Chronic occlusion of the superior sagittal sinus (SSS) by tumors in the midsagittal region causes the collateral venous pathway (CVP). Understanding common patterns of CVP is helpful in reducing surgical complications. This study aimed to investigate the CVP found in patients with SSS-invading tumors, and to provide information on the prevention of operative venous complications. From January 2015 to December 2022, this retrospective study collected patients with tumors that invaded the SSS and underwent digital subtraction angiography of intracranial vessels. Data collected included sex, age, tumor pathology, tumor location along the SSS, tumor side, degree of obstruction of the SSS, types and route patterns of the CVP, and the distance between the tumor and the diploic vein (DV). Twenty patients (6 males, 14 females) were recruited. The prevalence of CVP types was 90% for DV, 35% for end-to-end anastomosis of superficial cortical vein, 15% for meningeal vein, and 20% for other types of CVP. The pteriofrontoparietal and occipitoparietal diploic routes were found on the cerebral hemisphere contralateral to the tumor significantly more than in the cerebral hemisphere ipsilateral to the tumor. Of all patients with presence of collateral DV, 61% had a very close (less than 1 cm) distance between the nearest DV and tumor attachment in the SSS. DV in the cerebral hemisphere contralateral to the tumor was the most common type of CVP found in patients with tumor-induced SSS obstruction. Most of the collateral DV was located very close to the SSS tumor attachment. Neurosurgeons should realize these findings when planning a craniotomy.

UNASSIGNED: Solitary fibrous tumor/meningeal hemangiopericytoma (SFT/M-HPC) is a rare neoplasm which accounts for around 1% of the intracranial masses. This pathology has a high risk for recurrence and metastasis to distant locations such as the liver, lungs, and bones. Precise diagnosis necessitates detailed histopathological examination.
UNASSIGNED: We present two case reports of SFT/M-HPC. The first case is a 44-year-old female who presented with headache, nausea, vomiting, and frontal ataxia for several months. Imaging findings showed a large parasagittal extra-axial mass with compression of the frontal horns of both lateral ventricles. She underwent gross total resection with an uncomplicated postoperative period. The patient had no recurrent tumors or distal metastases in the follow-up period of 5 years. The second case is a 48-year-old male who presented with right-sided hemianopsia and hemiparesis. Computed tomography (CT) scans revealed a large parieto-occipital extra-axial mass with superior sagittal sinus engulfment and dislocation of the interhemispheric fissure. He underwent gross total resection with an uncomplicated postoperative period. Six years later, he presented with right-sided weakness. CT scan showed a multifocal recurrent mass at the previous location. He underwent subtotal resection with an uncomplicated postoperative period.
UNASSIGNED: SFT/M-HPC should be considered when presented with a meningioma-like tumor mass on preoperative imaging. Immunohistochemical study is crucial for the correct diagnosis. Strict long-term follow-up examinations and regular magnetic resonance imaging scans are key to preventing the appearance of metastases and large recurrent masses.

Meningiomas of the rolandic region are associated to high risk of postoperative motor deficits. This study discusses the factors affecting motor outcome and recurrences from the analysis of a monoinstitutional case series and eight studies from a literature review.
Data of 75 patients who underwent surgery for meningioma of the rolandic region were retrospectively reviewed. The analyzed factors included tumor location and size, clinical presentation, magnetic resonance imaging (MRI) and surgical findings, brain-tumor interface, extent of resection, postoperative outcome and recurrence. Eight studies from literature on rolandic meningiomas treated with or without intraoperative monitoring (IOM) were reviewed with the aim to define the impact of IOM on the extent of resection and motor outcome.
Among the 75 patients of the personal series, the meningioma was on the brain convexity in 34 (46%), at the parasagittal region in 28 (37%) and at the falx in 13 (17%). The brain-tumor interface was preserved in 53 cases (71%) at MRI and in 56 (75%) at surgical exploration. Simpson grade I resection was obtained in 43% of patients, grade II in 33%, grade III in 15% and grade IV in 9%. The motor function worsened postoperatively in 9 among 32 cases with preoperative deficit (28%) and in 5 among 43 with no preoperative deficit (11.5%); definitive motor deficit was evidenced in overall series at follow-up in 7 (9.3%). Patients with meningioma with lost arachnoid interface had significant higher rates of worsened postoperative motor deficit (p = 0.01) and seizures (p = 0.033). Recurrence occurred in 8 patients (11%). The analysis of the 8 reviewed studies (4 with and 4 without IOM) shows in the group without IOM higher rates of Simpson grades I and II resection (p = 0.02) and lower rates of grades IV resection (p = 0.002); no significant differences in postoperative immediate and long-term motor deficits were evidenced between the two groups.
Data from literature review show that the use of IOM does not affect the postoperative motor deficit Therefore, its role in rolandic meningiomas resection remains to be determined and will be defined in further studies.

The clearance pathways of brain waste products in humans are still under debate in part due to the lack of noninvasive imaging techniques for meningeal lymphatic vessels (mLVs). In this study, we propose a new noninvasive mLVs imaging technique based on an inter-slice blood perfusion MRI called alternate ascending/descending directional navigation (ALADDIN). ALADDIN with inversion recovery (IR) at single inversion time of 2300 ms (single-TI IR-ALADDIN) clearly demonstrated parasagittal mLVs around the human superior sagittal sinus (SSS) with better detectability and specificity than the previously suggested noninvasive imaging techniques. While in many studies it has been difficult to detect mLVs and confirm their signal source noninvasively, the detection of mLVs in this study was confirmed by their posterior to anterior flow direction and their velocities and morphological features, which were consistent with those from the literature. In addition, IR-ALADDIN was compared with contrast-enhanced black blood imaging to confirm the detection of mLVs and its similarity. For the quantification of flow velocity of mLVs, IR-ALADDIN was performed at three inversion times of 2000, 2300, and 2600 ms (three-TI IR-ALADDIN) for both a flow phantom and humans. For this preliminary result, the flow velocity of the dorsal mLVs in humans ranged between 2.2 and 2.7 mm/s. Overall, (i) the single-TI IR-ALADDIN can be used as a novel non-invasive method to visualize mLVs in the whole brain with scan time of ~ 17 min and (ii) the multi-TI IR-ALADDIN can be used as a way to quantify the flow velocity of mLVs with a scan time of ~ 10 min (or shorter) in a limited coverage. Accordingly, the suggested approach can be applied to noninvasively studying meningeal lymphatic flows in general and also understanding the clearance pathways of waste production through mLVs in humans, which warrants further investigation.

BACKGROUND: Chondromas are benign cartilaginous tumors that are rarely seen in the brain.
METHODS: A 58-year-old woman had undergone routine brain imaging after a motor vehicle accident and was incidentally found to have a right falcine lesion. Contrast magnetic resonance imaging showed a mostly nonenhancing mass with discontinuous rim enhancement. She was taken to the operating room and pathology revealed a chondroma.
CONCLUSIONS: Falcine intracranial chondromas are rare and typically misdiagnosed as meningiomas. Chondromas should be in the differential for patients presenting with nonenhancing falcine lesions.

暂无摘要。

OBJECTIVE: There is no study exploring the cortical veins (CVs) and connecting bridging veins (BVs) with neuroimaging modalities. The present study aimed to characterize these veins of the upper cerebral convexity.
METHODS: A total of 89 patients with intact cerebral hemispheres and covering meninges underwent thin-sliced, contrast magnetic resonance imaging (MRI). In addition, three injected specimens were dissected in this study.
RESULTS: In cadaver dissection, the BVs were observed to course in the arachnoid sheaths, suspended from the dura mater. The medial parts of the BVs, located near the superior sagittal sinus (SSS)-BV junction site, were occasionally exposed subdurally. The CVs were formed by venous channels arising from the cerebral gyri and those emerging from the sulci. On MRI, the CVs and connecting BVs were identified in the medial and latera convexity areas and medial surface of the cerebrum. These veins were highly variable in number, thickness, length, course, and distribution. In the medial convexity area, the CVs arising from the gyri were identified in 58% of patients, while they were found only in 11% of patients in the lateral convexity area.
CONCLUSIONS: In the medial convexity area, involving the parasagittal region, the CVs connect more densely with the BVs that may predispose to injury during neurosurgical procedures. Mechanical impact exerted the area, diameter of the veins in the craniocaudal direction, and number of venous afferences may affect the SSS-BV junctional region in an indirect manner and lead to the development of acute subdural hematoma.

Parasagittal meningiomas are defined as meningiomas that grow into at least one wall of the superior sagittal sinus. Long- and short-term morbidity is, in addition to cortical function, related to management of venous structures and flow. Clinical management needs to address the extent of removal in the sinus wall and to address relations to the adjacent cortex, which is highly eloquent in the Rolandic and calcarine areas.

The contralateral interhemispheric approach is utilized to provide the surgeon with a favorable trajectory for approaching lesions projecting contralaterally from the midline falcine dura. The contralateral approach also requires a less rigid retraction than other approaches, which is paramount when manipulating the eloquent cortex of the paracentral lobule. This patient had a large laterally projecting falcine meningioma. This case demonstrates well the effect that gravity has on the tumor, pulling the tumor medially into the surgeon\'s view and making the surgical approach ideal for this lesion. The lesion was removed en bloc with the falcine dura, and postoperative imaging demonstrated a gross total resection. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Foot drop represents a very common reason for a neurologist referral and is often first seen in emergency departments or by a general practitioner. This condition is defined as weakness of ankle dorsiflexion (mainly through tibialis anterior muscle weakness). The most common causes include lower motor neuron lesion, with L4-L5 radiculopathy and peroneal neuropathy being the most frequent ones. Classical diagnostic pathway includes a thorough medical history, detailed neurological examination, radiological studies (MRI of the lumbosacral spine), EMG and nerve conduction studies, and a battery of laboratory tests. The absence of abnormal radiological and neurophysiological findings when searching for the most common causes of foot drop, should raise a red flag and broaden the diagnostic yield for central nervous system pathology (upper motor neuron, UMN) as a possible cause of foot drop. Central causes of isolated foot drop are very rare, with less than 20 cases reported in literature so far, and seven of them being a meningioma. We present a case of a 79-year-old female patient with an isolated foot drop (with no UMN signs on the initial examination) and parasagittal meningioma. Central causes of foot drop should be suspected when foot drop is associated with UMN signs on examination (hyperreflexia of the patellar or ankle jerk and extensor plantar reflex) and when standard diagnostic work-up (MRI of the lumbar spine, EMG and NCS, standard laboratory screening for most common causes of foot drop) is negative or inconclusive. Although very rare, central lesions present a far more serious cause of foot drop and require a more urgent diagnostic work up and a potential neurosurgical referral and treatment. Keeping in mind the possible central causes of foot drop would eliminate unnecessary diagnostic work up and avoid delayed diagnosis and treatment.