Analyzing The Age Related Changes In The Human Cochlear Nerve: A Qualitative Microscopic Study

Background: Cochlear nerve serves as one of the nodal point for enabling the passage of sound in both directions.The knowledge of age related morphological changes in human cochlear nerve is important to understand itsrole in the manifestation of sensori-neural presbycusis.Materials and Methods: The study was conducted in 21 human cochlear nerve samples, collected in 3 differentage groups (0-30 years, 31-50 years, 51 years and above). Resin embedding of cochlear nerves was done. Semithin (1 µm) cross sections of the nerves were cut by glass knife on Reichert Ultra-microtome. Under light microscope,toluidine blue stained nerve sections were studied for shape, organization of connective tissue and number offascicles.Results: Cochlear nerve was comma-shaped across all the age groups studied. Majority of the nerve sections hada blunt round head and sharp tail. Few sections had blunt tail also. Nerve fascicles were well defined in all the21 samples studied. The approximate number of fascicles across the various age groups varied from 60 to 85 pernerve. Numerous Schwann cells and numerous small sized blood vessels were found in the endoneurium of olderage group compared to younger and middle aged groups.Conclusion: However, we didn’t observe major qualitative changes across different age groups, but the presentstudy provides novel baseline morphological data on the human cochlear nerve.

Multiple vascular anomalies in the abdomen: a gross anatomical study / Múltiples anomalías vasculares en el abdomen: un estudio anatómico macroscópico

Knowledge of the branching pattern of the abdominal aorta is clinically important for any abdominal surgeon operating on parts of the gut or neighboring structures like the suprarenals, spleen, pancreas, liver, kidneys and ureter. The presence of abnormal inferior phrenic artery associated with aberrant branch from the celiac trunk supplying the pancreas and duodenum is a rare anomaly. In the present case, we observed four branches of the celiac artery i.e. (a) left gastric artery (b) common hepatic artery (c) splenic artery and (d) an aberrant branch, which took a course inferiorly towards the pancreas. The aberrant artery supplied the body of the pancreas and gave a branch which supplied the horizontal part of the duodenum and then entered the transverse mesocolon to supply the hepatic flexure and some portions of the ascending and the transverse colon. The inferior phrenic artery was absent on the left side. Concomitant anomalies of such type are to be kept in mind by the surgeon, while operating cases of carcinoma head of pancreas and performing kidney transplantations.

El conocimiento del patrón de ramificación de la aorta abdominal es clínicamente importante para cualquier cirujano abdominal que opere en partes del intestino o estructuras vecinas, como glándulas suprarenales, bazo, páncreas, hígado, riñones y uréteres. La presencia anormal de la arteria frénica inferior asociada con una rama aberrante originada del tronco celiaco, supliendo el páncreas y duodeno, es una variación anatómica rara. En el presente caso, se observaron cuatro ramas de la arteria celiaca: (a) arteria gástrica izquierda (b) arteria hepática común (c) arteria esplénica y (d) una rama aberrante, que tuvo un curso inferior hacia el páncreas. La arteria aberrante suministraba irrigación al cuerpo del páncreas y daba una rama para la parte horizontal del duodeno para luego entrar en el mesocolon transverso para irrigar la flexura hepática y algunas partes del colon ascendente y transverso. La arteria frénica inferior estaba ausente en el lado izquierdo. Anomalías concomitantes de este tipo deben ser consideradas por el cirujano, en casos de operación de carcinoma de cabeza de páncreas y la realización de trasplante renal.

Variations of Thoracic Splanchnic Nerves and its Clinical Implications / Variaciones de los Nervios Esplácnicos Torácicos y sus Implicancias Clínicas

The present study reports an anomalous branching pattern of the thoracic sympathetic chain. At the level of T3 ganglion, an anomalous branch i.e accessory sympathetic chain (ASC) descended anteromedial to the main sympathetic chain (MSC). The MSC and the ASC communicated with each other at the level of T9, T10 and T11 ganglion, indicating the absence of classical pattern of greater, lesser and least splanchnic nerves on the right side. However, on the left side, the sympathetic chain displayed normal branching pattern. We opine that the ASC may be representing a higher origin of greater splanchnic nerve at the level of T3 ganglion and the branches from MSC at T9, T10 and T11 ganglion may be the lesser and least splanchnic nerves, which further joined the ASC (i.e presumably the greater splanchnic nerve) to form a common trunk. This common trunk pierced the right crus of diaphragm to reach the right suprarenal plexus after giving few branches to the celiac plexus. Awareness and knowledge of such anatomical variants of thoracic sympathetic chain may be helpful to surgeons in avoiding any incomplete denervation or preventing any inadvertent injury during thoracic sympathectomy.

El presente estudio relata un patrón de ramos anómalos de la cadena simpática torácica. A nivel del ganglio de T3, un ramo anómalo denominado cadena simpática accesoria (CSA), descendió anteroedialmente a la cadena simpática principal (CSP). La CSP y la CSA comunicadas cada una con la otra a nivel de los ganglios de T9, T10 y T11, indicaban la ausencia de patrones clásicos de nervios esplácnicos mayor, menor y mínimo del lado derecho. Sin embargo, en el lado izquierdo, la cadena simpática estaba dispuesta en un de patrón normal. Nuestra opinión es que la CSA estaría representando un origen alto del nervio esplácnico mayor a nivel del ganglio de T3 y que los ramos de CSP de los ganglios T9, T10 y T11 podrían ser los nervios esplácnicos menor y mínimo, los cuales se unían lejos a la CSA (presumiblemente el nervio esplácnico mayor) para formar un tronco común. Este tronco común perforaba la cruz derecha del diafragma para alcanzar el plexo suprarrenal derecho, dando después pequeños ramos para el plexo celiaco. El conocimiento de tales variaciones de la cadena simpática torácica pueden ser de ayuda para los cirujanos, pudiendo ser evitada alguna denervación incompleta o prevenir algún daño involuntario durante la simpactectomía torácica.