLUSIONS The study results suggest that continuous cEEG monitoring is highly specific in detecting DCI as well as angiographically assessed CVS. More prospective studies with predetermined thresholds and endpoints are needed to assess the predictive role of cEEG in aSAH.

Falcotentorial meningiomas arise along the junction of the falx cerebri and the tentorium cerebelli. The authors present a woman in her 60s with an incidentally discovered falcotentorial meningioma, approximately 3 cm in diameter, resected with a torcular craniotomy and posterior interhemispheric approach. The galenic complex was dissected away from the tumor. In the final view, the bilateral internal cerebral veins and basal veins of Rosenthal were seen. A Simpson grade I resection was achieved. The patient experienced transient contralateral hemianopsia and was discharged home. At 1-year follow-up, her neurological examination findings were unremarkable, and there was no radiographic evidence of tumor. The video can be found here: https://stream.cadmore.media/r10.3171/2021.4.FOCVID2125.

Arteriovenous malformations (AVMs) in the brainstem, specifically medullary AVMs, are exceedingly rare and difficult to treat. These lesions are commonly more aggressive than supratentorial AVMs and pose their own unique treatment challenges. Current treatment options for these AVMs consist of endovascular embolization or open surgery. Radiosurgery is not favored because it is associated with potential risk to the brainstem and lower obliteration rates. Here the authors report the case of a 27-year-old man with a ruptured anterior medullary AVM. The patient underwent a successful far-lateral craniotomy for resection of the AVM.The video can be found here: https://youtu.be/lyOfOQ3sBdU

OBJECTIVEStudies of resection of brain arteriovenous malformations (AVMs) in the elderly population are scarce. This study examined factors influencing patient selection and surgical outcome among elderly patients.METHODSPatients 65 years of age and older who underwent resection of an unruptured or ruptured brain AVM treated by two surgeons at two centers were identified. Patient demographic characteristics, AVM characteristics, clinical presentation, and outcomes measured using the modified Rankin Scale (mRS) were analyzed. For subgroup analyses, patients were dichotomized into two age groups (group 1, 65–69 years old; group 2, ≥ 70 years old).RESULTSOverall, 112 patients were included in this study (group 1, n = 61; group 2, n = 51). Most of the patients presented with hemorrhage (71%), a small nidus (< 3 cm, 79%), and a low Spetzler-Martin (SM) grade (grade I or II, 63%) and were favorable surgical candidates according to the supplemented SM grade (supplemented SM grade < 7, 79%). A smaller AVM nidus was statistically significantly more likely to be present in patients with infratentorial AVMs (p = 0.006) and with a compact AVM nidus structure (p = 0.02). A larger AVM nidus was more likely to be treated with preoperative embolization (p < 0.001). Overall outcome was favorable (mRS scores 0–3) in 71% of the patients and was statistically independent from age group or AVM grading. Patients with ruptured AVMs at presentation had significantly better preoperative mRS scores (p < 0.001) and more favorable mRS scores at the last follow-up (p = 0.04) than patients with unruptured AVMs.CONCLUSIONSOutcomes were favorable after AVM resection in both groups of patients. Elderly patients with brain AVMs treated microsurgically were notable for small nidus size, AVM rupture, and low SM grades. Microsurgical resection is an important treatment modality for elderly patients with AVMs, and supplemented SM grading is a useful tool for the selection of patients who are most likely to achieve good neurological outcomes after resection.