Ventricular Access Utilizing Cutaneous Reference Points: Statistical Analysis and Proposal of a New Ventricular Entry Point.

OBJECTIVES: Perform radiologic measurements and analysis of normal brain computed tomography (CT) scans; delineate a new ventricular entry point from cutaneous landmarks, highlighting the potential surgical implications of these findings. METHODS: Six radiologic distances (AR; BR; AL; BL, C, and D) were measured in normal brain CT scans using Horos software. Statistical analysis of the measurements was performed with minitab18 software based on age, sex, and side. RESULTS: 132 brain CT scans were analyzed, yielding the following mean results: AR distance: 2.1 cm; BR distance: 7 cm; AL distance: 2.1 cm; BL distance: 7.1 cm; C distance: 12.4 cm; D distance: 7 cm; new ventricular entry point: 12.4 cm posterior to the nasion, and 2.1 cm lateral to the midline. CONCLUSIONS: The freehand technique for accessing the lateral ventricles is a common neurosurgical procedure but is often accompanied by complications. To address this, we suggest a novel entry point for ventricular access, determined by cutaneous reference points. This point is situated 12.4 cm posterior to the nasion along the midline and 2.1 cm lateral to the midline. Although our findings may play a role in presurgical planning for ventricular pathologies, future prospective studies are warranted.

"Ping-pong" fracture: An exclusive entity of neonates and infants? A case analysis and literature review.

Background: "Ping-pong" fractures are a type of depressed fracture in which there is no rupture of the inner or outer table of the skull. It is produced by incomplete bone mineralization. Its appearance is frequent during neonatal and infant ages and is extremely rare outside of these age periods. The objective of this article is to present the case of a 16-year-old patient who presented a "ping-pong" fracture after a traumatic brain injury (TBI) and discuss the underlying physiopathogenesis of these types of fractures. Case Description: A 16-year-old patient presented to the emergency department with a TBI, referring headaches and nausea. Non-contrast brain computed tomography displayed a left parietal "ping-pong" fracture. Laboratory tests showed hypocalcemia, subsequently diagnosing hypoparathyroidism. The patient remained under observation for 48 h. He was managed conservatively and started on calcium carbonate and vitamin D supplements with a favorable evolution. Hospital discharge was granted with TBI discharge instructions and warning signs. Conclusion: The age of presentation of our case was atypical, according to the reported literature. When faced with a "ping-pong" fracture outside of an early age, underlying bone pathologies must be ruled out, which could potentially generate incomplete bone mineralization of the skull.

Surgical approach to the treatment of pituicytoma. Report of five cases and a literature review.

Background: Pituicytoma (PTs) is a rare tumor of the sella and suprasellar region, derived from the pituicytes of the neurohypophysis, having distinct histological characteristics of glial neoplasms. We reported, the clinical data, neuroimaging studies, surgical approaches and pathology in five patients with PTs and also, we reviewed the literature. Methods: Retrospective chart from five consecutive patients with PTs treated at one University Hospital from 2016 to 2021 were reviewed. In addition, we conducted a search in PubMed/Medline databases using the term "Pituicytoma". Data regarding age, gender, pathological findings, and treatment modality applied were extracted. Results: All patients were female, aged 29-63, complaining of headaches, visual loss and field defects, dizziness and normal or abnormal levels of circulating pituitary hormones. Magnetic Resonance Imaging (MRI) showed in all patients a sellar and suprasellar mass, which was removed through an endoscopic transsphenoidal approach. Our third patient had a subtotal resection followed by close observation. Histopathology showed a glial non-infiltrative tumors with spindle cells, and a final diagnosis of pituicytoma was made. After surgery, visual field defects in all patients were normalized, and in two patients normal levels of plasma hormones were restored. After a mean of three years follow-up, the patients were managed post-operatively through close clinical observation and serial MRI. None of the patients had recurrence of the disease. Conclusion: PTs is a rare glial tumor of the sellar and suprasellar region that arises from neurohypophyseal pituicytes. Disease control may be achieved by total excision.

Risk Factors Related to Transient Diabetes Insipidus Development Following Transsphenoidal Pituitary Adenoma Resection: A Multicentric Study.

OBJECTIVE: To analyze and find risk factors associated with developing transient diabetes insipidus (DI) using a multicenter case series after trans-sphenoidal surgery. METHODS: Medical records of patients who underwent trans-sphenoidal surgery for pituitary adenoma resection between 2010 and 2021 at 3 different neurosurgical centers by 4 experienced neurosurgeons were retrospectively analyzed. The patients were divided into 2 groups (DI group or control group). Logistic regression analysis was conducted to identify risk factors associated with postoperative DI. Univariate logistic regression was performed to identify variables of interest. Covariates with a P value <0.05 were incorporated into multivariate logistic regression models to identify independently associated risk factors for DI. All statistical tests were conducted using RStudio. RESULTS: A total of 344 patients were included; 68% were women, the mean age was 46.5 years, and nonfunctioning adenomas were the most frequent (171, 49.7%). The mean tumor size was 20.3 mm. Covariates associated with postoperative DI were age, female gender, and gross total resection. The multivariable model showed that age (odds ratio [OR] 0.97, CI 0.95-0.99, P = 0.017) and female gender (OR 2.92, CI 1.50-6.03, P = 0.002) remained significant predictors of DI development. Gross total resection was no longer a significant predictor of DI in the multivariable model (OR 1.86, CI 0.99-3.71, P = 0.063), suggesting that this variable may be confounded by other factors. CONCLUSIONS: The independent risk factors for the development of transient DI were female and young patients.

Un nuevo dispositivo, de fácil acceso y bajo costo para el tratamiento no quirúrgico de fracturas deprimidas en «ping pong»: Nota técnica / A new, readily accessed and low-cost, device for treating depressed ping pong fractures non-surgically: Technical note

Objetivo El objetivo del trabajo es describir un sistema de reducción con aspiración manual de bajo costo y fácil acceso (SiRAMa) utilizado para tratar fracturas deprimidas en «ping pong» en 3 pacientes. Método El SiRAMa está compuesto por una máscara de anestesia pediátrica, parte de un macrogotero, una llave de 3 vías y 2 jeringas de 60ml. Previamente a su utilización en los pacientes el sistema se testó en 5 voluntarios adultos utilizando su máxima potencia, los cuales no refirieron dolor durante el procedimiento ni presentaron otra complicación Presentamos 3 casos clínicos de pacientes con fractura deprimida en «ping pong», los cuales fueron tratados con el SiRAMa al lado de la cama sin anestesia. Los pacientes fueron monitorizados por el equipo de neonatología durante todo el procedimiento. Resultados La radiografía de cráneo evidenció la reducción de la fractura tras el procedimiento realizado con el SiRAMa en todos los pacientes. La ecografía transfontanelar y el examen neurológico de control fueron normales. Los pacientes evolucionaron favorablemente y fueron dados de alta a las 24horas. Conclusiones Debido a sus componentes el SiRAMa es un sistema de bajo costo y fácil acceso. En este caso permitió la reducción satisfactoria de la fractura en «ping pong» en todos los pacientes. Este sistema permitiría simplificar el tratamiento de las fracturas de este tipo que así lo requieran (AU)

Objective The aim of this paper is to describe a low-cost and readily accessed Manual Aspiration Reduction System (MARS) for use treating ping-pong fractures in three patients. Method The MARS is composed of a pediatric anesthesia mask, part of a macro dripper, a 3-way stopcock, and two 60-ml syringes. Prior to its use in our patient, the system was tested on five adult volunteers to maximum negative pressure, and none reported pain during the procedure or experienced any other complication. We present three clinical cases of patients with depressed ping-pong fracture who were treated with the MARS at the bedside without anesthesia. The patients were monitored by the neonatology team throughout the procedure. Results Skull radiography revealed reduction of the fracture after the procedure performed with the MARS in all patients. The transfontanellar ultrasound and follow-up neurological examination were normal. The patient progressed favorably and was discharged from our service after 24h. Conclusions Due to its components, the MARS is a low-cost and readily accessed system. In this case, it permitted satisfactory reduction of a ping-pong fracture in all patients. This system should greatly simplify the treatment of such fractures (AU)

Which biological pathways are responsible for the late appearance of brain metastases in renal cell carcinoma? Analysis of eight cases.

Background: Renal cell carcinoma (RCC) represents 1% of all cancers and its brain metastases amount to 8.1% of all metastatic tumors. Late brain metastases are defined as tumors that appear 10 years after diagnosis of the primary lesion. The objective of this work is to discuss which biological pathways are responsible for the late appearance of these metastases analyzing eight cases. Case Description: We report here eight cases of late brain metastases of RCC treated between 2018 and 2021. Patients consulted for different clinical complaints. Brain magnetic resonance imaging and computed tomography scan were performed on all patients. They were treated by complete surgical resection plus radiosurgery or by radiosurgery alone. The histology of most metastases showed clear cell RCC. Conclusion: In the presence of a patient with an intracranial tumor and a history of RCC with more than 10 years of evolution, the presence of late metastasis should always be considered. There are many theories described in the literature that try to explain the late appearance of brain metastases from RCC (low mitotic index, impaired immune system, cross talk, self-seeding, and among others).

Distance Between the Corpus Callosum and the Falx Cerebri: A Little Explored Measure with Potential Surgical Implication.

OBJECTIVE: To perform measurements in normal brain imaging studies from the free edge of the falx cerebri to the genu and the body of the corpus callosum and perform a statistical analysis based on age, type of study, and sex highlighting potential surgical implication of these measurements. METHODS: In 193 normal brain imaging studies, 3 anatomical points of the corpus callosum were used to measure the distance to the falx cerebri. Horos and RadiAnt DICOM Viewer software were used to perform the measurements. Statistical analysis of data was performed with Minitab18 software. RESULTS: The results obtained in computed tomography (CT) studies were: distance A, mean 2.1065 cm; distance B, mean 2.2677 cm; distance C, mean 1.765 cm. The results obtained in magnetic resonance imaging studies were: distance A, mean 1.7148 cm; distance B, mean 2.1197 cm; distance C, mean 1.5321 cm. Statistically significant differences were obtained in measurements related to the type of study and in measurements made in CT studies related to age. CONCLUSIONS: There is a distance from the free edge of the falx cerebri to the genu and body of the corpus callosum of at least 1 cm in both CT and magnetic resonance imaging studies of normal brains. Statistically significant differences were found in the measurements in relation to the type of study and in relation to age in the measurements made in CT studies. These measurements could be important in determining the extent of bone resection in certain types of decompressive craniectomies.

A new, readily accessed and low-cost, device for treating depressed ping pong fractures non-surgically: Technical note.

OBJECTIVE: The aim of this paper is to describe a low-cost and readily accessed Manual Aspiration Reduction System (MARS) for use treating ping-pong fractures in three patients. METHODS: The MARS is composed of a pediatric anesthesia mask, part of a macro dripper, a 3-way stopcock, and two 60-ml syringes. Prior to its use in our patient, the system was tested on five adult volunteers to maximum negative pressure, and none reported pain during the procedure or experienced any other complication. We present three clinical cases of patients with depressed ping-pong fracture who were treated with the MARS at the bedside without anesthesia. The patients were monitored by the neonatology team throughout the procedure. RESULTS: Skull radiography revealed reduction of the fracture after the procedure performed with the MARS in all patients. The transfontanellar ultrasound and follow-up neurological examination were normal. The patient progressed favorably and was discharged from our service after 24 h. CONCLUSIONS: Due to its components, the MARS is a low-cost and readily accessed system. In this case, it permitted satisfactory reduction of a ping-pong fracture in all patients. This system should greatly simplify the treatment of such fractures.

A new, low-cost device to treat depressed "ping-pong" fractures non-surgically: technical note.

OBJECTIVE: The aim of this paper is to describe a low-cost and readily accessed Manual Aspiration Reduction System (MARS) for use treating neonatal ping-pong fractures. METHODS: The MARS is composed of a pediatric anesthesia mask, part of a macro dripper, a 3-way stopcock, and two 60-ml syringes. Prior to its use in our patient, the system was tested on five adult volunteers to maximum negative pressure, and none reported pain during the procedure or experienced any other complication. CLINICAL CASE: A 15-day-old premature girl presented with a congenital ping-pong fracture. Her skull X-ray revealed a right parietal fracture. Neurological examination and transfontanellar ultrasound were normal. Treatment using the MARS was performed at the patient's bedside without sedation or anesthesia. The patient was monitored by the neonatology team throughout. RESULTS: Skull radiography revealed reduction of the fracture after the procedure performed with the MARS. The transfontanellar ultrasound and follow-up neurological examination were normal. The patient progressed favorably and was discharged from our service after 24 h. CONCLUSIONS: Due to its components, the MARS is a low-cost and readily accessed system. In this case, it permitted satisfactory reduction of a ping-pong parietal fracture. This system should greatly simplify the treatment of such fractures.

Microsurgical Anatomy and Approaches to the Cerebral Central Core.

OBJECTIVE: Through a cadaveric study, we divided the cerebral central core (CCC) into different areas and have proposed a corresponding neurosurgical approach for each sector. As a secondary objective, we analyzed the cortical and subcortical microsurgical anatomy of the CCC. The CCC includes the insula, extreme capsule, claustrum, external capsule, lenticular nucleus, internal capsule, caudate nucleus, and thalamus. METHODS: Twelve adult human brain hemispheres and one cadaveric head specimen were dissected and studied at the Laboratory of Neuroanatomic Microsurgical of the University of Buenos Aires. Nine cases of CCC neurosurgical pathologies were included in the present study and analyzed. Digital drawings were created of the approaches proposed for each sector of the CCC showing the most relevant surgical details. Photographs of each dissection and measurements obtained were taken. RESULTS: We divided the CCC into a medial, intermediate, and lateral sector, with specific subdivisions for the lateral and medial sectors. The lateral projection of the foramen of Monro was found deep to the third short gyri of the insula with the following distances: anterior insular limen margin, 23.95 mm; posterior insular limen margin, 22.92 mm; superior limiting sulcus, 14.99 mm, and inferior limiting sulcus, 13.76 mm. We have proposed the following approaches: an ipsilateral transcallosal approach, a contralateral transcallosal approach, a choroidal transfissure approach, a trans-splenial approach, transparietal access entering the intraparietal sulcus, and trans-sylvian approach. The preoperative imaging studies should be analyzed using our method to select the most accurate and safe approach. CONCLUSIONS: We have provided a description of the limits and anatomy of the CCC using brain dissection, an analysis of operated cases, and useful measurements for the neurosurgeon.

¿Es posible diferenciar líquido cefalorraquídeo de otras secreciones? Utilidad de la proteína Beta Trace como biomarcador de fístulas de líquido cefalorraquídeo / Is it possible to differentiate cerebrospinal fluid from other secretions? Usefulness of Beta Trace protein as a biomarker of cerebrospinal fluid fistulas

Objetivo: Describir el uso de la proteína Beta Trace (PBT) como marcador de líquido cefalorraquídeo (LCR) en una serie de casos de pacientes con sospecha de fístula de LCR (FLCR). Materiales y Métodos: Se realizó un estudio retrospectivo con datos recolectados en forma prospectiva, observacional y descriptiva. Se revisaron las historias clínicas, estudio por imágenes y datos de laboratorio de una serie de 19 pacientes con sospecha de FLCR en los cuales se había realizado la detección de la PBT mediante electroforesis bidimensional, entre julio 2015-julio 2018. Resultado: La edad promedio fue de 48,1 años, 9 fueron hombres y 10 mujeres, 10 pacientes provenían de neurocirugía, 7 de otorrinolaringología (ORL), y 2 de traumatología (OyT). De las 19 muestras, 14 fueron positivas para la detección de PBT. Cinco casos (26.32%) presentaron antecedente de meningitis, todos ellos con PBT positivo. De los casos positivos, 14 fueron tratados, 3 sin cirugía y 11 con cirugía. La principal causa fue post quirúrgica (n=9). El seguimiento promedio fue de 13,79 meses, 13 casos tuvieron resultado "favorable" y uno "desfavorable". Los 5 casos con PBT negativa fueron tratados con medidas no quirúrgicas. Todos con resultado "favorable". Conclusión: La PBT permitió, en los casos positivos, detectar LCR en las secreciones estudiadas, y en los negativos, descartarla.

Objective: To describe the use of beta-trace protein (BTP) as a cerebrospinal fluid (CSF) marker in patients with suspected CSF leakage. Methods and Materials: A retrospective study was conducted using data previously collected for a prospective, observational study. Data included the case records, imaging studies and laboratory data from a series of 19 patients with suspected CSF leakage in whom two-dimensional electrophoresis was performed for BTP detection, between July 2015 and July 2018. Results: Average patient age was 48.1 years old, with nine males and ten females. Ten patients were from neurosurgery, seven from otorhinolaryngology (ENT), and two from traumatology. Of the 19 samples, 14 were positive for BTP. Nine of the patients (47.4%) sustained their CSF leakage during surgery. Five patients (26.3%) had a history of meningitis, all with positive BTP. All 14 BTP-positive cases were treated, three without and 11 with surgery. Average post-operative follow-up was 13.8 months, with 13 patients experiencing a "favorable" and one "unfavorable" outcome. All five patients who screened negative for BTP were treated non-surgically and had a favorable outcome. Conclusions: In patients in whom BTP was identified, the marker was useful for detecting CSF in the secretions studied. Amongst those who screened negative for BTP, its absence helped to rule out the presence of a CSF leak.

Microsurgical anatomy of the safe entry zones on the anterolateral brainstem related to surgical approaches to cavernous malformations.

OBJECTIVE: To study the microanatomy of the brainstem related to the different safe entry zones used to approach intrinsic brainstem lesions. METHODS: Ten formalin-fixed and frozen brainstem specimens (20 sides) were analyzed. The white fiber dissection technique was used to study the intrinsic microsurgical anatomy as related to safe entry zones on the brainstem surface. Three anatomic landmarks on the anterolateral brainstem surface were selected: lateral mesencephalic sulcus, peritrigeminal area, and olivary body. Ten other specimens were used to study the axial sections of the inferior olivary nucleus. The clinical application of these anatomic nuances is presented. RESULTS: The lateral mesencephalic sulcus has a length of 7.4 to 13.3 mm (mean, 9.6 mm) and can be dissected safely in depths up to 4.9 to 11.7 mm (mean, 8.02 mm). In the peritrigeminal area, the distance of the fifth cranial nerve to the pyramidal tract is 3.1 to 5.7 mm (mean, 4.64 mm). The dissection may be performed 9.5 to 13.1 mm (mean, 11.2 mm) deeper, to the nucleus of the fifth cranial nerve. The inferior olivary nucleus provides safe access to lesions located up to 4.7 to 6.9 mm (mean, 5.52 mm) in the anterolateral aspect of the medulla. Clinical results confirm that these entry zones constitute surgical routes through which the brainstem may be safely approached. CONCLUSION: The white fiber dissection technique is a valuable tool for understanding the three-dimensional disposition of the anatomic structures. The lateral mesencephalic sulcus, the peritrigeminal area, and the inferior olivary nucleus provide surgical spaces and delineate the relatively safe alleys where the brainstem can be approached without injuring important neural structures.

[Microanatomical study of the choroidal fissure in ventricular and cisternal approaches]. / Estudo microanatômico da fissura coroidéia na abordagem dos ventrículos e cisternas cerebrais.

The choroidal fissure is a narrow cleft in the medial part of the lateral ventricle, in a C-shaped arc, between the fornix and the thalamus, where the choroidal plexus join. Due to absence nervous tissue between ependyma and pia-mater along this invagination, it is an important route in brain ventricles and cisterns. Five brains were studied by injecting colored silicone arteries and veins and five brains without colored silicone, in a total number of 20 brain hemispheres. It was analyzed and revised the neural, arterial and venous relationships and surgical approaches in all parts of the choroidal fissure. In conclusion, the previous knowledge detailed this microanatomy is primordial for neurosurgeons that will approach brain ventricular and cisternal lesions because the neurosurgeons gain a tridimensional notion that will be indispensable during surgery.