Ronaldo Nunes Toledo

Universidade Federal de São Paulo, San Paulo, São Paulo, Brazil

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Publications (15)7.58 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: To analyze the influence of the topical use of basic fibroblast growth factor (bFGF) in the regeneration of the facial nerve in rats. Experimental study. Twenty-eight Wistar adult male rats underwent complete section of the facial nerve trunk, followed by end-to-end anastomosis with epineural sutures. An osmotic minipump equipped with a delivery catheter was implanted subcutaneously near the neural anastomosis. During the subsequent 14 days, 14 animals received a solution containing 25 microg/ml of bFGF, 250 UI/ml of sodium heparin, and 1,000 microg/ml of human albumin diluted in Ringer lactate, and 14 animals received a control solution of the same components without bFGF. To evaluate facial nerve regeneration, the number of myelinated fibers evident on histologic sections was counted on the 14th (7 experimental and 8 control animals) and the 28th days (7 experimental and 6 control animals) after surgery, and the facial movements of vibrissae and the blink reflex were evaluated on alternate days until the 28th day. On histologic evaluation, the number of myelinated fibers was similar between groups on the 14th day and greater in the group that received bFGF on the 28th day. Behavioral evaluation showed that the animals of the bFGF group presented better functional results between the 6th and 16th days for the blink test and the 14th to the 16th days for vibrissae movements. This study showed that the regeneration of the facial nerve occurred earlier and resulted in significantly more myelinated nerve fibers in the animals that received topical bFGF.
    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 10/2009; 31(3):498-505. · 1.44 Impact Factor
  • Revista Brasileira de Otorrinolaringologia 01/2008; 74(5).
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    ABSTRACT: Intraoperative nerve monitoring has emerged as a valuable tool to facilitate recurrent laryngeal nerve identification during thyroid surgery, thereby avoiding its injury. The aim was to evaluate vocal fold mobility in patients who underwent thyroidectomy with intraoperative nerve monitoring. Cohort formed by a consecutive series of patients, at a tertiary cancer hospital. The subjects were patients who underwent thyroidectomy using intraoperative laryngeal nerve monitoring, between November 2003 and January 2006. Descriptive analysis of the results and comparison with a similar group of patients who did not undergo nerve monitoring were performed. A total of 104 patients were studied. Total thyroidectomy was performed on 65 patients. Vocal fold immobility (total or partial) was detected in 12 patients (6.8% of the nerves at risk) at the first postoperative evaluation. Only six (3.4% of the nerves at risk) continued to present vocal fold immobility three months after surgery. Our previous series with 100 similar patients without intraoperative nerve monitoring revealed that 12 patients (7.5%) presented vocal fold immobility at the early examination, and just 5 (3.1%) maintained this immobility three months after surgery, without significant difference between the two series. In this series, the use of intraoperative nerve monitoring did not decrease the rate of vocal fold immobility.
    Sao Paulo Medical Journal 06/2007; 125(3):186-90. · 0.59 Impact Factor
  • Revista Brasileira de Otorrinolaringologia 01/2007; 73(2).
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    ABSTRACT: Voice alterations after thyroidectomy can be found even with preserved function of laryngeal nerves. The purpose of this study was to evaluate voice before and after thyroid surgery and the role of orotracheal intubation on voice changes. We conducted a prospective nonrandomized study of patients who underwent thyroid surgery and compared the results with a control group of patients who underwent breast surgery. Subjects underwent a videolaryngoscopic exam, a subjective and an objective voice analysis and a Voice Handicap Index (VHI) questionnaire before and after surgery. A total of 100 patients who underwent thyroidectomy and 30 who underwent breast surgery were studied. Both groups were similar in demographic, clinical, and surgical variables. Postoperative videolaryngoscopy showed larynx alterations in 28% of the thyroidectomized patients, without significant alterations in the control group. There were subjective voice changes in 29.7% of the patients without vocal fold immobility after thyroid surgery and no statistically significant changes after breast surgery. Acoustic analysis showed significant increased values in the voice turbulence index (VTI) parameter in both groups, although higher in the thyroid one. In the VHI assessment, voice complaints were more frequently registered in the thyroid group rather than in the control group. Voice alterations are frequent after thyroidectomy even with preserved vocal fold mobility. Such alterations were more frequently detected in that group than in patients who underwent breast surgery. Orotracheal intubation is just one of the multiple factors involved.
    Head & Neck 01/2007; 28(12):1106-14. · 2.83 Impact Factor
  • Revista Brasileira de Otorrinolaringologia 01/2006; 72(6).
  • Revista Brasileira de Otorrinolaringologia 01/2006; 72(3).
  • Revista Brasileira de Otorrinolaringologia 01/2005; 71(5).
  • Otolaryngology-head and Neck Surgery - OTOLARYNGOL HEAD NECK SURG. 01/2003; 129(2).
  • Revista Brasileira de Otorrinolaringologia 10/2002; 68(5):730-734.
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    ABSTRACT: Promoting facial nerve regeneration is a significant challenge. To evaluate the possible neurotrophic influence of cyclic AMP on facial nerve regeneration of Wistar rats. The right facial nerve of thirty-two animals were completely transected and immediately sutured, followed by exposure or not to topical cyclic AMP. Behavioral and histometric analyses were done at 14 and 28 days. Statistical differences (p<0.05) were found in the behavioral and histometric analyses on the 14th day, suggesting an early regenerative response of the facial nerve to cAMP exposure. This study demonstrates a possible neurotrophic effect of cAMP on facial nerve regeneration in rats.
    Brazilian journal of otorhinolaryngology 74(5):675-83. · 0.55 Impact Factor
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    ABSTRACT: Otogenous lateral sinus thrombosis (OLST) is a rare disease and presents a controversial treatment. Clinical aspects and treatment were reported based on our experience. Retrospective study. Six cases of OLST were treated in our institution in the last ten years. Clinical and imaging data were analyzed. All six patients had the lateral sinus thrombosis detected during image evaluation for other symptoms related to chronic otitis media (COM) complications. Fever, headache and facial paralysis were the main clinical manifestation related to mastoiditis, meningitis and cerebellar abscess. We could not identify, in any case, specific features of lateral sinus thrombosis. In all cases a mastoidectomy was associated with large spectrum antibiotics maintained for 3 months. In three cases anticoagulation therapy was introduced and in three cases anticoagulation was not indicated. All cases presented a good clinical evolution, without sequelae. OLST is almost always associated with other complications of COM. It is diagnosed almost by accident during the investigative image study. We believe such disease is underestimated. In our experience, OLST presents a benign course, and mastoidectomy with antibiotics is the treatment of choice.
    Brazilian journal of otorhinolaryngology 73(2):165-70. · 0.55 Impact Factor
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    ABSTRACT: Out of the many forms of therapy for sudden deafness, some require hospitalization and present significant risks. This prospective study analyzes etiology and evolution in cases of sudden deafness (SD) where outpatient oral treatment was used. Clinical with transversal cohort. Forty cases of sudden hearing loss were followed for at least one year. All were submitted to initial clinical evaluation, auditory tests, routine blood analysis, and magnetic resonance imaging. All received initial treatment with pentoxifylline and prednisone. 45% (n=18) presented normal auditory thresholds, 40% (n=16) showed some improvement in hearing, 15% (n=6) maintained initial hearing level. Nine cases (22.5%) presented clinical conditions possibly implicated in hearing loss (viral infection, immunomediated hearing loss, vascular disorders, and so on); three (7.5%) had cerebellopontine tumors. Evolution of hearing in these 12 cases with presumed etiology presented no differences from hearing in the 28 cases without any known etiological factor. Clinical treatment within the first seven days was the only statistically significantly different condition in patients who improved hearing. An objective search for etiological bases should be conducted in any case of acute sensorineural hearing loss. The presence of cerebellopontine tumors in 7.5% of cases of SD, among other treated causes, justifies a thorough clinical investigation in these patients. Overall good evolution of hearing was observed in 67.5% of cases of SD, regardless of its etiology. Therapy within the first seven days of SD was significantly related to better outcomes in hearing.
    Brazilian journal of otorhinolaryngology 71(5):633-8. · 0.55 Impact Factor
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    ABSTRACT: Standardization of the technique to section the extratemporal facial nerve in rats and creation of a scale to evaluate facial movements in these animals before and after surgery. Experimental. twenty Wistar rats were anesthetized with ketamine xylazine and submitted to sectioning of the facial nerve near its emergence through the mastoid foramen. Eye closure and blinking reflex, vibrissae movement and positioning were observed in all animals and a scale to evaluate these parameters was then created. The facial nerve trunk was found between the tendinous margin of the clavotrapezius muscle and the auricular cartilage. The trunk was proximally sectioned as it exits the mastoid foramen and the stumps were sutured with a 9-0-nylon thread. An evaluation and graduation scale of facial movements, independent for eye and vibrissae, was elaborated, together with a sum of the parameters, as a means to evaluate facial palsy. Absence of eye blinking and closure scored 1; the presence of orbicular muscle contraction, without blinking reflex, scored 2; 50% of eye closure through blinking reflex, scored 3, 75% of closure scored 4. The presence of complete eye closure and blinking reflex scored 5. The absence of movement and posterior position of the vibrissae scored 1; slight shivering and posterior position scored 2; greater shivering and posterior position, scored 3 and normal movement with posterior position, scored 4; symmetrical movement of he vibrissae, with anterior position, scored 5. The rat anatomy allows easy access to the extratemporal facial nerve, allowing its sectioning and standardized suture. It was also possible to establish an evaluation and graduation scale of the rat facial movements with facial palsy based on the clinical observation of these animals.
    Brazilian journal of otorhinolaryngology 72(3):341-7. · 0.55 Impact Factor
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    ABSTRACT: To setup an experimental model is the first step to study neural regeneration. Setting up an experimental model on facial nerve regeneration. Wistar rats with complete sectioning and suturing of the extratemporal facial nerve trunk; with a behavioral and histological analysis for 9 weeks. Experimental prospective study. Progressive clinical and histological recovery of the animals. Our method is acceptable to study facial nerve regeneration in rats.
    Brazilian journal of otorhinolaryngology 72(6):775-84. · 0.55 Impact Factor