Intermuscular coherence as an early biomarker for amyotrophic lateral sclerosis: The protocol for a prospective, multicenter study.

OBJECTIVE: To describe the protocol of a prospective study to test the validity of intermuscular coherence (IMC) as a diagnostic tool and biomarker of upper motor neuron degeneration in amyotrophic lateral sclerosis (ALS). METHODS: This is a multicenter, prospective study. IMC of muscle pairs in the upper and lower limbs is gathered in ∼650 subjects across three groups using surface electrodes and conventional electromyography (EMG) machines. The following subjects will be tested: 1) neurotypical controls; 2) patients with symptomatology suggestive for early ALS but not meeting probable or definite ALS by Awaji Criteria; 3) patients with a known ALS mimic. The recruitment period is between 3/31/2021 and 12/31/2025. Written consent will be sought from the subject or the subject's legally authorized representative during enrollment. RESULTS: The endpoints of this study include: 1) whether adding IMC to the Awaji ALS criteria improve its sensitivity in early ALS and can allow for diagnosis earlier; 2) constructing a database of IMC across different ages, genders, and ethnicities. SIGNIFICANCE: This study may validate a new inexpensive, painless, and widely available tool for the diagnosis of ALS.

Intermuscular Coherence in Spinocerebellar Ataxias 3 and 6: a Preliminary Study.

Spinocerebellar ataxias (SCAs) are familial neurodegenerative diseases involving the cerebellum and spinocerebellar tracts. While there is variable involvement of corticospinal tracts (CST), dorsal root ganglia, and motor neurons in SCA3, SCA6 is characterized by a pure, late-onset ataxia. Abnormal intermuscular coherence in the beta-gamma frequency range (IMCßγ) implies a lack of integrity of CST or the afferent input from the acting muscles. We test the hypothesis that IMCßγ has the potential to be a biomarker of disease activity in SCA3 but not SCA6. Intermuscular coherence between biceps brachii and brachioradialis muscles was measured from surface EMG waveforms in SCA3 (N = 16) and SCA6 (N = 20) patients and in neurotypical subjects (N = 23). IMC peak frequencies were present in the ß range in SCA patients and in the γ range in neurotypical subjects. The difference between IMC amplitudes in the γ and ß ranges was significant when comparing neurotypical control subjects to SCA3 (p < 0.01) and SCA6 (p = 0.01) patients. IMCßγ amplitude was smaller in SCA3 patients compared to neurotypical subjects (p < 0.05), but not different between SCA3 and SCA6 patients or between SCA6 and neurotypical subjects. IMC metrics can differentiate SCA patients from normal controls.

Development of urinary diary mobile application and evaluation in patients with urinary incontinence.

OBJECTIVE: To develop a feasible smartphone urinary diary application (UDA), and evaluate reliability and patient acceptability as a collection, calculation, and sharing tool. MATERIALS AND METHODS: We developed the UDA for smartphones, which collects voiding, leakage, fluid intake, and grade of urgency data. A two-way cross-sectional study was conducted with 60 participants, participants split into two groups. Thirty participants completed UDA for 3 days either preceded or followed by a standard paper diary. We assessed the paper app reliability of the UDA with the Kappa variable and internal correlation coefficient (ICC). RESULTS: 29 (96.6%) participants completed the 3-day UDA in the first phase, 92.6% in the second phase, in comparison to 90% and 79.4% in paper form, respectively. Incomplete variable recording was observed at 10.3%-20% in the UDA group in comparison to 33.3%-34.8 % in the PF group. Of the 48 participants who experienced both diaries, 40 (83.3%) preferred the UDA. Paper app correlation was good to very good with ICC ranging from 0.60 to 0.90 for all variables (p < 0.001). Kappa values for incontinence, stress incontinence, urge incontinence, and increased frequency were 0.95, 0.94, 0.82 0.87, and 0.54; respectively (p < 0.001). CONCLUSION: The performance of developed smartphone UDA is comparable with and highly correlated with paper form with most users finding the app feasible. Convergent validity with urinary incontinence and other lower urinary tract dysfunctions is required.

Osteoplastic Pterional Craniotomy: Success Rate of Surgery in Patient Aspect.

AIM: To evaluate the effect of osteoplastic pterional craniotomy on temporal hollowing and its sequelae. MATERIAL AND METHODS: A total of 97 patients who underwent pterional craniotomy for an aneurysm were analyzed retrospectively. Of these 97 patients, 63 underwent surgery via the conventional pterional approach and 34 underwent surgery via the osteoplastic pterional approach. The temporal muscle volume was calculated bilaterally on CT images obtained in the sixth postoperative month. The results obtained in the conventional and osteoplastic approaches were compared. RESULTS: Of the 97 included patients, 45 were female and 52 were male. The mean patient age was 50.37 years. In the conventional group, 31 were female and 32 were male. In the osteoplastic group, 14 were female and 20 were male. The temporal muscle volume difference between the operated and non-operated side was not statistically significant in the osteoplastic group. However, the volume was slightly lesser on the operated side than on the non-operated side in the conventional group. CONCLUSION: The osteoplastic pterional approach is superior to the conventional approach in preserving the muscle volume and function. Patients who underwent osteoplastic craniotomy demonstrated higher levels of satisfaction with their facial appearance compared to those who underwent craniotomy using the conventional pterional approach.

Magnetic Resonance Imaging Evaluation of Multifidus Muscle in Patients with Low Back Pain after Microlumbar Discectomy Surgery.

Cross-sectional area (CSA) and signal intensity ratio (SIR) of the multifidus muscle (MFM) on magnetic resonance imaging (MRI) was used to evaluate the extent of injury and atrophy of the MFM in patients with negative treatment outcomes following microlumbar discectomy (MLD). Negative treatment outcome was determined by pain score improvement of <50% compared to baseline. Patients in groups 1, 2, and 3 were evaluated at <4 weeks, 4-24 weeks, and >24 weeks postoperatively, respectively. The associations between the follow-up, surgery time and the changes in the MFM were evaluated. A total of 79 patients were included, with 22, 27, and 30 subjects in groups 1, 2, and 3, respectively. The MFM SIR of the ipsilateral side had significantly decreased in groups 2 (p = 0.001) and 3 (p < 0.001). The ipsilateral MFM CSA significantly decreased postoperatively in groups 2 (p = 0.04) and 3 (p = 0.006). The postoperative MRI scans found significant MFM changes on the ipsilateral side in patients with negative treatment outcomes regarding pain intensity following MLD. As the interval to the postoperative MRI scan increased, the changes in CSA of the MFM and change in T2 SIR of the MFM showed a tendency to increase.

Spinal Cord Stimulation and Related Health Information on Social Media: An Analysis of Instagram Posts.

INTRODUCTION: Spinal cord stimulation (SCS) has been a well-established, effective, minimally invasive procedure for the treatment of chronic medically refractory neuropathic pain involving the limbs and trunk. Social media platforms, including Instagram, are increasingly being used for medical education and sharing patient experiences. This study aimed to investigate posts related to SCS on Instagram. METHODS AND MATERIALS: This study presents a comprehensive analysis of Instagram posts utilizing the hashtags #spinalcordneuromodulation, #spinalcordstimulation, #spinalcordstimulationsurgery, #spinalcordstimulationtherapy, and #spinalcordstimulationimplant, all of which were collected on August 1, 2023. The outcomes were organized into four distinct source-based categories: posts generated by medical practitioners (both surgeons and non-surgeons); content shared by medical organizations; content created by patients; and content from indeterminate categories. The content was further classified based on its nature, encompassing educational material and reflections on patient or physician experiences. Moreover, the impact of users was evaluated in terms of their follower count and the count of posts. RESULTS: The search yielded a total of 4983 posts. The majority of posts were created by medical practitioners (38.53%, n = 1920). The distribution of remaining Instagram posts about SCS was as follows: medical organizations for 35% (n = 1744), patients for 24.12% (n = 1202), and indeterminate categories for 2.35% (n = 117). Among the collected posts, 348 (41.4%) originated from accounts associated with medical practitioners, 286 (34%) from medical organizations, 145 (17.2%) from patients, and 62 (7.4%) remained unspecified. The statistical analysis revealed a significant difference in follower distribution between medical practitioners and all other groups (p<0.001). Reported side effects included pain over the implant (n = 257; 88.92%), lead migration (n = 18; 6.22%), infection (n = 9; 3; 11%), and seroma (n = 5; 1.73%). CONCLUSIONS: When searching for posts about SCS on Instagram, one is more likely to encounter posts authored by medical practitioners that are mostly focused on educational content. Posts created by medical practitioners may be overshadowed and buried among numerous other posts created by patients. We suggest posting educational medical content with the hashtag #MedEd in an attempt to make educational content more easily accessible.

Intermuscular coherence in spinocerebellar ataxias 3 and 6: a preliminary study.

Objective : Spinocerebellar ataxias (SCAs) are familial neurodegenerative diseases involving the cerebellum and spinocerebellar tracts. While there is variable involvement of corticospinal tracts (CST), dorsal root ganglia, and motor neurons in SCA3, SCA6 is characterized by a pure, late-onset ataxia. Abnormal intermuscular coherence in the beta-gamma frequency range (IMCbg) implies lack of integrity of CST or the afferent input from the acting muscles. We test the hypothesis that IMCbg has the potential to be a biomarker of disease activity in SCA3 but not SCA6. Methods: Intermuscular coherence between biceps and brachioradialis muscles was measured from surface EMG waveforms in SCA3 (N=16) and SCA6 (N=20) patients, and in neurotypical subjects (N=23). Results: IMC peak frequencies were present in the b range in SCA patients and in the g range in neurotypical subjects. The difference between IMC amplitudes in the g and b ranges was significant when comparing neurotypical control subjects to SCA3 (p < 0.01) and SCA6 (p = 0.01) patients. IMCbg amplitude was smaller in SCA3 patients compared to neurotypical subjects (p<0.05), but not different between SCA3 and SCA6 patients or between SCA6 and neurotypical subjects. Conclusion/significance: IMC metrics can differentiate SCA patients from normal controls.

Spinal Schwannomas: A Proposal for a New Classification to Aid Surgical Planning.

Background The treatment of spinal schwannomas, which is the most common nerve sheath tumor, is total microsurgical resection. The localization, size and relationship with the surrounding structures of these tumors are crucial in terms of preoperative planning. A new classification method is presented in this study for the surgical planning of spinal schwannoma. Methods All patients who underwent surgery for spinal schwannoma between 2008 and 2021 were reviewed retrospectively, along with radiological images, clinical presentation, surgical approach, and postoperative neurological status. Results A total of 114 patients, 57 male, and 57 females were included in the study. Tumor localizations were cervical in 24 patients, cervicothoracic in one patient, thoracic in 15 patients, thoracolumbar in eight patients, lumbar in 56 patients, lumbosacral in two patients, and sacral in eight patients. All tumors were divided into seven types according to the classification method. Type 1 and Type 2 groups were operated on with a posterior midline approach only, Type 3 tumors were operated on with a posterior midline approach and extraforaminal approach, and Type 4 tumors were operated on with only an extraforaminal approach. While the extraforaminal approach was sufficient in type 5 patients, partial facetectomy was required in 2 patients. Combined surgery including hemilaminectomy and extraforaminal approach was performed in the type 6 group. A posterior midline approach with partial sacrectomy/corpectomy was performed in Type 7 group. Conclusion Effective treatment of spinal schwannoma depends on preoperative planning, which includes correctly classifying tumors. In this study, we present a categorization scheme that covers bone erosion and tumor volume for all spinal localizations.

Peritumoural Oedema as a Predictor of Overall Survival for Patients with Posterior Fossa Metastases.

OBJECTIVE: To analyse the relationship between peritumoural oedema volume and tumour volume in relation to the impact of metastatic posterior fossa tumour survival rates. STUDY DESIGN: An observational study. PLACE AND DURATION OF STUDY: Umraniye Training and Research Hospital, Istanbul, Turkey, from 2011-2021. METHODOLOGY: Fifty-six cancer patients who had been operated upon for cerebellar metastases were analysed retrospectively. To investigate the effect of oedema on survival, patients with a single cerebellar metastasis were evaluated retrospectively. Those patients had a single metastasis located in the cerebellum and did not receive radiotherapy or corticosteroids before surgery. OsiriX MD DICOM viewer was used to calculate the volumes of the tumour and the oedema using fluid-attenuated inversion recovery (FLAIR) and contrast-enhanced magnetic resonance imaging (MRI). The patients were separated into two groups, and the cut-off limit for the oedema to-tumour ratio was set to two. Survival analysis was performed on the two groups. RESULTS: When the primary sites of the tumours were evaluated, 60.7% were located in the lungs (n = 34), 10.7% were located in the breasts (n = 6), 10.7% were located in the gastrointestinal tract (n = 6), 7.1% were located in the renal region (n = 4), 5.4% were located in the gynaecologic tract (n = 3), and 5.4% were located in other parts of the body (n = 3). A univariate analysis showed that overall survival duration was significantly longer in the subgroup with breast cancer (83.3%) and in those patients with a peritumoural oedema volume to tumour volume ratio of less than two (27.6%, p <0.05). Negative prognostic factors were lung cancer and high peritumoural oedema volume. CONCLUSION: Significant peritumoural oedema was linked to a poor prognosis for cancer patients with a single cerebellar metastasis, especially with lung cancer as the primary source. KEY WORDS: Cerebellar metastases, Cerebellum, OsiriX MD, Tumour volume.

Additive manufacturing and three-dimensional printing in obstetrics and gynecology: a comprehensive review.

Three-dimensional (3D) printing, also known as additive manufacturing, is a technology used to create complex 3D structures out of a digital model that can be almost any shape. Additive manufacturing allows the creation of customized, finely detailed constructs. Improvements in 3D printing, increased 3D printer availability, decreasing costs, development of biomaterials, and improved cell culture techniques have enabled complex, novel, and customized medical applications to develop. There have been rapid development and utilization of 3D printing technologies in orthopedics, dentistry, urology, reconstructive surgery, and other health care areas. Obstetrics and Gynecology (OBGYN) is an emerging application field for 3D printing. This technology can be utilized in OBGYN for preventive medicine, early diagnosis, and timely treatment of women-and-fetus-specific health issues. Moreover, 3D printed simulations of surgical procedures enable the training of physicians according to the needs of any given procedure. Herein, we summarize the technology and materials behind additive manufacturing and review the most recent advancements in the application of 3D printing in OBGYN studies, such as diagnosis, surgical planning, training, simulation, and customized prosthesis. Furthermore, we aim to give a future perspective on the integration of 3D printing and OBGYN applications and to provide insight into the potential applications.

The possible effects of sodium fluoroscein to primary cell culture sampling in glioblastoma surgery.

•FL increases beta-galactosidase activity in GBM cell cultures.•FL cause a decrease in GBM cell numbers.•Sampling in GBM cell culture should be performed before using FL.

Use of 3-Dimensional Modeling and Augmented/Virtual Reality Applications in Microsurgical Neuroanatomy Training.

BACKGROUND: Understanding the microsurgical neuroanatomy of the brain is challenging yet crucial for safe and effective surgery. Training on human cadavers provides an opportunity to practice approaches and learn about the brain's complex organization from a surgical view. Innovations in visual technology, such as virtual reality (VR) and augmented reality (AR), have immensely added a new dimension to neuroanatomy education. In this regard, a 3-dimensional (3D) model and AR/VR application may facilitate the understanding of the microsurgical neuroanatomy of the brain and improve spatial recognition during neurosurgical procedures by generating a better comprehension of interrelated neuroanatomic structures. OBJECTIVE: To investigate the results of 3D volumetric modeling and AR/VR applications in showing the brain's complex organization during fiber dissection. METHODS: Fiber dissection was applied to the specimen, and the 3D model was created with a new photogrammetry method. After photogrammetry, the 3D model was edited using 3D editing programs and viewed in AR. The 3D model was also viewed in VR using a head-mounted display device. RESULTS: The 3D model was viewed in internet-based sites and AR/VR platforms with high resolution. The fibers could be panned, rotated, and moved freely on different planes and viewed from different angles on AR and VR platforms. CONCLUSION: This study demonstrated that fiber dissections can be transformed and viewed digitally on AR/VR platforms. These models can be considered a powerful teaching tool for improving the surgical spatial recognition of interrelated neuroanatomic structures. Neurosurgeons worldwide can easily avail of these models on digital platforms.

Factors Associated with Nontraumatic Spontaneous Subdural Hematomas in Pediatric Patients.

OBJECTIVE: In our study, we aimed to summarize the etiology of subdural hematoma that was not traumatic and required operation in pediatric patients. The subdural hematoma characteristics, possible etiologies, and treatment, as well as the patient outcomes, were analyzed. METHODS: A retrospective examination was made of pediatric patients with subdural hematoma who were operated on at Ümraniye Training and Research Hospital. Patients with a history of trauma were excluded. Data on patient sex, age, bleeding location, type of hematoma based on computed tomography imaging, surgical treatment, presenting symptoms, presence of comorbidities, Glasgow Coma Scale, thrombocyte counts, and international normalized ratio values were recorded. RESULTS: Of the 19 patients included in the study, 4 were female and 15 were male. Their ages ranged between 0 and 15 (mean = 5.84) years. In 57.8% of the patients, comorbidities, including acute myeloid leukemia, a history of shunt operation, epilepsy, mucopolysaccharidosis, known subdural effusion, autism, coagulopathy, ventricular septal defect/tetralogy of Fallot, cerebrospinal fluid leakage after baclofen pump administration, Marfan's syndrome, and late neonatal sepsis were present, while 21% had arachnoid cysts and 21% had no reported comorbidities. CONCLUSION: This study suggests that, in pediatric patients with subdural hematoma with an amount of bleeding requiring surgical management, any underlying comorbidities should be investigated regardless of the presence of a history of trauma. While investigating systemic diseases, special attention should be paid to the presence of arachnoid cysts or disruption in cerebrospinal fluid dynamics along with a history of hematologic diseases.

The Relationship between Health Expenditures and Economic Growth in EU Countries: Empirical Evidence Using Panel Fourier Toda-Yamamoto Causality Test and Regression Models.

The aim of this study is to investigate the effect of health expenditures on economic growth in the period 2000-2019 in 27 European Union (EU) countries. First, the causality relationship between the variables was analyzed using the panel Fourier Toda-Yamamoto Causality test. The findings demonstrate a bidirectional causality relationship between health expenditures and economic growth on a panel basis. Secondly, the effects of health expenditures on economic growth were examined using the Random Forest Method for the panel and then for each country. According to the Random Forest Method, health expenditures positively affected economic growth, but on the country basis, the effect was different. Then, government health expenditures, private health expenditures, and out-of-pocket expenditures were used, and these three variables were ranked in order of importance in terms of their effects on growth using the Random Forest Method. Accordingly, government health expenditures were the most important variable for economic growth. Finally, Support Vector Regression, Gaussian Process Regression, and Decision Tree Regression models were designed for the simulation of the data used in this study, and the performances of the designed models were analyzed.

Successful outcome following a multimodal pelvic rehabilitation program in a woman with neurogenic bladder and bowel dysfunction: A case report.

BACKGROUND: Neurogenic bladder and bowel dysfunctions lead to physical, social, and emotional disability and affects one's quality of life. Initial treatment is conservative including several rehabilitation techniques such as pelvic floor muscle training, biofeedback, electrical stimulation, and posterior tibial nerve stimulation. OBJECTIVE: In this case report, a 45-year-old woman with neurogenic bladder and bowel dysfunction was presented. CASE DESCRIPTION: Her urinary and fecal incontinence symptoms began twenty years before this episode of care, after an incomplete spinal cord injury secondary to spinal ependymoma and syringomyelia. She discontinued medical treatments due to side effects and ceased intermittent catheterization. A multimodal pelvic rehabilitation program was administered consisting of posterior tibial nerve stimulation, active pelvic floor muscle training accompanied by biofeedback, and electrical stimulation of pelvic floor muscles. OUTCOMES: There were clinically important favorable differences in the scores of King's health questionnaire (reductions in symptom severity from 25 to 18 and in each of the impact of incontinence, physical and social limitations, personal relationships, sleep/energy, and severity measures from 100 to 67), pelvic floor distress inventory (decreased from 257 to 146) and female sexual function index (increased from 15.1 to 25.1) after 12 weeks of a multimodal pelvic rehabilitation program. Manual muscle tests demonstrated improvements in pelvic floor muscle strength and endurance. CONCLUSION: A 12-week multimodal pelvic rehabilitation program reduced urinary and fecal incontinence symptoms, together with improvements in her sexual life and alleviation of neuropathic pain.

Surgical Treatment of Spinal Arachnoid Cysts: Cyst Excision or Fenestration?

AIM: Arachnoid cysts in the spinal canal account for 1%-3% of all spinal canal lesions. There is no consensus on surgical treatment yet. Dural defect repair is crucial in surgical treatment patients with an extradural component. Fenestration or total resection of the spinal arachnoid cyst is among the preferred methods. This study aimed to examine a series of surgically treated spinal arachnoid cysts in light of the literature. MATERIAL AND METHODS: This was a retrospective study of patients treated in the Istanbul Umraniye Training and Research Hospital Neurosurgery Clinic. A total of 18 patients with spinal arachnoid cysts underwent surgical treatment between 2012 and 2021. All patients were assessed before and after surgery for muscle strength, pain, sensory changes, and bowel-bladder symptoms. All patients underwent magnetic resonance imaging and computed tomography for diagnosis and treatment. RESULTS: Among the 18 patients, 8 were men and 10 were women, with a mean age of 43.7 (25-66) years. Congenital conditions were discovered in 15 of the patients, 2 after lumbar drainage and 1 after spinal anesthesia. Intradural extramedullary and intra-extradural cysts were found in 17 patients and 1 patient, respectively. The cyst was smaller than level 3 in 14 patients and greater than level 3 in 4 patients. Cyst excision and cyst fenestration were performed in 11 and 7 patients, respectively. Cyst excision was performed in four of the patients who underwent cyst fenestration because their complaints did not improve. CONCLUSION: Surgery should be considered in patients with symptomatic spinal arachnoid cysts. Fenestration may be a suitable alternative, especially if magnetic resonance imaging reveals no intracystic adhesion or trabeculation. Residual and recurrence rates are high in patients with a history of intradural intervention, adhesions, or trabeculation. When there is trabeculation, the best option is cyst removal.

Cardiometabolic profiles in women with adenomyosis.

The aim of this study was to investigate the reproductive profiles, metabolic parameters and cardiometabolic risk assessed by surrogate indexes in women with adenomyosis. Ninety-six premenopausal women who were diagnosed with adenomyosis by transvaginal ultrasound and 97 age-body mass index (BMI) matched controls with normal ultrasound during routine examination were included. Women with adenomyosis were more likely to have higher gravidity and had more abortions than women without adenomyosis. Regarding the individual metabolic syndrome components, the adenomyosis group was more likely to have higher prevalence of hypertension, low HDL-C and central obesity. No significant difference was found between the groups in terms of visceral adiposity index, lipid accumulation product and fatty liver index. Only higher blood pressure (BP) remained statistically significant after adjustment for confounding factors in multivariate analysis. Women with adenomyosis had remarkably high risk of hypertension. It may be advisable to monitor their BP closely.Impact StatementWhat is already known on this subject? The only anthropometric characteristic assessed in women in relation to adenomyosis is body mass index (BMI). A case-control study showed that women who are obese are more likely to have adenomyosis. The gravidity, number of spontaneous abortions and previous uterine surgeries such as dilatation and curettage (D&C) and caesarean section were found significantly associated with adenomyosis.What do the results of this study add? A remarkable finding of our study was the increased incidence of higher systolic BP in women with adenomyosis. No difference was observed in adiposity indices between women with and without adenomyosis. Higher prevalence of central obesity and lower HDL-C levels were seen in women with adenomyosis.What are the implications of these findings for clinical practice and/or further research? The study identifies that adenomyosis is associated with an increased risk of hypertension, and women with adenomyosis may be monitored closely for blood pressure changes. Our report also provides novel information about the metabolic risk profiles associated with adenomyosis.

Endoscopic Endonasal Approaches to the Clivus with No Violation of the Nasopharynx: Surgical Anatomy and Clinical Illustration.

Background Despite the use of vascularized intranasal flaps, endoscopic endonasal posterior fossa defects remain surgically challenging with high rates of postoperative cerebrospinal fluid leak. Objective The aim of the study is to describe a novel surgical technique that allows complete drilling of the clivus and exposure of the craniovertebral junction with preservation of the nasopharynx. Methods Two formalin-fixed latex-injected anatomical specimens were used to confirm feasibility of the technique. Two surgical approaches were used: sole endoscopic endonasal approach and transnasion approach. The sole endonasal approach was used in a patient with a petroclival meningioma. Results In both anatomical dissections, the inferior clivectomy with exposure of the foramen magnum was achieved with a sole endoscopic endonasal approach. The addition of the transnasion approach helped to complete drilling of the inferior border of the foramen magnum and exposure of the arch of C1. Conclusion This study shows the anatomical feasibility of total clivectomy and exposure of the craniovertebral junction with preservation of the nasopharynx. A more favorable anatomical posterior fossa defect for the reconstruction is achieved with this technique. Further clinical studies are needed to assess if this change would impact the postoperative CSF leak rate.

Contralateral vs. Ipsilateral Approach to Superior Hypophyseal Artery Aneurysms: An Anatomical Study and Morphometric Analysis.

Introduction: Surgical clipping of superior hypophyseal artery (SHA) aneurysms is a challenging task for neurosurgeons due to their close anatomical relationships. The development of endovascular techniques and the difficulty in surgery have led to a decrease in the number of surgical procedures and thus the experience of neurosurgeons in this region. In this study, we aimed to reveal the microsurgical anatomy of the ipsilateral and contralateral approaches to SHA aneurysms and define their limitations via morphometric analyses of radiological anatomy, three-dimensional (3D) modeling, and surgical illustrations. Method: Five fixed and injected cadaver heads underwent dissections. In order to make morphometric measurements, 75 cranial MRI scans were reviewed. Cranial scans were rendered with a module and used to produce 3D models of different anatomical structures. In addition, a medical illustration was drawn that shows different sizes of aneurysms and surgical clipping approaches. Results: For the contralateral approach, pterional craniotomy and sylvian dissection were performed. The contralateral SHA was reached from the prechiasmatic area. The dissected SHA was approached with an aneurysm clip, and maneuverability was evaluated. For the ipsilateral approach, pterional craniotomy and sylvian dissection were performed. The ipsilateral SHA was reached by mobilizing the left optic nerve with left optic nerve unroofing and left anterior clinoidectomy. MRI measurements showed that the area of the prechiasm was 90.4 ± 36.6 mm2 (prefixed: 46.9 ± 10.4 mm2, normofixed: 84.8 ± 15.7 mm2, postfixed: 137.2 ± 19.5 mm2, p < 0.001), the distance between the anterior aspect of the optic chiasm and the limbus sphenoidale was 10.0 ± 3.5 mm (prefixed: 5.7 ± 0.8 mm, normofixed: 9.6 ± 1.6 mm, postfixed:14.4 ± 1.6 mm, p < 0.001), and optic nerves' interneural angle was 65.2° ± 10.0° (prefixed: 77.1° ± 7.3, normofixed: 63.6° ± 7.7°, postfixed: 57.7° ± 5.7°, p: 0.010). Conclusion: Anatomic dissections along with 3D virtual model simulations and illustrations demonstrated that the contralateral approach would potentially allow for proximal control and neck control/clipping in smaller SHA aneurysm with relatively minimal retraction of the contralateral optic nerve in the setting of pre- or normofixed chiasm, and ipsilateral approach requires anterior clinodectomy and optic unroofing with considerable optic nerve mobilization to control proximal ICA and clip the aneurysm neck effectively.