Morphometric Analysis of the Retrolabyrinthine Approach to the Posterior Fossa.

INTRODUCTION: The retrolabyrinthine approach provides shorter working distance and less cerebellar retraction compared to the retrosigmoid approach to the internal acoustic canal (IAC) and cerebellopontine angle cistern. However, exposure of the ventral surface of the brainstem and petroclival region may be restricted. The Trautmann's triangle (TT), an area intimately related to this region, demonstrates significant anatomical variability, which may adversely affect the ease of the approach. The aim of this study is to evaluate anatomic parameters of the posterior fossa that may anticipate a challenging situation in approaching the IAC and the petroclival region through the retrolabyrinthine approach. METHODS: It was performed a radioanatomical analysis of 75 cerebral angiotomography exams to identify parameters that can potentially reduce areas of surgical exposure. RESULTS: Large variations were observed in the area of exposure of the TT (553%) and the height of the jugular bulb (234%). Shorter distances from the sigmoid sinus to the posterior semicircular canal and high-riding jugular bulb were associated to smaller areas of exposure. Dominant and laterally positioned sigmoid sinuses and less pneumatized mastoids were associated with potentially unfavorable conditions, including a narrower angle of attack to the IAC. Increased petrous slopes and petroclival angles were associated with smaller petroclival areas and shallower clival depths. CONCLUSIONS: This study of the posterior fossa reveals remarkable anatomic variation in the region. These findings should be taken into consideration during the preoperative planning of retrolabyrinthine approaches in order to offer safer and more effective surgical procedures.

Cortical Auditory Evoked Potentials in Children with Prenatal Exposure to Zika Virus.

Prenatal exposure to ZIKV can cause neurologic and auditory damage. The electrophysiological responses obtained by Cortical Auditory Evoked Potentials (CAEP) may provide an objective method to investigate the function of cortical auditory pathways in children exposed to ZIKV. This case series analyzed the findings of CAEP in prenatal-period ZIKV-exposed children with and without microcephaly. The CAEP was performed in a total of 24 children. Five magnetic resonance imaging (MRI) images of the inner ear and brain of microcephalic children were analyzed and compared with CAEP measurements. Ventriculomegaly (80%), cortical/subcortical calcification (80%), and brain reduction (60%) were the most common alterations in the MRI. The P1-N1-P2 complex of the CAEP was observed in all children evaluated. The peak N2 was absent in two children. In the comparison of the CAEP measurements between the groups, children with microcephaly presented a higher amplitude of P2 (p = 0.017), which may reflect immaturity of the auditory pathways. Microcephalic and normocephalic children with prenatal exposure to ZIKV presented with the mandatory components of the CAEPs, regardless of changes in the CNS, suggesting that this population has, to some extent, the cortical ability to process sound stimuli preserved.

Auditory processing performance in blind people.

UNLABELLED: Hearing has an important role in human development and social adaptation in blind people. OBJECTIVE: To evaluate the performance of temporal auditory processing in blind people; to characterize the temporal resolution ability; to characterize the temporal ordinance ability and to compare the performance of the study population in the applied tests. METHODS: Fifteen blind adults participated in this study. A cross-sectional study was undertaken; approval was obtained from the Pernambuco Catholic University Ethics Committee, no. 003/2008. RESULTS: Temporal auditory processing was excellent--the average composed threshold in the original RGDT version was 4. 98 ms; it was 50 ms for all frequencies in the expanded version. PPS and DPS results ranged from 95% to 100%. There were no quantitative differences in the comparison of tests; but oral reports suggested that the original RGDT original version was more difficult. CONCLUSIONS: The study sample performed well in temporal auditory processing; it also performed well in temporal resolution and ordinance abilities.

Influence of hypercalcemia in the formation of tympanosclerosis in rats.

HYPOTHESIS: Hypercalcemia is thought to perform an important role in the etiopathogenesis of tympanosclerosis. The purpose of the present study was to assess the influence of hypercalcemia in the development of tympanosclerosis in rats with or without acute otitis media. BACKGROUND: The pathogenesis of tympanosclerosis is still unclear. Histologically, it is characterized by a hyaline degeneration in the lamina propria of the middle ear and mastoid mucosa and may lead to a calcification process. The process of calcification is similar to that of other pathologically calcified tissues, such as vessels, heart valves, cornea, and others, which depend on calcium serum levels. METHODS: Twenty-four Wistar rats were divided into two different groups, with one group submitted to hypercalcemia status through calcium diet supplementation and the other used as a control group (normal calcium content diet). Both were submitted to induction of tympanosclerosis by inoculation of Streptococcus pneumoniae on the right middle ear only. Otomicroscopy was conducted every 15 days, and after 7 weeks of inoculation, the animals were killed and the tympanic bullae were resected to be analyzed through light and electron microscopy. RESULTS: The group submitted to hypercalcemia presented a prevalence of tympanosclerosis of 25% against 16.7% in the control group, presenting a relative risk of 1.27 (p=0.72). CONCLUSION: The results suggest that hypercalcemia can have an influence in the development of tympanosclerosis.

Hearing impairment diagnosis in Pernambuco: services of intermediate complexity--2003.

UNLABELLED: Universal and equal access to health care, granted to the population as of the brazilian constitution of 1988, made it easier the early diagnosis of hearing impairment. Thus, through the sistema único de saúde (sus), public and private health care providers granted this health coverage to the whole brazilian population, in the different levels of complexity. AIM: this paper aims at studying the supply of intermediate complexity hearing impairment diagnosis in pernambuco in the first semester of 2003. MATERIALS AND METHODS: a study of series analyzed 17669 procedures and 372 professionals in the field of hearing impairment in the 185 municipalities in the state of Pernambuco--Brazil--data taken from the outpatient information system of the ministry of health. RESULTS: the results showed that the procedures are being carried out in only five municipalities, most of them managed in municipal units. We also identified an unequal distribution of diagnostic procedures. CONCLUSION: we then concluded that much is still necessary to provide hearing impairment diagnostic in a horizontal fashion, considering the community differences through an universal, integrated and efficient model, as the one proposed by the sistema único de saúde.

Profile of hospitalizations due to otorhinolaryngologic morbidity requiring surgical treatment. Brazil, 2003.

AIM: To analyze the profile of the surgical procedures related to otorhinolaryngology in Brazil in the year 2003. STUDY DESIGN: This was an observational, descriptive, cross-sectional study. METHODS: We analyzed 80,030 surgical procedures performed in 27 Brazilian States during the period from January to December 2003. The data were obtained from the Hospital Information System of the Ministry of Health. The inclusion factor was a surgical procedure in otorhinolaryngology (ORL). All files were processed with the TABWIN software. RESULTS: In 2003, 80,030 ORL-related surgical procedures were performed in Brazil. The Southeast region had the largest number of procedures (53.08%), followed by the South and Northeast regions (19.6% and 15.6%, respectively). Regarding the group of procedures, surgeries of the pharynx represented 45% of ORL procedures. Procedures of high complexity were more numerous in the ear surgery group. Regarding the distribution of the type of attending institution, the highest concentration of surgical procedures occurred in philanthropic hospitals, followed by state and university public hospitals. The table adopted by SUS for payment of ORL surgical procedures has not been updated for the procedures currently performed, with the consequent inappropriate notification of some types of surgery. CONCLUSION: Knowledge about the profile of surgical hospitalizations related to ORL permits the identification of the peculiarities of the different regions that can help health-managing authorities to make decisions in order to guarantee the principles recommended by SUS regarding access to health services.