No abstract available.
Fistula* ; Perilymph*

No abstract available.
Perilymph* ; Sodium Salicylate* ; Sodium*

No abstract available.
Animals ; Guinea Pigs* ; Guinea* ; Perilymph*

Perilymph fistula (PLF) is a disease for which diagnostic criteria have not been established yet. For this reason, at the present time, the definitive diagnosis of PIS can only be made by direct identification of perilymphatic leak during exploratory tympanotomy. But it can be difficult to distinguish between serous transudates from operative incisions and the clear fluid expected with a true fistula. Infiltrated lidocaine makes the distinction even more difficult as well. Recently, endoscopies have been used in middle ear by transtympanic or transtubal approach. However, endoscopic diagnosis of PLF in the literature is very rare. We diagnosed 2 cases of PLF by transtympanic endoscopy. Because transtympanic endoscopy did not require lidocaine infiltration nor performing a tympanomeatal flap, confirmation of perilymphatic leakage was easier. This study therefore recommends transtympanic endoscopy as one method of improving diagnosis of PLF.
Diagnosis* ; Ear, Middle ; Endoscopy ; Exudates and Transudates ; Fistula* ; Lidocaine ; Perilymph*

OBJECTIVES: Treatment of traumatic perilymph fistula (PLF) remains controversial between surgical repair and conservative therapy. The aim of this study is to analyze the outcomes of early surgical exploration in suspected barotraumatic PLF. METHODS: Nine patients (10 cases) who developed sudden sensorineural hearing loss and dizziness following barotrauma and underwent surgical exploration with the clinical impression of PLF were enrolled. Types of antecedent trauma, operative findings, control of dizziness after surgery, postoperative hearing outcomes, and relations to the time interval between traumatic event and surgery were assessed retrospectively. RESULTS: All patients had sudden or progressive hearing loss and dizziness following trauma. Types of barotrauma were classified by the origin of the trauma: 4 external (car accident, slap injury) and 6 internal traumas (lifting, nasal blowing, straining). Surgical exploration was performed whenever PLF was suspected with the time interval of 2 to 47 days after the trauma. The possible evidence of PLF was found during surgery in 9 cases: a fibrous web around the oval window (n=3), fluid collection in the round window (RW; n=6) and bulging of the RW pseudomembrane (n=1). In every patient, vestibular symptoms disappeared immediately after surgery. The hearing was improved with a mean gain of 27.0+/-14.9 dB. When the surgical exploration was performed as early as less than 10 days after the trauma, serviceable hearing (< or =40 dB) was obtained in 4 out of 7 cases (57.1%). CONCLUSION: Sudden or progressive sensorineural hearing loss accompanied by dizziness following barotrauma should prompt consideration of PLF. Early surgical exploration is recommended to improve hearing and vestibular symptoms.
Barotrauma ; Dizziness ; Fistula ; Hearing ; Hearing Loss ; Hearing Loss, Sensorineural ; Humans ; Perilymph

While systemic steroid therapy is most widely considered as a main treatment for idiopathic sudden sensorineural hearing loss (SSHL), the disadvantages of its use are numerous side effects. Intratympanic steroid injection (ITS) delivers steroids through transtympanic route, hence avoids possible side effects with higher perilymph concentration. We conducted a reviewed 47 clinical studies after an online search of the PubMed databases for the following terms "sudden hearing loss, intratympanic steroid". Although the study settings are varied among reviewed articles, most studies in this review consistently showed some benefit of hearing in salvage cases. In addition, it is suggested that intratympanic steroids are equivalent to systemic steroid therapy as initial treatment for SSHL. In patients with contraindications against the use of systemic steroid, ITS may be considered as valuable option for primary therapy. Further studies are necessary to elucidate the optimal protocol of administration.
Hearing ; Hearing Loss ; Hearing Loss, Sensorineural ; Hearing Loss, Sudden ; Humans ; Perilymph ; Steroids

While systemic steroid therapy is most widely considered as a main treatment for idiopathic sudden sensorineural hearing loss (SSHL), the disadvantages of its use are numerous side effects. Intratympanic steroid injection (ITS) delivers steroids through transtympanic route, hence avoids possible side effects with higher perilymph concentration. We conducted a reviewed 47 clinical studies after an online search of the PubMed databases for the following terms "sudden hearing loss, intratympanic steroid". Although the study settings are varied among reviewed articles, most studies in this review consistently showed some benefit of hearing in salvage cases. In addition, it is suggested that intratympanic steroids are equivalent to systemic steroid therapy as initial treatment for SSHL. In patients with contraindications against the use of systemic steroid, ITS may be considered as valuable option for primary therapy. Further studies are necessary to elucidate the optimal protocol of administration.
Hearing ; Hearing Loss ; Hearing Loss, Sensorineural ; Hearing Loss, Sudden ; Humans ; Perilymph ; Steroids

BACKGROUND AND OBJECTIVES: High dose systemic steroid therapy is currently the mainstay of the treatment for sudden sensorineural hearing loss (SSNHL). However, it makes a glycemic control worse in patients with diabetes. Intratympanic steroid injection (ITSI) can result in reduced systemic steroid toxicity and higher perilymph steroid level selectively. The purpose of this study is to compare the efficacy of ITSI (IT group) with that of systemic steroid (IV group) on SSNHL with diabetes. SUBJECTS AND METHOD: Thirty eight SSNHL patients who were diagnosed with diabetes were divided into the IV group (19 patients) and the IT group (19 patients). In the IV group, prednisolone was administrated intravenously for 7 days followed by tapered doses orally for 7 days. In the IT group, dexamethasone was administrated 4 times within a 2 week-period. Hearing outcome was assessed before and after treatment. RESULTS: In the IV group, 10 patients (58.8%) showed an improvement in the pure tone audiogram (PTA), with a mean improvement of 17.6 dB (p=0.023). In the IT group, 16 patients (84.2%) showed improvement in the PTA, with the mean improvement of 25.1 dB (p=0.000). But there was no significant difference in hearing gain and the recovery rate between the two groups. And it is more difficult to control blood sugar in the IV group rather than in the IT group. CONCLUSION: ITSI treatment is as effective as the systemic steroid treatment for SSNHL patients with diabetes and it can avoid a significant side effect of systemic steroids. So it could be considered as an initial treatment for the SSNHL patient with diabetes.
Blood Glucose ; Dexamethasone ; Hearing ; Hearing Loss, Sensorineural ; Hearing Loss, Sudden ; Humans ; Perilymph ; Prednisolone ; Steroids

OBJECTIVES: Lidocaine is one of the therapeutic trials to treat tinnitus. However, the exact mechanism of the effect of lidocaine remains unclear. The aim of this study was to elucidate the action site of lidocaine in the cochlea by measuring compound action potential (CAP) and transient evoked otoacoustic emission (TEOAE) amplitude in guinea pigs. METHOD: Artificial perilymph was perfused into the scala tympani of the guinea pig cochlea in the control group, and lidocaine diluted with artificial perilymph was perfused into the scala tympani of the experimental groups. Electrocochleogram (ECoG) and TEOAE were measured in each groups both before and after lidocaine perfusion. RESULTS: Artificial perilymph perfused to the scala tympani of the guinea pig cochleae did not affect either the CAP threshold or the TEOAE response. But, lidocaine perfused into the scala tympani of the guinea pig cochleae produced a dose-dependent increase in CAP threshold, but did not affect TEOAE response. CONCLUSION: This study revealed that lidocaine perfused into the scala tympani of the guinea pig cochlea affects the CAPthreshold but not the TEOAE amplitude and reproducibility. It means that the locally perfused lidocaine affects the cochlear nerve greater than the outer hair cells.
Action Potentials ; Animals ; Cochlea* ; Cochlear Nerve ; Guinea Pigs* ; Guinea* ; Hair ; Lidocaine* ; Perfusion ; Perilymph ; Scala Tympani ; Tinnitus

OBJECTIVES: The aims of this study were to investigate the feasibility of isosorbide delivery into perilymph through the round window membrane (RWM), and to compare the intracochlear isosorbide concentration in perilymph after oral administration (PO) versus that after round window perfusion (RWP). METHODS: Sixteen male guinea pigs (32 ears) were used. Isosorbide, an osmotic diuretic, was administered via RWP or PO. First, to investigate the optimal perfusion time, perilymph sampling of scala tympani from the RWM was performed after RWP for 15, 30, or 60 minutes. Second, to compare the drug concentration after RWP versus that after PO, perilymph was aspirated at 3 and 6 hours after administration. Intracochlear concentration of isosorbide was analyzed by high-performance liquid chromatography coupled to refractive index detection. RESULTS: Isosorbide passed through the RWM into perilymph after RWP. After RWP for 15, 30, and 60 minutes, mean isosorbide concentrations in perilymph were 116.27+/-44.65, 245.48+/-112.84, and 279.78+/-186.32 mM, respectively. The intracochlear concentration after RWP for 30 minutes was higher than that after RWP for 15 minutes (P=0.043). At 3 and 6 hours after PO, isosorbide concentrations in perilymph were 28.88+/-4.69 and 12.67+/-2.28 mM, respectively. In contrast, the corresponding concentrations after RWP were 117.91+/-17.70 and 75.03+/-14.82 mM at 3 and 6 hours, respectively. Isosorbide concentrations in perilymph following RWP were significantly higher than those following PO at both 3 and 6 hours (P=0.025 and P=0.034, respectively). CONCLUSION: Isosorbide can rapidly pass through the RWM after RWP in guinea pigs, and 30 minutes of perfusion is considered to be appropriate. In addition, over a 6-hour period, RWP can deliver higher concentrations of isosorbide into perilymph than those achieved with PO.
Administration, Oral* ; Animals ; Chromatography, Liquid ; Diuretics, Osmotic ; Guinea Pigs* ; Humans ; Isosorbide* ; Male ; Membranes ; Meniere Disease ; Perfusion* ; Perilymph* ; Refractometry ; Scala Tympani