RESUMO
INTRODUCTION: Osteoma is a benign slow growing bone tumor with a prevalence of 3% of all benign paranasal sinuses tumors, with a peak incidence between the fourth and sixth decades, mostly involving frontal sinuses.(1) PRESENTATION OF CASE: We present a case of a large right ethmoidal sinus osteoma in a 12-year-old boy, complaining of frontal headaches and excessive lacrimation of the right eye. CT scan showed a very large tumor in the right anterior ethmoidal sinus (30mm×25mm×15mm). DISCUSSION: Large osteomas of the paranasal sinuses are usually resected by external approaches. However, the minimally invasive endonasal approach, which minimizes external facial scarring, is challenging for such large lesions in pediatrics. In the presented case, the osteoma was successfully resected exclusively by endoscopy-guided endonasal approach assisted by neuronavigation, with no peri or postoperative complications. CONCLUSION: An endoscopic approach assisted with neuronavigation may be a minimally invasive and safe procedure for managing large osteoma of the ethmoidal sinus in pediatrics patients.
RESUMO
BACKGROUND: In normal-hearing subjects, monaural stimulation produces a normal pattern of asynchrony and asymmetry over the auditory cortices in favour of the contralateral temporal lobe. While late onset unilateral deafness has been reported to change this pattern, the exact influence of the side of deafness on central auditory plasticity still remains unclear. The present study aimed at assessing whether left-sided and right-sided deafness had differential effects on the characteristics of neurophysiological responses over auditory areas. Eighteen unilaterally deaf and 16 normal hearing right-handed subjects participated. All unilaterally deaf subjects had post-lingual deafness. Long latency auditory evoked potentials (late-AEPs) were elicited by two types of stimuli, non-speech (1 kHz tone-burst) and speech-sounds (voiceless syllable/pa/) delivered to the intact ear at 50 dB SL. The latencies and amplitudes of the early exogenous components (N100 and P150) were measured using temporal scalp electrodes. RESULTS: Subjects with left-sided deafness showed major neurophysiological changes, in the form of a more symmetrical activation pattern over auditory areas in response to non-speech sound and even a significant reversal of the activation pattern in favour of the cortex ipsilateral to the stimulation in response to speech sound. This was observed not only for AEP amplitudes but also for AEP time course. In contrast, no significant changes were reported for late-AEP responses in subjects with right-sided deafness. CONCLUSION: The results show that cortical reorganization induced by unilateral deafness mainly occurs in subjects with left-sided deafness. This suggests that anatomical and functional plastic changes are more likely to occur in the right than in the left auditory cortex. The possible perceptual correlates of such neurophysiological changes are discussed.
