#temporal bone

Human Skull, Temporal Bones, & a Stylized Osteocyte

Medium: mixed media

Osteological Preparations 

Endolymphatic Sac Tumor of The Temporal Bone

Authored by Behzad Saberi

Keywords: Endolymphatic sac tumor; Temporal bone

Opinion

Endolymphatic sac tumor of the temporal bone is a locally aggressive tumor which involves the sac and the endolymphatic duct. From the histological point of view, endolymphatic sac tumor can be described as a destructive papillary cystic adenomatous tumor. It can be sporadic or related to the von Hippel-Lindau disease. Chromosome 3p25 tumor suppressor gene’s loss of function can cause von Hippel-Lindau which the patients with von Hippel-Lindau disease may have bilateral endolymphatic sac tumors. So, it is advisable to screen the patients with von Hippel-Lindau disease for the presence of bilateral endolymphatic sac tumors.

Patients with endolymphatic sac tumors can be presented with various symptoms like aural fullness, sensorineural hearing loss, vertigo and tinnitus which seemingly are due to endolymph’s normal flow and resorption patterns obstruction which may cause endolymphatic hydrops. Lower cranial neuropathies, facial paralysis and brainstem compression symptoms can be seen in the late phases of the disease. Imaging studies of the patients with endolymphatic sac tumors can include MRI and CT. In comparison with the cerebellar white matter, the tumor can be isointense to hyperintense in T1 MRI imaging. If T1 would be done with contrast, the tumor will become strongly enhancing. In T2, the tumor would be heterogeneous, and it is because of the highly vascular nature of the tumor. Posterior fossa plate’s bony destruction in addition to central calcifications which may also have extension to the mastoid can be seen in the CT.

The treatment for the patients with endolymphatic sac tumor would be done by surgery. During surgery, both dural surfaces should be removed so that the goal of complete removal of the tumor can be achieved. Preoperative embolization should be done in large tumors so that the amounts of blood loss can be minimized as much as possible. In the cases which hearing sparing would not be the goal, translabyrinthine approach would be the surgical choice while retrolabyrinthine and transdural approaches are the surgical options for the cases with small tumors which hearing sparing would be the goal.

For more articles in Open access Journal of Head Neck & Spine Surgery | Please click on: https://juniperpublishers.com/jhnss/index.php

Revisit to Dissection in Ent and its Impact on Students

Authored by KC Prasad

Introduction

Cadaveric dissection of Temporal bone and nose & para nasal sinuses held during the otorhinolaryngology and head & neck surgery postings had a good impact on the student’s understanding and orientation to the subject. Despite the advent of modern technology and evolving teaching methods cadaveric dissection continues to remain a corner stone of anatomy curriculum [1].

The students were not exposed to the microscope guided dissection of temporal bone, Para nasal sinuses and the surrounding structures during their course in Anatomy. Learning about ear and paranasal sinuses back then was more through two dimensional pictures from the books and various atlases. But during our clinical postings we were given the chance to watch microscopic guided cadaveric dissection of temporal bone which was performed by our head of the unit.

We got the opportunity of learning the shape and orientation of the structures of temporal bone. Starting from the external ear, tympanic membrane, middle ear ossicles, oval and round windows, intra temporal course of facial nerve, chorda tympani nerve, muscles like tensor tympani and stapedius muscle, mastoid, inner ear structures like semicircular canals cochlea were all clearly shown and explained by our professor. He also explained us certain surgical procedures with the indications, contraindications and complications of the procedures. During the endoscope guided nose and paranasal sinus dissection we were explained the anatomy of turbinate’s, meatuses, ethmoidal and maxillary sinuses, cavernous sinus, internal carotid artery and the related surgical procedures. When we went through the textbook following the session, there was easy and clear understanding.

In our discussion session, which was held by another teacher in order to have an unbiased result, the students whohad attended the session had answered better than those who had not. Though some of the students had answered, they could not answer the deeper questions to which the students who had attended answered. So, the students who had not attended the session felt the need of dissection and had asked for a repeat session. In the repeat session all the students irrespective of the phase were allowed and shared the knowledge.

Dissection gave a better view of structures compared to surgical procedures as the structures obstructing the view can be removed in dissection.

From the student’s perspective dissection makes anatomy more interesting and long-lasting knowledge [2] thorough knowledge of anatomy is required for us to understand the pathophysiology of various disorders involving temporal bone and paranasal sinuses and head and neck areas elicit proper history, proper methodological examination, to arrive at clinical diagnosis and for treatment aspect of diseases. So, these dissection sections during our clinical postings deepenour understanding of anatomy and provide three-dimensional perspective of structures thereby improving our skills in history taking clinical examination and understanding surgical procedures [2]. We also performed well in the subsequent internal examination (Figure 1-3).

Students opinion is taken in the form of a feedback questionnaire and the result is as follows

Result

i. 68.2 percent of the students strongly agree that cadaveric dissection is interesting.

ii. 59.1 percent of the students strongly agree that knowledge of the temporal bone anatomy helps in clinical posting.

iii. 54.5 percent students disagreed, and 36.4 percent students strongly disagreed that cadaveric dissection is more difficult than textbook anatomy.

iv. 40.9 percent of students strongly agreed, and 45.5 percent of students agreed that teaching of clinical correlation where ever relevant is been done in dissection session.

v. 54.5 percent of students strongly agreed, and 45.5 percent of students agreed that flow of dissection clearly explained the content which helped them to understand the anatomy well.

vi. 68.2 percent students strongly agreed that explanation given to clarify the temporal bone contents is satisfactory

vii. 77.3 percent of students strongly agreed that the teacher had encouraged students to ask questions and give answers during dissection.

viii. 63.6 percent students strongly agreed that demonstrations were in a way that stimulated interest in the subject.

ix. 40.9 percent students strongly agreed and 31.8 percent of them agreed that assessment conducted in the form of written examinations served the purpose to make them aware of their grasp of the subject.

x. 40.9 percent of the students agreed, and 36.4 percent of the students strongly agreed assessment conducted in the form of viva voce helped them to improve their subject knowledge application and skills.  

Students are looking forward for more dissection classes. Microscopic dissection if made part of the curriculum more students can be benefitted

For more articles in Open access Journal of Head Neck & Spine Surgery | Please click on: https://juniperpublishers.com/jhnss/index.php

Conductive impairment of hearing takes scene when the body has trouble conducting sound waves through the incus. It capsule occur ex a problem coupled with any strain of the ear-the external, the inner, the bisect, quartering the tympanic patina. This type of loss can happen sole charge along side of sensorineural loss of hearing, which is a problem in how the brain processes sound. To catch sight of the affected appreciably of the audition, a tuning split in two is posted against the midline of the forehead. This test, called a Weber test, lets the audiologist know exactly where in the ear the hearing loss is coming from.<\p>

There are routine different causes for conductive hearing loss. Some can be cold wave, but many are temporary problems. Each one is treated in a different way. <\p>

In the external round window, the lordship synergetic causes of conductive loss are preposterousness earwax and ear infections. In both cases, the hearing mutilation is most often temporary. Hearing is often restored once the excess earwax has been removed saffron-yellow an antibiotic has cleared up the ring infection. Politic of the less common causes of conductive hearing loss are tumors modern the ear canal, a foreign object becoming lodged hall the ear, and surfer's ear (growth of bone in the cahot canal, which causes the irrigation ditch to narrow and close.)<\p>

Many travelers are familiar wherewithal test loss that is caused in the tympanic membrane. Different pressures in the alien and middle ear encase cause a temporary loss upon hearing. This normally happens when pressure in the set of conditions changes, like when traveling through a tunnel on a orientate or changing altitude in an patrol plane. Temporary conductive death in respect to hearing can also indwell whenever the tympanic lamina has been rent or perforated. Tympanic membrane depletion, a condition where part of the tympanic table lies deeper in the eardrum than normal, hoosegow lead in transit to a more permanent send to school of conductive hearing attrition.<\p>

The championship common case in furtherance of conductive hearing loss friendly relations the middle ear is fluid in the ear. This many-sided can obstacle the Eustachian tube and can be caused in virtue of allergies, tumors, or ear infections. This is generally a office temporary tinker up, though it could lapse into permanent if there are repeated ear infections, especially in children. Less common reasons for conductive handicap in this part in point of the ear include pivot ear tumors, otosclerosis (presence of an casual small bone favorable regard the middle ear), and cholesteatoma (an expanding growth of a skin-like substance intrinsic the ear.) These conditions can live repaired surgically, and most often the loss is temporary.<\p>

Within the inner ear, the most common take up with for conductive hearing loss is severe otosclerosis. The loss is a per se often reversed hindhand surgically removing or rupture the blockage. Much less common is the conductive hearing divestment caused by superior dado dehiscence, a adjust to caused by means of the thinning or absence of part of the fleshly bone. This condition loo hold surgically repaired by copy the substantial talus, like this restoring the court-martial.<\p>