A method with ultra-high angular resolution for X-ray diffraction experiments.

In X-ray diffraction measurements, the angular resolution has a detection limit due to the receiving size of the detector. In many cases this detection limit is too large and must be breached to obtain the desired information. A novel method is proposed here by making the detector simultaneously measuring and moving. Using the deconvolution algorithm to remove the convolution effect, the pixel size limitation is finally broken. The algorithm used is not a common one, and suppresses signals at high frequencies, ensuring the reliability of the peak shape after restoration. The feasibility of this method is verified by successfully measuring the crystal truncation rod signal of SrTiO3 single crystal, and the resolution is nearly ten times higher than that of a single pixel. Moreover, this method greatly reduces the noise and improves the signal-to-noise ratio.

Patient profiles and outcomes following repair of irreducible and reducible Ventral Wall Hernias.

PURPOSE: The belief that irreducible hernias are repaired less successfully and with higher morbidity drives patients to seek elective repair. The aims of this study were threefold. First, this study sought to compare characteristics of patients undergoing irreducible and reducible ventral hernia repair. Second, to compare morbidity rates. Third, to determine which factors, including irreducibility, might be associated with recurrence. METHODS: This observational study was a retrospective review of 252 consecutive ventral hernia patients divided into two cohorts: 101 patients who underwent repair of an irreducible ventral hernia, and 152 patients underwent repair of a reducible ventral hernia. The mean follow-up time was approximately 4 years in both groups. RESULTS: Patients undergoing repair of irreducible hernias had higher median BMI (31 vs. 27 kg/m2, p = 0.005), had their hernias longer (median 34 months compared to 12 months, p = 0.043), had more defects on average (mean 1.8 vs. 1.4, p < 0.001), and were more likely to be symptomatic (83 vs. 55%, p = 0.002). Interestingly, neither hernia size (p = 0.821), nor the location of hernia (p = 0.261) differed significantly between the two groups. Morbidity rates, including rates of surgical site infection, obstruction, and recurrence, did not differ significantly; nor did recurrence-free survival (RFS) distributions. Risk factors for hernia recurrence on multivariate analysis included the repaired hernia being itself recurrent (HR = 2.06, 95% CI = 1.07-3.99, p = 0.031), the occurrence of post-operative surgical site infection (HR = 5.10, 95% CI = 2.18-11.91, p < 0.001), and the occurrence of post-operative intestinal obstruction (HR = 5.18, 95% CI = 1.82-14.75, p = 0.002). Irreducibility was not a significant predictor of recurrence (p = 0.152). CONCLUSION: Despite differing profiles, patients with these two types of hernias did not have statistically significant differences in morbidity. Recurrence was not observed to be associated with irreducibility but was found to be associated with other post-operative complications.

Major patterns of laryngeal electromyography and their clinical application.

Laryngeal electromyography (LEMG) is clinically valuable in the evaluation of laryngeal dysfunction and vocal fold immobility. To facilitate clinical application of this electrophysiologic test, a detailed description of modified LEMG techniques is presented. The techniques were applied for simultaneous bilateral recordings of the thyroarytenoid, cricothyroid, and posterior cricoarytenoid muscles. The basic patterns of LEMG are classified into three different types: normal, neuropathy, and myopathy. In an attempt to characterize these patterns, we have reported eight LEMG-documented cases: unilateral laryngeal paralysis, bilateral laryngeal paralysis, cricoarytenoid joint dislocation, cricoarytenoid joint ankylosis, laryngeal myopathy, pharyngeal paralysis (soft palate paralysis), spasmodic dysphonia, and unilateral laryngeal paralysis with anastomosis. The significance of the major LEMG patterns is discussed.

Laryngeal evoked brainstem responses in humans: a preliminary study.

Laryngeal evoked brainstem responses (LBRs) were recorded in normal human subjects in an attempt to develop a central laryngeal function test and enhance our understanding of neurolaryngologic disorders. The results showed that the human LBR consists of five positive peaks and five negative peaks reproducible within 10 ms after a vibratory stimulation to the superior laryngeal nerve (SLN). The waveform reproducibility was verified by blocking the SLN and topically anesthetizing the hypopharyngeal cavity. The morphology and latency of peak 5 were similar to results obtained in animal LBR experiments. It was concluded that a vibratory stimulation to the SLN was a noninvasive method to elicit far-field potentials from the central laryngeal pathway. These findings encourage further effort to establish normative data and explore clinical correlations.

Time course of Bell palsy.

This study was designed to quantitatively characterize the time course of facial palsy and the relationship between electroneurography and the facial nerve grading percentage as a function of onset time. Bilateral electroneurographic recordings during different stages in the course of the disease were repeated and compared with categorized videotaped facial movements using the House-Brackmann facial nerve grading system in 32 patients with Bell palsy. Preliminary results of this study demonstrate a time gap between the percentage of electroneurographic response and the category of the facial nerve grading system during the same period of disease progress. A theoretical model of the time course and specific patterns regarding the recovery of facial function is established. The theoretical time course of facial palsy is divided into 3 stages; preclinical, clinical, and postclinical. Based on the time course of electroneurographic and facial grading functions, the period between 10 and 14 days after onset was found to be most valuable for prediction of recovery. According to this theoretical model, a given time course pattern based on the results of serial electroneurographic recordings provides reliable prognostic information on recovery from Bell palsy.

Audiologic manifestations of Noonan syndrome.

A comprehensive audiologic study of a family with Noonan syndrome is reported together with a review of 20 cases of this syndrome with regard to hearing sensitivity and middle ear status. An incidence of progressive sensorineural hearing loss at the high frequencies is found for 50% of the ears. It is emphasized that early audiologic management may improve the quality of life for patients with Noonan syndrome.

Effects of brain stem lesions on cochlear function: mechanism of hearing improvement after removal of a brain stem tumor.

EOAEs are well correlated with changes of hearing sensitivity during the clinical course of brain stem lesions, as shown in this case study. They may serve as sensitive indicators to evaluate the possible effects of a brain stem lesion on cochlear function and monitor the attempted preservation of hearing during CPA or brain stem surgeries. It is thereby suggested that EOAEs should be included in an audiologic test battery in a differential diagnosis of retrocochlear lesions.

Value of electromyography in differential diagnosis of laryngeal joint injuries after intubation.

Laryngeal joint injury or arytenoid dislocation is not an uncommon complication resulting from intubation trauma, and is best evaluated by laryngeal electromyography (EMG) combined with laryngoscopic examinations. Two cases of cricoarytenoid joint injuries after intubation are reported along with laryngeal EMG findings. Early diagnosis of arytenoid dislocation is important for appropriate surgical management and better prognosis. However, the reported cases, because of delayed referrals, showed prolonged cricoarytenoid joint injuries associated with thyroarytenoid muscle denervation or myopathy, and resultant vocal fold immobility. The results of laryngeal EMG in cricoarytenoid joint injuries can be classified into three different patterns: 1) normal recruitment, 2) myopathy, and 3) denervation or reinnervation of the thyroarytenoid muscles. It is particularly valuable to sample different portions of the thyroarytenoid muscles with EMG in order to evaluate different patterns or pathologic changes of the muscles and nerve paralysis.

Current evaluation of pseudohypacusis: strategies and classification.

Some cases of pseudohypacusis may involve medicolegal aspects and require a confirmed and quantitative diagnosis. These challenging cases must be identified, and then evaluated with basic audiologic and sophisticated electrophysiologic tests. Data on 64 patients with pseudohypacusis collected over a 4-year period are reported. A classification system was developed from an analysis of these cases and is presented for clinical evaluation and diagnosis. In many cases, conventional audiologic evaluation involving pure tone and speech audiometry may be adequate and sufficient for diagnosis. In more complex cases, evoked otoacoustic emissions (EOAEs) and auditory brain stem responses (ABRs) are needed for confirmation of peripheral auditory sensitivity. We found that EOAEs were the most rapid economical, and objective method, and confirmed the diagnosis of hearing loss in 78.1% of cases. Fifteen percent of subjects required ABRs to substantiate the diagnosis. The reliability of basic audiologic tests based on previous clinical investigations and data from the literature are discussed. We conclude that a thorough knowledge and understanding of pseudohypacusis is essential to verify the existence of pseudohypacusis, to determine its type, and to quantify the auditory thresholds.

Neurophysiological evaluation of acute facial paralysis in children.

Objective evaluation of facial nerve paralysis represents a unique challenge to the clinician. Electroneurography (ENoG) and the acoustic reflex (AR) have been widely used as neurophysiological tests in an assessment of facial nerve function. However, ENoG or AR alone does not suffice diagnostic and prognostic purposes of facial function evaluation in children. To further investigate the diagnostic aspects of facial nerve paralysis, the prognostic value of AR and ENoG, and the time course of the disease in pediatric population, a series of 30 children with acute facial paralysis were investigated by correlation of findings from video-taped House-Brackmann facial grading system. AR and ENoG. The results showed that AR was absent or abnormal for thresholds in 68.2% of patients with Bell's palsy and normal middle ear function. Shorter duration and higher percentage of recovery were found in the children with a normal AR than those with an abnormal AR. Three children showed an abnormal tympanogram and hearing loss associated with acute facial paralysis. These findings should alert the clinician to the presence of a specific, treatable disease in the evaluation of Bell's palsy. The percentage of electroneurographic response varied with different days after onset. ENoG showed minimal responses at weeks 1 3 after onset of Bell's palsy in most patients. The study of the time-course in the children with Bell's palsy demonstrated a functional gap in the early (< 1 week) and late clinical stage (after 6 weeks) of the disease, suggesting that ENoG predicted well only during weeks 1-4 after onset. In general, ENoG showed a good recovery in children, however, recurrent Bell's palsy becomes a concern. The need for neurophysiological follow-up for possible incomplete recovery of the facial nerve is emphasized. It is recommended that AR and ENoG should be included in the diagnostic workup when evaluating pediatric facial function.

Audiological findings in glomus tumours.

Glomus tumours involving the middle ear and the cerebellopontine angle are reported with emphasis on audiological findings. Magnetic resonance imaging (MRI), angiographic and pathological results are presented. Audiological tests, including impedance audiometry, evoked otoacoustic emissions and auditory brainstem responses, are valuable in evaluation of the effect of glomus tumours on the auditory system as well as their pathological extent.

Neurotologic evaluation of facial nerve paralysis caused by gunshot wounds.

Facial nerve injury is one of the most common neurotologic sequelae of a gunshot wound (GSW) to the head or neck. However, few neurotologic studies have been performed on the nature and time course of such facial nerve impairments. This study was designed to characterize the neurotologic manifestations and time course of facial nerve paralysis caused by GSWs to the head and neck. We conducted a battery of electrodiagnostic tests on 10 patients who had experienced traumatic facial paralysis due to a GSW to the head or neck. The etiologies of facial nerve paralysis--including direct injury, compression, fracture, and concussion of the temporal bone--were demonstrated by audiologic, radiologic, and surgical findings. Hearing loss and other cranial nerve injuries were also seen. Six of the 10 patients experienced a complete paralysis of the facial nerve and a poor recovery of its function. We also present a comprehensive case report on 1 patient as a means of discussing the evaluation of facial nerve function during the course of management.