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1.
Cells ; 8(8)2019 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-31408967

RESUMO

The primary loss of cochlear glutamatergic afferent nerve synapses due to noise or ageing (cochlear neuropathy) often presents as difficulties in speech discrimination in noisy conditions (hidden hearing loss (HHL)). Currently, there is no treatment for this condition. Our previous studies in mice with genetic deletion of the adenosine A2A receptor (A2AR) have demonstrated better preservation of cochlear afferent synapses and spiral ganglion neurons after noise exposure compared to wildtype mice. This has informed our current targeted approach to cochlear neuroprotection based on pharmacological inhibition of the A2AR. Here, we have used organotypic tissue culture of the Wistar rat cochlea at postnatal day 6 (P6) to model excitotoxic injury induced by N-methyl-d-aspartate (NMDA)/kainic acid (NK) treatment for 2 h. The excitotoxic injury was characterised by a reduction in the density of neural processes immediately after NK treatment and loss of afferent synapses in the presence of intact sensory hair cells. The administration of istradefylline (a clinically approved A2AR antagonist) reduced deafferentation of inner hair cells and improved the survival of afferent synapses after excitotoxic injury. This study thus provides evidence that A2AR inhibition promotes cochlear recovery from excitotoxic injury, and may have implications for the treatment of cochlear neuropathy and prevention of HHL.


Assuntos
Cóclea/efeitos dos fármacos , Cóclea/lesões , Purinas/farmacologia , Animais , Perda Auditiva Provocada por Ruído/tratamento farmacológico , Modelos Biológicos , Ratos , Ratos Wistar , Técnicas de Cultura de Tecidos , Traumatismos do Nervo Vestibulococlear/tratamento farmacológico
2.
J Int Adv Otol ; 14(2): 330-333, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30256206

RESUMO

We present a rare case of traumatic facial and vestibulocochlear nerve injury in the internal acoustic canal in the absence of a temporal bone fracture. A 2.5-year-old female presented with sudden-onset left-sided facial paralysis and ipsilateral total hearing loss after being hit by a falling television. High-resolution computed tomography revealed an occipital fracture line that spared the temporal bone and otic capsule. Diagnostic auditory brainstem response testing showed that wave V at 90-db normal hearing level was absent in the left ear. Needle electromyography revealed severe axonal injury. Facial paralysis regressed to House-Brackmann grade IV 9 months after the trauma, and no surgical intervention was scheduled. Traumatic facial and vestibulocochlear nerve injury can occur in the absence of a temporal bone fracture. Thus, careful evaluation of the internal acoustic canal is mandatory if concurrent 7th and 8th cranial nerve paralyses exist with no visible fracture line.


Assuntos
Surdez/diagnóstico , Traumatismos do Nervo Facial/complicações , Paralisia Facial/diagnóstico , Fraturas Cranianas/diagnóstico por imagem , Pré-Escolar , Tratamento Conservador , Surdez/etiologia , Lesão Axonal Difusa/diagnóstico , Lesão Axonal Difusa/fisiopatologia , Orelha Interna/inervação , Orelha Interna/patologia , Eletromiografia/métodos , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Nervo Facial/patologia , Traumatismos do Nervo Facial/diagnóstico , Traumatismos do Nervo Facial/fisiopatologia , Paralisia Facial/etiologia , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Índice de Gravidade de Doença , Fraturas Cranianas/patologia , Osso Temporal/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Traumatismos do Nervo Vestibulococlear/complicações , Traumatismos do Nervo Vestibulococlear/diagnóstico
3.
Neurosurgery ; 82(2): E44-E46, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29309641

RESUMO

Question 1: Does intraoperative facial nerve monitoring during vestibular schwannoma surgery lead to better long-term facial nerve function? Target Population: This recommendation applies to adult patients undergoing vestibular schwannoma surgery regardless of tumor characteristics. Recommendation: Level 3: It is recommended that intraoperative facial nerve monitoring be routinely utilized during vestibular schwannoma surgery to improve long-term facial nerve function. Question 2: Can intraoperative facial nerve monitoring be used to accurately predict favorable long-term facial nerve function after vestibular schwannoma surgery? Target Population: This recommendation applies to adult patients undergoing vestibular schwannoma surgery. Recommendation: Level 3: Intraoperative facial nerve can be used to accurately predict favorable long-term facial nerve function after vestibular schwannoma surgery. Specifically, the presence of favorable testing reliably portends a good long-term facial nerve outcome. However, the absence of favorable testing in the setting of an anatomically intact facial nerve does not reliably predict poor long-term function and therefore cannot be used to direct decision-making regarding the need for early reinnervation procedures. Question 3: Does an anatomically intact facial nerve with poor electromyogram (EMG) electrical responses during intraoperative testing reliably predict poor long-term facial nerve function? Target Population: This recommendation applies to adult patients undergoing vestibular schwannoma surgery. Recommendation: Level 3: Poor intraoperative EMG electrical response of the facial nerve should not be used as a reliable predictor of poor long-term facial nerve function. Question 4: Should intraoperative eighth cranial nerve monitoring be used during vestibular schwannoma surgery? Target Population: This recommendation applies to adult patients undergoing vestibular schwannoma surgery with measurable preoperative hearing levels and tumors smaller than 1.5 cm. Recommendation: Level 3: Intraoperative eighth cranial nerve monitoring should be used during vestibular schwannoma surgery when hearing preservation is attempted. Question 5: Is direct monitoring of the eighth cranial nerve superior to the use of far-field auditory brain stem responses? Target Population: This recommendation applies to adult patients undergoing vestibular schwannoma surgery with measurable preoperative hearing levels and tumors smaller than 1.5 cm. Recommendation: Level 3: There is insufficient evidence to make a definitive recommendation. The full guideline can be found at: https://www.cns.org/guidelines/guidelines-manage-ment-patients-vestibular-schwannoma/chapter_4.


Assuntos
Nervo Facial/fisiologia , Monitorização Neurofisiológica Intraoperatória/métodos , Neuroma Acústico/cirurgia , Nervo Vestibulococlear/fisiologia , Adulto , Traumatismos do Nervo Facial/etiologia , Traumatismos do Nervo Facial/prevenção & controle , Feminino , Humanos , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos/efeitos adversos , Procedimentos Neurocirúrgicos/métodos , Traumatismos do Nervo Vestibulococlear/etiologia , Traumatismos do Nervo Vestibulococlear/prevenção & controle
4.
eNeuro ; 3(2)2016.
Artigo em Inglês | MEDLINE | ID: mdl-27257624

RESUMO

Prevention of auditory hair cell death offers therapeutic potential to rescue hearing. Pharmacological blockade of JNK/c-Jun signaling attenuates injury-induced hair cell loss, but with unsolved mechanisms. We have characterized the c-Jun stress response in the mouse cochlea challenged with acoustic overstimulation and ototoxins, by studying the dynamics of c-Jun N-terminal phosphorylation. It occurred acutely in glial-like supporting cells, inner hair cells, and the cells of the cochlear ion trafficking route, and was rapidly downregulated after exposures. Notably, death-prone outer hair cells lacked c-Jun phosphorylation. As phosphorylation was triggered also by nontraumatic noise levels and none of the cells showing this activation were lost, c-Jun phosphorylation is a biomarker for cochlear stress rather than an indicator of a death-prone fate of hair cells. Preconditioning with a mild noise exposure before a stronger traumatizing noise exposure attenuated the cochlear c-Jun stress response, suggesting that the known protective effect of sound preconditioning on hearing is linked to suppression of c-Jun activation. Finally, mice with mutations in the c-Jun N-terminal phosphoacceptor sites showed partial, but significant, hair cell protection. These data identify the c-Jun stress response as a paracrine mechanism that mediates outer hair cell death.


Assuntos
Biomarcadores/metabolismo , Células Ciliadas Vestibulares/metabolismo , Perda Auditiva Provocada por Ruído/patologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Traumatismos do Nervo Vestibulococlear/patologia , Animais , Animais Recém-Nascidos , Apoptose , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Feminino , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Canamicina/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos CBA , Camundongos Transgênicos , Ruído/efeitos adversos , Inibidores da Síntese de Proteínas/toxicidade , Fatores de Tempo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Traumatismos do Nervo Vestibulococlear/induzido quimicamente
5.
Otol Neurotol ; 36(4): 670-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25280052

RESUMO

HYPOTHESIS: Electrocauterization and subsequent transection of the cochlear nerve induce greater injury to the cochlear nucleus than sharp transection alone. BACKGROUND: Some studies show that neurofibromatosis Type 2 (NF2) patients fit with auditory brainstem implants (ABIs) fail to achieve speech perception abilities similar to ABI recipients without NF2. Reasons for these differences remain speculative. One hypothesis posits poorer performance to surgically induced trauma to the cochlear nucleus from electrocautery. Sustained electrosurgical depolarization of the cochlear nerve may cause excitotoxic-induced postsynaptic nuclear injury. Equally plausible is that cautery in the vicinity of the cochlear nucleus induces necrosis. METHODS: The cochlear nerve was transected in anesthetized adult gerbils sharply with or without bipolar electrocautery at varying intensities. Gerbils were perfused at 1, 3, 5, and 7 days postoperatively; their brainstem and cochleas were embedded in paraffin and sectioned at 10 µm. Alternate sections were stained with flourescent markers for neuronal injury or Nissl substance. In additional experiments, anterograde tracers were applied directly to a sectioned eighth nerve to verify that fluorescent-labeled profiles seen were terminating auditory nerve fibers. RESULTS: Cochlear nerve injury was observed from 72 hours postoperatively and was identical across cases regardless of surgical technique. Postsynaptic cochlear nucleus injury was not seen after distal transection of the nerve. By contrast, proximal transection was associated with trauma to the cochlear nucleus. CONCLUSION: Distal application of bipolar electrocautery seems safe for the cochlear nucleus. Application near the root entry zone must be used cautiously because this may compromise nuclear viability needed to support ABI stimulation.


Assuntos
Implante Auditivo de Tronco Encefálico , Nervo Coclear/cirurgia , Núcleo Coclear/patologia , Eletrocoagulação/efeitos adversos , Eletrocoagulação/métodos , Traumatismos do Nervo Vestibulococlear/complicações , Animais , Implante Auditivo de Tronco Encefálico/efeitos adversos , Implante Auditivo de Tronco Encefálico/métodos , Implantes Auditivos de Tronco Encefálico , Nervo Coclear/lesões , Modelos Animais de Doenças , Gerbillinae , Masculino
6.
J Assoc Res Otolaryngol ; 15(1): 31-43, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24113829

RESUMO

Ouabain application to the round window can selectively destroy type-I spiral ganglion cells, producing an animal model of auditory neuropathy. To assess the long-term effects of this deafferentation on synaptic organization in the organ of Corti and cochlear nucleus, and to ask whether surviving cochlear neurons show any post-injury plasticity in the adult, we quantified the peripheral and central synapses of type-I neurons at posttreatment times ranging from 1 to 3 months. Measures of normal DPOAEs and greatly reduced auditory brainstem responses (ABRs) confirmed the neuropathy phenotype. Counts of presynaptic ribbons and postsynaptic glutamate receptor patches in the inner hair cell area decreased with post-exposure time, as did counts of cochlear nerve terminals in the cochlear nucleus. Although these counts provided no evidence of new synapse formation via branching from surviving neurons, the regular appearance of ectopic neurons in the inner hair cell area suggested that neurite extension is not uncommon. Correlations between pathophysiology and histopathology showed that ABR thresholds are very insensitive to even massive neural degeneration, whereas the amplitude of ABR wave 1 is a better metric of synaptic degeneration.


Assuntos
Nervo Coclear/patologia , Degeneração Neural/induzido quimicamente , Plasticidade Neuronal/efeitos dos fármacos , Ouabaína/efeitos adversos , Ouabaína/farmacologia , Sinapses/efeitos dos fármacos , Traumatismos do Nervo Vestibulococlear/induzido quimicamente , Animais , Cóclea/efeitos dos fármacos , Cóclea/inervação , Cóclea/fisiopatologia , Nervo Coclear/efeitos dos fármacos , Modelos Animais de Doenças , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/farmacologia , Feminino , Camundongos , Camundongos Endogâmicos CBA , Degeneração Neural/patologia , Degeneração Neural/fisiopatologia , Órgão Espiral/patologia , Órgão Espiral/fisiopatologia , Terminações Pré-Sinápticas/efeitos dos fármacos , Terminações Pré-Sinápticas/parasitologia , Receptores de Glutamato/efeitos dos fármacos , Receptores de Glutamato/fisiologia , Sinapses/patologia , Fatores de Tempo , Traumatismos do Nervo Vestibulococlear/patologia , Traumatismos do Nervo Vestibulococlear/fisiopatologia
7.
Acta Neurochir (Wien) ; 156(3): 571-5, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24306235

RESUMO

BACKGROUND: Cranial nerve VIII is at risk during microvascular decompression (MVD) for hemifacial spasm (HFS). The primary aim of this study is to evaluate the empirical factors associated with brainstem auditory evoked potential monitoring and its correlation to post operative hearing loss (HL) after MVD for HFS. METHODS: Pre-operative and post-operative audiogram data and BAEP from ninety-four patients who underwent MVD for HFS were analyzed. Pure tone audiometry (PTA) and Speech Discrimination Score (SDS) were performed on all patients before and after surgery. Intraoperative neurophysiological data were reviewed independently. HL was assessed using the AAO-HNS classification system for non-serviceable hearing loss (Class C/D), defined as PTA >50 dB and/or SDS <50% within the speech range of frequencies. RESULTS: Patients with HL had higher rates of loss in the amplitude of wave V and prolongation in the interpeak latency of peak I-V latency during MVD. Gender, age, side, and MVD duration did not increase the risk of HL. There was no correlation between successive number of BAEP changes (reflective of the number of surgical attempts) and HL. There was no association between the speed of recovery of BAEPs and HL. CONCLUSIONS: Patients with new post-operative HL have a faster rate of change in the amplitude of wave V and the interpeak I-V latency during intraoperative BAEP monitoring for HFS. Our alarm criteria to inform the surgeon about impending nerve injury might have to be modified and prospectively tested to prevent rapid change in BAEPs.


Assuntos
Potenciais Evocados Auditivos do Tronco Encefálico , Perda Auditiva/prevenção & controle , Espasmo Hemifacial/cirurgia , Cirurgia de Descompressão Microvascular/métodos , Monitorização Intraoperatória/métodos , Traumatismos do Nervo Vestibulococlear/diagnóstico , Traumatismos do Nervo Vestibulococlear/prevenção & controle , Audiometria de Tons Puros , Surdez/diagnóstico , Surdez/prevenção & controle , Feminino , Perda Auditiva/diagnóstico , Humanos , Complicações Intraoperatórias/diagnóstico , Complicações Intraoperatórias/etiologia , Complicações Intraoperatórias/prevenção & controle , Masculino , Cirurgia de Descompressão Microvascular/efeitos adversos , Pessoa de Meia-Idade , Estudos Retrospectivos , Traumatismos do Nervo Vestibulococlear/etiologia
8.
Neurosurg Focus ; 34(3): E6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23451756

RESUMO

OBJECT: Microvascular decompression (MVD) of the facial nerve is an effective treatment for patients with hemifacial spasm. Intraoperative monitoring of brainstem auditory evoked potentials (BAEPs) during MVD can reduce the incidence of hearing loss. In this study the authors' goal was to evaluate changes in interpeak latencies (IPLs) of Waves I-V, Waves III-V, and Waves I-III of BAEP Waveforms I, III, and V during MVD and correlate them with postoperative hearing loss. To date, no such study has been performed. Hearing loss is defined as nonuseful hearing (Class C/D), which is a pure tone average of more than 50 dB and/or speech discrimination score of less than 50%. METHODS: The authors performed a retrospective analysis of IPLs of BAEPs in 93 patients who underwent intraoperative BAEP monitoring during MVD. Patients who did not have hearing loss were in Class A/B and those who had hearing loss were in Class C/D. RESULTS: Binary logistic regression analysis of independent IPL variables was performed. A maximum change in IPLs of Waves I-III and Waves I-V and on-skin change in IPLs of Waves I-V increases the odds of hearing loss. However, on adjusting the same variables for loss of response, change in IPLs did not increase the odds of hearing loss. CONCLUSIONS: Changes in IPL measurements did not increase the odds of postoperative hearing loss. This information might be helpful in evaluating the value of IPLs as alarm criteria during MVD to prevent hearing loss.


Assuntos
Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Doenças do Nervo Facial/cirurgia , Perda Auditiva Neurossensorial/prevenção & controle , Espasmo Hemifacial/cirurgia , Complicações Intraoperatórias/prevenção & controle , Cirurgia de Descompressão Microvascular , Monitorização Intraoperatória/métodos , Síndromes de Compressão Nervosa/cirurgia , Traumatismos do Nervo Vestibulococlear/prevenção & controle , Nervo Vestibulococlear/fisiopatologia , Audiometria de Tons Puros , Eletromiografia , Nervo Facial/cirurgia , Doenças do Nervo Facial/complicações , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/epidemiologia , Espasmo Hemifacial/etiologia , Humanos , Incidência , Complicações Intraoperatórias/diagnóstico , Complicações Intraoperatórias/epidemiologia , Síndromes de Compressão Nervosa/complicações , Cuidados Pós-Operatórios , Valor Preditivo dos Testes , Cuidados Pré-Operatórios , Tempo de Reação , Estudos Retrospectivos , Traumatismos do Nervo Vestibulococlear/diagnóstico , Traumatismos do Nervo Vestibulococlear/epidemiologia
9.
Noise Health ; 13(55): 392-401, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22122955

RESUMO

In military outdoor shooting training, with safety measures enforced, the risk of a permanent, noise-induced hearing loss is very small. But urban warfare training performed indoors, with reflections from walls, might increase the risk. A question is whether antioxidants can reduce the negative effects of noise on human hearing as it does on research animals. Hearing tests were performed on a control group of 23 military officers before and after a shooting session in a bunker-like room. The experiments were repeated on another group of 11 officers with peroral adminstration of N-acetyl-cysteine (NAC), directly after the shooting. The measurements performed were tone thresholds; transient-evoked otoacoustic emissions, with and without contralateral noise; and psycho-acoustical modulation transfer function (PMTF), thresholds for brief tones in modulated noise. Effects from shooting on hearing thresholds were small, but threshold behavior supports use of NAC treatment. On the PMTF, shooting without NAC gave strong effects. Those effects were like those from continuous noise, which means that strict safety measures should be enforced. The most striking finding was that the non-linearity of the cochlea, that was strongly reduced in the group without NAC, as manifested by the PMTF-results, was practically unchanged in the NAC-group throughout the study. NAC treatment directly after shooting in a bunkerlike room seems to give some protection of the cochlea.


Assuntos
Acetilcisteína/uso terapêutico , Limiar Auditivo/efeitos dos fármacos , Perda Auditiva Provocada por Ruído/prevenção & controle , Traumatismos do Nervo Vestibulococlear/prevenção & controle , Acetilcisteína/farmacologia , Adulto , Análise de Variância , Audiometria , Estudos de Casos e Controles , Feminino , Depuradores de Radicais Livres/farmacologia , Depuradores de Radicais Livres/uso terapêutico , Perda Auditiva Provocada por Ruído/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Militares , Estresse Oxidativo/efeitos dos fármacos , Estudos Prospectivos , Espécies Reativas de Oxigênio/efeitos adversos , Suécia , Traumatismos do Nervo Vestibulococlear/complicações , Traumatismos do Nervo Vestibulococlear/etiologia , Adulto Jovem
10.
Otolaryngol Head Neck Surg ; 145(6): 1007-15, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21947792

RESUMO

OBJECTIVE: The degeneration of hair cells and spiral ganglion neurons (SGNs) is an important pathologic process in the development of sensorineural hearing loss. In a murine model, predictable and reproducible damage to SGNs occurs through the application of ouabain to the round window. Recent evidence has shown that the chemokine stromal cell-derived factor-1 (SDF-1) is a potent chemoattractant of hematopoietic stem cells (HSCs) and provides trophic support to injured tissues during development and maturation. The hypothesis for the current study is that expression of SDF-1 plays an important role in protecting SGNs and preventing further degeneration in the setting of cochlear injury. STUDY DESIGN: Prospective, controlled. SETTING: Academic research laboratory. SUBJECT AND METHODS: Auditory brainstem response (ABR) and the expression of SDF-1 mRNA and protein were examined 1, 3, 7, 14, and 30 days after application of ouabain in 35 adult mice. RESULTS: Following ouabain application, real-time reverse-transcription polymerase chain reaction for SDF demonstrates increased mRNA expression following ouabain injury in nontransplanted mice. A significant increase in SDF protein expression was also observed using immunolabeling techniques and Western blot analysis. CONCLUSIONS: SDF-1 expression is increased in the auditory nerve following cochlear injury. Further knowledge about the cochlear microenvironment, including SDF-1, is critical to maximizing HSC engraftment in the injured cochlea and providing a therapeutic option for sensorineural hearing loss.


Assuntos
Quimiocina CXCL12/metabolismo , Nervo Coclear/lesões , Perda Auditiva Neurossensorial/metabolismo , Traumatismos do Nervo Vestibulococlear/patologia , Animais , Western Blotting , Quimiocina CXCL12/genética , Nervo Coclear/patologia , Intervalos de Confiança , Modelos Animais de Doenças , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Regulação da Expressão Gênica , Perda Auditiva Neurossensorial/patologia , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos CBA , Ouabaína/farmacologia , Distribuição Aleatória , Valores de Referência , Traumatismos do Nervo Vestibulococlear/metabolismo
11.
Otol Neurotol ; 31(9): 1508-10, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20856161

RESUMO

OBJECTIVE: To describe a case of facial, vestibular, and cochlear nerve avulsion secondary to blunt trauma without an associated temporal bone fracture. STUDY DESIGN: Clinical capsule report. SETTING: University hospital. PATIENT: A 3.5-year-old girl presented with immediate facial nerve paralysis and complete deafness after being struck by an automobile. High-resolution computed tomography demonstrated a depressed occipital bone fracture with no visible fracture of the temporal bone. Magnetic resonance imaging sequence raised the question of VIIth nerve bundle discontinuity at the distal end of the internal auditory canal. INTERVENTION: The patient underwent a posterior fossa craniotomy via a translabyrinthine approach 9 months after the initial injury, and facial and auditory nerve avulsion at the fundus was confirmed at the time of surgery. The proximal segment of the facial nerve had formed a traumatic neuroma, which was resected, and primarily anastomosed to the rerouted distal segment. MAIN OUTCOME MEASURES: Facial nerve function. RESULTS: Patient has regained facial function to Grade III/VI House-Brackmann with no asymmetry at rest. CONCLUSION: An unusual pattern of injury is described. We suggest that in patients presenting with facial nerve paralysis secondary to blunt trauma, without an associated temporal bone fracture, high-resolution magnetic resonance imaging is recommended to evaluate internal auditory canal discontinuity of the VIIth and VIIIth nerve complexes. A potential mechanism of avulsion is explained.


Assuntos
Orelha Interna/patologia , Nervo Facial/patologia , Osso Temporal/patologia , Nervo Vestibulococlear/patologia , Acidentes de Trânsito , Audiometria , Pré-Escolar , Surdez/etiologia , Surdez/patologia , Doenças do Nervo Facial/etiologia , Doenças do Nervo Facial/patologia , Feminino , Humanos , Procedimentos Cirúrgicos Otológicos , Tomografia Computadorizada por Raios X , Traumatismos do Nervo Vestibulococlear
13.
Acta Neurochir (Wien) ; 151(8): 1003-4; discussion 1004, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19404569

RESUMO

Geniculate neuralgia is a rare cause of craniofacial pains. The anterior inferior cerebellar artery is the offending vessel which compress nervus intermedius in the patients with typical geniculate neuralgia. We report a patient whose pain was atypical for either geniculate neuralgia and trigeminal neuralgia. At operation the anterior inferior cerebellar artery was coursing with the nerves and was separated. After the decompression the pain resolved immediately.


Assuntos
Artéria Basilar/patologia , Doenças do Nervo Facial/patologia , Nervo Facial/patologia , Dor Facial/patologia , Herpes Zoster da Orelha Externa/patologia , Adulto , Artéria Basilar/fisiopatologia , Artéria Basilar/cirurgia , Descompressão Cirúrgica/métodos , Nervo Facial/fisiopatologia , Nervo Facial/cirurgia , Doenças do Nervo Facial/etiologia , Doenças do Nervo Facial/fisiopatologia , Dor Facial/etiologia , Dor Facial/fisiopatologia , Feminino , Perda Auditiva Neurossensorial/etiologia , Herpes Zoster da Orelha Externa/etiologia , Herpes Zoster da Orelha Externa/fisiopatologia , Humanos , Procedimentos Neurocirúrgicos/métodos , Complicações Pós-Operatórias/etiologia , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares/métodos , Vertigem/etiologia , Nervo Vestibulococlear/cirurgia , Traumatismos do Nervo Vestibulococlear
14.
Surg Neurol ; 70(3): 312-7; discussion 318, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18261778

RESUMO

BACKGROUND: Sudden sensorineural deafness is a well-known symptom mostly of unknown etiology. CASE DESCRIPTION: A case of sudden sensorineural deafness is reported to be caused by a small, remote, ipsilateral tentorial meningioma not compressing the vestibulocochlear nerve or auditory tract. Surgical resection of the meningioma immediately restored the patient's hearing. CONCLUSION: The authors hypothesize that the sudden sensorineural deafness resulted from a growing meningioma inducing a neurovascular compression of the vestibulocochlear nerve, the vertebral artery already being in close relationship with the vestibulocochlear nerve in the premorbid phase. Resection of the meningioma allows for an autodecompression of this vascular conflict resulting in hearing restoration.


Assuntos
Dura-Máter/patologia , Perda Auditiva Neurossensorial/etiologia , Neoplasias Meníngeas/complicações , Meningioma/complicações , Doenças do Nervo Vestibulococlear/etiologia , Traumatismos do Nervo Vestibulococlear , Doença Aguda/terapia , Idoso , Audiometria , Artéria Basilar/lesões , Artéria Basilar/patologia , Artéria Basilar/fisiopatologia , Fossa Craniana Posterior/patologia , Descompressão Cirúrgica , Feminino , Perda Auditiva Neurossensorial/patologia , Perda Auditiva Neurossensorial/fisiopatologia , Humanos , Imagem por Ressonância Magnética , Neoplasias Meníngeas/patologia , Neoplasias Meníngeas/fisiopatologia , Meningioma/patologia , Meningioma/fisiopatologia , Microcirurgia , Procedimentos Neurocirúrgicos , Recuperação de Função Fisiológica , Resultado do Tratamento , Insuficiência Vertebrobasilar/etiologia , Insuficiência Vertebrobasilar/patologia , Insuficiência Vertebrobasilar/fisiopatologia , Nervo Vestibulococlear/patologia , Nervo Vestibulococlear/fisiopatologia , Doenças do Nervo Vestibulococlear/patologia , Doenças do Nervo Vestibulococlear/fisiopatologia
15.
Audiol Neurootol ; 12(3): 145-54, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17259700

RESUMO

Hearing impairment is a well-known consequence of closed head injury (CHI). The aim of this study was to elucidate the pathogenesis of CHI-induced hearing loss, using a rabbit model. Twelve New Zealand white rabbits were divided into two groups of 6. In the first group, CHI was induced mechanically, whereas the rabbits of the second group served as controls. Baseline distortion product otoacoustic emissions (DPOAEs), contralateral suppression (CS) of the DPOAEs and auditory brainstem response (ABR) were obtained. The same measurements were performed in the first group after CHI. Three hours later, the animals were sacrificed and their brain was excised and subjected to histopathologic examination. Mean I-III ABR latencies were increased and DPOAE amplitudes and CS values were reduced in the trauma group after CHI, at a statistically significant level. Histopathologic examination of the temporal lobe and brainstem showed multiple hemorrhagic and necrotic areas, with edema in the surrounding region. The vestibulocochlear nerve was severely damaged at its emerging site at the brainstem. In conclusion, both peripheral and central involvement of the auditory pathway was found after CHI. Otoacoustic emissions in conjunction with ABR may provide significant information on both peripheral and central auditory function.


Assuntos
Vias Auditivas , Traumatismos Cranianos Fechados/patologia , Traumatismos Cranianos Fechados/fisiopatologia , Estimulação Acústica , Animais , Vias Auditivas/lesões , Vias Auditivas/patologia , Vias Auditivas/fisiopatologia , Núcleo Coclear/lesões , Núcleo Coclear/patologia , Núcleo Coclear/fisiopatologia , Modelos Animais de Doenças , Potenciais Evocados Auditivos do Tronco Encefálico , Lateralidade Funcional , Núcleo Olivar/lesões , Núcleo Olivar/patologia , Núcleo Olivar/fisiopatologia , Emissões Otoacústicas Espontâneas , Coelhos , Nervo Vestibulococlear/patologia , Nervo Vestibulococlear/fisiopatologia , Traumatismos do Nervo Vestibulococlear
16.
Brain Res Bull ; 66(4-6): 526-31, 2005 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-16144643

RESUMO

Recent biochemical and histochemical analyses explored different components of the extracellular matrix (ECM) in the nervous system, and either permissive or non-permissive roles in neuronal development and regeneration were suggested. The aim of this study was to detect the distribution pattern of a few of these molecules in the nervous system of intact frogs and during nerve regeneration. The hyaluronan (HA) and tenascin C reactions were negative in the peripheral nerves, but appeared in their entry zones. In the CNS, different populations of neurons were surrounded with HA and tenascin C-positive material, forming a perineuronal net (PN). The phosphacan reaction was weakly positive in the PNS, and a moderate intensity was detected in the entry zone and in the PN. Laminin and fibronectin immunoreactivity was strong in the PNS, but laminin could not be detected in the CNS. In animals with cut and regenerating vestibulocochlear nerve, the distribution of the ECM molecules in the CNS and PNS characteristically changed from that of the normal pattern. Our results showed a non-homogenous distribution of ECM components in the frog nervous system that could be associated with their different roles in physiological and pathological processes.


Assuntos
Matriz Extracelular/fisiologia , Regeneração Nervosa/fisiologia , Sistema Nervoso/metabolismo , Animais , Axotomia/métodos , Fibronectinas/metabolismo , Ácido Hialurônico/metabolismo , Imuno-Histoquímica/métodos , Laminina/metabolismo , Sistema Nervoso/citologia , Neurônios/metabolismo , Rana esculenta , Tenascina/metabolismo , Fatores de Tempo , Nervo Vestibulococlear/fisiologia , Traumatismos do Nervo Vestibulococlear
17.
Med Arh ; 59(3): 160-3, 2005.
Artigo em Bosnio | MEDLINE | ID: mdl-15997673

RESUMO

INTRODUCTION: Vestibular schwannoma (VS) is a benign tumour of cerebellopontine angle which total microsurgical resection is considered as a complex surgery. In Bosnia, VS microsurgical resection is performed occasionally and exclusively at the University Neurosurgical Depart. in Sarajevo, but radiosurgery of these tumours is completely absent. METHODS AND RESULTS: The role of microsurgery in resection of VS is being presented. Through analyzed series of operated patients (MJLink), we evaluated the correlation of VII and VIII nerves postoperative lesion with different operative approaches. House-Brackmann grading scale is used for VII nerve deficit appraisal. Current postoperative results of recognized experts are compared with our series and the similar morbidity rates are found. DISCUSSION: Microsurgery is a dominant and superior way of VS treatment. However, the most frequently used microsurgical approaches (retrosigmoid, translabyrinthine and extradural subtemporal) are still connected with certain morbidity rate, especially regarding the postoperative VII and VIII nerves lesion. CONCLUSION: Team approach, intraoperative cranial nerves monitoring and microsurgery with utilizing different surgical approaches optimize the outcome of VS neurosurgical treatment. In Bosnia, we are just stepping in the field of serious approach to this problem.


Assuntos
Microcirurgia , Neuroma Acústico/cirurgia , Traumatismos do Nervo Vestibulococlear , Traumatismos do Nervo Facial/etiologia , Humanos , Complicações Intraoperatórias , Microcirurgia/efeitos adversos , Neuroma Acústico/patologia
18.
Neurosurg Focus ; 18(4): e10, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15844862

RESUMO

The extraordinary improvement of patient outcome after surgical treatment for vestibular schwannomas is relatively recent and has occurred mainly over the last 30 years. The introduction of microsurgical techniques has resulted in increasing degrees of precise anatomical and functional preservation of the facial and cochlear nerves. An expanded microsurgical technique accompanied by continuous electrophysiological monitoring has resulted in marked changes in the primary goals for this surgery. Whereas in the past the primary goal of vestibular schwannoma management was to preserve the patient's life, the objective in vestibular schwannoma treatment today is to preserve neurological function. Long-term follow-up examinations show negligible recurrence rates, indicating that the aim of preservation of nerve function does not limit the completeness of tumor removal with modern neurosurgical techniques. Despite these advances in preserving the anatomical integrity of, for example, the cochlear nerve, losses of function and even deafness may occur postoperatively in some cases. Current biological and technical research in experimental and clinical settings addresses these problems. In this article, the authors report in detail the developments achieved in vestibular schwannoma surgery and the great clinicians to whom these results can be credited.


Assuntos
Microcirurgia/história , Neuroma Acústico/história , Neuroma Acústico/cirurgia , Neurocirurgia/história , Procedimentos Neurocirúrgicos/história , Nervo Vestibulococlear/cirurgia , Surdez/etiologia , Surdez/prevenção & controle , Traumatismos do Nervo Facial/etiologia , Traumatismos do Nervo Facial/prevenção & controle , História do Século XVIII , História do Século XIX , História do Século XX , Humanos , Microcirurgia/métodos , Recidiva Local de Neoplasia/prevenção & controle , Neurocirurgia/métodos , Procedimentos Neurocirúrgicos/métodos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/patologia , Complicações Pós-Operatórias/prevenção & controle , Nervo Vestibulococlear/patologia , Traumatismos do Nervo Vestibulococlear
19.
Laryngorhinootologie ; 83(10): 647-52, 2004 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-15476136

RESUMO

BACKGROUND: The subtemporal approach is indicated in intrameatal CPA tumors type A in order to preserve hearing. The exploration of the inner auditory canal for tumor exposure varies. It reaches from a locally limited uncovering of the bony inner auditory canal to a complete removal of the surrounding bony bed with the circular skeletization (360 degrees ) according to Wigand of the 7 (th) and 8 (th) nerve. Concerning the preservation of the function of the cranial nerve as well as an avoidable hyperelevation of the temporal cerebral lobe with a possible consecutive organic brain syndrome, both approaches have often been discussed controversially. METHOD: In a quality assurance analysis, we examined patients suffering from a unilateral, intrameatally limited CPA tumor type A in tumor stages 1 to 5. The functions of the 7 (th) and 8 (th) cranial nerves were assessed according to the consensus conference "Systems for reporting results in acoustic neuroma", Tokyo, November 2001, under consideration of the recommendations of the "American Academy of Otolaryngology, Head and Neck Surgery -- Committee on hearing and equilibrium guidelines for the evaluation of hearing preservation in acoustic neuroma", 1995, as well as indications for a possible organic brain syndrome. The results then were compared to current literature. RESULTS: 37 patients with an intrameatal confined CPA tumor after subtemporal tumor exstirpation were evaluated. In these patients, the inner auditory canal was only exposed in the area of the bony tectum (90 degrees - 120 degrees ) adjusted to the volume of the tumor, as described by House: 1 patient with tumor stage 1, 2 patients stage 2, 12 patients stage 3, 16 patients stage 4 and 6 patients with a tumor stage 5. The N. VII was anatomically preserved in 100 %. Immediately after surgery the function of N. VII was assessed in 32 % of the cases as stage I, 43 % stage II, 3 % stage IIIa, 14 % stage IIIb, 3 % stage IV, 0 % stage V, 5 % stage VI. All patients in stage VI had a restricted function of N. VII in stage II or IIIa already before surgery. N. VIII could be preserved anatomically in 78 % of the cases. 1 to 6 months postoperatively the hearing was at stage A in 10 % of the cases, at 25 % in stage B, 33 % in stage C, 16 % in stage D, 5 % in stage E and 11 % in stage F. One patient demonstrated signs of a possible organic brain syndrome postoperatively even after 12 months of latency (headache, unsteady walking, attention disorders). CONCLUSION: When comparing own data with the clinical results from literature, no differences can be found concerning the function of the 7 (th) and 8 (th) cranial nerves. There are no data concerning the incidence of a potential organic brain syndrome. The advantage of the House method is a noticeably reduced drilling time as well as possibly a reduced elevation of the temporal cerebral lobes. The Wigand method, however, allows a better overview and is needed for extrameatally growing tumors anyway.


Assuntos
Traumatismos dos Nervos Cranianos/prevenção & controle , Craniotomia/métodos , Orelha Interna/cirurgia , Traumatismos do Nervo Facial/prevenção & controle , Transtornos Neurocognitivos/prevenção & controle , Neuroma Acústico/cirurgia , Complicações Pós-Operatórias/prevenção & controle , Traumatismos do Nervo Vestibulococlear , Traumatismos dos Nervos Cranianos/etiologia , Traumatismos do Nervo Facial/etiologia , Humanos , Transtornos Neurocognitivos/etiologia , Neuroma Acústico/patologia , Avaliação de Processos e Resultados em Cuidados de Saúde , Complicações Pós-Operatórias/etiologia , Garantia da Qualidade dos Cuidados de Saúde , Fatores de Risco , Lobo Temporal/lesões , Lobo Temporal/cirurgia
20.
HNO ; 52(10): 897-907, 2004 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-15067412

RESUMO

BACKGROUND: Neurophysiologic intraoperative monitoring (NIM) has gone through a renaissance since the advent of computer technology. Currently, both motor and sensory cranial nerves, including the IInd and VIIIth cranial nerves, can be intraoperatively controlled by means of small and mobile systems. PATIENTS AND METHODS: In order to estimate the value of NIM using the new generation of computer systems, we analyzed the records of 379 patients who underwent skull base surgery since 1996. These comprised NIM of the IInd, VIIth, VIIIth cranial nerves in most cases and of the IXth, Xth, XIth, and XIIth cranial nerves in selected cases. RESULTS: Whereas 72% of these cases demonstrated changes in the recorded intraoperative NIM signals, only 29% of them gave evidence of either clinical or electrophysiological neural function alterations during the postoperative follow-up. CONCLUSIONS: NIM is the only available system capable of providing the surgeon with instant intraoperative neural status-related feedback.


Assuntos
Traumatismos dos Nervos Cranianos/prevenção & controle , Complicações Intraoperatórias/prevenção & controle , Monitorização Intraoperatória/instrumentação , Traumatismos do Nervo Óptico/prevenção & controle , Neoplasias Otorrinolaringológicas/cirurgia , Sistemas Automatizados de Assistência Junto ao Leito , Processamento de Sinais Assistido por Computador/instrumentação , Neoplasias da Base do Crânio/cirurgia , Traumatismos do Nervo Vestibulococlear , Sistemas Computacionais , Traumatismos dos Nervos Cranianos/fisiopatologia , Eletrodos , Eletrorretinografia/instrumentação , Potenciais Evocados Auditivos/fisiologia , Potencial Evocado Motor/fisiologia , Potenciais Evocados Visuais/fisiologia , Humanos , Complicações Intraoperatórias/fisiopatologia , Nervo Óptico/fisiopatologia , Traumatismos do Nervo Óptico/fisiopatologia , Neoplasias Otorrinolaringológicas/fisiopatologia , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/fisiopatologia , Complicações Pós-Operatórias/prevenção & controle , Tempo de Reação/fisiologia , Valores de Referência , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fatores de Risco , Neoplasias da Base do Crânio/fisiopatologia , Nervo Vestibulococlear/fisiopatologia
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