A novel electroneurography method in facial palsy.

CONCLUSION: The novel midline electroneurography (ENoG) method may have advantages over the standard method in terms of ease of electrode setting, and the ENoG value may be a useful prognostic factor. OBJECTIVE: We compared ENoG performed in patients with facial palsy using two different methods--the new midline method and standard method--in terms of the amplitudes of the compound muscle action potentials(CMAPs) and relationship between the ENoG value and clinical course. METHODS: A total of 64 patients with facial palsy were enrolled. CMAPs were recorded using the midline method, in which the recording electrodes were placed on the mental protuberance and philtrum over the orbicularis oris muscle, and the standard method, in which the recording electrodes were set close to the nasolabial fold. Percutaneous electrical stimulation was applied to the main trunk of the facial nerve.The amplitudes of the CMAPs and the relationship between the ENoG value and the period to full recovery from the facial palsy were compared. RESULTS: The midline method had larger CMAP amplitudes on both sides and a stronger negative correlation in the relationship between the ENoG value and period to full recovery from palsy than the standard method statistically.

Postoperative aeration in the middle ear and hearing outcome after canal wall down tympanoplasty with soft-wall reconstruction for cholesteatoma.

OBJECTIVE: Canal wall down (CWD) tympanoplasty with soft-wall reconstruction (SWR) is a unique technique for cholesteatoma surgery. The external auditory canal shape after surgery-retracted like a radical mastoid cavity or preserved intact-depends on postoperative aeration in the mastoid cavity. However, the relationship between postoperative middle ear aeration and hearing outcome with this procedure is unknown. We characterized this relationship and propose an ideal state of middle ear aeration to obtain satisfactory postoperative hearing after CWD tympanoplasty with SWR. STUDY DESIGN: Retrospective case series. PATIENTS: Seventy-eight patients (78 ears) with fresh cholesteatomas treated surgically at our hospital by planned 2-stage CWD tympanoplasty and SWR were included. MAIN OUTCOME MEASURES: Postoperative middle ear aeration was scored 1 year after second-stage surgery by computed tomography. The patients were divided into 4 bins according to postoperative audiometric air-bone (A-B) gaps: 0-10, 11-20, 21-30, and greater than 30 dB. RESULTS: Postoperative middle ear aeration was significantly greater in the smaller gap bins (0-10 and 11-20 dB) compared with the larger A-B gap bins (21-30 and >30 dB). In contrast to the larger A-B gap bins, those with smaller A-B gaps showed reaeration of the antrum and mastoid cavity. No significant differences were observed in postoperative middle ear aeration or hearing outcome between the 2 cholesteatoma types. CONCLUSION: Promoting postoperative aeration of the entire middle ear is necessary to achieve better hearing outcome in patients undergoing CWD tympanoplasty and SWR for cholesteatoma.

Planned fractionated boron neutron capture therapy using epithermal neutrons for a patient with recurrent squamous cell carcinoma in the temporal bone: a case report.

BACKGROUND: We describe the first case of extensive squamous cell carcinoma in the temporal bone recurring after surgery, conventional radiotherapy, and chemotherapy, which was treated using planned fractionated boron neutron capture therapy (BNCT). METHODS: A 42-year-old patient received BNCT twice with a 1-month interval to ensure neutron capture in the deep lesion. We used an epithermal neutron beam as the neutron source and boronophenylalanine as the boron compound. The total radiation doses in the tumor beneath the skin, at the deepest point of the tumor, and in the skin around the right auricle were estimated as 41.8, 36.9, and 15.8 Gy-Eq, respectively. RESULTS: Radiological studies performed 6 months after the first BNCT showed obvious tumor shrinkage and no evidence of residual tumor. CONCLUSION: We believe that planned fractionated BNCT is an effective treatment option for patients with inoperative extended carcinomas in the temporal bone.

Ultrasonography for preoperative localization of enlarged parathyroid glands in secondary hyperparathyroidism.

OBJECTIVE: Parathyroidectomy (PTx) is sometimes performed to treat secondary hyperparathyroidism (2HPT) related to long-term dialysis. In this procedure, all four parathyroid glands should be resected. However, in patients with 2HPT, the four glands are not uniformly enlarged; therefore, preoperative diagnosis is difficult in comparison with primary hyperparathyroidism. We compared glands detected on preoperative ultrasonography (US) with those resected during PTx to examine the usefulness and limitations of US. METHODS: The subjects were 44 patients with 2HPT who underwent PTx between December 2003 and November 2007. Surgery was indicated for patients meeting the following three conditions: a serum intact PTH (iPTH) level of 500 pg/ml or more; a maximum glandular volume of 500 mm3 or more; and increased bone metabolism. Before surgery, we detected the parathyroid glands using US, and three-dimensionally measured their sizes. PTx was performed based on US diagnosis, and resected glands were weighed. RESULTS: Assuming that four parathyroid glands are present in each patient, the total number of glands in the 44 patients was 176. Of the 176 glands, 139 were detected on preoperative US. However, 27 could not be resected. Therefore, the detection rate on US was 63.6% (112/176). Of 37 glands that could not be detected on preoperative US, 30 were detected during surgery, and resected. There was a positive correlation between the glandular volume measured on US and isolated gland weight. However, there was no correlation between the preoperative serum iPTH level and the sum of the four isolated gland weights. CONCLUSION: On preoperative US, approximately 80% of the glands were detected. However, the misdiagnosis rate was approximately 20%. The rate of accurate diagnosis was 63.6%. Even when glands were misdiagnosed or could not be confirmed on preoperative US, approximately 80% of them could be detected and resected during surgery. It may be impossible to estimate the glandular volume based on the preoperative serum iPTH level.

Residual cholesteatoma: incidence and localization in canal wall down tympanoplasty with soft-wall reconstruction.

OBJECTIVE: To compare the incidence and localization of residual cholesteatomas in canal wall down tympanoplasty with soft-wall reconstruction with results with the canal wall down and open tympanoplasty or canal wall up tympanoplasty. DESIGN: Retrospective case-series study. SETTING: Tertiary care university hospital. PATIENTS: Eighty-five patients (85 ears) with fresh extensive cholesteatomas who underwent canal wall down tympanoplasty with soft-wall reconstruction as first-stage surgery and a second operation after 1 year to confirm residual cholesteatomas and perform ossiculoplasty. MAIN OUTCOME MEASURES: The incidence and localization of residual cholesteatomas in the middle ear were compared between surgery using the canal wall down and open tympanoplasty and canal wall up tympanoplasty. Possible technical causes of the residua were reviewed in a retrospective videotape analysis of the first-stage operations. RESULTS: Of the 85 ears operated on, 18 had residual cholesteatomas, for an overall incidence of 21%, with 1 residuum per ear. Six cholesteatomas were located in the epitympanum (33%), 3 in the sinus tympani (17%), 3 in the antrum (17%), 2 on the stapes (11%), 2 on the tympanic membrane (11%), 1 on the tympanic portion of the facial canal (6%), and 1 just under the skin of the external auditory canal (6%). The retrospective videotape analysis revealed that the main cause of residual cholesteatomas in the epitympanum and sinus tympani was incomplete removal of the matrix under an indirect surgical view because of insufficient drilling. Residual matrix in a bony defect in the middle cranial fossa or facial canal was the cause of residual cholesteatomas in the antrum or facial canal. Inappropriate keratinizing epithelium rolling during tympanic membrane or external auditory canal reconstruction was the cause of residual cholesteatomas in the tympanic membrane or external auditory canal. CONCLUSIONS: The incidence of residual cholesteatomas in patients who underwent canal wall down tympanoplasty with soft-wall reconstruction was similar to that in patients who underwent surgery involving the canal wall down and open tympanoplasty or canal wall up tympanoplasty. In terms of localization, with canal wall down tympanoplasty with soft-wall reconstruction, there is the possibility of residua not only in the tympanic cavity but also in the antrum or mastoid cavity, as with the canal wall up method. Results of this study suggest that in patients with extensive cholesteatoma, canal wall down tympanoplasty with soft-wall reconstruction should be followed by a second procedure to detect any residual cholesteatomas in the tympanic cavity, antrum, or mastoid cavity.

A new method for measuring compound muscle action potentials in facial palsy: a preliminary study.

To establish a simple, reproducible procedure for studying facial motor nerve conduction (MNC), we determined the optimal electrode position to record evoked compound muscle action potentials (CMAPs) from perioral muscles in normal subjects. We examined three new electrode positions in which the electrode connected to the one input of the amplifier was placed on the mental protuberance, and the one connected to the other input was placed on the skin over the orbicularis oris muscle (the philtrum, mouth angle, or lower lip). We then compared the morphology and amplitudes of the CMAPs, right-left differences, and the reproducibility of CMAP amplitudes with recordings taken from the standard electrode position in which one electrode was placed on the nasolabial fold closely lateral to the ala nasi, and the other was placed on the skin over the orbicularis oris. Percutaneous supramaximal electrical stimulation was applied to the main trunk of the facial nerve. All three of the new recording positions showed greater amplitudes and more obvious biphasic CMAPs than the standard method. Positioning the electrode connected to the negative input on the philtrum was optimal in terms of right-left differences and the reproducibility of CMAP amplitudes. Therefore, this midline recording is a simple, reproducible method for calculating the CMAP amplitude ratio. However, prior to clinical use of this procedure, analyses of patients with facial palsy are required.

Physiological role of L-type Ca2+ channels in marginal cells in the stria vascularis of guinea pigs.

Using immunohistochemical and electrophysiological methods, we investigated the role of L-type Ca(2+) channels in the regulation of the endocochlear potential (EP) of the endolymphatic surface cells (ESC) of the guinea pig stria vascularis. The following findings were made: (1) Administration of 30 microg/ml nifedipine via a vertebral artery significantly suppressed the transient asphyxia-induced decrease in the EP (TAID) and the transient asphyxia-induced increase in the Ca(2+), referred to as TAIICa, concentration in the endolymph ([Ca](e)). (2) The endolymphatic administration of 1 microg/ml nifedipine significantly inhibited the TAID as well as the TAIICa. The endolymphatic administration of nifedipine (0.001-10 microg/ml) inhibited the TAID in a dose-dependent manner. (3) The endolymphatic administration of (+)-Bay K8644, an L-type Ca(2+) channel closer, significantly inhibited the TAID, whereas (-)-Bay K8644, an L-type Ca(2+) channel opener, caused a large decrease in the EP from approximately +75 mV to approximately +20 mV at 10 min after the endolymphatic administration. (4) By means of immunohistochemistry, a positive staining reaction with L-type Ca(2+) channels was detected in the marginal cells of the stria vascularis. (5) Under the high [Ca](e) condition, we examined the mechanism of the TAIICa and hypothesized that the TAIICa might have been caused by the decrease in the EP through a shunt pathway in the ESC. (6) The administration of nifedipine to the endolymph significantly inhibited the Ba(2+)-induced decrease in the EP. These findings support the view that L-type Ca(2+) channels in the marginal cells regulate the EP, but not directly the TAIICa.

Prognosis for Bell's palsy: a comparison of diabetic and nondiabetic patients.

CONCLUSION: The present study indicates that recovery from Bell's palsy in a diabetic group (DG) is delayed, and the facial movement score remains low in comparison with a nondiabetic group (NDG). More aggressive treatments, such as higher-dose corticosteroid administration and/or facial nerve decompression surgery, might be considered in diabetic patients with severe Bell's palsy. OBJECTIVES: The purpose of this study was to reveal prognostic differences for Bell's palsy in the DG and NDG. PATIENTS AND METHODS: The grades of facial palsy in 19 diabetic and 57 nondiabetic patients with Bell's palsy were assessed using the House-Brackmann grading system (HB system). Recovery was defined as grade I. The average of HB system grades and recovery rates were compared in the DG and NDG at the start of the treatment, and 1 month, 3 months, and 6 months after onset. RESULTS: There were no differences in the HB system between the DG and NDG at the start of treatment and at 1 month after onset. However, facial movement in the DG was poorer than that in the NDG at 3 months and 6 months after onset. In terms of the recovery rate, the rate in the DG (52.6%) was much lower than that in the NDG (82.5%) at 6 months after onset.

Lipomatous pleomorphic adenoma of the ceruminous gland.

A case of lipomatous pleomorphic adenoma in the ceruminous gland is reported. A 69-year-old Japanese woman presented with a mass in the posterior wall of the cartilaginous external auditory canal. Light microscopic examination revealed a well-circumscribed tumor composed of tubular structures with apocrine secretion and ceroid deposition, extensive mature adipocytes, and spindle-shaped myoepithelial cells in the myxoid and fibrous stroma. This case demonstrates the peculiar location of a lipomatous pleomorphic adenoma in the external auditory canal.

Endolymphatic perfusion with EGTA-acetoxymethyl ester inhibits asphyxia- and furosemide-induced decrease in endocochlear potential in guinea pigs.

We examined the effect of the Ca(2+) concentration in the endolymph ([Ca](e)) or in the endolymphatic surface cells ([Ca](i)) on the endocochlear potential (EP) by using an endolymphatic or perilymphatic perfusion technique, respectively. (i) A large increase in [Ca](e) up to approximately 10(-3) M with a fall in the EP was induced by transient asphyxia ( approximately 2 min) or by the intravenous administration of furosemide (60 mg/kg), and a significant correlation was obtained between the EP and p[Ca](e) (= -log [Ca](e), r = 0.998). (ii) Perfusion of the endolymph with 10 mM EGTA for 5 min neither produced any significant change in the EP nor altered the asphyxia-induced change in EP (DeltaEP(asp)), suggesting that neither [Ca](e) nor the Ca(2+) concentration gradient across the stria vascularis contributed directly to the generation of the EP in the condition of low [Ca](e). In contrast, endolymphatic perfusion with high Ca(2+) (more than 10 mM) produced a decrease in EP and a significant correlation was obtained between the EP and the Ca(2+) concentration of perfusion solution (r = 0.982), suggesting that Ca(2+) permeability may exist across the stria vascularis. (iii) The administration of a Ca(2+) chelator, EGTA-acetoxymethyl ester (AM, 0.3 mM), to the endolymph, which produced a gradual increase in EP, suppressed significantly, by 60-80%, DeltaEP(asp) or furosemide-induced changes in EP. In contrast, perilymphatic administration of 0.5 mM EGTA-AM caused no significant suppression of the DeltaEP(asp). These findings suggest that [Ca](i) plays an important role in generating/maintaining a large positive EP.

Asphyxia and diuretic-induced changes in the Ca2+ concentration of endolymph.

Using Ca2+ -selective microelectrodes based on the neutral carrier, ETH-1001 with polyvinyl chloride (PVC), we have measured changes in the free Ca2+ concentration of guinea pig cochlear endolymph ([Ca](e)) after transient asphyxia or intravenous administration of diuretics. Under the control conditions, the endocochlear potential (EP) was +80 mV, and the [Ca](e) was in the range 1.4 x 10(-7)-2.4 x 10(-6) M (n = 16). Transient asphyxia (1-1.5 min) produced an increase in the [Ca](e) with a fall in the EP, whereas the cessation of the asphyxia led to a quick recovery of both [Ca](e) and EP to their control levels. Intravenous administration of furosemide (60 mg/kg) or bumetanide (30 mg/kg) also caused an increase in the [Ca](e) with a fall in the EP, followed by a gradual recovery of both [Ca](e) and EP. From these results, we obtained a significant correlation between EP and p[Ca](e) (= -log[Ca](e)), and conclude that (1) the [Ca](e) is extremely low, around 10(-6) M or less, under normal conditions and (2) the [Ca](e) is directly correlated with EP under physiological conditions.