Neglected tracts of the brainstem: transverse peduncular tract of Gudden and taenia pontis.

OBJECTIVE: The anatomy and function of the brainstem have fascinated scientists for centuries; however, the brainstem remains one of the least studied regions of the human brain. As the authors delved into studying this structure, they observed a growing tendency to forget or neglect previously identified structures. The aim of this study was to describe two such structures: the transverse peduncular tract, also known as the Gudden tract, and the taenia pontis. The authors analyzed the potential effects of neglecting these structures during brainstem surgery and the implications for clinical practice. METHODS: After removal of the arachnoid and vascular structures, 20 human brainstem specimens were frozen and stored at -16°C for 2 weeks, according to the method described by Klingler. The specimens were then thawed and dissected with microsurgical techniques. The results of microsurgical fiber dissection at each step were photographed. RESULTS: This study revealed two previously neglected or forgotten structures within the brainstem. The first is the transverse peduncular tract of Gudden, which arises from the brachium of the superior colliculus. This tract follows an arcuate course along the lateral and ventral surfaces of the midbrain, perpendicular to the cerebral peduncle, and terminates in the nuclei of the transverse peduncular tract within the interpeduncular fossa. The second structure is the taenia pontis, which originates contralaterally in the interpeduncular fossa. It becomes visible at the level of the pontomesencephalic sulcus and extends to the base of the lateral mesencephalic sulcus, where it divides into several thin bundles. Along the interpeduncular sulcus, between the superior and middle cerebellar peduncles, it reaches the parabrachial recess and enters the cerebellum. CONCLUSIONS: Recently, with increasing understanding and expertise in brainstem research, surgical approaches to this area have become more common, emphasizing the importance of a detailed knowledge of the brainstem. The two structures mentioned in this paper are described in history books and were widely studied in the 19th century but have not been mentioned in modern literature. The authors propose that a deeper understanding of these structures may prove valuable in neurosurgical practice and help reduce patient comorbidity.

The Extreme Anterior Interhemispheric Transcallosal Approach for Pure Aqueduct Tumors: An Anatomical Study.

AIM: To show the normal anatomy of the cerebral aqueduct, and the feasibility of the extreme anterior interhemispheric transcallosal approach to remove tumors within the aqueduct. MATERIAL AND METHODS: This human cadaveric brain research was composed of ten formalin-fixed human brains and one injected head. The dissection was performed under an operative microscope with 6x to 40x magnification. The cerebral aqueduct anatomy was delineated along with the relationship to nearby structures in the extreme anterior interhemispheric transcallosal approach. RESULTS: We described the anatomy of the cerebral aqueduct within the brain and showed that, with the proper angle for the extreme anterior interhemispheric transcallosal approach, lesions in the cerebral aqueduct can be reached in a single session without damaging periventricular structures. CONCLUSION: The extreme anterior interhemispheric transcallosal approach provides a direct corridor to the cerebral aqueduct and, thus, is feasible for resecting pure aqueduct tumors in an already dilated intraventricular foramen.

Evaluation of anthropometric indices as predictors of metabolic syndrome: 3-year cohort in Ecuadorian military personnel / Evaluación de índices antropométricos como predictores de síndrome metabólico: cohorte de 3 años en personal militar ecuatoriano

ABSTRACT Introduction: The metabolic syndrome is a condition that predisposes to the development of cardiovascular and metabolic diseases, where the presence of altered blood pressure, insulin resistance, hyperglycemia, dyslipidemia and abdominal obesity is evaluated in order to know the risk of developing this disease. Objective: To evaluate the anthropometric indices that predict the presence of developing metabolic syndrome in Ecuadorian military personnel. Methods: The research work is quantitative, observational and longitudinal with a correlational scope, it was made analyzing the annual medical records of preventive medicine, in the military personnel of the Army Soldiers Training School "Vencedores del Cenepa", during a 3-year cohort from 2019 to 2021. Results: The study shows an overweight military population, with a prevalence of metabolic syndrome: according to Asociación Latinoamericana de Diabetes criteria of 1 %, 1.66 % and 0.76 %, in the years 2019, 2020 and 2021 respectively; in contrast, according to Adult Treatment Panel III criteria, with a prevalence of 6.67 %, 6.31 % and 5.70 % in the years 2019, 2020 and 2021 respectively. Conclusions: The anthropometric indices, such as the waist-height index, abdominal perimeter and body mass index significantly predict the development of metabolic syndrome in the military personnel of the "Vencedores del Cenepa" Army Soldier Training School.

RESUMEN Introducción: El síndrome metabólico predispone al desarrollo de enfermedades cardiovasculares y metabólicas; en este se evalúa la presencia de presión arterial alterada, resistencia a la insulina, hiperglucemia, dislipidemia y obesidad abdominal, para conocer el riesgo de desarrollar esta enfermedad. Objetivo: Evaluar los índices antropométricos que predicen la presencia de síndrome metabólico en desarrollo, en militares ecuatorianos. Métodos: El trabajo de investigación es cuantitativo, observacional y longitudinal con alcance correlacional, se realizó analizando las historias clínicas anuales de medicina preventiva, en el personal militar de la Escuela de Formación de Soldados del Ejército "Vencedores del Cenepa", en una cohorte de 3 años, de 2019 a 2021. Resultados: El estudio muestra una población militar con sobrepeso, con la siguiente prevalencia de síndrome metabólico: según criterios de la Asociación Lationoamericana de Diabetes, de 1 %, 1,66 % y 0,76 %, en los años 2019, 2020 y 2021 respectivamente; en cambio, según criterios del Adult Treatment Panel III, 6,67 %, 6,31 % y 5,70 % en los años 2019, 2020 y 2021 respectivamente. Conclusiones: Los índices antropométricos, como el cintura-altura, perímetro abdominal e índice de masa corporal predicen significativamente el desarrollo del síndrome metabólico en el personal militar de la Escuela de Formación de Soldados del Ejército "Vencedores del Cenepa".

Microsurgical anatomy and insular connectivity of the cerebral opercula.

OBJECTIVE: Radiological, anatomical, and electrophysiological studies have shown the insula and cerebral opercula to have extremely high functionality. Because of this complexity, interventions in this region cause higher morbidity compared to those in other areas of the brain. In most early studies of the insula and white matter pathways, insular dissection was begun after the opercula were removed. In this study, the authors examined the insula and deep white matter pathways to evaluate the insula as a whole with the surrounding opercula. METHODS: Twenty formalin-fixed adult cerebral hemispheres were studied using fiber microdissection techniques and examination of sectional anatomy. Dissections were performed from lateral to medial, medial to lateral, inferior to superior, and superior to inferior. A silicone brain model was used to show the normal gyral anatomy. Sections and fibers found at every stage of dissection were photographed with a professional camera. MRI tractography studies were used to aid understanding of the dissections. RESULTS: The relationships between the insula and cerebral opercula were investigated in detail through multiple dissections and sections. The relationship of the extreme and external capsules with the surrounding opercula and the fronto-occipital fasciculus with the fronto-orbital operculum was demonstrated. These findings were correlated with the tractography studies. Fibers of the extreme capsule connect the medial aspect of the opercula with the insula through the peri-insular sulcus. Medial to lateral dissections were followed with the removal of the central core structures, and in the last step, the medial surface of the cerebral opercula was evaluated in detail. CONCLUSIONS: This anatomical study clarifies our understanding of the insula and cerebral opercula, which have complex anatomical and functional networks. This study also brings a new perspective to the connection of the insula and cerebral opercula via the extreme and external capsules.

Prevalence of Dyslipidemia in Military Students and Military Personnel Attending Primary Care in Ecuador and Correlation with Anthropometric Values / Prevalencia de dislipidemia en estudiantes militares y personal militar de atención primaria en Ecuador y correlación con valores antropométricos / Prevalência de dislipidemia em estudantes militares e pessoal militar da atenção primária no Equador e correlação com valores antropométricos

Abstract: Objective: to establish the prevalence of dyslipidemia and its relationship with the body mass index, waist-height index and waist circumference in students ofthe highertechnology specialization in military sciences, as well as military personnel who work at the University ofthe Armed Forces of Ecuador - ESPE. Methodology: this was an analytical, non-experimental study with a sample of 495 second-year students of the Superior Technology Specialization in Military Sciences and 196 military personnel who work at ESPE. Results: the study found 8,48 % (n: 42) prevalence of general dyslipidemia in students, differentiated by hypercholesterolemia 1,82 % (n: 9), hypertriglyceridemia 6,26 % (n: 31) and mixed dyslipidemia 0,4% (n: 2). Additionally, it found 58,67 % (n: 115) prevalence of general dyslipidemia in professional military personnel, with hypercholesterolemia 9,18 % (n: 18), hypertriglyceridemia 25,51 % (n: 50) and mixed dyslipidemia 23,98 % (n: 47). Finally, the lower limit to diagnose dyslipidemia for body mass index in students was 25,67 kg/m2, for waist circumference 76,5 cm and for waist height ratio 0,47, and in professional military personnel, body mass index of 26,3 kg/m2, waist circumference of 86 cm and waist height ratio of 0,52. Conclusions: the students and military personnel studied have a significantly low prevalence of dyslipidemia compared to the general student and military personnel population and the values of WC and WHtR were seen to be good predictors of dyslipidemia in military personnel but not in the students.

Resumen: Objetivo: establecer la prevalence de dislipidemia y su relación con el índice de masa corporal, índice cintura-talla y circunferencia de cintura en estudiantes de la especialización tecnológica superior en ciencias militares, así como en personal militar que labora en la Universidad de las Fuerzas Armadas de Ecuador - ESPE. Metodología: este es un estudio analítico, no experimental, con una muestra de 495 estudiantes de segundo año de la Especialización Tecnológica Superior en Ciencias Militares y 196 militares que laboran en la ESPE. Resultados: el estudio encontró un 8,48 % (n: 42) de prevalencia de dislipidemia general en estudiantes, diferenciada por hipercolesterolemia 1,82 % (n: 9), hipertrigliceridemia 6,26 % (n: 31) y dislipidemia mixta 0,4 % (n: 2). Adicionalmente, encontró una prevalencia de dislipidemia general en personal militar profesional de 58,67% (n: 115), con hipercolesterolemia 9,18% (n: 18), hipertrigliceridemia 25,51 % (n: 50) y dislipidemia mixta 23,98 % (n: 47). Finalmente, el límite inferior para diagnosticar dislipidemia para índice de masa corporal en estudiantes fue de 25,67 kg/m2, para circunferencia de cintura 76,5 cm y para índice de altura de cintura 0,47, y en personal militar profesional, índice de masa corporal de 26,5 cm. 3 kg/m2, circunferencia de cintura de 86 cm e índice de altura de cintura de 0,52. Conclusiones: los estudiantes y militares estudiados tienen una prevalencia de dislipidemia significativamente baja en comparación con la población general de estudiantes y militares y los valores de WC y WHtR se consideraron como buenos predictores de dislipidemia en militares, pero no en estudiantes.

Resumo: Objetivo: estabelecer a prevalência de dislipidemia e sua relagáo com o índice de massa corporal, índice cintura-estatura e circunferência da cintura em estudantes da especialiçado tecnológica superior em ciencias militares, bem como militares que trabalham na Universidade das forças Armadas do Equador - ESPE. Metodologia: trata-se de um estudo analítico, ñao experimental, com urna amostra de 495 alunos do segundo ano da Especialiçado Tecnológica Superior em Ciencias Militares e 196 militares que atuam na ESPE. Resultados: o estudo encontrou 8,48 % (n: 42) prevaléncia de dislipidemia geral em estudantes, diferenciada por hipercolesterolemia 1,82 % (n: 9), hipertrigliceridemia 6,26 % (n: 31) e dislipidemia mista 0,4% (n: 2). Além disso, encontrou 58,67% (n: 115) prevaléncia de dislipidemia geral em militares profissionais, com hipercolesterolemia 9,18% (n: 18), hipertrigliceridemia 25,51% (n: 50) e dislipidemia mista 23,98 % (n: 47). Por fim, o limite inferior para diagnóstico de dislipidemia para o índice de massa corporal em escolares foi de 25,67 kg/m2, para circunferência da cintura 76,5 cm e razão cintura-estatura 0,47, e em militares profissionais, índice de massa corporal de 26, 3 kg/m2, circunferência da cintura de 86 cm e relagáo altura da cintura de 0,52. Conclusões: os estudantes e militares estudados apresentam urna prevaléncia de dislipidemia significativamente baixa em comparaçáo com a populaçao geral de estudantes e militares e os valores de CC e RCE foram vistos como bons preditores de dislipidemia em militares, mas não em estudantes.