This study aimed to provide data on extended outcomes in primary clival chordomas, focusing on progression-free survival (PFS) and overall survival (OS).
A retrospective single-center analysis was conducted on patients with clival chordoma treated between 1987 and 2022 using surgery, stereotactic radiosurgery, or proton radiation therapy (PRT).
The study included 100 patients (median age 44 years, 51% male). Surgery was performed using the endoscopic endonasal approach in 71 patients (71%). Gross-total resection (GTR) or near-total resection (NTR) was attained in 39 patients (39%). Postoperatively, new cranial nerve deficits occurred in 7%, CSF leak in 4%, and meningitis in none of the patients. Radiation therapy was performed in 79 patients (79%), with PRT in 50 patients (50%) as the primary treatment. During the median follow-up period of 73 (interquartile range [IQR] 38-132) months, 41 recurrences (41%) and 31 deaths (31%) were confirmed. Patients with GTR/NTR had a median PFS of 41 (IQR 24-70) months. Patients with subtotal resection or biopsy had a median PFS of 38 (IQR 16-97) months. The median PFS of patients who received radiation therapy was 43 (IQR 26-86) months, while that of patients who did not receive radiation therapy was 18 (IQR 5-62) months. The Kaplan-Meier method showed that patients with GTR/NTR (p = 0.007) and those who received radiation therapy (p < 0.001) had longer PFS than their counterparts. The PFS rates following primary treatment at 5, 10, 15, and 20 years were 51%, 25%, 17%, and 7%, respectively. The OS rates at the same intervals were 84%, 60%, 42%, and 34%, respectively. Multivariate Cox regression analysis showed that age < 44 years (p = 0.02), greater extent of resection (EOR; p = 0.03), and radiation therapy (p < 0.001) were associated with lower recurrence rates. Another multivariate analysis showed that age < 44 years (p = 0.01), greater EOR (p = 0.04), and freedom from recurrence (p = 0.02) were associated with lower mortality rates. Regarding pathology data, brachyury was positive in 98%, pan-cytokeratin in 93%, epithelial membrane antigen in 85%, and S100 in 74%. No immunohistochemical markers were associated with recurrence.
In this study, younger age, maximal safe resection, and radiation therapy were important factors for longer PFS in patients with primary clival chordomas. Preventing recurrences played a crucial role in achieving longer OS.

OBJECTIVE: To analyze clinical and imaging characteristics of post-traumatic posterior fossa extradural hematoma (PFEDH).
METHODS: Between 2018 and 2022, 51 patients were admitted to our tertiary care trauma center with a diagnosis of PFEDH. The management decision was tailored by an individual consultant based on clinicoradiological findings. We did a prospective analysis of patient characteristics, radiology, clinical presentation, management, and outcome at discharge and onemonth follow-up.
RESULTS: Of the 51 patients diagnosed with a PFEDH, 45 (88.2%) were male, and six (11.8%) were female with a mean age of 31.2 years (range 2-77 years). Twenty-six patients needed surgical evacuation of the EDH, while the rest 25 patients were managed conservatively. There was one crossover patient from the conservative to the surgical arm. Road traffic accidents (RTA) were the most common cause of injury (n=35; 68.6%), followed by falls from height (n=16; 31.4%). Most patients presented with vomiting and loss of consciousness (LOC). At presentation, 30 patients (58.5%) had a GCS 15. Seven patients (13.7%) presented with a GCS of 9-14, and 14 patients (27.5%) with GCS ≤ 8. The mean EDH volume in conservatively and surgically managed patients was 14.1 and 25.1cc, respectively. Five patients (9.8%) had significant midline shift with obliteration of basal cisterns, 15 patients (29.4%) had effacement of the fourth ventricle, and 11 patients (21.5%) had the presence of hydrocephalus. All patients with features suggestive of tight posterior fossa (hydrocephalus, obliterated basal cisterns, and fourth ventricle compression) needed surgical intervention. Of the 25 conservatively managed patients, 24 (96%) had favorable GOS scores at discharge, while one (4%) had an unfavorable score. 16/26 (61.5%) surgically treated patients had a good outcome at discharge (GOS=4-5), while ten patients (38.4%) had adverse outcomes (GOS < 4). Initial EDH volume was inversely correlated with presenting GCS and GOS with a mean volume of 21.5 ± 8.5 cc in patients presenting with a GCS ?8. Patients with a GCS of 15 at presentation had a mean EDH volume of 16.1 ± 8.2 cc. Patients with smaller EDH had much higher GOS scores than patients with higher volume EDH (GOS 1 = 22.0 ± 9.83 cc vs. GOS 5 = 18.9 ± 12.2 cc). Outcomes mainly depended on factors like GCS at arrival and associated supratentorial, thoracic/ abdominal polytrauma.
CONCLUSIONS: In patients with a clot volume of < 15 cm3 and GCS of 15 at presentation with no mass effect and absence of tight posterior fossa, a conservative trial under strict clinicoradiological monitoring in a neuro-critical multidisciplinary setting can be offered with good results. In cases of altered GCS, findings of a TPF, or clinicoradiological deterioration, immediate surgery is warranted.

OBJECTIVE: To assess the impact of tumor extension into the occipital condyle (OC) in lower clival chordoma management and the need for occipito-cervical fusion (OCF).
METHODS: A retrospective analysis was conducted on 35 patients with lower clival chordoma. The preoperative area of the intact OCs, Hounsfield units, and the integrity of the apical ligament and the tectorial membrane were assessed using preoperative imaging.
RESULTS: Seven (20%) patients were in the OCF group. The OCF group exhibited a higher prevalence of preoperative pain in the neck or head (P = 0.006), ligament absence (P = 0.022), and increased propensity for postoperative wound issues (P = 0.022) than the non-OCF group. The OCF group had less intact OCs (P < 0.001) and higher spinal instability neoplastic score (P = 0.002) than the non-OCF group. All patients with intact OCs < 60% underwent OCF, and those with OCs ≥ 70% were treated without OCF. Those with OCs between 60% and 69% underwent OCF if the ligaments were eroded, and did not undergo OCF if the ligaments were intact. Treatment strategies varied, with endoscopic endonasal approach alone being common. Radiation therapy was administered to 89% of patients. All 3 patients treated with OCF after tumor resection had wound issues; none treated with OCF before resection had wound issues. None developed atlanto-occipital instability. Survival rates did not significantly differ between groups.
CONCLUSIONS: In the absence of mobility-related neck pain, patients with lower clival chordoma and intact OC ≥ 60%, intact apical ligament, and intact tectorial membrane, may not require OCF.

Neuronavigation systems coupled with previously reported external anatomical landmarks assist neurosurgeons during intracranial procedures. We aimed to verify whether the posterior auricularis muscle (PAM) could be used as an external landmark for identifying the sigmoid sinus (SS) and the transverse-sigmoid sinus junction (TSSJ) during posterior cranial fossa surgery.
The PAM was dissected in 10 adult cadaveric heads and after drilling the underlying bone, the relationships with the underlying SS and TSSJ were noted. The width and length of the PAM, and the distance between the muscle and reference points (asterion, mastoid tip, and midline), were measured.
The PAM was identified in 18 sides (9 left, 9 right). The first 20 mm of the muscle length (mean 28.28 mm) consistently overlay the mastoid process anteriorly and the proximal half of the SS slightly posteriorly on all sides. The superior border was a mean of 2.22 mm inferior to the TSSJ and, especially when the muscle length exceeded 20 mm, this border extended closer to the transverse sinus; it was usually found at a mean of 3.11 mm (range 0.0-13.80 mm) inferior to the distal third of the transverse sinus.
Superficial landmarks give surgeons improved surgical access, avoiding overexposure of deep neurovascular structures and reducing brain retraction. On the basis of our cadaveric study, the PAM is a reliable and accurate direct landmark for identifying the SS and TSSJ. The PAM could potentially be used for guiding the retrosigmoid approach.

Extended endoscopic endonasal approaches (EEAs) to petroclival chondrosarcomas (PCs) require a thorough understanding of skullbase anatomy, especially the anatomy of petrous internal carotid artery (pICA), as ICA injury is the most dreaded complication of extended EEAs. We conducted this study to determine the displacement patterns of pICA in patients with PCs.
Contrast enhanced computed tomography scan and angiography images of patients with PCs were analyzed for following parameters-antero-posterior, cranio-caudal, medio-lateral, and direct distances between anterior genu of petrous internal carotid artery (AGpICA) and posterior end of Vidian canal (pVC). pICA encasement/narrowing by tumor was noted on magnetic resonance imaging.
We studied 11 patients with histopathologically proven PCs. pICA encasement/narrowing and pVC destruction were observed in one patient each. The mean antero-posterior and cranio-caudal distances on tumor side/normal side were 7.7 ± 1.9/6.4 ± 1.0 mm & 4.5 ± 1.5/3.4 ± 0.9 mm, respectively. The overall displacement was posterior & superior. Medio-lateral displacement was seen in 4 patients (lateral in 3 and medial in 1). In rest, AGpICA was centered on pVC. The mean direct distance was 9.4 ± 2.5 mm. In 3 patients with displacement seen in all three axes, direct distance was measured by the \"cuboid method.\" Overall, posterior-superior-lateral, posterior-superior, and anterior-inferior were the common displacement patterns of AGpICA relative to pVC.
The displacement patterns of AGpICA in PCs are variable. An individualized approach with meticulous analysis of preoperative imaging can help in determining the relation between AGpICA and pVC. This detailed morphometric information can facilitate better orientation to altered anatomy, which can be helpful in preventing pICA injury during extended EEAs.

Cerebral vein and dural venous sinus thromboses (CVST) account for 0.5%-1% of all strokes. Some structural factors associated with a potentially higher risk for developing CVST have been described. However, angulation of the dural venous sinuses (DVS) has yet to be studied as a structural factor. The current study was performed because this variable could be related to alterations in venous flow, thus predisposing to a greater risk of CVST development. Additionally, such information could help shed light on venous sinus stenosis (VSS) at or near the transverse-sigmoid junction. The angulations formed in the different segments of the grooves of the transverse (TS), sigmoid (SS), and superior sagittal sinuses (SSS) were measured in 52 skulls (104 sides). The overall angulation of the TS groove was measured using two reference points. Other variables were examined, such as the communication pattern at the sinuses\' confluence and the sinus grooves\' lengths and widths. The patterns of communication between sides were compared statistically. The most typical communication pattern at the sinuses\' confluence was a right-dominant TS groove (82.98%). The mean angulations of the entire left TS groove at two different points (A and B) were 46° and 43°. Those of the right TS groove were 44° and 45°. The median angulations of the left and right SSS-transverse sinus junction grooves were 127° and 124°. The mean angulations of the left and right TS-SSJsv grooves were 111° (range 82°-152°) and 103° (range 79°-130°). Differentiating normal and abnormal angulations of the DVSs of the posterior cranial fossa can help to explain why some patients are more susceptible to pathologies affecting the DVSs, such as CVST and VSS. Future application of these findings to patients with such pathologies is now necessary to extrapolate our results.

OBJECTIVE: The changes in the proportion of posterior cranial fossa structures during pediatric development remain unclear. This retrospective study aimed to investigate the growth patterns and ratios of these structures using CT scans.
METHODS: Head CT scans of pediatric patients with minor head trauma from Osaka Women\'s and Children\'s Hospital between March 2006 and May 2023 were analyzed. The study segmented the intracranial volume (ICV), posterior cranial fossa volume (PCFV), cerebellum volume (CBMV), and brainstem volume (BSV). Correlation coefficients were calculated among the parameters. Patients aged 0 to 10 years were divided into 15 age-related clusters, and mean and standard deviation values were measured. Growth curves were created by plotting mean values sequentially. Ratios such as PCFV/ICV and (CBMV + BSV)/PCFV were examined. Statistical analyses, including unpaired t tests and logarithmic curve fitting, were performed.
RESULTS: A total of 234 CT scans (97 from females, 115 from infants under 1 year of age) were analyzed. Positive correlations were observed among the parameters, with the strongest between PCFV and CBMV. The growth curves for ICV, PCFV, CBMV, and BSV exhibited a two-phase process, with rapid growth until approximately 4 years of age, followed by stabilization. The ratios PCFV/ICV and (CBMV + BSV)/PCFV showed increasing trends from birth onwards, stabilizing by 4 and 1 years of age, respectively.
CONCLUSIONS: This study provides insights into the growth patterns and ratios of posterior cranial fossa structures in the pediatric population. The findings demonstrate a two-phase growth process and increasing trends in the examined ratios.

An adolescent male presented with orthostatic headaches following head trauma. MRI showed cerebellar tonsil displacement and a bony defect in the clival skull base. Digital subtraction myelography (DSM) confirmed a cerebrospinal fluid-venous fistula (CVF). This was repaired endoscopically. CVFs cause uncontrolled flow of CSF into the venous system resulting in symptoms of intracranial hypotension. They\'re often difficult to identify on initial imaging. This is the first reported CVF originating in the central skull base, and the first treated via endoscopic trans-nasal approach. CVFs may elude initial imaging, making DSM crucial for unexplained spontaneous intracranial hypotension. Laryngoscope, 134:645-647, 2024.

This study was conducted to evaluate the anatomical and clinical features of Trautman\'s triangle (TT) and to better understand the possible surgical corridor for other surgical approaches involving the petroclival region, especially the presigmoid retrolabyrinthine approach.
In this study, morphological analysis of structures related to TT was performed from cone beam computed tomography images of 134 female and 206 male individuals aged 18-65 years.
The TT area was observed as 5.6% (n = 19) type I, 63.2% (n = 215) type II, and 31.2% (n = 106) type III. It was determined that 87.6% of the sigmoid sinus (SS) was lateral to the posterior semicircular canal and 12.4% was medial. It was determined that the TT area showed a positive correlation with petrous slope and a negative correlation with mastoid aeration. In other words, as the TT area increased, the petrous inclination angle also increased, but the mastoid aeration decreased. It was also found that the TT area was associated with the location of the SS and the largest TT area (164.84 ± 42.29 mm2) was observed in the posteriorly located SS.
The relationship between TT and SS, petroclival angle, mastoid aeration, and subarcuate fossa has a very dynamic structure. Understanding the variations and clinical significance of these structures in the petroclival region is critical in determining the surgical approaches to be applied and understanding the etiology of vestibular system diseases.

The purpose of this study was to evaluate the prevalence and characteristics of 3 anatomical variations of the clivus: fossa navicularis magna (FNM), canalis basilaris medianus (CBM), and craniopharyngeal canal (CPC). Findings were correlated with sex, age, and facial skeletal pattern. A total of 602 cone beam computed tomography scans of Brazilian adults were retrospectively evaluated by 2 independent examiners. The presence of an FNM, CBM, or CPC was recorded, and length, depth, and width were measured. The CBM was classified according to type (3 complete and 3 incomplete varieties). All data were correlated with sex, age, and facial skeletal pattern. Results were tested using chi-square, Mann-Whitney U, and Kruskal-Wallis tests (P < 0.05). The prevalence rates for FNM, CBM, and CPC were 15.78% (n = 95), 6.64% (n = 40), and 0.17% (n = 1), respectively. No significant differences in the prevalence of the variations were found based on sex or facial skeletal patterns (P > 0.05). The median length, depth, and width of FNM were 5.55, 1.83, and 4.81 mm, respectively, with no significant differences (P > 0.05) between the variables. The prevalence of FNM was significantly higher in patients aged 18 to 33 years than in those aged 34 and older (P < 0.001). An incomplete variant of the CBM, presenting as an inferior recess, was more common (32.5%). The FNM is the most prevalent anatomical variation of the clivus, especially in young adults. The sex and facial skeletal pattern of the individual do not affect the frequency of FNM, CBM, or CPC. Because of their clinical relevance, recognition of these anatomical variations is essential, as they can be misdiagnosed as pathologies.