Facial Nerve Intraoperative Monitoring in Otologic Surgeries under Sedation and Local Anesthesia - A Case Series and Literature Review

Abstract Introduction Local anesthesia with sedation has been employed for an increasingly number of otolaryngology procedures, and might be associated with lower surgical morbidity and costs. Facial nerve monitoring is often advisable in otology to minimize the risks of injuries to this cranial nerve, but the principles, techniques and parameters involved have only been studied for procedures under general anesthesia. Objective To report the preliminary outcomes of intraoperative facial nerve moni- toring during otologic procedures under sedation and local anesthesia. Methods A total of five procedures and their respective intraoperative electrophysi- ological main findings were described. Facial neuromonitoring was performed using the same device by an electrophysiologist. The monitor sensitivity was set at 100 mV, and a stimulating probe was used whenever needed. Results Progressively decreasing low-amplitude baseline values were usually obtained as the level of anesthesia increased, with isolated oscillations possibly related to some degree of voluntary muscular activity. These oscillations could be easily distinguished from those of the surgical manipulation or electrical stimulation of the nerve, which tended to be of much greater amplitude and shorter latency, occurring during specific surgical steps. Conclusion With a surgical team with proper procedural knowledge and broad expertise regarding the technique, intraoperative facial nerve monitoring under local anesthesia with sedation seemed both feasible and reliable. Thus, the need for intraoperative neuromonitoring should not be an obstacle for otologic procedures under less aggressive anesthetic management.

Outcome of different facial nerve reconstruction techniques / Resultados de diferentes técnicas de reconstrução do nervo facial

Abstract Introduction: There is no technique of facial nerve reconstruction that guarantees facial function recovery up to grade III. Objective: To evaluate the efficacy and safety of different facial nerve reconstruction techniques. Methods: Facial nerve reconstruction was performed in 22 patients (facial nerve interpositional graft in 11 patients and hypoglossal-facial nerve transfer in another 11 patients). All patients had facial function House-Brackmann (HB) grade VI, either caused by trauma or after resection of a tumor. All patients were submitted to a primary nerve reconstruction except 7 patients, where late reconstruction was performed two weeks to four months after the initial surgery. The follow-up period was at least two years. Results: For facial nerve interpositional graft technique, we achieved facial function HB grade III in eight patients and grade IV in three patients. Synkinesis was found in eight patients, and facial contracture with synkinesis was found in two patients. In regards to hypoglossal-facial nerve transfer using different modifications, we achieved facial function HB grade III in nine patients and grade IV in two patients. Facial contracture, synkinesis and tongue atrophy were found in three patients, and synkinesis was found in five patients. However, those who had primary direct facial-hypoglossal end-to-side anastomosis showed the best result without any neurological deficit. Conclusion: Among various reanimation techniques, when indicated, direct end-to-side facial-hypoglossal anastomosis through epineural suturing is the most effective technique with excellent outcomes for facial reanimation and preservation of tongue movement, particularly when performed as a primary technique.

Resumo Introdução: Não existe uma técnica de reconstrução do nervo facial que garanta a recuperação da função facial até o grau III. Objetivo: Avaliar a eficácia e segurança de diferentes técnicas de reconstrução do nervo facial. Método: Ao todo, 22 pacientes foram submetidos a reconstrução do nervo facial (enxerto com interposição do nervo facial em 11 pacientes e com transferência do nervo hipoglosso facial em 11 pacientes). Todos os pacientes apresentavam função facial de grau VI (de acordo com a classificação de House-Brackmann - HB) causada por trauma ou pela ressecção de um tumor. A reconstrução do nervo principal foi efetuada, exceto em sete pacientes, nos quais a reconstrução foi realizada entre duas semanas a quatro meses após a cirurgia inicial. O período de acompanhamento foi de, no mínimo, dois anos. Resultados: Para a técnica de enxerto com interposição de nervo facial, o grau de função facial obtido foi HB III em oito pacientes e HB IV em três pacientes. Sincinesia foi observada em oito pacientes e contratura facial com sincinesia em dois pacientes. Em relação à transferência do nervo hipoglosso facial com o uso de diferentes modificações, obtivemos função facial HB grau III em nove pacientes e HB grau IV em dois pacientes. Contratura facial, sincinesia e atrofia lingual foram observadas em três pacientes e sincinesia observada em cinco pacientes. No entanto, aqueles submetidos a anastomose primária direta hipoglosso-facial término-lateral apresentaram o melhor resultado, sem qualquer déficit neurológico. Conclusão: Entre as várias técnicas de reanimação, sempre que possível, a anastomose direta término-lateral hopoglosso-facial por meio de sutura epineural é a técnica mais eficaz, com excelentes resultados para reanimação facial e preservação do movimento da língua, especialmente quando realizada como técnica primária.

The extracisternal approach in vestibular schwannoma surgery and facial nerve preservation / A abordagem extracisternal na cirurgia de schwannoma vestibular e preservação do nervo facial

The classical surgical technique for the resection of vestibular schwannomas (VS) has emphasized the microsurgical anatomy of cranial nerves. We believe that the focus on preservation of the arachnoid membrane may serve as a safe guide for tumor removal. Method The extracisternal approach is described in detail. We reviewed charts from 120 patients treated with this technique between 2006 and 2012. Surgical results were evaluated based on the extension of resection, tumor relapse, and facial nerve function. Results Overall gross total resection was achieved in 81% of the patients. The overall postoperative facial nerve function House-Brackmann grades I-II at one year was 93%. There was no recurrence in 4.2 years mean follow up. Conclusion The extracisternal technique differs from other surgical descriptions on the treatment of VS by not requiring the identification of the facial nerve, as long as we preserve the arachnoid envelope in the total circumference of the tumor. .

A técnica cirúrgica clássica para ressecção de schwannomas vestibulares enfatiza a anatomia microcirúrgica dos nervos cranianos. Acreditamos que o foco na preservação da membrana aracnóide pode servir como parâmetro seguro para a remoção do tumor. Método A abordagem extracisternal é descrita em detalhe. Analisamos o prontuário de 120 pacientes tratados com esta técnica entre 2006 e 2012. Os resultados cirúrgicos foram baseados em extensão de ressecção, recorrência tumoral e função do nervo facial. Resultados Ressecção total foi obtida em 81% dos pacientes. O resultado global da função do nervo facial (House-Brackmann graus I-II) após um ano da cirurgia foi de 93%. Não houve recidiva em um seguimento médio de 4,2 anos. Conclusão A técnica extracisternal difere de outras descrições cirúrgicas no tratamento de schwannoma vestibular pois não requer a identificação do nervo facial, contanto que o plano de aracnóide seja preservado em toda circunferência do tumor. .

The blink reflex test does not show abnormalities in a large group of patients with chronic migraine / O teste do reflexo do piscamento nao mostra alteracoes em um grande grupo de pacientes com enxaqueca cronica

The blink reflex – a simple, non-invasive and inexpensive test – may be indicative of lesions or dysfunctions of the brainstem, and particularly assesses the trigeminal-facial arch. Results from alterations of the blink reflex in patients with headaches have provided controversial data. Method Registration of the waves R1 and R2 (ipsilateral to the stimulus) and R2c (contralateral to the stimulus) by electroneuromyography. Results A large number of controls (n=160) and patients with chronic migraine (n=160) were studied. No significant differences were observed between the two groups. Conclusion It is possible that this relatively simple and primitive reflex is not affected unless there is significant damage to the brainstem. .

O reflexo do piscamento é um teste simples, não invasivo de baixo custo que pode direcionar o raciocínio para lesões ou disfunções do traonco cerebral, avaliando particularmente o arco trigêmeo-facial. Resultados de reflexo do piscamento em pacientes com cefaleias têm mostrado dados controversos. Método Registro das ondas R1 e R2 (ipsilaterais ao estímulo) e R2c (contralateral ao estímulo) por eletroneuromiografia. Resultados Um grande número de controles (n=160) e pacientes com enxaqueca crônica (n=160) foi avaliado. Não foram encontradas diferenças significativas no reflexo do piscamento entre os dois grupos. Conclusão É possível que este reflexo, por ser relativamente simples e primitivo, não esteja alterado a menos que ocorram danos significativos no tronco cerebral. .

Parálisis facial en otitis media: revisión bibliográfica / Facial paralysis in otitis media: literature review

La parálisis facial secundaria a una otitis media es una conocida complicación de infecciones agudas y crónicas. Su fisiopatología es desconocida pero la presión elevada en el oído medio, la osteítis, la invasión bacteriana y la neurotoxicidad, podrían estar involucradas. Los exámenes de laboratorio no entregan mayor información para determinar la etiología de la parálisis facial y la tomografía computada de oídos sería el estudio radiológico de elección ya que permite identificar el compromiso óseo, la extensión de la enfermedad y posibles alteraciones anatómicas existentes, además de ser utilizado para el diagnóstico de eventuales complicaciones intracraneales. El tratamiento de la parálisis en el curso de una otitis media aguda es médico, con antibióticos y esteroides, con buen pronóstico de recuperación; mientras en una otitis media crónica el tratamiento es quirúrgico y el pronóstico global peor.

Facial paralysis secondary to otitis media is a well known complication of acute and chronic infection. The physiopathology of facial nerve paralysis secondary to otitis media of not known, but high middle ear pressure, osteitis, direct bacterial invasion and neurotoxicity could be involved. Laboratory studies have failed to provide clues as to determining the etiology of facial nerve palsy. Ear CT is the radiologic study of choice, as it allows the identification of bone destruction, disease extension and possible anatomic alterations, and may also be used as a screening for intracranial complications. Acute otitis media treatment is medical with antibiotics and steroids, with good prognosis, whereas in chronic otitis media the treatment is surgical, with worst global prognosis.