Superior canal dehiscence syndrome: A review.

Superior canal dehiscence syndrome (SCDS) is a vestibular disorder in which the presence of a pathological third window in the labyrinth causes several vestibular and cochlear symptoms. Herein, we review the diagnostic criteria and treatment of SCDS. The cause of SCDS is considered to be congenital or acquired; however, its etiology is not well known. Symptoms: Vertigo and/or oscillopsia induced by loud sounds (Tullio phenomenon) or stimuli that change the middle ear or intracranial pressure (fistula symptoms) with vestibular symptoms and hyperacusis and aural fullness with cochlear symptoms are characteristic clinical complaints of this syndrome. Neurological tests: Vertical-torsional eye movements can be observed when the Tullio phenomenon or fistula symptoms are induced. Conductive hearing loss with both a decrease in the bone conduction threshold at lower frequencies and an increase in the air conduction threshold at lower frequencies may be present on audiometry. Cervical and/or ocular vestibular evoked myogenic potentials are effective in strongly suspecting the presence of a pathologic third window in the labyrinth. Computed tomography (CT) imaging: High-resolution CT findings with multiplanar reconstruction in the plane of the superior semicircular canal consistent with dehiscence indicate SCDS. The Pöschl view along the plane of the superior semicircular canal and the Stenvers view perpendicular to it are recommended as CT imaging conditions. Findings from all three major diagnostic categories (symptoms, neurological tests, and/or CT imaging) are needed to diagnose SCDS. The surgical approaches for SCDS are as follows: the 1) middle cranial fossa approach, 2) transmastoid approach, and 3) round window and oval window reinforcement. Each technique has advantages and disadvantages.

High Cardio-Ankle Vascular Index Values in Idiopathic Sudden Sensorineural Hearing Loss Patients Indicate Better Prognosis.

OBJECTIVE: Vascular disorders and viral infections are the presumed etiologies of idiopathic sudden sensorineural hearing loss (ISSNHL) and acute sensorineural hearing loss, with no identifiable cause. However, no clinical test for estimating the extent of vascular involvement in ISSNHL has been reported despite its potential impact on prognosis and treatment. We investigated the correlation between the cardio-ankle vascular index (CAVI), which reflects arterial stiffness and elasticity, and hearing improvement to ascertain its usefulness as an additional indicator of ISSNHL prognosis and etiology. METHODS: We enrolled 182 patients diagnosed with definite ISSNHL. The percentage of mild ISSNHL patients and that of patients experiencing no change were compared between the high-CAVI and low-CAVI groups. Age, initial and final pure-tone average (PTA) values, CAVI, presence or absence of vertigo, and medical histories were retrospectively reviewed and included in univariate and multivariate analyses. RESULTS: The percentage of mild ISSNHL patients was smaller in the high-CAVI group than in the low-CAVI group, whereas the percentage of patients experiencing no change was smaller in the high-CAVI group than in the low-CAVI group, although patients in the high-CAVI group were significantly older than those in the low-CAVI group. The Cox proportional hazard model revealed that high CAVI, hypertension, younger age, and initial PTA <90 dB were associated with hearing improvement. CONCLUSIONS: ISSNHL in patients with high CAVI was more severe but had a better prognosis than that in those with low CAVI. CAVI may help evaluate diseases of vascular and other etiologies, as well as ISSNHL.

Higher Cardio-Ankle Vascular Index Values in Patients With Vestibular Neuritis May Indicate a Better Prognosis.

BACKGROUND: The presumed etiology of vestibular neuritis (VN), a sudden onset of spontaneous vertigo without auditory or cranial nerve symptoms, includes viral infections and vascular disorders. However, no clinical test for estimating vascular disorders in VN has been reported. Moreover, estimating the etiology of VN is important to predict the prognosis and select appropriate treatment. This study aimed to evaluate the cardio-ankle vascular index (CAVI), which reflects arterial stiffness and elasticity, as an additional indicator for estimating the prognosis and etiology of VN. MATERIALS AND METHODS: Among 207 consecutive patients with suspected VN, 88 patients diagnosed with definite VN were enrolled. Age, initial and final percent canal paresis (CP) in the caloric test, CAVI, presence or absence of vestibular-evoked myogenic potential asymmetry, and medical history were evaluated using univariate and multivariate analyses. RESULTS: Patients with VN with high CAVI had a better prognosis than those with low CAVI. High CAVI was a factor for improvement in percent CP, in addition to younger age and less severe initial percent CP in the Cox proportional hazard model. CONCLUSION: CAVI can be an additional indicator for estimating the prognosis and etiology of VN. This indicator can potentially be applied to other diseases, including vascular disorders with other etiologies.

The Caloric Test Is More Consistent With the Presence of Endolymphatic Hydrops Than the Vestibular-Evoked Myogenic Potential Test in Meniere's Disease.

Objective This study aimed to investigate the correlation between enhanced inner ear magnetic resonance imaging (MRI) findings and vestibular and cochlear function test results in patients with definite Meniere's disease and confirmed endolymphatic hydrops. Methods Among 70 consecutive patients diagnosed with definite Meniere's disease, 49 underwent contrast-enhanced 3-T inner ear MRI. The patients also underwent pure-tone audiometry, glycerol, caloric, and vestibular-evoked myogenic potential (VEMP) tests. Correlations between the pure-tone audiometry, glycerol test, caloric test, VEMP test, and MRI findings were evaluated using the chi-square test or Fisher's exact test, Student's t-test, one-way ANOVA, and Bonferroni's post-hoc test. Results Contrast-enhanced inner ear MRI revealed that 33 of 49 patients (67.3%) had endolymphatic hydrops. Among them, 19 patients had bilateral endolymphatic hydrops, and 14 had unilateral hydrops. The mean hearing threshold was higher in patients with endolymphatic hydrops than those without (p< 0.001). The proportion of patients with positive glycerol test results was higher among those with endolymphatic hydrops than in those without (p= 0.01). The rate of abnormal caloric response in patients with and without endolymphatic hydrops was not significantly different (p= 0.09). Furthermore, the rate of abnormal VEMP response in patients with and without endolymphatic hydrops was not significantly different (p= 0.70). On the affected side, in the caloric test, the ratio of the presence of vestibular and cochlear hydrops was similar (p= 1.00). On the affected side, in the VEMP test, the ratio of the presence of vestibular and cochlear hydrops was also similar (p= 0.80). The consistency of the caloric test in detecting cochlear hydrops was higher than that of the VEMP test (p= 0.04). The consistency of the caloric test in detecting vestibular hydrops tended to be higher (but not significantly) than that of the VEMP test (p= 0.11). Conclusion The cochlea and vestibule on the clinically affected side were more likely to have endolymphatic hydrops revealed by contrast-enhanced 3-T inner ear MRI than on the unaffected side. The sum of the three low frequencies (125, 250, and 500 Hz) of the pure-tone audiometry was higher in patients with endolymphatic hydrops than in those without endolymphatic hydrops. The caloric test was more consistent in detecting endolymphatic hydrops, especially cochlear hydrops, than the VEMP test in patients with definite Meniere's disease. The results of this study may contribute to the future diagnosis of Meniere's disease and improve the understanding of endolymphatic hydrops.

Pterygopalatine fossa metastasis with severe trigeminal neuralgia from neuroendocrine carcinoma of the breast.

A 57-year-old woman presented to our department with a 2-month history of pain and paresthesia on the left side of the face 12 years after having undergone surgery for breast cancer. We performed an endoscopic biopsy and diagnosed metastatic breast cancer to the pterygopalatine fossa. There has been no recurrence for two years since the metastatic tumor was treated by radiation therapy. A literature search shows only one case of metastatic breast cancer with severe trigeminal neuralgia located in the V2 division of the trigeminal nerve area. Metastatic disease should be considered part of the differential diagnosis in patients presenting with trigeminal neuropathy.

[Tracking axis of the body tracking test(BTT)].

We report herein on the use of the body tracking test (BTT), which is a method for quantitatively evaluating dynamic body balancing function, and how the body center moves during tracking by healthy subjects. We investigated 779 healthy subjects with no history of vertigo or balance disorder and a mean age of 37.9 years. Breakdown is as follows. Under 10 years old is 81 (37 boy and 44 girl), 10 years of age is 162 (73 boy and 89 girl), 20 years of age is 110 (43 men and 67 women), 30 years of age is 73 (44 male, 29 female), 40 years of age is 79 (49 men and 30 women), 50 years of age is 77 (40 men and 37 women), 60 years of age is 100 (53 men and 47 women), 70 years of age is 73 (27 men and 46 women), 80 years of age is 24 (15 men and 9 women). For the visual stimulus, we used a constant-speed antero-posterior (A-P) stimulus BTT and a constant-speed lateral BTT. BTT analysis involved principal axis analysis, in which the principal axis was the first principal component according to a principal component analysis technique. The axis tilt in the principal axis direction was assessed by calculating the coordinate Y-axis and X-axis tilt. In the anteroposterior (A-P) BTT, subjects of all ages exhibited an angle of tilt in the clockwise direction (the "plus" direction), together with the position vector and velocity vector. In the lateral BTT, we observed that the subjects tracked with a tilt in the counter-clockwise direction (the "minus" direction), together with the position vector and velocity vector. In terms of the subjects' ages, the angle of tilt from 0 degree in the antero-posterior (A-P) BTT showed the clockwise direction (the "plus" direction). In the lateral BTT, subjects 10 to 30 years of age exhibited tracking along the X-axis, with no observable tilt. Movement of the center of gravity may be a major acquired ability (practice) with respect to the direction of tilt of the tracking axis. Spatial sensory ability primarily involves the right parietal lobe of the brain, and somatosensory information from the left side of the body is believed to be used more for the positional relationships between the legs and the torso. Deviation of the principal axis appears to be related to the relationship between the dominant foot and the pivot foot, as well as to the functions of the parietal lobe that are involved in spatial sensing.

Facial paralysis after superselective intra-arterial chemotherapy via the middle meningeal artery in maxillary cancer.

Previous studies have suggested that the severity of facial paralysis after superselective intra-arterial chemotherapy (SSIAC) is usually mild. Here we present two cases of facial paralysis after SSIAC via the middle meningeal artery (MMA). In case 1, the patient completely recovered from his facial paralysis (to H-B grade I) in 6 months after the onset of paralysis. However, in case 2, his facial movement remained at House-Brackmann (H-B) grade IV with severe synkinesis. We must be careful that SSIAC via the MMA may potentially increase the risk of facial paralysis.

Combined effects of vestibular stimulation and gaze direction on orientation of sound lateralization.

Dichotic sound discrimination is influenced by either visual or vestibular stimulation. This study investigated the effect of simultaneous gaze and vestibular inputs on dichotic sound discrimination. The subjects (n=12) closed their eyes or gazed at a red target light placed at a distance of 50cm from their eyes, and the ITD discrimination test was simultaneously performed in either the supine or in the right lateral decubitus position, in which gravitational linear acceleration causes utricular stimulation in the lower ear. In the ITD discrimination tests, the amplitudes of saw-tooth waves in the supine position with straight gaze were significantly different from those in the lateral decubitus position with downward or upward gaze. The saw-tooth waves in the lateral decubitus position with eye closed significantly shifted toward the upper ear compared to that in the supine position with eye closed. The saw-tooth waves in the lateral decubitus position with upward and with downward gaze shifted significantly toward the upper and lower ears, respectively, as compared to that in the supine position with straight gaze. We concluded that a sound image resulting from dichotic stimulation may be more dominantly influenced by the direction of eccentric gaze than by utricular stimulation that occurs due to gravitational linear acceleration.