Preoperative Simulation of Intraoperative Findings in Surgical Clipping of Posterior Communicating Artery Aneurysms Using T2-Weighted 3D Images.

BACKGROUND: Tentorium resection and detachment from the oculomotor nerve are sometimes required for surgical clipping of unruptured posterior communicating artery (PCoA) aneurysms. Using T2-weighted 3D images, we aimed to identify the preoperative radiological features required to determine the necessity of these additional procedures. METHODS: We reviewed 30 patients with unruptured PCoA aneurysms who underwent surgical clipping and preoperative simulation using T2-weighted 3D images for measurement of the distance between the tentorium and aneurysm. Aneurysms were classified into superior type (superior to the tentorium) and inferior type (inferior to the tentorium). RESULTS: Seven patients (23%) underwent tentorium resection; all had the inferior type (superior vs. inferior, 0% vs. 33%, p = 0.071). In the 21 patients with the inferior type, the distance from the tentorium to the aneurysmal neck was 2.2 ± 1.1 mm and 0.0 ± 0.5 mm without and with tentorium resection (p < 0.01), respectively. An optimal cutoff value of ≤ +0.84 mm was identified for tentorium resection (area under the curve (AUC) = 0.96). Furthermore, 17 patients (57%) showed tight aneurysm attachment to the oculomotor nerve; all had the inferior type (0% vs. 81%, p < 0.01). The distance from the aneurysm tip to the tentorium was 1.1 ± 1.2 mm and -1.7 ± 1.4 mm without and with attachment (p < 0.01). The optimal cutoff value was ≤ +0.45 mm (AUC = 0.92). CONCLUSIONS: Measurement of the distance between the tentorium and aneurysmal neck or tip with T2-weighted 3D images is effective for preoperative simulation for surgical clipping of PCoA aneurysms.

Cerebrospinal fluid protein concentration in patients with lumbar spinal stenosis.

Background: In this study, we examined the impact and degree of lumbar stenosis on cerebrospinal fluid (CSF) protein concentration. Methods: In this retrospective study, we analyzed protein concentrations in CSF samples of 61 patients with lumbar spinal stenosis (LSS) obtained during pre-operative myelography. Patients were divided into two groups: those showing no block to contrast (Group A) versus those showing medium block to contrast below the lumbar puncture level (Group B). Results: The CSF protein concentration in Group B (104.3 ± 59 g/dL) patients with medium block was significantly greater than that in Group A (65.1 ± 33 g/dL) patients without medium block. Conclusion: A higher average CSF protein concentration was seen in Group B patients with significant lumbar stenosis versus Group A patients without significant lumbar stenosis. Theoretically, damage to the cauda equina in patients with LSS may cause these elevated CSF protein levels.

CT correlation of spinal canal diameter with pedicle size for safer posterior cervical pedicle screw fixation.

Background: Utilizing computed tomography (CT) studies, we correlated cervical spinal canal diameters (SCDs) with pedicle size between the C3 and C7 levels to more safely perform posterior cervical surgery. Methods: We retrospectively analyzed CT studies for 71 patients with cranial or spinal disorders and correlated the cervical SCD with the pedicle outer width (POW) between the C3 and C7 levels. Patients were divided into normal (SCD ≥12 mm at any level, n = 30) and stenosis groups (SCD <12 mm at any level, n = 41). Results: C7 exhibited the largest SCD and POW values, while C3 and C4 exhibited the smallest SCD and POW values. Moderate correlations (r = 0.3, P = 0.002) were observed at the C3 and C4 levels but no significant correlations were observed from the C5 to C7 levels. For SCD values, the normal group demonstrated significantly greater values between the C3 and C7 levels versus the stenosis group. For POW values, only the C4 level differed significantly between the two groups (P = 0.014, Mann-Whitney U-test). Conclusion: Preoperative pedicle size evaluation remains an essential manoeuvre before performing cervical C3-C7 pedicle screw placement. In 71 cervical CT studies, we found no consistent correlation between POW and SCD values, indicating that it is difficult to estimate POW values based on spinal canal size.

Systemic Embolism Following Mechanical Thrombectomy for Acute Ischemic Stroke: A Case of Suspected Catastrophic Antiphospholipid Syndrome.

Objective: Catastrophic antiphospholipid syndrome (CAPS) is a disease characterized by a poor prognosis and a high mortality rate, leading to systemic thrombosis. Approximately two-thirds of CAPS cases are associated with conditions such as infections, malignancies, surgical interventions, and events linked to the disease activity of systemic lupus erythematosus (SLE). Herein, we present a case of CAPS with multiorgan ischemia following ischemic stroke. Case Presentation: In this case report, a 33-year-old woman with a history of SLE and prolonged steroid use manifested impaired consciousness. Detection of the right internal carotid artery (ICA) occlusion led to successful ICA recanalization through endovascular thrombectomy. Postoperatively, she experienced pulmonary embolism and renal infarction. Although antiphospholipid syndrome (APS) was suspected, APS-related antibodies were negative. Anticoagulation therapy was initiated, presuming corticosteroid-induced thrombosis. However, she developed multiorgan thrombosis, culminating in multiple organ failure. Based on her clinical course, a diagnosis of CAPS was established. Intensive care and plasma exchange therapy were instrumental in her recovery, and she was discharged with a modified Rankin Scale score of 4. Conclusion: When encountering multiorgan ischemia following ischemic stroke in a young adult patient with an autoimmune disease, the consideration of CAPS as a differential diagnosis is crucial, even if APS-related antibodies test negative.

Radiological Analysis of Cerebrospinal Fluid Dynamics at the Craniovertebral Junction Using Time-Spatial Labeling Inversion Pulse Magnetic Resonance Imaging in Patients with Cervical Spinal Canal Stenosis.

OBJECTIVE: Spondylotic changes in the cervical spine cause degeneration, leading to cervical spinal canal stenosis. This stenotic change can affect cerebrospinal fluid (CSF) dynamics by compressing the dural sac and reducing space in the subarachnoid space. We examined CSF dynamics at the craniovertebral junction (CVJ) using time-spatial labeling inversion pulse magnetic resonance imaging (Time-SLIP MRI) in patients with cervical spinal canal stenosis. METHODS: The maximum longitudinal movement of the CSF at the CVJ was measured as length of motion (LOM) in the Time-SLIP MRI of 56 patients. The sum of ventral and dorsal LOM was defined as the total LOM. Patients were classified into 3 groups depending on their spinal sagittal magnetic resonance imaging findings: control (n = 27, Kang classification grades 0 and 1), stenosis (n = 14, Kang classification grade 2), and severe stenosis (n = 15, Kang classification grade 3). RESULTS: Time-SLIP MRI revealed pulsatile movement of the CSF at the CVJ. The mean total, ventral, and dorsal LOM was 14.2 ± 9, 8.1 ± 5.7, and 3.8 ± 2.9 mm, respectively. The ventral LOM was significantly larger than the dorsal LOM. The total LOM was significantly smaller in the severe stenosis group (6.1 ± 3.4 mm) than in the control (16.0 ± 8.4 mm) or stenosis (11 ± 5.4 mm) groups (P < 0.001, Kruskal-Wallis H-test). In 5 patients, postoperative total LOM was improved after adequate decompression surgery. CONCLUSIONS: This study demonstrates that CSF dynamics at the CVJ are influenced by cervical spinal canal stenosis. Time-SLIP MRI is useful for evaluating CSF dynamics at the CVJ in patients with spinal canal stenosis.

Surgical aspects in craniopharyngioma treatment.

OBJECTIVES: Total surgical resection is the gold standard in the treatment of craniopharyngioma. However, there is concern that aggressive surgical resection might result in high rates of endocrinologic, metabolic, and behavioral morbidities. Subtotal resection (SR) with subsequent radiation therapy (RT) may reduce surgical complications, but it may also increase the risk of tumor recurrence and radiation-induced side effects. Therefore, the optimal surgical strategy remains debatable. METHODS: To determine the optimal surgical strategy, we assessed the clinical courses of 39 patients (19 male patients and 20 female patients) with newly diagnosed craniopharyngioma who were treated at our institute. The median age at diagnosis was 34 years (range: 0-76 years). The median follow-up period was 8.5 years (range: 3-160 months). Our treatment strategy comprised gross total resection (GTR) for craniopharyngioma in patients that were not at surgical risk. Conversely, after adequate tumor decompression, we used RT, mainly Gamma Knife radiosurgery, in patients at risk. We divided the patients into the following three groups depending on the treatment course: GTR, SR with RT, and SR with staged surgery. We compared tumor characteristics, as well as patients' conditions at the preoperative stage and last follow-up, among the three groups. RESULTS: There were 8, 21, and 10 patients in the GTR, SR with RT, and SR with staged surgery groups, respectively. There were no differences in the maximum tumor diameter, tumor volume, composition, and presence of calcification among the groups. Among the 39 patients, 24 underwent transcranial microsurgery and 15 underwent trans-sphenoidal surgery as the initial treatment. No cases involving surgical mortality, cerebrospinal fluid leakage, severely deteriorated visual function, or severe hypothalamic damage were observed. No tumor recurrence was noted in the GTR group. One patient required additional RT, and one patient underwent second surgery for tumor recurrence in the SR with RT group. In the SR with staged surgery group, 8 of the 10 patients eventually underwent RT, but tumor control was achieved in all patients at the latest follow-up. In this group, the third trans-sphenoidal surgery caused a severe vascular injury in one patient. At the final follow-up, 33 (85%) patients were undergoing anterior pituitary hormone replacement, and the rate of diabetes insipidus was 51%. There was no significant difference in the pituitary dysfunction rate among the groups. CONCLUSIONS: We observed a low rate of surgical complications and a sufficient tumor control rate in response to our treatment strategy. Despite attempting preservation of the pituitary stalk, we found it difficult to rescue anterior pituitary function.

Craniopharyngiomas, including Recurrent Cases, Lack TERT Promoter Hotspot Mutations.

Adamantinomatous craniopharyngiomas (ACP) are characterized by alterations in the CTNNB1 gene while almost all papillary craniopharyngiomas (PCP) harbor a canonical V600E mutation in the BRAF gene. Although other recurrent driver genes have not been described to date in craniopharyngiomas, the heterogeneous clinical course of these tumors might be associated with the acquisition of further genomic alterations. It is well known that telomerase reverse transcriptase (TERT) promoter (TERTp) alterations, including mutations or methylation, upregulate the expression of TERT and increase telomerase activity, promoting tumorigenesis. We investigated whether TERTp mutations or methylation are associated with tumor relapse in a subset of craniopharyngiomas. Samples from 42 patients with histologically confirmed craniopharyngioma were retrieved. We determined TERTp, BRAF, and CTNNB1 hotspot mutations in all samples using targeted sequencing and the TERTp methylation status by methylation-specific polymerase chain reaction (PCR) in 30 samples. While BRAF V600E mutations and CTNNB1 mutations were detected in 12 (28.6%) and 21 patients (50%) in the initial tumors and subsequent recurrences, respectively, none of the patients in our cohort, including those with multiple relapses, harbored a TERTp mutation. Furthermore, TERTp methylation was detected in 14 out of 24 cases (58.3%) with available primary samples; however, no correlation between TERTp methylation with the pathological subtype, genotype, or tumor aggressiveness was detected. These data suggest that elevated telomerase activity via acquisition of TERTp mutations is an infrequent pathway in the tumorigenesis of craniopharyngiomas, regardless of their clinical course.

Navigation-Guided Measurement of the Inferior Limit Through the Endonasal Route to the Craniovertebral Junction.

BACKGROUND: The endoscopic endonasal approach (EEA) has been accepted as an alternative option for diseases at the craniovertebral junction. However, the inferior destination through the endoscopic endonasal approach is anatomically higher than that of the transoral approach. Therefore, preoperative assessment of accessibility is mandatory for appropriate selection of indication. Using a navigation system, we examined the inferior limit through the endonasal route and evaluated the relationships between surrounding anatomicl structures and the lowest point. METHODS: This study included patients who underwent endoscopic transsphenoidal surgery for intrasellar lesions at our hospital (N = 23). At the start of surgery, the lowest point (target point [TP]) was marked with a straight probe under guidance of the navigation system. We measured 4 parameters on preoperative computed tomography: nasal length, hard palate length, anterior-posterior diameter of the nasopharynx, and nasopalatine angle. Patients were classified into groups depending on whether the TP was at or above (group A) or below (group B) the hard palatine line. RESULTS: TPs were above the hard palatine line in 15 patients (group A) and below the hard palatine line in 8 patients (group B). No TPs reached the nasopalatine line. Nasal length (P = 0.03) and nasopalatine angle (P = 0.01) were larger in group B than in group A. There were no significant differences in anterior-posterior diameter of the nasopharynx or hard palate length. CONCLUSIONS: The hard palatine line is a reliable parameter for assessing the inferior limit of the endoscopic endonasal approach. Nostril size affects accessibility with surgical instruments.

A Thyroid-stimulating Hormone (TSH) Producing Adenoma in a Patient with Severe Hypothyroidism: Thyroxine Replacement Reduced the TSH Level and Tumor Size.

We treated an extremely rare thyroid-stimulating hormone (TSH)-producing pituitary adenoma in a 63-year-old woman with severe hypothyroidism due to autoimmune thyroiditis. She was presented with dizziness and fatigue. The blood level of TSH, prolactin, and fT4 was 288.2 µIU/mL, 72.9 ng/mL, and 0.24 ng/dL, respectively. Magnetic resonance imaging demonstrated a large pituitary tumor, 31 mm in height, and a normal pituitary gland. Preoperative thyroxine replacement reduced the TSH level to 2.05 µIU/mL and produced a significant reduction in the tumor volume. Histopathologically, the surgically removed tumor was a TSH-producing pituitary adenoma.

Asymptomatic spinal dural arteriovenous fistula: case series and systematic review.

OBJECTIVE: Spinal dural arteriovenous fistulas (SDAVFs) commonly present with symptoms of myelopathy due to venous congestion in the spinal cord; asymptomatic SDAVFs are rarely encountered. To elucidate the clinical characteristics of asymptomatic SDAVFs, the authors present 5 new cases of asymptomatic SDAVF and report the results of their systematical review of the associated literature. METHODS: Five databases were systematically searched for all relevant English-language articles on SDAVFs published from 1990 to 2018. The clinical features and imaging findings of asymptomatic SDAVFs were collected and compared with those of symptomatic SDAVFs. RESULTS: Twenty cases, including the 5 cases from the authors' experience, were found. Asymptomatic SDAVFs were more prevalent in the cervical region (35.0%); cervical lesions account for only 2% of all symptomatic SDAVFs. The affected perimedullary veins tended to drain more cranially (50.0%) than caudally (10.0%). Four cases of asymptomatic SDAVF became symptomatic, 1 case spontaneously disappeared, and the remaining 15 cases were unchanged or surgically treated. CONCLUSIONS: The higher prevalence of asymptomatic SDAVFs in the cervical spine might be a distinct feature of asymptomatic SDAVFs. Given that venous congestion is the pathophysiology of a symptomatic SDAVF, abundant collateral venous pathways and unique flow dynamics of the CSF in the cervical spine might prevent asymptomatic cervical SDAVFs from becoming symptomatic. In cases in which venous congestion is avoidable, not all asymptomatic SDAVFs will become symptomatic.

A Clinical Rule for Preoperative Prediction of BRAF Mutation Status in Craniopharyngiomas.

BACKGROUND: Papillary craniopharyngiomas are characterized by BRAFV600E mutations. Targeted therapy can elicit a dramatic radiographic regression of these tumors. Therefore, prediction of BRAF mutation status before definitive surgery could enable neoadjuvant treatment strategies. OBJECTIVE: To establish preoperative prediction criteria to identify patients with a BRAF mutant craniopharyngioma. METHODS: Sixty-four patients with craniopharyngioma were included in this study. We determined BRAF mutation status by targeted sequencing. After scoring interobserver variability between presurgical clinical data and radiographic features, we established a diagnostic rule for BRAF mutation in our discovery cohort. We then validated the rule in an independent cohort. RESULTS: The BRAFV600E mutation was detected in 12 of 42 patients in the discovery cohort. There were no patients under age 18 with BRAF mutation. Calcification was rare in tumors with BRAF mutation (P < .001), and 92% of them were supradiaphragmatic in location. Combining these 3 features-older than 18 years, absence of calcification, and supradiaphragmatic tumor location-we established a rule for predicting BRAF mutation. In cases where all 3 criteria were fulfilled, the sensitivity and specificity for the presence of BRAF mutation were 83% and 93%, respectively. In the validation cohort (n = 22), the sensitivity was 100% and specificity was 89%. CONCLUSION: We propose predictive criteria for a BRAF mutation in craniopharyngioma using preoperative clinical and radiographic data. This rule may be useful in identifying patients who could potentially benefit from neoadjuvant BRAFV600E-targeted systemic therapies.