Functional near-infrared spectroscopy to probe state- and trait-like conditions in chronic tinnitus: a proof-of-principle study.

OBJECTIVE: Several neuroscience tools showed the involvement of auditory cortex in chronic tinnitus. In this proof-of-principle study we probed the capability of functional near-infrared spectroscopy (fNIRS) for the measurement of brain oxygenation in auditory cortex in dependence from chronic tinnitus and from intervention with transcranial magnetic stimulation. METHODS: Twenty-three patients received continuous theta burst stimulation over the left primary auditory cortex in a randomized sham-controlled neuronavigated trial (verum = 12; placebo = 11). Before and after treatment, sound-evoked brain oxygenation in temporal areas was measured with fNIRS. Brain oxygenation was measured once in healthy controls (n = 12). RESULTS: Sound-evoked activity in right temporal areas was increased in the patients in contrast to healthy controls. Left-sided temporal activity under the stimulated area changed over the course of the trial; high baseline oxygenation was reduced and vice versa. CONCLUSIONS: By demonstrating that rTMS interacts with auditory evoked brain activity, our results confirm earlier electrophysiological findings and indicate the sensitivity of fNIRS for detecting rTMS induced changes in brain activity. Moreover, our findings of trait- and state-related oxygenation changes indicate the potential of fNIRS for the investigation of tinnitus pathophysiology and treatment response.

Quality of life after microsurgery for vestibular schwannoma via the middle cranial fossa approach.

The aim of this study was to analyse the quality of life (QOL) of patients who had undergone microsurgery for vestibular schwannomas (VS). A questionnaire was sent to 117 consecutive patients who had been operated on using the middle cranial fossa (MCF) approach between October 2005 and June 2011. The response rate was 91/117 (78%) of which 86 were suitable for analysis. The questionnaire consisted of the Short Form-36 (SF-36) Health Survey including a self-designed, disease-specific section. Demographic data, tumour size, hearing status and facial nerve function were extracted from our VS database. Patients scored significantly lower in seven of the eight subscales of the SF-36 compared to German normative QOL data. But when compared to a normative group of patients with hearing loss, only two subscales were affected. The alteration of the subscales was correlated with objective and subjective parameters. Vertigo and postoperative hearing status could be identified as the parameters with the strongest influence on QOL.

Outcome on hearing and facial nerve function in microsurgical treatment of small vestibular schwannoma via the middle cranial fossa approach.

Encouraging results regarding hearing preservation and facial nerve function as well as increasing understanding of the natural behaviour of vestibular schwannomas have led to the recommendation of an early treatment in small VS. The aim of the present study was to evaluate current data on functional outcome of patients with small VS treated by middle cranial fossa (MCF) approach. A retrospective chart study of all cases treated by MCF approach between October 2007 and September 2011 was performed. Records were analyzed regarding demographical data, tumor size, hearing status, vestibular function and facial nerve function. Facial nerve function was classified according to the House-Brackmann scale (HB). Hearing status was classified according to the American Association of Otolaryngology-Head and Neck Surgery (AAO-HNS) and a modified classification of Gardner and Robertson (GR). Eighty-nine patients were included in the study; 41 % of VS was classified as intracanalicular (stage 1) and 59 % as stage 2. From 65 patients with a preoperative hearing status according to AAO-HNS A or B, 74 % still presented with A or B after surgery. Using a modified GR classification, from 70 patients categorized as class I or II prior to surgery, 70 % were still class I or II. Looking to the facial nerve function 1 week after surgery, 82 % of patients presented with HB 1 or 2. Three to twelve months later, 96 % demonstrated HB 1 or 2. A persisting facial palsy was recorded in four patients. Preoperative hearing status was evaluated as a prognostic factor for postoperative hearing, whereas no influence was detected in ABR, vestibular function and tumor length. Early diagnosis of small VS due to high-sensitive MRI requires the management of this tumor entity. Natural behaviour of VS in many cases demonstrates an increase of tumor size over time with deterioration of hearing status. The presented data underline the recommendation of an early surgical treatment in small VS as a valuable option for hearing preservation in the therapy of VS.

Use of flexible CO2 laser fiber in microsurgery for vestibular schwannoma via the middle cranial fossa approach.

The aim of this study was to analyze the results of microsurgery in vestibular schwannomas (VS) with assistance of a flexible CO(2) laser fiber (Omniguide(®)) using the middle cranial fossa (MCF) approach. For that purpose we performed a prospective non-randomized clinical trial. In 20 consecutive patients suffering from VS and elected for microsurgery via the MCF approach, tumor resection was performed with the aid of the flexible CO(2) laser ("laser group", LG). Twenty patients with similar tumor volume and pre-operative hearing status out of a cohort of 76 patients previously treated by the same surgeon without laser were used as comparison group ("conventional group", CG) (matched-pair-technique). Facial weakness (House-Brackmann (HB) 2-4) was seen in early postoperative (p.o.) days in six patients in each group and all recovered completely by 3 months p.o., except one patient with HB 2 in CG. Facial nerve preservation rate (HB 1 + 2) was 100% in both groups. Hearing preservation rate (Gardner/Robertson class 1 + 2 or AAO-HNS A + B, pre- and postoperatively) was 72% in LG and 82% in CG, without significant difference. Overall time from incision to skin suture was 157 min (SD 55.9) in CG and 160 min (SD 39.7) in LG. Tumor preparation time was 23.2 min (SD 19.7) in CG and 36.1 min (SD 33.8) in LG. The use of a handheld flexible CO(2) laser fiber in VS-microsurgery is safe and subjectively facilitates tumor resection especially in "difficult" (e.g., highly vascularized) tumors. However, in this limited prospective trial the excellent functional outcome following conventional microsurgery could not be further improved, nor the surgical time reduced by means of the non-contact laser-tool. Focusing the use of the flexible CO(2) laser on "difficult" tumors may lead to different results in future.

Breathing and voice quality after surgical treatment for bilateral vocal cord paralysis.

OBJECTIVE: To evaluate long-term results of surgical treatment for bilateral vocal cord paralysis using objective and subjective measures of breathing and voice quality. DESIGN: Prospective cross-sectional case series. SETTING: Tertiary care otolaryngology and speech pathology referral center. PATIENTS: Ten patients with bilateral vocal cord paralysis who underwent surgical treatment between October 1996 and May 2006 at the Department of Otorhinolaryngology-Head and Neck Surgery, University of Würzburg, were examined at a mean of 27.2 months after surgery. MAIN OUTCOME MEASURES: Glottal area, voice range profile, Voice Handicap Index, pulmonary function test results, Göttingen Hoarseness Diagram, microlaryngostroboscopic findings, chronic respiratory disease questionnaire, and European Organization for Research and the Treatment of Cancer quality-of-life questionnaire, including the head and neck module. RESULTS: Residual recurrent nerve function was seen in 9 of 10 patients. Pulmonary data varied widely and did not correlate with the size of the glottal area. Quality of life, subjective dyspnea, and physical functioning correlated with expiratory airflow measures. Voice range was reduced in all patients. High breathiness and reduced maximum phonation time led to increased Voice Handicap Index scores. CONCLUSIONS: Microlaryngostroboscopic findings did not necessarily correlate with subjective dyspnea and vocal complaints. Reduction of inspiratory speaking efforts and acquisition of special breathing techniques improve airflow stability and effectiveness of respiration, leading to enhanced quality of life.

Intraoperative monitoring using cochlear microphonics in cochlear implant patients with residual hearing.

OBJECTIVES: To describe a technique for the intraoperative monitoring of residual hearing during a cochlear implant (CI) procedure and, thus, to identify the time of occurrence and surgical steps leading to hearing loss. STUDY DESIGN: Prospective audiologic analysis in a patient series. SETTING: Tertiary referral center. SUBJECTS: Patients with residual hearing subjected to cochlear implantation. INTERVENTIONS: During cochlear implantation, cochlear microphonics (CMs) in response to frequency-specific stimuli were recorded in patients with residual hearing. Thresholds were determined before and after opening of the cochlea, with a limited portion of the electrode array inserted, and after full insertion. RESULTS: Monitoring of the hearing state using CMs was quick, reliable, and capable of detecting an intracochlear trauma. In a first series of patients, thresholds were preserved in all patients after opening of the cochlea. Thresholds were preserved in 5 of 6 patients after limited insertion and half of the patients after full insertion of the electrode array. Despite threshold preservation until the end of surgery, the residual hearing was lost in patients with deep insertions 1 week postoperative. CONCLUSION: Intraoperative monitoring of CM thresholds may be valuable for identifying the exact point of time at which residual hearing is affected in CI patients. Opening of the cochlea itself seems to be unrelated to hearing loss. A significant proportion of patients may have hearing loss caused by secondary effects rather than a direct trauma.

Antitumor activity of photo-stimulated zinc oxide nanoparticles combined with paclitaxel or cisplatin in HNSCC cell lines.

Zinc oxide nanoparticles (ZnO-NPs) exhibit photocatalytic properties and are used in sunscreen cosmetics and for the degradation of environmental pollutants. Furthermore, ZnO-NPs have proven to induce tumor-selective cell death in human squamous cell carcinoma (HNSCC) in vitro. The aim of the current study was to evaluate cytotoxic effects of UVA-1-activated ZnO-NPs in combination with paclitaxel and cisplatin in HNSCC. Three HNSCC cell lines (HLaC-78, Cal-27 and PJ-41) were incubated with ZnO-NPs at concentrations of 0.02 and 0.2 µg/ml in combination with paclitaxel (0.5-5 nM) or cisplatin (0.03-3 µM) for 24 h. Afterwards, cells were irradiated with UVA-1 for 15 min. Viability was measured by MTT assay, fluorescein-diacetate (FDA) test and annexin/propidiumiodide flow cytometry. A significant decrease in viable cells could be observed in all three HNSCC cell lines treated by photocatalytic therapy with 0.2 µg/cm(2) ZnO-NPs alone. A combination with paclitaxel or cisplatin at low concentrations resulted in a further increase in cytotoxicity in vitro revealing a synergistic effect. Flow cytometry revealed a combination of apoptosis and necrosis. These results indicate that photocatalytic therapy of HNSCC with ZnO-NPs could enhance the cytotoxic action of chemotherapeutic agents synergistically, indicating a promising potential for ZnO-NPs in antitumor applications.