Association of the superior semicircular canal and tegmen tympani dehiscences and its relationship with the pneumatisation of the temporal bone.

PURPOSE: To analyse the degree of pneumatisation of the temporal bone when there is an association between dehiscence of the superior semicircular canal and dehiscence of the tegmen tympani. MATERIALS AND METHODS: We analysed a retrospective CT study of 124 selected cases. A single inclusion criterion was applied: the presence of a dehiscence of the tegmen tympani. On the other hand, the degree of temporal pneumatisation was assessed by axial and coronal planes, and has been divided into the following grades O, I, II and III, according to the status and relationship of the mastoid, the bony labyrinth, the petrous segment of the carotid canal and sigmoid sinus. RESULTS: Of the 124 cases studied, 35 (28.2%) presented both dehiscences. In 26 of the 35 (47.3%), grade II pneumatisation, 4 (14,8%), grade I, and 5 (11,9%) grade III was observed, with a statistically significant relationship (p < 0.001). On the other hand, we did not find a significant relationship when relating both dehiscences in any age or sex group. However, when relating the degree of pneumatisation to sex, among those with grade III pneumatisation, the proportion of men (52.4%) was significantly higher than that of women (47.6%) (p = 0.017). CONCLUSION: We have detected a statistically significant relationship between the coexistence of grade II pneumatisation and the presence of both dehiscences in the temporal bone.

Mucocutaneous leishmaniasis must be included in the differential diagnosis of midline destructive disease: two case reports.

Midline destructive lesions have multiple possible etiologies, which can be grouped into neoplastic, infectious, or vasculitis-associated. The purpose of these case reports and literature review was to highlight the need to include mucocutaneous leishmaniasis in the diagnosis of midfacial lesions in any patient who has lived in Leishmania-endemic areas because this entity meets all of the clinical criteria to be considered a form of midline destructive lesion. We present two cases of mucocutaneous leishmaniasis that occurred in a Bolivian male immigrant and a European male traveler to Panama, in whom lesions were misdiagnosed as different midline destructive lesions with different causes (Wegener, vasculitis, and natural killer or T-cell lymphoma [NKTL]). The conclusion of our work is that all patients with midline destructive lesions should undergo histologic and molecular studies to be evaluated for mucosal leishmaniasis, particularly patients whose clinical history suggests this possibility. In cases of uvular involvement, biopsy of this region might be a possible alternative to nasal biopsy.

[Superior semicircular canal dehiscence syndrome. Embryological and surgical consideration]. / Síndrome de dehiscencia del canal semicircular superior. Aspectos embriológicos y quirúrgicos.

OBJECTIVE: Presenting the first case of superior semicircular canal dehiscence syndrome in the Spanish literature and to establish, using embryological studies, the period in wich superior semicircular canal dehiscence originates. MATERIAL AND METHODS: 52 embryos and foetuses, from 6 mm to foetal maturity, were studied. The case of a patient suffering from superior semicircular canal dehiscence syndrome is presented. RESULTS: The superior semicircular canal and the intracranial space are communicated through bony lacunae, in the period between the 24th and 28th week of foetal development, but this communication is discontinued in the 30th week. Permeability of these lacunae, later in life, could result in the development of superior semicircular canal dehiscence syndrome. The clinical results of the surgical repair of this abnormal communication, in this particular case, using a middle fossa approach and a transmastoid approach is presented. CONCLUSIONS: Superior Semicircular Canal Dehiscence Syndrome could be due to an abnormality in foetal development and its genesis, therefore, could be prenatal. Surgical repair via transmastoid approach is a reasonable alternative treatment to the middle fossa approach.

[Peculiarities of the parietal organisation of the superficial temporal artery]. / Peculiaridades de la organización parietal de la arteria temporal superficial.

INTRODUCTION: The study of the structure in the arterial wall has been essential to use vessels in the coronary and cerebral bypass. The superficial temporal artery, owing to its high elastic content and its topography, close to the middle cerebral artery, has made possible the revascularization surgery in cerebral areas with ischemia. AIM. The purpose of this study is define the structure of the superficial temporal artery. MATERIAL AND METHODS: The material of the present study are 60 arteries from medico legal necropsies without apparent vascular pathology. Pieces were fixed in 10% formol, embedded in Paraplast, sectioned in sequence of 7 mm and were stained to detect elastic, collagen and reticulin fibers. Histochemical techniques have been done too. RESULTS: The superficial temporal artery shows a high elastic content, above all in the middle outer of the tunica media. The negative aspect is the great quantity of collagen in this tunica, that produces the progressive hardness of this vessel with the increase of the age. Histochemistry shows how the accumulation of acid mucosubstances interferes in the correct nourishing of the internal elastic membrane, that is disorganized in the cushions. CONCLUSION: The superficial temporal artery is an appropriate vessel to the coronary and cerebral bypass, due to its high elastic content in this tunica and the limitants. It have not been observed in our material zones without internal elastic membrane. Histochemistry shows abundant acid mucosubstances that difficult the nourishing in the arterial wall.

[Ontogenic peculiarities of the human tympanic ossicular chain]. / Peculiaridades en la organización de la cadena osicular timpánica humana a lo largo de su ontogenia.

We have studied the development of the tympanic ossicles in 40 embryo-foetal human series aged between 32 days (6 mm) and newborn. Once performed the measurements to date chronologically embryos and foetuses, we did a meticulous dissection of temporal bones. After fix in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in a sequence of 7 mm, and stained with Martin's trichrome. The tympanic ossicles are developed in the mesenchyme of the two first pharyngeal archs. The head of the malleus, the body and the short limb of the incus arise from the first arch while the handle of the malleus, the long limb of the incus and the mass of the stapes arise from the second arch. The vestibular side of the stapedial footplate develops in the otic capsule. The tympanic ossicles develop from endochondral ossification, while anterior process of the malleus has the membranous ossification. In their ontogenia 6 stages are observed. First stage, the formation of their sketch by mesenchimal condensation, in the second stage, "pre-cartilaginous", the cells of the primordia are differentiated into condroblasts, in the third stage "cartilaginous" the ossicles show a cartilaginous structure, in the forth stage the primary ossification centers are developed, in the fifth stage the ossicles arise in the periostic annulus and inside the endochondral bone, and in the last stage the osseous tissue grows until it acquires a compact osseous structure.

[Contribution to the development of the union between the manubrium of the malleus and the tympanic membrane in human fetus]. / Contribución al desarrollo de la unión del mango del martillo y la membrana del tímpano en fetos humanos.

The development of the union between the manubrium of the malleus and the tympanic membrane was studied in human embryo. For that purpose 25 temporal bones of human foetus, aged from 36 days (14 mm) to 29 weeks (270 mm) were analyzed. Samples were fixed in a 10% formaldehyde solution, decalcified with 2% nitric acid, embedded in Paraplast, cut in sections of 7 microns thick and stained with Martin's trichrome method. During the development a pseudojoint between the malleus and the tympanic membrane several stages were seen. In the first stage, the manubrium was adhered to membrane mesenchyme of primitive tympanum, in the second one this mesenchyme was loose and there appeared capillars in it, in the third one there were collagen fibers in a radial disposition, and in the forth stage, the hollow in the meatal plug gave independence to the tympanic membrane for the external acoustic meatus. The distal portion of the manubrium, included in tympanic membrane, has remained with a cartilaginous structure during end of the time it has been studied by us. The collagen fibers at the level of the umbo surround the manubrium, while the rest of it remains in its anterior edge.