Papers by Ricardo Dorigueto
Brazilian Journal of Otorhinolaryngology, 2019
Introduction: Neurotology is a rapidly expanding field of knowledge. The study of the vestibular ... more Introduction: Neurotology is a rapidly expanding field of knowledge. The study of the vestibular system has advanced so much that even basic definitions, such as the meaning of vestibular symptoms, have only recently been standardized. Objective: To present a review of the main subjects of neurotology, including concepts, diagnosis and treatment of Neurotology, defining current scientific evidence to facilitate decision-making and to point out the most evidence-lacking areas to stimulate further new research. Methods: This text is the result of the I Brazilian Forum of Neurotology, which brought together the foremost Brazilian researchers in this area for a literature review. In all, there will be three review papers to be published. This first review will address definitions and therapies, the second one will address diagnostic tools, and the third will define the main diseases diagnoses. Each author performed a bibliographic search in the LILACS, SciELO, PubMed and MEDLINE databases on a given subject. The text was then submitted to the other Forum participants for a period of 30 days for analysis. A special chapter, on the definition of vestibular symptoms, was translated by an official translation service, and equally submitted to the other stages of the process. There was then a in-person meeting in which all the texts were orally presented, and there was a discussion among the participants to define a consensual text for each chapter. The consensual texts were then submitted to a final review by four professors of neurotology disciplines from three Brazilian universities and finally concluded. Based on the full text, available on the website of the Brazilian Association of Otorhinolaryngology and Cervical-Facial Surgery, this summary version was written as a review article. Result: The text presents the official translation into Portuguese of the definition of vestibular symptoms proposed by the Bárány Society and brings together the main scientific evidence for each of the main existing therapies for neurotological diseases. Conclusion: This text rationally grouped the main topics of knowledge regarding the definitions and therapies of Neurotology, allowing the reader a broad view of the approach of neurotological patients based on scientific evidence and national experience, which should assist them in clinical decision-making, and show the most evidence-lacking topics to stimulate further study.
Otolaryngology - Head and Neck Surgery, 2009
OBJECTIVES: 1) Understand that acetaminophen is intrinsically ototoxic to hair cells in mice, and... more OBJECTIVES: 1) Understand that acetaminophen is intrinsically ototoxic to hair cells in mice, and that hydromorphone, the active form of hydrocodone, may augment this toxicity. 2) Learn that acetaminophen/hydrocodone ototoxicity may be due to oxidative stress in hair cells. METHODS: Using Math-1 GFP neonatal mouse cochlear culture, we previously demonstrated a dose-dependent hair cell killing with acetaminophen (APAP), but not with hydrocodone. In this controlled experiment, cultures were incubated for 24 hours in 4000ug/mL APAP with 0, 5, 10 or 20 ug/mL hydromorphone, the active form of hydrocodone. Separate cultures were treated with APAP and increasing concentrations of the antioxidant, L-carnitine. Using fluorescent microscopy, hair cells from a 600 micron basal segment were quantified before and after treatment. The average percent cell survival from two cochleas per group was determined, and comparisons were performed using Student t-Test statistical analysis. RESULTS: Cultures exposed to APAP plus the highest concentration of hydromorphone showed 35% survival compared to 85% survival with APAP alone (pϭ0.05). The highest dose of hydromorphone alone did not cause significant hair cell killing compared to controls. Separate cultures showed 83% survival when exposed to L-carnitine plus APAP, compared to 59% with APAP alone (pϭ0.07). CONCLUSIONS: Hair cell ototoxicity is observed in mice after APAP exposure, and hydromorphone may augment APAP's toxic effects. The mechanism of APAP-induced hair cell death may be due to oxidative cell stress. Understanding the mechanism of APAP/hydrocodone ototoxicity may lead to future treatment strategies for hearing loss from ototoxic medications.
Auris Nasus Larynx, 2014
Primary objective of this study was to find a statistical link between the most worldwide comorbi... more Primary objective of this study was to find a statistical link between the most worldwide comorbidities affecting the elderly population (hypertension, diabetes, osteoarthrosis, osteoporosis and depression) and recurrent episodes of BPPV. Secondary objective was defining possible "groups of risk" for people suffering recurrent positional vertigo related to the presence of a well documented comorbidity. This was an observational, cross-sectional, multicenter, spontaneous, non-pharmacological study. The data of 1092 patients suffering BPPV evaluated in 11 different Departments of Otolaryngology, Otoneurology and Neurology, referring Centers for positional vertigo evaluation, were retrospectively collected. Regarding evaluated comorbidities (hypertension, diabetes, osteoarthrosis, osteoporosis and depression), data analysis showed the presence of at least one comorbid disorder in 216 subjects (19.8%) and 2 or more in 408 subjects (37.4%). Moreover there was a statistical significant difference between the number of comorbidities and the number of recurrences, otherwise said as comorbidity disorders increased the number of relapses increased too. The presence of a systemic disease may worsen the status of the posterior labyrinth causing a more frequent otolith detachment. This condition increases the risk for patients suffering BPPV to have recurrent episodes, even if correctly managed by repositioning maneuvers. The combination of two or more of aforementioned comorbidities further increases the risk of relapsing BPPV, worsened by the presence of osteoporosis. On the basis of this results it was possible to define "groups of…
Otolaryngology-head and Neck Surgery, 2009
OBJECTIVES: 1) Understand that acetaminophen is intrinsically ototoxic to hair cells in mice, and... more OBJECTIVES: 1) Understand that acetaminophen is intrinsically ototoxic to hair cells in mice, and that hydromorphone, the active form of hydrocodone, may augment this toxicity. 2) Learn that acetaminophen/hydrocodone ototoxicity may be due to oxidative stress in hair cells. METHODS: Using Math-1 GFP neonatal mouse cochlear culture, we previously demonstrated a dose-dependent hair cell killing with acetaminophen (APAP), but not with hydrocodone. In this controlled experiment, cultures were incubated for 24 hours in 4000ug/mL APAP with 0, 5, 10 or 20 ug/mL hydromorphone, the active form of hydrocodone. Separate cultures were treated with APAP and increasing concentrations of the antioxidant, L-carnitine. Using fluorescent microscopy, hair cells from a 600 micron basal segment were quantified before and after treatment. The average percent cell survival from two cochleas per group was determined, and comparisons were performed using Student t-Test statistical analysis. RESULTS: Cultures exposed to APAP plus the highest concentration of hydromorphone showed 35% survival compared to 85% survival with APAP alone (pϭ0.05). The highest dose of hydromorphone alone did not cause significant hair cell killing compared to controls. Separate cultures showed 83% survival when exposed to L-carnitine plus APAP, compared to 59% with APAP alone (pϭ0.07). CONCLUSIONS: Hair cell ototoxicity is observed in mice after APAP exposure, and hydromorphone may augment APAP's toxic effects. The mechanism of APAP-induced hair cell death may be due to oxidative cell stress. Understanding the mechanism of APAP/hydrocodone ototoxicity may lead to future treatment strategies for hearing loss from ototoxic medications.
Revista Brasileira De Otorrinolaringologia, 2007
OBJETIVO: Avaliar se a repetição de manobras de Epley em uma mesma sessão resulta em um menor núm... more OBJETIVO: Avaliar se a repetição de manobras de Epley em uma mesma sessão resulta em um menor número de sessões para abolir o nistagmo de posicionamento do que uma única manobra por sessão. MÉTODO: A manobra de Epley foi realizada em 123 pacientes com VPPB unilateral por ductolitíase do canal posterior. O grupo I foi composto por 75 pacientes submetidos a uma única manobra de Epley por sessão semanal e o grupo II foi constituído por 48 pacientes submetidos a quatro manobras na primeira sessão. RESULTADOS: O grupo II apresentou latência e duração do nistagmo maiores do que o grupo I (p<0,05). A média e o desvio-padrão do número de sessões apresentados pelo grupo I foram maiores do que no grupo II (p=0,008). Observou-se associação significante entre a distribuição do número de sessões e o grupo (p=0,039). O grupo II apresentou 21,4% a mais de pacientes que necessitaram apenas de uma sessão (IC 95% [7,7% - 35,1%]). CONCLUSÃO: A repetição de manobras de Epley em uma mesma sessão resulta em um menor número de sessões para abolir o nistagmo de posicionamento do que uma única manobra por sessão.
Revista Brasileira De Otorrinolaringologia, 2005
O uso de restrição de movimentação cefálica após a manobra de Epley ainda é controverso. OBJETIVO... more O uso de restrição de movimentação cefálica após a manobra de Epley ainda é controverso. OBJETIVO: Verificar a importância da restrição de movimentação cefálica na evolução clínica de pacientes com vertigem posicional paroxística benigna por ductolitíase de canal semicircular posterior, quando submetidos a uma única manobra de Epley. FORMA DE ESTUDO: clínico prospectivo. MATERIAL E MÉTODO: Cinqüenta e oito pacientes com ductolitíase do canal semicircular posterior foram divididos aleatoriamente em dois grupos após a aplicação de uma manobra de Epley. Os pacientes do grupo 1 foram orientados quanto às restrições da movimentação cefálica e os pacientes do grupo 2 não foram orientados. Após uma semana, os dois grupos foram avaliados quanto à presença do nistagmo de posicionamento e à evolução clínica da vertigem. RESULTADOS: O nistagmo de posicionamento não esteve presente em 82,1% dos pacientes do grupo 1 e em 73,3% dos pacientes do grupo 2 após uma semana da manobra de Epley (p=0,421). Houve melhora clínica subjetiva em 96,0% dos pacientes do grupo 1 e em 94,0% dos pacientes do grupo 2 (p=0,781). CONCLUSÃO: O uso das restrições de movimentação cefálica não interferiu na evolução clínica dos pacientes com vertigem posicional paroxística benigna por ductolitíase de canal semicircular posterior, submetidos à única manobra de Epley.
Revista Brasileira De Otorrinolaringologia, 2005
OBJETIVO: Avaliar o número de manobras necessárias para abolir o nistagmo posicional em pacientes... more OBJETIVO: Avaliar o número de manobras necessárias para abolir o nistagmo posicional em pacientes com Vertigem Posicional Paroxística Benigna e verificar possíveis influências do substrato fisiopatológico e/ou canal semicircular acometido. FORMA DE ESTUDO: clínico prospectivo com coorte transversal. MATERIAL E MÉTODO: Sessenta pacientes com Vertigem Posicional Paroxística Benigna foram tratados por meio das manobras de reposicionamento de estatocônios, repetidas semanalmente até a abolição do nistagmo. A Análise de Variância foi aplicada para verificar diferenças entre as variáveis dos fatores "substrato fisiopatológico" e "canal semicircular acometido". RESULTADOS: Foram necessárias de 1 a 8 manobras, em média 2,13 para abolir o nistagmo posicional. A cupulolitíase necessitou de um número maior de manobras que a ductolitíase (p=0,0002*) e não houve diferença entre os canais semicirculares (p=0,5213). Nos canais anterior e posterior, a ductolitíase precisou em média de uma a duas manobras e a cupulolitíase precisou em média de três manobras. No canal lateral, tanto a ductolitíase quanto a cupulolitíase precisaram de duas manobras, em média. CONCLUSÕES: São necessárias de uma a oito manobras semanais de reposicionamento de estatocônios, em média duas, para eliminar o nistagmo posicional na Vertigem Posicional Paroxística Benigna. A cupulolitíase necessita de maior número de manobras que a ductolitíase. O canal semicircular acometido não influencia o número de manobras terapêuticas.
Brazilian Journal of Otorhinolaryngology (impresso), 2009
Beni gn paroxysmal positional vertigo (BPPV) is one of the most common vestibular disorders. Aim:... more Beni gn paroxysmal positional vertigo (BPPV) is one of the most common vestibular disorders. Aim: To study the recurrence and persistence of BPPV in patients treated with canalith repositioning maneuvers (CRM) during the period of one year. Study design: longitudinal contemporary cohort series. Materials and Methods: One hundred patients with BPPV were followed up during 12 months after a treatment with CRM. Patients were classified according to disease evolution. Aquatic physiotherapy for vestibular rehabilitation (APVR) protocol was applied in cases of persistent BPPV. Results: After CRM, 96% of the patients were free from BPPV's typical nystagmus and dizziness. During the follow up period of 1 year, 26 patients returned with typical BPPV nystagmus and vertigo. Nystagmus and vertigo were persistent in 4% of the patients. Persistent BPPV presented improvement when submitted to APVR. Conclusion: During the period of one year, BPPV was not recurrent in 70% of the patients, recurrent in 26% and persistent in 4%.
Brazilian Journal of Otorhinolaryngology (impresso), 2009
Met abolic disorders can cause dizziness. Aim: to study the prevalence of glucose and glucose-ins... more Met abolic disorders can cause dizziness. Aim: to study the prevalence of glucose and glucose-insulin alterations in patients with peripheral vestibular disorders by studying the four-hour glucose-insulin curve; to check at what time there was the highest prevalence of altered cases and whether the glucose and insulin curves together are better than the isolate glucose curve and fasting glucose curve. Materials and Methods: retrospective study, analyzing 81 four-hour glucose-insulin curves in patients with peripheral vestibular dizziness. Results: Four-hour glucose-insulin curve alterations happened in 87.7% of the patients. Hypoglycemia was seen in 61.7% of the cases, hyperinsulinemia in 55.5%, hyperglycemia in 27.2%, glucose intolerance in 12.3% and hypoinsulinemia in 1.2%. Normal tests were seen in 12.3 % of the cases and altered fasting glucose in 23.5%. Conclusions: The fourhour glucose-insulin curve analysis showed that 87.7% of the patients with dizziness and suspicion of peripheral vestibular disorder had glucose or insulin metabolism disorders. The highest number of alterations was seen up to the third and fourth hour of the glucose-insulin curve. The glucose and insulin curves together overcame the glucose curve alone and fasting glucose curve in regards of the prevalence of altered cases.
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Papers by Ricardo Dorigueto