Anatomical variation of the anterior belly of the digastric muscle: case report and clinical implications

The digastric muscle is a suprahyoid muscle composed of two bellies connected by an intermediate tendon.This muscle participates in deglutition and mandibular movements. The anterior belly of the digastric muscleis localized superficially to the mylohyoid and deeply to the platysma muscle. During dissection of this regionof an embedded cadaver, an accessory anterior belly of digastric muscle was observed bilaterally. The accessorybellies were similar but not symmetrical. They were composed of two segments, one long and one short, onboth sides, and when observed together these appeared to form the letter “X”. The accessory fibers, on bothsides, originated from the anterior digastric muscle and inserted medially to the digastric fossa. Anatomicvariations of the digastric muscle may influence mastication and deglutition. Moreover, the accessory digastricmuscle affects diagnostic imaging and therapeutic procedures in head and neck surgery and must be consideredin procedures involving this area.

Choroid plexus cysts and their anatomical correlations: importance in fetal prognosis. A critical literature review

The objective of this investigation was to carry out a literature review on the choroid plexus cysts and theirimportance in fetal prognosis with search on PubMed, Web of Science, LILACS and MEDLINE databases usingkeywords in English without time restrictions. Choroid plexus cysts, which are also termed intraventricularneuroepithelial cysts, choroid epithelial cysts or ependimary cysts, are structures localized within the interiorof the lateral ventricles, comprising secretory epithelium, the principal function of which is the production ofcerebrospinal fluid. Ultrasound images of the choroid plexuses within the lateral ventricles consist of hyperechogenicstructures at the level of the body, trigon and inferior horn of the ventricles. Between the 16th andthe 20th week of gestation, cystic structures in the interior of the ventricular plexuses may be observed at arate of 0.3-1.0% in an ultrasound examination of the fetal head, as is shown. Most choroid plexus cysts regressspontaneously without after effects, although there is a possible association with chromosomal abnormalities,notably trisomy 18 (Edwards’ syndrome) and less frequently cited, trisomy 21 (Down syndrome). The presenceof this kind of cyst is considered to be a lesser marker for them, except when combined with other morefrequently used and accepted ecographic markers, such as nuchal translucency, intracardiac echogenic focusand others. Its isolated presence as the sole characteristic of this aneuploidy is rare. The majority of choroidcysts are transitory and of little clinical significance, and may be identified through a computerized tomographyexamination. As such, the existence of isolated choroid cysts does not indicate the confirmation of chromosomalaneuploidies so much as an alarm that should trigger an investigation in greater depth in search ofother more important markers, emphasizing the importance of pre-natal monitoring.

Asymmetries of the Left and Right Temporal Lobes / Asimetría de los Lóbulos Temporales Izquierdo y Derecho

Anatomical brain asymmetries are subtle and still little studied in humans. Among all the animals, humans have the most asymmetric brains Crow (2004). The language faculty and handedness are localized on the left side. The objective this paper is to verify whether the temporal lobes are anatomically different. Our sample was composed of 40 post mortem adult brains of both sexes, which were investigated at the Human Anatomy Laboratory of the Nove de Julho University Center in Sao Paulo, Brazil. The brains were fixed in a solution of 5% paraformaldehyde. Three different measurements were taken using a pachimeter (Mitutoyo) and a goniometer (Card) on both hemispheres: Ml - the length of the lateral sulcus; M2 - the distance from the lateral sulcus to the inferior margin of the inferior temporal gyrus, and M3 - the angle formed between the lines of the collateral sulcus and the inferior margin of the inferior temporal gyrus. Results were submitted to a statistical analysis (ANOVA) and demonstrated that Ml was larger in the left hemisphere, by contrast with the data obtained for M2 and M3, which were larger in the right hemisphere. The measurements taken showed differences between the right and left temporal lobes.

Las asimetrías anatómicas del cerebro humano son sutiles y aún poco estudiadas. Entre todos los animales, el Hombre es el que presenta el cerebro más asimétrico (Crow, 2004). En el lado izquierdo del cerebro se localiza la facultad del lenguaje, como también de la lateralidad manual. El objetivo del trabajo fue verificar si los lóbulos temporales son anatómicamente diferentes. La muestra estuvo compuesta de 40 encéfalos adultos, post mortem, de ambos sexos, del Laboratorio de Anatomía del Centro Universitario Nove de Julho, en Sao Paulo, SP, Brasil. Los encéfalos fueron fijados en solución de formalina al 5%. Fueron realizadas 3 medidas diferentes utilizando un pié de metro Mitutoyo y goniómetro (Carci), en ambos hemisferios: medida MI, largo del surco lateral; medida M2 distancia del surco lateral hasta el margen inferior del giro temporal inferior y la medida M3 el ángulo formado entre las líneas del surco colateral y margen inferior del giro temporal inferior. Los resultados se sometieron a análisis estadístico y mostraron que MI era mayor en el hemisferio izquierdo, en contraposición a los datos obtenidos en M2 y M3, que fueron mayores en el hemisferio derecho. Las medidas realizadas presentaron diferencias entre los lóbulos temporales derecho e izquierdo.