New Modified Transoral Approach to Remove a Hilar Stone of the Submandibular Gland: A Case Report

Nerve damage and intraoperative bleeding for the removal of the hilar stones are possible. We used the new modified lateral oral floor approach with a 2-3 cm longitudinal mucosal incision outside of the Wharton's. There were no complications and our technique seemed to be effective.

Effects of External Auditory Meatus Occlusion on Ocular Vestibular Evoked Myogenic Potentials Induced by Bone Conducted Sound

To facilitate more reliable recordings of the ocular vestibular evoked myogenic potentials (oVEMP) induced by bone-conducted sound using the B81 bone conduction transducer, we preliminarily studied the effects of external auditory meatus occlusion using an earplug on such oVEMP. Eight healthy volunteers (four males and four females, 26–48 years of age, mean age: 34. 5 years) and 14 patients with vestibular disease (2 males and 12 females, 18–59 years of age, mean age: 41.5 years) were enrolled. oVEMP testing was performed using a B81 placed on the temple. Tone bursts (500 Hz, rise/fall time: 2 ms, plateau time: 2 ms, and 70 dB nHL) were presented at a rate of 5.1 Hz. N1-P1 amplitudes were measured and analyzed. Occlusion resulted in significantly larger N1-P1 amplitudes [mean ± SE (SD): 12.3 ± 1.67 (6.71) μV vs. 9.55 ± 1.55 (6.21) μV; p = 0.020, paired t-test]. While four patients did not exhibit any response on either side in the absence of occlusion, all of them showed unilateral or bilateral responses when occlusion was employed. In any patient occlusion did not result in loss of oVEMP responses. External auditory meatus occlusion using an earplug could allow more reliable recordings of bone conduction transducer-induced oVEMP.

Multifactorial analysis of local control and survival in patients with early glottic cancer

OBJECTIVES

The purpose of this study is to determine the effects of various prognostic factors for early glottic cancer patients who underwent radiotherapy.

METHODS

We retrospectively reviewed the all patients who were treated at our hospital for early glottic squamous cell carcinoma from 2004 to 2016. Data included patient's age, sex, T classification, tumor size, pathological grade, anterior commissure involvement, subglottic extension, laryngeal ventricle involvement, and restriction of vocal cord movement.

RESULTS

There were 74 patients with T1 tumors and 31 with T2 tumors. Recurrence was found in four patients with T1 and eight patients with T2. There were 99 males and six females enrolled, and the mean age was 67.5 ± 9.2 years for T1a, 67.3 ± 11.2 years for T1b, and 67.4 ± 7.9 years for T2. One patient with recurrence after 1 month was thought to have a residual tumor. The 5-year overall survival (OS) rate and the 5-year disease-specific survival (DSS) rate for T1-T2 patients were both 100%. The rate of larynx preservation was 94.6% for T1 and 74.2% for T2. A univariate analysis showed that the effective factors were age, T, size, SE. A multivariate logistic regression analysis showed that age influenced the recurrence status. Size is also suspected to be a prognostic factor.

CONCLUSIONS

This study revealed that the effective factors were age, T, size, and SE.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:1701-1706, 2020.

Endoscopic Type 1 Tympanoplasty in Chronic Otitis Media: Comparative Study with a Postauricular Microscopic Approach

OBJECTIVE

To compare surgical outcomes after tympanoplasty without ossiculoplasty for chronic otitis media between transcanal endoscopic ear surgery (TEES) and postauricular microscopic ear surgery (PAMES).

STUDY DESIGN

Case-control study.

SETTING

Tertiary care university hospital.

SUBJECTS AND METHODS

Consecutive patients (N = 122) who had undergone tympanoplasty without ossiculoplasty for chronic otitis media were enrolled in this retrospective study and divided into 2 groups: TEES (n = 47) and PAMES (n = 75). Middle ear condition was graded with the middle ear risk index. Hearing, repair of tympanic membrane perforation, and surgical time were assessed.

RESULTS

The surgical success rate for hearing (air-bone gap ≤20 dB) was 95.7% in the TEES group and 84.0% in the PAMES group. Lower middle ear risk resulted in similar mean (95% CI) closure of air-bone gaps (TEES: 9.6, 6.5-12.6; PAMES: 8.0, 6.4-9.7; P = .333), whereas higher middle ear risk demonstrated significantly larger closure of air-bone gaps for the TEES group (10.1, 3.3-16.9) than the PAMES group (-0.2, -4.5 to 4.2; P = .009). The surgical success rate for repair of tympanic membrane perforation and surgical time were equivalent between TEES and PAMES.

CONCLUSION

Under favorable conditions of the middle ear, TEES and PAMES resulted in similar hearing improvement by tympanoplasty without ossiculoplasty. However, under adverse conditions of the middle ear, TEES was a more beneficial approach for hearing improvement than PAMES.

Overall survival and post-progression survival are potent endpoint in phase III trials of second/third-line chemotherapy for advanced or recurrent epithelial ovarian cancer

Purpose: A growing number of treatment options and active compounds in treatments have led to better outcomes for patients with advanced or recurrent epithelial ovarian cancer. We examined the association between progression-free survival (PFS), post-progression survival (PPS) and overall survival (OS) in phase III trials of second- and third-line chemotherapy for advanced or recurrent epithelial ovarian cancer. We aim to determine whether PFS or PPS is a surrogate of OS so that we can decide progress of disease is optimal endpoint for ovarian cancer.

Methods: We identified 22 trials conducted between January 1, 2000 through December 31, 2014 by literature search. We divided OS into PFS and PPS, and assessed the association between OS and PFS/PPS. We also examined whether the year of trial enrollment completion was associated with any variables.

Results: The median PPS was slightly longer in recent trials compared to older trials (10.0 vs. 8.8 months). While PPS was strongly associated with OS (r = 0.88) in all trials, PFS was moderately correlated with OS (r = 0.72). The correlation between OS and PPS in recent trials (r = 0.93) was stronger than in older trials (r = 0.84).

Conclusions: Our findings indicate that PPS is highly associated with OS in second/third-line chemotherapy for advanced or recurrent epithelial ovarian cancer, while the association between PFS and OS is moderate. We recommend using OS as primary endpoint for clinical trial of ovarian cancer, however PFS is still an optional endpoint.

Nasal, oral, and pharyngolaryngeal manifestations of pemphigus vulgaris: Endoscopic ororhinolaryngologic examination

Pemphigus vulgaris is an autoimmune blistering disorder that involves the skin and mucous membranes. Few reports have described nasal and oropharyngolaryngeal lesions in pemphigus vulgaris using an endoscopic ororhinolaryngologic examination. We retrospectively reviewed the clinical records of 11 patients with pemphigus vulgaris between 2001 and 2013 with respect to their symptoms, lesion sites, lesion features, and treatments received. All patients had undergone an endoscopic ororhinolaryngologic examination. Their mucosa-related symptoms were sore throat, oral pain, odynophagia, gingival bleeding, hoarseness, and epistaxis. The most frequent sites were the oral cavity (gingiva and buccal mucosa), larynx (epiglottis and vocal fold), oropharynx (soft palate), and nasal cavity (nasal septum). Lesions were typically characterized by erosion, erosion with a whitish exudate, and erythematous patches. Thus, our study findings reveal that pemphigus vulgaris involves both the nasal and oropharyngolaryngeal regions. Patients with pemphigus vulgaris should undergo an endoscopic ororhinolaryngologic examination to determine the range of their lesions.

Residual cholesteatoma revealed by endoscopy after microsurgery

Residual cholesteatoma revealed by endoscopy after microsurgery.

OBJECTIVE

To endoscopically examine common sites of residual cholesteatoma occurrence after microscopic ear surgery.

METHODS

Thirty patients (15 men and 15 women; age range: 7-81 years) who underwent treatment for middle ear cholesteatoma (20 patients with pars flaccida :holesteatoma and 10 patients with pars tensa cholesteatoma) were selected. Following the removal of the cholesteatoma matrix via microscopy, residual matrix presence was assessed using an endoscope system. Additional resection was performed if the residual matrix was detected. Sites of residual matrix and their rates of incidence were then investigated.

RESULTS

Residual matrix was observed in nine out of the 30 (30%) patients by endoscopy after microscopic surgery. Residual matrix was observed in eight out of the 20 (40%) patients with pars flaccida cholesteatoma and in one out of :he 10 (10%) patients with pars tensa cholesteatoma. Residual matrix was observed in six out of the 14 (43%) patients who underwent canal wall up (CWU) tympanomastoidectomy and in three out of the 13 (23%) patients who underwent -anal wall down (CWD) tympanomastoidectomy. Sites of residual matrix included the tegmen tympani in two patients, he medial scutal surface in three patients, the tympanic sinus in two patients and the anterior epitympanic recess in three patients. The risk of residual matrix was greater in patients with pars flaccida cholesteatoma than in those with pars tensa :holesteatoma. The attic, tympanic sinus and anterior epitympanic recess are common sites of residual cholesteatoma.

CONCLUSION

Endoscopy is advantageous for the assessment of residual cholesteatoma in hidden areas.

Features of oral, pharyngeal, and laryngeal lesions in bullous pemphigoid

Bullous pemphigoid is an autoimmune bullous disease characterized by skin lesions, with or without oral lesions. The occurrence of pharyngolaryngeal lesions is very rare in affected patients. We conducted a study to investigate the characteristics of oral and pharyngolaryngeal lesions in bullous pemphigoid. Our study population was made up of 6 consecutively presenting outpatients-2 men and 4 women, aged 40 to 83 years (mean: 68.2)-who had been referred to our department over an 11-year period. Presenting symptoms included sore throat in all 6 patients and oral pain in 3. The sites of mucosal lesions included the soft palate, epiglottis, gingiva, hypopharynx, tongue, nasal cavity, and buccal mucosa. These lesions appeared as erosions, erosions with white coating, erythematous patches, and/or blisters. Mucosal lesions preceded skin lesions in 2 patients, appeared after skin lesions in 1 patient, and appeared simultaneously with skin lesions in 3 patients. We conclude that bullous pemphigoid sometimes involves the mucosa, such as that of the laryngopharynx and the oral cavity, and it can manifest as skin lesions. In the differential diagnosis of refractory pharyngolaryngeal lesions, bullous pemphigoid should be considered.

[A Clinical Study of Acute Epiglottitis]

We carried out a retrospective review of 285 cases of acute epiglottitis (180 males, 105 females, mean age 49.6 years) that required inpatients hospital care between 1998 and 2014. All the patients complained of sore throat, and 62 patients complained of respiratory discomfort; 17 patients had severe dyspnea, and 27 patients required airway management (tracheotomy in 25, cricothyroidotomy in 2 patients). All the patients survived. As acute epiglottitis can cause rapidly progressive airway obstruction and death, emergent airway management should be undertaken in patients with dyspnea. However, it is difficult to determine the indications for prophylactic respiratory management in patients without dyspnea. Therefore, the disease severity of the epiglottitis was evaluated on a five-grade scale according to the degree of swelling of both the epiglottis and the arytenoids. Although prospective evaluation is necessary, this scoring system may be beneficial to determine the indication for airway management, because all of the patients who complained of severe dyspnea or underwent airway management had grade 4 or 5 disease, while none of the patients with grade 1-3 disease required tracheotomy or cricothyroidotomy. Moreover, we compared the white blood cell count, body temperature, serum CRP and the interval from the onset between the group that required airway management and the group that did not require airway management. The white blood-cell count and body temperature were significantly higher, and the interval from the onset was significantly shorter in the group that required airway management than in the group that did not require airway management; however, the serum CRP level did not differ between the two groups.

Potentially lethal pharyngolaryngeal edema with dyspnea in adult patients with mumps: A series of 5 cases

In this article we describe 5 rare cases of mumps-associated pharyngolaryngeal edema. To the best of our knowledge, this report includes the first case of mumps-associated pharyngolaryngeal edema in a patient who had previously received mumps vaccination, and these cases represent the sixth report of mumps-associated pharyngolaryngeal edema in the English literature. All 5 of our patients with mumps infection were adults and manifested airway stenosis due to pharyngolaryngeal edema. This edema responded favorably to steroid treatment without tracheotomy. We conclude that a pharyngolaryngeal examination is recommended for patients with mumps infection. Steroid treatment is usually effective against pharyngolaryngeal edema; however, in certain cases tracheotomy may be inevitable.

Correlation of progression-free and post-progression survival with overall survival in phase III trials of first-line chemotherapy for advanced epithelial ovarian cancer

PURPOSE OF INVESTIGATION

The authors examined the relation between post-progression survival (PPS) and overall survival (OS) in phase III trials of first-line chemotherapy for advanced epithelial ovarian cancer.

MATERIALS AND METHODS

The authors partitioned OS into progression-free survival (PFS) and PPS and evaluated the relation between OS and either PFS or PPS. They also examined whether any association might be affected by the year of completion of trial enrollment.

RESULTS

The average PPS was longer in recent trials than in older trials (26.9 vs. 20.2 months,p = 0.0002). For all trials, PPS was strongly associated with OS (r = 0.94), whereas PFS was more moderately but still strongly correlated with OS (r = 0.83). The average proportion of median OS accounted for by median PPS significantly increased from 54.1% in older trials to 60.3% in recent trials (p = 0.0001).

CONCLUSION

The present findings indicate that, especially for recent trials, PPS is more highly associated than PFS with OS in first-line chemotherapy for advanced epithelial ovarian cancer.

Integrated genomic and functional analyses reveal glyoxalase I as a novel metabolic oncogene in human gastric cancer

Chromosomal abnormalities are good guideposts when hunting for cancer-related genes. We analyzed copy number alterations of 163 primary gastric cancers using array-based comparative genomic hybridization and simultaneously performed a genome-wide integrated analysis of copy number and gene expression using microarray data for 58 tumors. We showed that chromosome 6p21 amplification frequently occurred secondary to ERBB2 amplification, was associated with poorer prognosis and caused overexpression of half of the genes mapped. A comprehensive small interfering RNA knockdown of 58 genes overexpressed in tumors identified 32 genes that reduced gastric cancer cell growth. Enforced expression of 16 of these genes promoted cell growth in vitro, and six genes showing more than two-fold activity conferred tumor-forming ability in vivo. Among these six candidates, GLO1, encoding a detoxifying enzyme glyoxalase I (GLO1), exhibited the strongest tumor-forming activity. Coexpression of other genes with GLO1 enhanced growth-stimulating activity. A GLO1 inhibitor, S-p-bromobenzyl glutathione cyclopentyl diester, inhibited the growth of two-thirds of 24 gastric cancer cell lines examined. The efficacy was found to be associated with the mRNA expression ratio of GLO1 to GLO2, encoding glyoxalase II (GLO2), another constituent of the glyoxalase system. GLO1 downregulation affected cell growth through inactivating central carbon metabolism and reduced the transcriptional activities of nuclear factor kappa B and activator protein-1. Our study demonstrates that GLO1 is a novel metabolic oncogene of the 6p21 amplicon, which promotes tumor growth and aberrant transcriptional signals via regulating cellular metabolic activities for energy production and could be a potential therapeutic target in gastric cancer.

Computer-aided beam arrangement based on similar cases in radiation treatment-planning databases for stereotactic lung radiation therapy

The purpose of this study was to develop a computer-aided method for determination of beam arrangements based on similar cases in a radiotherapy treatment-planning database for stereotactic lung radiation therapy. Similar-case-based beam arrangements were automatically determined based on the following two steps. First, the five most similar cases were searched, based on geometrical features related to the location, size and shape of the planning target volume, lung and spinal cord. Second, five beam arrangements of an objective case were automatically determined by registering five similar cases with the objective case, with respect to lung regions, by means of a linear registration technique. For evaluation of the beam arrangements five treatment plans were manually created by applying the beam arrangements determined in the second step to the objective case. The most usable beam arrangement was selected by sorting the five treatment plans based on eight plan evaluation indices, including the D95, mean lung dose and spinal cord maximum dose. We applied the proposed method to 10 test cases, by using an RTP database of 81 cases with lung cancer, and compared the eight plan evaluation indices between the original treatment plan and the corresponding most usable similar-case-based treatment plan. As a result, the proposed method may provide usable beam arrangements, which have no statistically significant differences from the original beam arrangements (P > 0.05) in terms of the eight plan evaluation indices. Therefore, the proposed method could be employed as an educational tool for less experienced treatment planners.

Bilateral objective tinnitus in an infant with tuberous sclerosis

This is the first report of objective tinnitus presenting as audible spontaneous otoacoustic emission in a patient with tuberous sclerosis. The tinnitus was loud, continuous, and high pitched: 7757.8 and 6257.8 Hz. The auditory system may be dysfunctional in patients with tuberous sclerosis. Possible causes of tinnitus in these patients are abnormal myelination and dysfunctional axons and neurons associated with tuberous sclerosis. A disturbance of the outer hair cells or the MOC efferent fibers innervating the outer hair cells is considered to be the source of the loud spontaneous otoacoustic emission.

Computerized estimation of patient setup errors in portal images based on localized pelvic templates for prostate cancer radiotherapy

We have developed a computerized method for estimating patient setup errors in portal images based on localized pelvic templates for prostate cancer radiotherapy. The patient setup errors were estimated based on a template-matching technique that compared the portal image and a localized pelvic template image with a clinical target volume produced from a digitally reconstructed radiography (DRR) image of each patient. We evaluated the proposed method by calculating the residual error between the patient setup error obtained by the proposed method and the gold standard setup error determined by consensus between two radiation oncologists. Eleven training cases with prostate cancer were used for development of the proposed method, and then we applied the method to 10 test cases as a validation test. As a result, the residual errors in the anterior-posterior, superior-inferior and left-right directions were smaller than 2 mm for the validation test. The mean residual error was 2.65 ± 1.21 mm in the Euclidean distance for training cases, and 3.10 ± 1.49 mm for the validation test. There was no statistically significant difference in the residual error between the test for training cases and the validation test (P = 0.438). The proposed method appears to be robust for detecting patient setup error in the treatment of prostate cancer radiotherapy.

Oral Frostbite Due to Dry Ice

Objectives:

Dry ice is a commercially available cryogen that is used worldwide. It may cause frostbite if misused. However, frostbite of the oral cavity due to dry ice has not been previously reported. Here, we describe the first case of dry ice–induced frostbite of the oral cavity.

Methods:

We present a case of oral frostbite due to dry ice and subsequent swelling of the submandibular area and lower lip. We discuss the clinical features of oral frostbite due to volatile substance abuse.

Results:

Oral frostbite not only may result in the impairment of the affected mucosae directly, but also may adversely affect the tissues in the vicinity of the oral cavity floor indirectly. Oral frostbite may cause edema of the upper airway tract. In case of severe pharyngolaryngeal edema, either tracheal intubation or tracheostomy is necessary. Steroids and antibiotics may be effective in preventing the development of pharyngolaryngeal edema.

Conclusions:

It is important to bear in mind that volatile substance abuse may possibly induce unusual events. In particular, special attention should be paid to delayed unusual events.

SU-E-I-115: Wavelet Analysis of Ultrasound Image for the Diagnosis of Sjögren's Syndrome

PURPOSE

Sjögren's syndrome (SS) is an auto-immune disease presenting with dry eyes and mouth (keratoconjunctivitis sicca and xerostomia). Ultrasonography is used for the initial and non-invasive investigation of the parotid gland in the disease. The purpose of this study is to develop an image processing for diagnosis of SS by applying wavelet analysis to ultrasound image.

METHODS

Ultrasound B-mode images of the parotid gland were captured and analyzed by a personal computer. A square region of interest (ROI) was set on the image and two-dimensional discrete wavelet transform was performed within the ROI. As a Result, the image was decomposed into an approximate image and three detailed images in vertical, horizontal and diagonal directions in different scales. A feature quantity for image classification was defined by calculating from the wavelet coefficients of detailed images within selected scales. The ultrasound images of 80 patients who had been referred to Nagasaki University Hospital because of suspicion of SS were analyzed. A total of 37 patients fulfilled the criteria for SS, whereas the remaining 43 patients did not. The severity of SS was graded into four degrees by sialography. The images with each feature quantity were classified by statistical cluster analysis.

RESULTS

In this method, the images can be divided into two groups which mainly contained SS and non-SS. The sensitivity and specificity in the detection of SS was 78% and 95%, respectively. It was also found that the defined feature quantity tended to change with the severity of SS.

CONCLUSIONS

In ultrasonography, the image analysis based on wavelet transform was useful for the diagnosis of Sjögren's syndrome.

Dysphagia due to isoniazid therapy for tuberculosis in a patient with Lewy body dementia

Dementia with Lewy bodies (DLB) potentially causes dysphagia; however, the features and underlying mechanism causing dysphagia have still not been clarified. We are the first to report a case of dysphagia resulting from isoniazid therapy for tuberculosis in a DLB patient. A 74-year-old woman with DLB developed dysphagia during treatment for tuberculous pleurisy. Oral videoendoscopic and videofluorographic swallowing examinations showed oropharyngeal dysphagia. The increased administration of levodopa successfully ameliorated dysphagia. Therefore, dysphagia was ascribed to diminished levodopa efficacy due to interaction with isoniazid. Thus, DLB patients receiving anti-tuberculous therapy should be closely examined for potential changes in swallowing and Parkinsonism.

Idiopathic tinnitus concomitant with eye closure

OBJECTIVE

To describe 2 patients presenting with idiopathic tinnitus concomitant with eye closure.

STUDY DESIGN

Clinical capsule report.

SETTING

University hospital.

PATIENTS

Two patients presented with intermittent tinnitus synchronous with eye closing or blinking. Otoscopic examination revealed inward movement of tympanic membranes concomitantly with eye blinking or eye closure in 1 patient. Neither patient had facial nerve disease or myoclonus.

INTERVENTIONS

Compliance in impedance audiometry was recorded.

RESULTS

Compliance in impedance audiometry was reduced during eye blinking and eye closure in both cases. The tinnitus was attributed to muscular tinnitus via stapedial muscle contraction during eye closure.

CONCLUSION

These are the rare 2 reported patients presenting with idiopathic muscular tinnitus concomitant with eye closure. The reductive change of compliance in impedance audiometry during tinnitus coincident with eye closure is a feature of this form of tinnitus. We suggest evaluation of compliance change in impedance audiometry to be a key examination in patients with stapedial muscular tinnitus concomitant with eye closure.

Quantitative image analysis of nuclear chromatin distribution for cytological diagnosis

OBJECTIVE

We previously reported on the classification of the nuclear chromatin distribution into 3 types, that is peripheral (P), mixed (M) and central (C), which were related to the malignancy of cervical glandular lesions. However, the classification was subjective as it was performed by visual assessment. In the present study, quantitative assessment of nuclear chromatin distribution using image analysis by computer was applied for objective classification of cervical squamous epithelial lesions, which are the most common cervical lesions.

STUDY DESIGN

A total of 130 cells (44 cells of type P, 78 of type M and 8 of type C) from cytological specimens of cervical squamous epithelial lesions (dysplasia, squamous cell carcinoma) were analyzed. An image analysis program was developed as a plug-in macro program of an existing image processing software. The radial distribution (RD) value, which represents the gradient of the staining intensity from the center to the edge of a nucleus, was defined as an index of the chromatin distribution.

RESULTS

The RD values calculated in type P, type M and type C cells showed significant statistical differences as assessed by the t test (p < 0.001).

CONCLUSIONS

Quantification of the nuclear chromatin distribution by image analysis is fast and highly objective. The RD value could be useful as an index for malignancy.

Digital magnification mammography with matched incident exposure: physical imaging properties and detectability of simulated microcalcifications

Our purpose was to evaluate the usefulness of digital magnification mammography with matched incident exposure by investigating the physical imaging properties and doing an observer performance test. A computed radiography system and a mammographic unit were used in this study. Contact and magnification radiographies of 1.2-1.8 in combination with focal spot sizes of 0.1 mm without grid and 0.3 mm with grid were performed. Physical imaging properties, namely, scatter fraction, total modulation transfer function (MTF) including the presampled MTF and the MTF of focal spot size, and Wiener spectrum (WS), were measured. Detail visibility was evaluated by use of free-response receiver operating characteristic analysis of the detectability of simulated microcalcifications. Scatter fractions decreased considerably as the magnification factor increased without grid technique. In the grid technique, scatter fractions for all magnification techniques were comparable. The total MTFs of magnification techniques with a focal spot size of 0.1 mm improved significantly compared with the conventional contact technique. However, the improvement of the total MTFs of magnification techniques with the combination of 0.3 mm focal spot size was small. The WSs degraded with an increase of the magnification factor compared with the contact technique due to the maintained exposure incident on the object. The observer performance test indicated that the 1.8 magnification technique with the 0.1 mm focal spot size provided higher detectability than did the contact technique. Digital magnification mammography under the same incident exposure conditions improved the detectability of microcalcifications.

Comparison of viewing angle and observer performances in different types of liquid-crystal display monitors

It is known that the performance of liquid-crystal display (LCD) monitors, such as the luminance and contrast ratio, is dependent on the viewing angle. Our purpose in this study was to compare the angular performance and the effect on observer performance of different types of LCD monitors. The luminance performance and contrast ratio as a function of viewing angle (-60 degrees to 60 degrees) in each direction for two types of LCD monitors, namely, a general-purpose LCD monitor and one especially designed for medical use, were measured in this study. Furthermore, the observer performance at various viewing angles in the horizontal direction for a medical-grade LCD monitor was investigated by eight observers based on a contrast-detail diagram. The two types of LCD monitors showed notable variations in luminance and contrast ratio as a function of the viewing angle. Acceptable viewing angles in terms of the contrast ratio were much smaller in each direction than those for nominal viewing angles in the specifications provided by the manufacturers, and those for the medical-grade LCD monitor in the horizontal and vertical directions were broader than those of the general-purpose LCD monitor. There was no significant difference in observer performance between 0 degrees and 40 degrees. On the other hand, our results showed a statistically significant difference in observer performance between 0 degrees and 60 degrees.

Difference of climbing fiber input sources between the primate oculomotor-related cerebellar vermis and hemisphere revealed by a retrograde tracing study

The cerebellar flocculus-paraflocculus complex, vermal lobule VII (V-7) and hemispheric lobule VII (H-7) are involved in learning-dependent smooth pursuit eye movement control. To locate the sources of climbing fiber inputs to the H-7 and V-7, we injected retrograde tracers and examined the locations of retrogradely labeled neurons in the inferior olive in 4 monkeys. After the injection of cholera toxin B (CTB) into the H-7, retrogradely labeled neurons were observed abundantly in cell group d, i.e., dorsal cap, of the caudal medial accessory olive (MAO) and ventral lamella of principal olive (PO). After injections of fast blue (FB) into the V-7, retrogradely labeled neurons were observed mainly in cell group b of MAO, but rarely in cell group d or PO. Cell group d is known to receive inputs from the nucleus optic tract (NOT) and project climbing fibers to the flocculus and ventral paraflocculus, and cell group b is known to receive inputs from the superior colliculus. These results suggest that the three oculomotor cerebellar areas may use different visual signals for the control of smooth pursuit: the flocculus-paraflocculus complex and H-7 receive visual climbing fiber inputs derived mainly from the NOT via cell group d, while the V-7 receive visual climbing fiber inputs derived mainly from the superior colliculus via cell group b.