The relationship between traumatic tympanic membrane perforations and pneumatization of the mastoid

We evaluated the possible relationship between tympanic membrane perforations resulting from blast trauma or slap and pneumatization of the mastoid cells. A total of 25 male patients with tympanic membrane perforations resulting from blast injury (n = 7), slap (n = 17), and football hit (n = 1) and 20 healthy male volunteers without any ear problem had temporal bone computed tomographic scans in the axial plane, parallel to the infraorbitomeatal line, with 2 mm slice thickness and 2-mm intervals using bone algorithm with a ProSpeed Spiral tomography machine. The area of air cells in each slice was measured using trace and area measurement functions of the tomography machine, and by multiplying the resulting area by slice thickness, the volume of each slice was calculated. For each ear, the total of volumes of air cells was calculated by adding the volumes of each slice containing air cells. The calculated volumes of mastoid cells were evaluated by comparing microscopic findings. Both patient and control groups consisted of males, and their ages ranged from 17 to 32 (mean 24.5) years. Microscopic examinations revealed that perforations were frequently located in the lower quadrants and that most of them were less than 3 mm. There were no pars flaccida and marginal perforations. Ossicular chain destruction was noted neither in temporal bone tomographic nor during intraoperative examinations. The mean (+/- SD) volumes of right and left ear mastoid air cells in patient and control groups were 6.92 +/- 2.45 vs. 7.00 +/- 2.59 cm(3) and 9.04 +/- 4.55 vs. 8.95 +/- 4.53 cm(3), respectively, and the differences were not statistically significant. It was found that the level of mastoid pneumatization has no statistically significant effect on tympanic membrane pathologies due to blast or other injuries.     

Experimental sinusitis in nasally catheterised rabbits

AIM: The aim of the study was to create an experimental rabbit model for investigating the effects of nasal catheterization on rhinosinus mucosa, bacterial flora and observing the development of bacterial sinusitis. METHODS: Healthy adult white rabbits of either sex and with body weights of 2.5-3 kg were used. Rabbits were randomly separated into two groups; the first group was catheterized by 12 French and the second group was catheterized by 8 French catheters blindly and the non-catheterized left sides were accepted as control. Three randomly chosen rabbits from each group were examined by computerized tomography scans (CT) and sacrified in the first, second and the fourth week of the study. Microbiological and histopathological examinations were performed. RESULTS: In both study groups after the first week of nasal catheterization, opacity or air-fluid level was detected in maxillary sinuses by CT scans, which was significant in group 1. Inflammation spread by the prolongation of nasal catheterization and rapidly development of sinusitis was observed by thicker catheters' usage. CONCLUSION: In this study, the role of nasal catheterization as a predisposing factor in the development of sinusitis and the increase of sinusitis development risk in relation with the catheterization period and the catheters' thickness was shown.     

Der petromastoidale Kanal

Background

The petromastoid canal was first described in 1904 by Mouret and Rouviere. Since then, there have been very few publications about this canal. Modern high-resolution computed tomography (CT) enables a slice thickness of 1 mm and less, so the course of the petromastoid canal is visible. In this study the petromastoid canal is introduced and its dimensions measured.

Materials and methods

This study involved 316 CT scans of normal temporal bones of subjects age 19.6–84.2: 156 temporal bones of women and 160 temporal bones of men. The slice thickness of the CT scan was 0.5 mm, and 16-slice or 64-slice CT was used. The middle diameter, length, and angle of the petromastoid canal were measured.

Results

The middle diameter of the petromastoid canal was 1.16±0.4 mm (0.25–2.5 mm), the length was 10.7±0.9 mm (4.25–16.1 mm), and the angle was 134.5±17.3° (124–157°).

Conclusion

The study shows for the first time the length and angle of the petromastoid canal. A slice thickness of at least 1 mm guarantees 100% imaging of the petromastoid canal. The petromastoid canal is an important anatomical landmark and is of clinical relevance.     

Investigative modalities of mandibular invasion by squamous cell carcinoma

OBJECTIVES/HYPOTHESIS: To compare preoperative investigations with histological findings in squamous cell carcinoma (SCC) of the oral mucosa that abuts the mandible. Both clinical and radiological examinations fail to predict accurately invasion of the mandible by intraoral SCC. STUDY DESIGN: This two-part, prospective study is of a consecutive series of patients whose first malignancy of the upper aerodigestive tract abutted the lingual surface of the mandible. METHODS: AR patients presented to the Queensland Radium Institute Head and Neck Clinic between 1993 and 1997 with a biopsy-proven SCC that abutted the mandible. These tumors were investigated clinically, radiologically, and histologically. Sensitivity, specificity, and predictive values were calculated for various approaches. In the second part of the study, single photon emission computed tomography (SPECT) bone scans were included. Quantification ratios of bone scans compared the average counting statistics in visually identified mandibular abnormal uptake with normal cervical spine and jaw. RESULTS: Sixty-seven patients were followed for 55 months and assessed with orthopantomogram (OPG), computed tomography (CT) scans, and, in the second part of the study, SPECT bone scans. Thirty-six tumors showed histological evidence of bony invasion. Bony involvement was suggested by OPG in 36 and confirmed histologically in 27 patients. CT scans showed evidence of bone invasion in 22 cases, with 18 of these histologically confirmed. Technetium 99m methylene diphosphonate (MDP) bone scans with planar imaging and SPECT were performed in 24 patients, and histological appearance was suitable for analysis in 14. Three patients with tumor (cervical spine ratios greater than 1.5 predicting malignant involvement) had this confirmed histologically. CONCLUSIONS: The first part of the study confirms our hypothesis that currently used investigations, as well as clinical assessment, fail to predict accurately invasion of the mandible by intraoral SCC. The second part suggests that SPECT scanning with high quantification ratios is promising in the prediction of tumor involvement.     

Computer tomography of cerebellopontine angle lesions.

Computer tomography (CT) was used in 53 consecutive patients with a working diagnosis of cerebellopontine angle tumor. The CT was performed with the 160 X 160 matrix scanner, height of sections was 13 mm. Metrizoate sodium (1.5 ml/kg of body weight) was used for tumor enhancement. Seventeen CT scans revealed tumors; one patient proved at operation to be false-positive. Thirty-six CT scans revealed no tumors; two examinations may prove to be false-negative, but surgical verification has so far not been obtained. The smallest tumor demonstrated by CT extended 7 mm into the angle, while one of the possible false-negative CT scans after iophendylate injection cisternography showed a tumor extending 5 mm into the angle. It is concluded that CT is a harmless, noninvasive neuroradiological procedure, and should precede invasive procedures. It can be used safely in patients with increased intracranial pressure.     

Endosonographic imaging of tumor thickness in oral squamous cell cancer and its effect on the incidence of lymph node metastases]

BACKGROUND: The correlation between increasing tumor thickness and lymph node metastases as well as reduced survival in oral cancer has been proven by several studies. In most investigations the tumor thickness was assessed in histological sections. The aim of our prospective study was to assess tumor thickness in oral squamous cell carcinoma (OSCC) by intraoral ultrasonography and to evaluate the predictive value of tumor thickness for incidence of cervical lymph node involvement and survival. PATIENTS AND METHODS: A total of 64 patients with primary carcinomas of the oral cavity (stage I-IV) were included. Endosonographic assessment of patients was carried out using a 7.5-mHz probe (Hitachi EUP F334). The primary tumor could be visualized in all cases as a hypoechoic, sometimes irregular mass. RESULTS: The average tumor thickness in all tumors was 14+/-7 mm. The N+ patients showed a greater tumor thickness (15+/-7 mm) than N0 OSCCs with 12+/-6 mm (p =0.032, t -test). Less advanced T1/T2 carcinomas revealed a tumor thickness of 10+/-5 mm in contrast to T3/T4 carcinomas with 16+/-7 mm (p <0.001, t-test). The overall survival was reduced in patients with tumors thicker than 14 mm (48.9 versus 28.3 months, p =0,0102 log rank test). CONCLUSION: Although this technique facilitates the accurate assessment of tumor thickness in OSCC, only in less advanced tumors could endosonography provide additional information, since these tumors were not visible on CT or MRT scans. Nonetheless endosonography is a fast, cost-effective, and reliable technique for assessment of tumor extent in oral cancer.     

Cine-MRI contribution to assess swallowing mechanism and oro-pharyngeal dysphagia

OBJECTIVE: This study aimed at evaluating the performance of Cine-MRI to assess swallowing in patients previously treated for head and neck cancer. MATERIALS AND METHODS: 10 healthy control subjects and a cohort of 10 patients with 8 partial glossectomies, 1 total laryngectomy and 1 glossolaryngectomy underwent imaging from October 2005 to February 2007. The MRI examinations were performed on a 1.5 Tesla system (Siemens Avanto), with True-Fisp sequences (TR = 170 ms, TE = 1 ms, slice thickness = 10 mm) at a rate of 8 pictures per second, during dry swallowing. RESULTS: Results are relevant for real-time spatial resolution from lips to larynx and dynamic motions analyses of tongue, velum, posterior pharyngeal wall and larynx during dry swallowing. Oro-pharyngo-laryngeal occlusion deficiency induces aspiration in case of partial glossectomy. Total laryngectomy modifies tongue, velum and pharynx landmarks. CONCLUSION: Cine-MRI i) provides functional insight from the oral cavity to the larynx, ii) gives accurate informations about impairments due to the pathology and its treatment, iii) completes others investigations like fiberoptic endoscopy or transit time, iiii) allows a precise analysis of the muscular movements involved in the deficient swallowing mechanism, in order to optimize rehabilitative strategies and results.     

How reliable is the measurement of tracheal stenosis by means of computed tomography?

BACKGROUND: A reliable preoperative appraisal of laryngotracheal stenoses is necessary for airway surgery as well as stent implantation. Through progress of modern radiological modalities, particularly the computer tomography (CT), sectional image data and three dimensional airway reconstruction gain increasingly in meaning in Otorhinolaryngology. METHODS: The aim of this study was to evaluate the reliability of this modern CT data in comparison to laser scan data. For this purpose deep frozen pig tracheal segments were prepared and examined by means of helical CT at different CT sets. Subsequently the measurement of the tracheal lumen employing a highly precise laser scanner was performed. RESULTS: As a result we found that a CT slice thickness of 3 mm, a maximal pitch of 1.5 as well as the application of the so-called: edge enhancing modus seems to be the best compromise between the precision of CT airway measurement on one hand and breath-hold time for patient and total X-ray dose on the other hand. CONCLUSIONS: The ENT specialist requires a good cooperation with the radiologist for the measurement of laryngotracheal stenoses using CT scans. We recommend the working out of standard parameters for respiratory tract-CTs.     

Mitek QuickAnchor fixation of cochlear implants using a minimal access technique

RATIONALE: In children with thick cortical bone, surgical exposure for cochlear implant fixation is difficult when using a minimal access technique. We report our experience in these children using the Mitek QuickAnchor system. METHODS: A retrospective review of all children undergoing cochlear implantation over a 12-month period was performed to identify those children in which a Mitek QuickAnchor was used. Measurements of cortical bone thickness at the receiver-stimulator well site were obtained from pre-operative CT scans of temporal bones of all children. The application of the Mitek QuickAnchor system was also reviewed. RESULTS: Cochlear implant fixation using the Mitek QuickAnchor system was performed in 14 children (mean age 12 years) during the study period. The mean cortical bone thickness was 5.6mm in patients receiving the Mitek QuickAnchor system and 3.2mm in patients undergoing conventional fixation. The difference in cortical thickness was highly statistically significant. Successful secure fixation was obtained in all cases. CONCLUSIONS: The Mitek QuickAnchor system provides an effective method of cochlear implant fixation when using a minimal access technique in children with thick cortical bone.     

Configuration of ethmoid roof in children 0-14 years of age

BACKGROUND: Knowledge of the unique anatomy of the nose, paranasal sinuses and skull base, particular concerning dangerously low positioned or deep lying cribriform plates is most important, as functional endoscopic sinus surgery has become an increasingly popular procedure for the management of pediatric sinus disease. OBJECTIVES AND METHODS: In addition to Keros who studied the ethmoidal roof and cribriform plate in 450 adult specimen and divided them into 3 groups, retrospective analysis in 272 patients between 0 and 14 years was performed by means of coronal CT scans of the paranasal sinuses with a slice thickness of 2 mm. Measurements were carried out in the frontal, middle and dorsal section of the ethmoid. RESULTS: The depth and width of the fossa olfactoria were significantly less in patients aged 0 - 12 months than in other age groups (p < 0.001). Among the other age groups, beginning at 2 years no differences were found: 14.2 % presented with type I according to Keros, 70.6 % with Keros II and 15.2 % with Keros III. The prevalence of asymmetric position of the ethmoidal roof was 15 % (41 patients). The height of the ethmoidal sinuses consistently increased over the years from 5 - 7 mm to 15 - 20 mm. CONCLUSION: The current data may serve as a reference for evaluation of normal and abnormal development of the roof of the ethmoid and may be of great value in diagnostic and therapeutic management of pediatric sinus disease. Our data obviously show that the classification into the 3 types of positions of the ethmoid roof and cribriform plate according to Keros is possible in children from the second year of life.     

Magnetic resonance determination of tumor thickness as predictive factor of cervical metastasis in oral tongue carcinoma

OBJECTIVES: To establish an accurate and reproducible means of measuring tumor thickness as a preoperative prognostic factor for cervical metastasis in oral tongue carcinoma. STUDY DESIGN: Retrospective review. METHODS: Charts from 30 patients were reviewed, and the correlation between histopathological and magnetic resonance imaging (MRI) findings of actual tumor thickness or reconstructed tumor thickness measured between a reconstructed mucosal line and the deepest extent of the tumor was investigated. Magnetic resonance images were acquired on a 1.5 T-scanner with a T2-weighted sequence in the axial plane using 3-mm-thick sections and a 256 x 256 matrix. The correlation between N stage and tumor thickness acquired by histopathological scrutiny or MRI was also assessed. RESULTS: The correlation between histopathological and MRI examinations was more significant in terms of reconstructed than actual tumor thickness. No cervical metastasis was detected in patients with tumors of less than 6 mm of reconstructed thickness in the MRI examination. The difference in cervical metastasis between the two groups, namely, less than 6 or more than 6 mm, was statistically significant (P = .0051). CONCLUSIONS: Magnetic resonance imaging examination provides useful data for prognostic assessment and planning strategies with which to treat oral tongue carcinoma. The preoperative decision as to whether to attempt neck dissection could be based on a tumor thickness of 6 mm for patients with oral tongue carcinoma.     

Diagnostic value of cone-beam CT in histologically confirmed otosclerosis

This retrospective case review was performed with the aim to asses the value of cone-beam computed tomography (CBCT) in the preoperative diagnosis of otosclerosis. A total of 32 patients with histologically confirmed stapedial otosclerosis, who underwent unilateral stapedectomies were analyzed. Preoperative temporal bone CBCT scans were performed in all cases. CBCT imaging was characterized by a slice thickness of 0.3 mm and multiplanar image reconstruction. Histopathologic examination of the removed stapes footplates was performed in all cases. Findings of CBCT were categorized according to Marshall’s grading system (from grade 0 to grade 3). Histopathologic results were correlated to multiplanar reconstructed CBCT scans, respectively. Histologically active foci of otosclerosis (n = 21) were identified by CBCT in all cases with a sensitivity of 100 %. However, CBCT was unable to detect histologically inactive otosclerosis (n = 11, sensitivity = 0 %). According to CBCT scans, no retrofenestral lesions were found and all positive cases were recruited into the grade 1 group indicating solely fenestral lesions at the anterior pole of stapes footplates. In conclusion, CBCT is a reliable imaging method with considerably lower radiation dose than high-resolution CT (HRCT) in the preoperative diagnosis of otosclerosis. These results indicate that CBCT has high sensitivity and specificity in the detection of hypodense lesions due to histologically active otosclerosis.     

Effectiveness of conservative management of acoustic neuromas

OBJECTIVE: The goal of this study was to assess the effectiveness of the conservative management in patients with acoustic neuroma (vestibular schwannoma). STUDY DESIGN: This retrospective study was performed in a university hospital. PATIENTS: Patients were selected for this wait-and-see policy on the basis of age, general condition, audiometric results, tumor size, and patient preference. The study group included 97 patients, 87 of whom had at least two neuroradiologic examinations. The mean age of this population was 63 years (29 to 89 years). The mean length of follow-up of this population was 31 months. Eighty-seven of these patients had at least two radiologic examinations (magnetic resonance imaging or computed tomography). The mean interval between the initial and follow-up radiologic examinations was 15 months. MAIN OUTCOME MEASURES: Tumor size was measured by use of two-dimensional data in all patients. The mean tumor size was 12 mm. The growth rate of the tumor was estimated by comparison of the results of the measurements from the initial and follow-up neuroradiologic examinations. RESULTS: Of the 97 patients studied, 6 patients required surgery and 6 required radiotherapy. Sixty patients (62%) were still being treated conservatively at the end of the study period. Three patients of 28 who were classified as candidates for hearing preservation surgery lost their candidacy during the observation period. The mean annual tumor growth rate was 1.52 mm/year. The tumor was stable in size in 36% of patients, regressed in 11% of patients, or grew in 53% of patients. The growth patterns of the acoustic neuroma fell into five categories: continuous growth in 15% of patients, negative growth in 5%, growth followed by negative growth in 40%, negative growth followed by growth in 20%, and no variation of tumor size in 20%. CONCLUSION: Conservative management of acoustic neuromas carries difficulties: long-term follow-up of the patients and unpredictability of the tumor growth pattern. A reliable and reproducible radiologic method for evaluating tumor size is of great importance.     

Scalar localization of the electrode array after cochlear implantation: a cadaveric validation study comparing 64-slice multidetector computed tomography with microcomputed tomography.

HYPOTHESIS: Improved resolution available with 64-slice multidetector computed tomography (MDCT) could potentially be used clinically to localize the cochlear implant (CI) electrode array within the basal turn. BACKGROUND: In CI surgery, the electrode array should be inserted into and remain within the scala tympani to avoid injury to Reissner's membrane and the scala media. Correlating the position of the electrode in the basal turn with surgical technique and implant design could be helpful in improving outcomes. METHODS: After a standard left mastoid exposure of the round window niche through the facial recess performed on a cadaver head, an electrode array from a Nucleus Softip Contour CI was fully inserted through a cochleostomy. The head was then scanned axially on a 64-slice MDCT with 0.4-mm slice thickness and reconstructed into the oblique axial, oblique coronal, and oblique sagittal planes of the cochlea. The temporal bone was then harvested and imaged on a microcomputed tomographic scanner using 20-microm slice thickness. Identical reconstructions were made and compared with the 64-slice images to confirm exact location of the electrode array. RESULTS: The 64-slice MDCT accurately localized the electrode array to the scala tympani. This was best demonstrated in the oblique sagittal plane, identifying the electrode array in the posterior inferior portion of the basal turn, posterior to the spiral lamina. CONCLUSION: This ex vivo validation study suggests that 64-slice MDCT has the potential to allow accurate localization of the CI electrode array within the basal turn of the cochlea.     

Contour and paired-point registration in a model for image-guided surgery

OBJECTIVES/HYPOTHESIS: This study assesses target registration error (TRE) of contour-based registration (CBR) and paired-point registration (PPR) for endoscopic sinus surgery. STUDY DESIGN: The experimental registration model consisted of a replica of a human head (Sawbones #1345-27; Pacific Research Laboratories, Vashon, WA). Twelve surface fiducial markers were affixed to the simulated skin on the model, and titanium screws were placed in the regions of the anterior ethmoid (AE) and sphenoid face (SF). An axial computed tomography scan (1-mm slice thickness) was then obtained. METHODS: Registration was then performed on the InstaTrak 3500 Plus (GE Surgical Navigation & Visualization, Lawrence, MA) with the standard PPR protocol with 12 points and CBR protocol with 500, 250, 125, 50, and 4 points. TRE was then calculated at the AE and SF targets. RESULTS: Target registration error was significantly lower for paired-point registration compared with contour-based registration (AE, 0.5 mm vs. 1.5 mm, P < .0001; SF, 0.8 mm vs. 1.5 mm, P < .0001). Among contour-based registration protocols, target registration error at the sphenoid face was lowest with 50 points (1.5 mm, P < .02). At the anterior ethmoid, contour-based registration with 50 points produced a lower target registration error than contour-based registration with 125 points (1.5 vs. 1.8 mm, P < .01). Other target registration error values for CBR were similar at both regions. The target registration error interquartile range was lowest with CBR-125 at both regions. CONCLUSIONS: Paired-point registration provided significantly lower target registration error. Contour-based registration with 125 points (and possibly as few as 50 points) produces clinically acceptable target registration error. This registration model elucidates important concepts about registration for surgical navigation for sinus surgery.     

Reliability of frozen section in determining tumor thickness intraoperatively in laryngeal cancer

OBJECTIVES: The relationship between locoregional lymph metastasis and tumor thickness in head and neck cancer has been well documented in recent years. Determining tumor thickness by frozen section may help the surgeon decide intraoperatively whether to perform elective neck dissection, whereas paraffin section results could be obtained at a later time for this decision. The aim of this study was to evaluate the accuracy of tumor thickness measurements obtained by macroscopic measurement and by frozen section intraoperatively in laryngeal cancer. STUDY DESIGN: Prospectively we compared the tumor thickness results obtained by gross visual examination, by frozen section, and by paraffin section in 20 total, near-total, and horizontal supraglottic laryngectomy specimens. METHODS: The sections were stained with hematoxylin and eosin and tumor thickness was measured under a light microscope with an ocular micrometer. RESULTS: A strong correlation was found between frozen section and paraffin section tumor thickness measurements (Pearson correlation coefficient = 0.993, P <.001). Paired t test showed a 4.59 mm mean difference between macroscopic and paraffin section measurements, and a 0.76 mm mean difference between frozen and paraffin section measurements. CONCLUSION: Assessment of tumor thickness in laryngeal cancer intraoperatively by frozen section is a reliable method.     

Evaluation of nasal valve by CT imaging

The nasal valve was studied using coronal scans by computed tomography (CT). SUBJECTS: Coronal images were 5 mm thick obtained from 133 subjects 93 men and 40 women averaging 46 years of age. METHODS: The valvular area was studied in 2 slices containing nasal valve, anterior and posterior slices 5 mm apart. After defining standard points for evaluation, breadth, height and area were evaluated using NIH Image Version 1.59 from left and right as an unit. RESULTS: Results were follows: 1. The breadth of the nasal valvular area is larger in men than in women, and the height greater. The angle of valvular area is similar in both. 2. A comparison of anterior and posterior slices showed the smallest breadth of valvular area in the anterior slice to be smaller than in the posterior slice. The breadth of the vestivular area below the valvular area is larger in the anterior than posterior slice. The angle in the anterior slice is larger than that in the posterior slice. The area of valvular area in the anterior slice is smaller than that in the posterior slice.     

In vivo measurements of temporal bone on reconstructed clinical high-resolution computed tomography scans

PURPOSE: To retrospectively assess the accuracy of measurements of temporal bone anatomy made from reconstructed clinical high-resolution computed tomography (HRCT) scans. METHODS: Nine HRCT scans were performed on unselected clinical cases in which the subjects had a temporal bone study judged to be normal. The orbitomeatal line was prescribed for the direct axial sections. Variations in head position (rotation at the neck and lateral bending of the neck) were corrected by using the software supplied by the manufacturer. All measurements were done on standard 1-mm axial sections and axial reconstructions obtained from 1-mm coronal slices. The images were viewed at 4000 Hounsfield units (HU) window width and 1000 HU window level. Measurements (n = 3) made on 1-mm direct axial HRCT scans were compared with the measurements made on reconstructed axial HRCT images from the same nine patients. These values were also compared with published cadaver data. RESULTS: The measurements obtained from axial reconstructed and direct HRCT series approximated each other in each of the nine individual studies and also fell within the range of published cadaver values. They demonstrated the expected normal temporal bone variability between individuals. CONCLUSION: Useful anatomic approximations can be measured in vivo from reconstructed clinical HRCT images. Pitfalls are improper window settings, head tilt, and rotation. This protocol is widely available and can be implemented retrospectively from clinical HRCT scans.     

A clinical study on the magnetic stimulation of the facial nerve

OBJECTIVES: A clinical study on the usefulness of magnetic stimulation of the facial nerve, with special attention paid to the selection of the coil shape and stimulation procedures. STUDY DESIGN: The subjects consisted of 55 patients with Bell's palsy, 1 patient with a cerebellopontine angle (CPA) tumor, 1 patient with multiple sclerosis (MS), and 30 normal subjects. Three types of coils were used in this study; a 90-mm large single coil, a 40-mm small single coil, and a 20-mm small double coil. METHODS: The compound muscle action potentials (CMAPs) and long latency response were evoked by transcranial magnetic stimulation (TMS) with a 90-mm large single coil. The 40-mm small single coil was used to test blink reflex by aiming it at the supraorbital nerve as the target site. The subcutaneous activation of the infra-auricular facial nerve was performed with the 20-mm double coil. RESULTS: The reproducible CMAP and long latency responses were obtained from normal subjects with TMS. However, responses were observed only in patients with relatively mild Bell's palsy. The magnetic stimulation-evoked responses reflected the brainstem function in the patients with a CPA tumor and MS. CONCLUSION: Although magnetic stimulation remains inferior to conventional electric stimulation in some sense and requires further study, this method is potentially useful because it can stimulate the facial nerve continuously from the cortex to the periphery and can effectively evoke responses reflecting the brainstem function.