Upper end of the central canal of the human spinal cord: Quantitative anatomical study and 3D modeling.

The upper end of the central canal of the human spinal cord has been repeatedly implicated in the pathogenesis of various diseases, yet its precise normal position in the medulla oblongata and upper cervical spinal cord remains unclear. The purpose of this study is to describe the anatomy of the upper end of the central canal with quantitative measurements and a three-dimensional (3D) model. Seven formalin-embalmed human brainstems were included, and the central canal was identified in serial axial histological sections using epithelial membrane antigen antibody staining. Measurements included the distances between the central canal (CC) and the anterior medullary fissure (AMF) and the posterior medullary sulcus (PMS). The surface and perimeter of the CC and the spinal cord were calculated, and its anterior-posterior and maximum lateral lengths were measured for 3D modeling. The upper end of the CC was identified in six specimens, extending from the apertura canalis centralis (ACC) to its final position in the cervical cord. Positioned on the midline, it reaches its final location approximately 15 mm below the obex. No specimen showed canal dilatation, focal stenosis, or evidence of syringomyelia. At 21 mm under the ACC in the cervical cord, the median distance from the CC to the AMF was 3.14 (2.54-3.15) mm and from the CC to the PMS was 5.19 (4.52-5.43) mm, with a progressive shift from the posterior limit to the anterior third of the cervical spinal cord. The median area of the CC was consistently less than 0.1 mm2. The upper end of the CC originates at the ACC, in the posterior part of the MO, and reaches its normal position in the anterior third of the cervical spinal cord less than 2 cm below the obex. Establishing the normal position of the upper end of this canal is crucial for understanding its possible involvement in cranio-cervical junction pathologies.

Anatomy of the medial wall of the cavernous sinus: A systematic review of the literature.

The existence, composition, and continuity of the medial wall of the cavernous sinus (MWCS) have been extensively studied and debated. However, the precise nature of this membrane remains unknown. Understanding the anatomical characteristics of the MWCS is crucial, notably in relation to pituitary adenomas, which often invade the cavernous sinus. Indeed, surgical treatment of those tumors is frequently incomplete because of such invasion. The anatomical and molecular basis of the peculiar and often lateralized tropism of adenomatous cells to the cavernous sinus is not yet understood and it has been suggested repeatedly that the MWCS is physiologically frail. During the past three decades, there have been several conflicting accounts of the existence, composition, and continuity of this medial wall, but methodological differences and varying definitions could have contributed to the current lack of consensus regarding it. The aim of this systematic review was to summarize previously published data concerning the existence, anatomy, composition, and continuity of the MWCS.

Effect of microorganisms isolated by preoperative osseous sampling on surgical site infection after autologous cranioplasty: A single-center experience.

PURPOSE: The most frequent postoperative complication in autologous cranioplasty (AC) is infection. European recommendations include osseous sampling before cryogenic storage of a bone flap. We evaluated the clinical impact of this sampling. METHODS: All patients who underwent decompressive craniectomy (DC) and AC in our center between November 2010 and September 2021 were reviewed. The main outcome was the rate of reoperation for infection of the cranioplasty. We evaluated risk factors for bone flap infection, rate of reoperation for any reason (hematoma, skin erosion, cosmetic request, or bone resorption), and radiological evidence of bone flap resorption. RESULTS: A total of 195 patients with a median age of 50 (interquartile range: 38.0-57.0) years underwent DC and AC between 2010 and 2021. Of the 195 bone flaps, 54 (27.7%) had a positive culture, including 48 (88.9%) with Cutibacterium acnes. Of the 14 patients who underwent reoperation for bone flap re-removal for infection, 5 and 9 had positive and negative bacteriological cultures, respectively. Of patients who did not have bone flap infection, 49 and 132 had positive and negative bacteriological cultures, respectively. There were no significant differences between patients with and without positive bacteriological culture of bone flaps in the rates of late bone necrosis and reoperation for bone flap infection. CONCLUSIONS: A positive culture of intraoperative osseous sampling during DC is not associated with a higher risk of re-intervention after AC.

How to understand an enlarged Meckel's cave? An anatomical study.

PURPOSE: Dilatation of the trigeminal cavum, or Meckel's cave (MC), is usually considered a radiological sign of idiopathic intracranial hypertension. However, the normal size of the trigeminal cavum is poorly characterized. In this study, we describe the anatomy of this meningeal structure. METHODS: We dissected 18 MCs and measured the length and width of the arachnoid web and its extension along the trigeminal nerve. RESULTS: Arachnoid cysts were clearly attached to the ophthalmic (V1) and maxillary (V2) branches until they entered the cavernous sinus and foramen rotundum, respectively, without extension to the skull base. Arachnoid cysts were close to the mandibular branch toward the foramen ovale, with a median anteromedial extension of 2.5 [2.0-3.0] mm, lateral extension of 4.5 [3.0-6.0] mm, and posterior extension of 4.0 [3.2-6.0] mm. The trigeminal cavum arachnoid had a total width of 20.0 [17.5-25.0] mm and length of 24.5 [22.5-29.0] mm. CONCLUSION: Our anatomical study revealed variable arachnoid extension, which may explain the variability in size of the trigeminal cavum in images and calls into question the value of this structure as a sign of idiopathic intracranial hypertension. The arachnoid web extends beyond the limits described previously, reaching almost double the radiological size of the cavum, particularly at the level of V3 afference of the trigeminal nerve. It is possible that strong adhesion of the arachnoid to the nerve elements prevents the formation of a true subarachnoid space that can be visualized by magnetic resonance imaging.

When to discharge patients following a neuronavigation-assisted brain biopsy for supratentorial lesion? A single-center experience.

OBJECTIVE: Most brain biopsies are performed using the frame-based stereotactic technique and several studies describe the time taken and rate of complications, often allowing an early discharge. In comparison, neuronavigation-assisted biopsies are performed under general anesthesia and their complications have been poorly described. We examined the complication rate and determined which patients will worsen clinically. METHODS: All adults who underwent a neuronavigation-assisted brain biopsy for a supratentorial lesion from Jan, 2015, to Jan, 2021, in the Neurosurgical Department of the University Hospital Center of Bordeaux, France, were analyzed retrospectively in accordance with the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) statement. The primary outcome of interest was short-term (7 days) clinical deterioration. The secondary outcome of interest was the complication rate. RESULTS: The study included 240 patients. The median postoperative Glasgow score was 15. Thirty patients (12.6 %) showed acute postoperative clinical worsening, including 14 (5.8 %) with permanent neurological worsening. The median delay was 22 h after the intervention. We examined several clinical combinations that allowed early postoperative discharge. A preoperative Glasgow prognostic score of 15, Charlson Comorbidity Index ≤ 3, preoperative World Health Organization Performance Status ≤ 1, and no preoperative anticoagulation or antiplatelet treatment predicted postoperative worsening (negative predictive value, 96.3 %). CONCLUSION: Optical neuronavigation-assisted brain biopsies might require longer postoperative observation than frame-based biopsies. Based on strict preoperative clinical criteria, we consider to plan postoperative observation for 24 h a sufficient hospital stay for patients who undergo these brain biopsies.

Skin landmarks as ideal entry points for ventricular drainage, a radiological study.

PURPOSE: Ventricular drainage remains a usual but challenging procedure for neurosurgical trainees. The objective of the study was to describe reliable skin landmarks for ideal entry points (IEPs) to catheterize brain ventricles via frontal and parieto-occipital approaches. METHODS: We included 30 subjects who underwent brain MRI and simulated the ideal catheterization trajectories of lateral ventricles using anterior and posterior approaches and localized skin surface IEPs. The optimal frontal target was the interventricular foramen and that for the parieto-occipital approach was the atrium. We measured the distances between these IEPs and easily identifiable skin landmarks. RESULTS: The frontal IEP was localized to 116.8 ± 9.3 mm behind the nasion on the sagittal plane and to 39.7 ± 4.9 mm lateral to the midline on the coronal plane. The ideal catheter length was estimated to be 68.4 ± 6.4 mm from the skin surface to the interventricular foramen. The parieto-occipital point was localized to 62.9 ± 7.4 mm above the ipsilateral tragus on the coronal plane and to 53.1 ± 9.1 mm behind the tragus on the axial plane. The ideal catheter length was estimated to be 48.3 ± 9.6 mm. CONCLUSION: The IEP for the frontal approach was localized to 11 cm above the nasion and 4 cm lateral to the midline. The IEP for the parieto-occipital approach was 5.5 cm behind and 6 cm above the tragus. These measurements lightly differ from the classical descriptions of Kocher's point and Keen's point and seem relevant to neurosurgical practice while using an orthogonal insertion.

Calcified Epidural Hematoma after Conservative Treatment of Acute Epidural Hematoma in the Pediatric Population: A Systematic Review.

BACKGROUND: Acute traumatic epidural hematoma (EDH) is a complication in 2-3% of pediatric head injuries. Surgery is mandatory in symptomatic cases; otherwise, conservative treatment is a valid approach, especially in the pediatric population. Ossified epidural hematomas (OEHs) have been reported in the pediatric population as a rare complication of conservative EDH management, although the exact incidence remains unknown. The progressive increase in conservative management may lead to increases in the OEH incidence over the next few years. Our study aimed to systematically review OEH incidence, management strategies, characteristics (thickness, inner/outer calcifications), complication rates, time to surgery after the EDH diagnosis, and clinical outcomes. SUMMARY: A systematic review was conducted in accordance with the PRISMA guidelines. Studies reporting diagnoses and clear descriptions of OEH after EDH in pediatric patients were considered eligible. Sixteen studies, including 18 pediatric patients aged 0-18 years, were included. Head trauma was the most common cause of OEH. Seven (38.8%) OEHs were treated less than 1 month after EDH diagnosis. Surgery was performed in 17 cases (94.44%), while 1 asymptomatic case (5.56%) was managed conservatively. KEY MESSAGES: Surgery was the most commonly used treatment for OEH. Data for conservative treatment of OEH are limited. Magnetic resonance imaging or ultrasound within the first 2 months, to check for EDH resolution, may be crucial to rule out complications in pediatric patients.

Skin landmarks to main cerebral structures: how to identify the main cerebral sulci? A radiological study about lateral, central, and parietooccipital sulci.

PURPOSE: In a previous cadaveric work, we identified and described useful and reproducible surface skin landmarks to lateral sulcus, central sulcus and preoccipital notch. Potential limitations of this cadaveric study have been raised. Thus, the objective of this study was to confirm radiologically the accuracy of these previously described surface skin landmarks on brain magnetic resonance imaging (MRI) of healthy subjects. METHODS: Healthy adult volunteers underwent a high-resolution brain MRI and measurements of the orthogonal skin projection (OSP) of the anterior sylvian point (AsyP), the superior Rolandic point (SroP) and the parietooccipital sulcus were made from nasion, zygomatic bone and inion, respectively. These measures were compared to our previous cadaveric findings. RESULTS: Thirty-one healthy volunteers were included. ASyP was 33 ± 2 mm above the zygomatic arch, and 32.3 ± 3 mm behind the orbital rim. The lateral sulcus was 63.5 ± 4 mm above the tragus. The SRoP was 196.9 ± 6 mm behind the nasion. The superior point of the parietooccipital sulcus was 76.0 ± 4 mm above the inion. These measurements are comparable to our previously described cadaveric findings. CONCLUSION: We here described three useful, simple and reproducible surface skin landmarks to lateral, central and parietooccipital sulci. Knowledge of these major landmarks is mandatory for Neurosurgical practice, especially in an emergency setting.

Intramedullary Spinal Cord Lesions: A Single-Center Experience.

OBJECTIVE: Spinal cord tumors constitute a small part of spinal surgery owing to their rarity. This retrospective study describes their current management. METHODS: Forty-eight patients were treated for an intramedullary tumor between 2014 and 2020 at a single institution. Patients' files were retrospectively studied. We detailed clinical status according to neurological deficit and ambulatory ability using the modified McCormick Scale, radiological features like number of levels, associated syringomyelia, surgical technique with or without intraoperative electrophysiological monitoring, pathological findings, and postoperative outcome. RESULTS: The median age of this population was 43 years, including 5 patients under 18 years. The median delay before first neurosurgical contact was 3 months after the first clinical complaint. Treatment was gross total resection in 43.8%, subtotal resection in 50.0%, and biopsy in 6.2%. A laminectomy was performed for all the patients except 2 operated using the laminoplasty technique. Pathological findings were ependymoma in 43.8%, hemangioblastoma in 20.8%, and pilocytic astrocytoma in 10.4%. Six patients were reoperated for a tumor recurrence less than 2 years after the first surgical resection. One patient was reoperated for a postoperative cervical kyphosis. CONCLUSION: Intramedullary tumors are still a challenging disease and they are treated by various surgical techniques. They must be managed in a specialized center including a trained surgical, radiological, electrophysiological, and pathological team. Arthrodesis must be discussed before performing extensive laminectomy to avoid postoperative kyphosis.

Long term results of Dorsal Root Entry Zone (DREZ) lesions for the treatment of intractable pain: A systematic review of the literature on 1242 cases.

BACKGROUND: Different Dorsal root entry zone (DREZ) lesion techniques have been reported as effective treatment for intractable painful conditions, though with contradictory results. Overall, good results were reported especially in specific conditions, such as pain due to brachial plexus avulsion, spinal cord injuries and oncological pain management. However, data on long term results in different clinical conditions are still missing. OBJECTIVE: This study aims to systematically review the pertinent literature to evaluate indications, clinical outcomes, and complications of DREZ lesion (DREZotomy), in chronic pain management. METHODS: A systematic literature review was conducted according to the PRISMA statement. Papers on DREZotomy for chronic pain in cancer, brachial plexus avulsion, spinal cord injury, post herpetic neuralgia, and phantom limb pain were considered for eligibility. For each category we further identified two sub-group according to the length of follow up: medium term and long term follow up (more than 3 years) respectively. RESULTS: 46 papers, and 1242 patients, were included in the present investigation. When considering long term results DREZotomy provided favorable clinical outcomes in brachial plexus avulsion and spinal cord injury, in 60.8% and 55.8% of the cases respectively. Conversely, the success rate was 35.3% in phantom limb pain and 28.2% in post herpetic neuralgia. A poor clinical outcome was reported in over than 25% of the patients suffering from phantom limb pain, post herpetic neuralgia and spinal cord injury. The mean complications rate was 23.58%. While BPA and SCI patients presented stable improvement over time, good outcomes among PHN and PLP groups dropped by - 46.2%; and - 14.7% at long term follow up respectively. CONCLUSION: DREZotomy seems to be an effective treatment for chronic pain conditions, especially for brachial plexus avulsion, spinal cord injury and intractable cancer/post-radiation pain. According to the low level of evidence of the pertinent literature, further studies are strongly recommended, to better define potential benefits and limitations of this technique.

Skin landmarks to main cerebral structures: how to identify the main cerebral sulci? An anatomical study.

PURPOSE: Neuronavigation is used in neurosurgical practice to locate the cortical structures. If this tool is unavailable, basic anatomical knowledge should be used. Craniometry has been rarely detailed in recent literature, systematically using bony landmarks. The aim of this study is to describe skin landmarks for neurosurgical practice. METHODS: Dissection of 10 hemispheres with insertion of radio-opaque markers within the limits of lateral sulcus, central and pre-central sulci, and preoccipital notch. Computed tomography was performed in all cases and multiplanar reconstructions were performed. Maximal intensity projection (MIP) fusion images were used for measurements between known skin landmarks and sulci of interests. RESULTS: The Anterior Sylvian Point is measured 31.8 ± 2.8 mm behind the orbital wall, 36.9 ± 3 mm above the zygomatic arch. The horizontal part of the lateral sulcus is measured 59 ± 6 mm above the tragus. The Superior Rolandic Point is measured 190.7 ± 4.5 mm behind the nasion. The Pre-occipital Notch is measured 37.0 ± 6.9 mm above the tragus and 67.1 ± 6.4 mm behind. The Ideal Entry Points (IEP) for ventricular punctures are measured 120.2 ± 7 mm behind the nasion and 33.8 ± 3 mm laterally for the frontal IEP, and 61.3 mm ± 2.5 mm above and 64.7 ± 6.8 mm behind the tragus for the parieto-occipital IEP. CONCLUSION: In this study, we described simple skin landmarks for lateral sulcus, central sulcus, preoccipital notch, and an IEP for ventricular drainage. Precise knowledge of brain sulcal anatomy will guide patient's positioning, skin incision, and craniotomies; and permits checking of imaging data provided by neuronavigation systems.

Sustained growth of intraosseous hormone-associated meningiomas after cessation of progestin therapy.

Hormone-associated meningiomas tend to stop growing or decrease in size after cessation of certain progestins, mainly cyproterone acetate. We report three observations on the natural history of hormone-associated intraosseous meningiomas, showing in a first patient that those tumors may grow rapidly under nomegestrol. We then demonstrate the sustained growth of intraosseous hormone-associated meningiomas after cessation of promesgestone and nomegestrol, independently of the intracranial portion, which concurrently decreased in size in the second case or was resected at the time of nomegestrol withdrawal in the third case, thus giving new insights into the tumorigenesis mechanisms of hormone-associated intraosseous meningiomas.

Why Methodology Is Important: Coffee as a Candidate Treatment for COVID-19?

BACKGROUND: During this pandemic situation, some studies have led to hasty conclusions about Corona Virus Disease-19 (COVID-19) treatment, due to a lack of methodology. This pedagogic study aimed to highlight potential biases in research on COVID-19 treatment. METHODS: We evaluate the effect of coffee's active part, 1,3,7-trimethylxanthine (TMX) on patients with COVID-19. A cohort of 93 patients, with a diagnosis of COVID-19 is analyzed. RESULTS: TMX group and control group included, respectively, 26 and 67 patients. In the TMX group, patients had a median length of stay in hospital of 5.5 days shorter than in the control group (9.5 vs. 15 days, p < 0.05). Patients in the control group were more severe than patients in the TMX group with a significantly higher National Early Warning Score 2 (NEWS-2 score) (8 vs. 6, p = 0.002). CONCLUSIONS: Multiple biases prevents us from concluding to an effect of coffee on COVID-19. Despite an important social pressure during this crisis, methodology and conscientiousness are the best way to avoid hasty conclusions that can be deleterious for patients. Identifier: NCT04395742.

Female gender and exogenous progesterone exposition as risk factors for spheno-orbital meningiomas.

OBJECTIVE: The great heterogeneity of meningiomas is challenging and we need to distinguish relevant subgroups. Spheno-orbital osteomeningiomas (SOOM) constitute a clinically specific entity, with slow-growing benign osteo-meningiomatous tumors, which recur after surgery in one fourth of cases. Neurosurgical daily practice, supported by the literature, shows that the vast majority of patients with SOOM are women, and we explored whether their epidemiological and hormonal profiles suggest a progesterone influence. METHODS: We retrospectively documented all radiologically and histologically confirmed cases of SOOM operated in 2005-2019 in our institution. We completed the clinical and hormone history by systematic telephone interviews. RESULTS: In the literature, SOOM occur significantly more often in women than other meningiomas (749/847, 86.4% versus 73.8%, p = 0.002). Among 175 cases, we included 124 patients, 93.5% were women, younger than men (51 ± 5 versus 63 ± 8, p = 0.02). Women' meningiomas showed more progesterone receptors (96.4% versus 50%, p < 0.001). Exogenous hormonal intake, reliable in 82 cases, concerned 83.3% (64/78) of women, with frequent progesterone intake: 13 oestroprogestogenic treatment only, with old-generation progesterone analogs, 41 progesterone analogs (cyproterone acetate, nomegestrol acetate, chlormadinone, promegestone, etonogestrel, levonogestrel), 7 substitutive hormonal therapy for menopause, 3 others. Duration of treatment was 2-40 years, median 10 years. CONCLUSIONS: SOOM develop preferentially in women in their fifties, who often received progesterone analogs, and show progesterone receptors. Progesterone analogs are incriminated in skull base meningiomas, and this is the first report on the prevalence of exogenous hormone therapy specifically in SOOM. Whether SOOM reduce after treatment discontinuation, in particular the osteoma part, needs to be explored. Anti-progesterone treatments may represent an avenue for future research in soom.

Isolated Bilateral Hypoglossal Palsy Complicating a Fourth Ventricle Ependymoma Surgery.

BACKGROUND: Isolated bilateral hypoglossal palsy is a rare condition that has never been described after surgery in the lower part of the fourth ventricle. In this article, we discuss various possible etiologies and relevant anatomy considerations of the rhomboid fossa. CASE DESCRIPTION: We describe a case of bilateral hypoglossal palsy with tongue ptosis following surgery of an ependymoma in the lower part of the fourth ventricle. Immediate postoperative imaging showed ischemic lesions in both hypoglossal nuclei, not compatible with any known arterial territory. Two etiologies could be identified: a venous medullary infarct of the medulla oblongata or direct injury of both hypoglossal nuclei due to their midline position. Finally, the patient improved progressively and returned to normal. CONCLUSIONS: Intraoperative neurophysiologic monitoring of hypoglossal nerves, in addition to facial nerves, should be performed for tumors in this location.