Reproducibility (test–retest) of vestibular evoked myogenic potential

IntroductionThere is still no consensus in the literature as to the best acoustic stimulus for capturing vestibular evoked myogenic potential (VEMP). Low-frequency tone bursts are generally more effective than high-frequency, but recent studies still use clicks. Reproducibility is an important analytical parameter to observe the reliability of responses.ObjectiveTo determine the reproducibility of p13 and n23 latency and amplitude of the VEMP for stimuli with different tone-burst frequencies, and to define the best test frequency.MethodsCross-sectional cohort study. VEMP was captured in 156 ears, on the sternocleidomastoid muscle, using 100 tone-burst stimuli at frequencies of 250, 500, 1000, and 2000 Hz, and sound intensity of 95 dB nHL. Responses were replicated, that is, recorded three times on each side.ResultsNo significant difference was observed for p13 and n23 latencies of the VEMP, captured at three moments with tone-burst stimuli at 250, 500, and 1000 Hz. Only the frequency of 2000 Hz showed a difference between captures of this potential (p < 0.001). p13 and n23 amplitude analysis was also similar in the test–retest for all frequencies analyzed.Conclusionp13 and n23 latencies and amplitudes of VEMP for tone-burst stimuli at frequencies of 250, 500, and 1000 Hz are reproducible.     

Design of an intravenous oxygenator

The aim of this study was to design a new intravenous blood–gas exchange device and to estimate the design characteristics of the device with a dimensionless function by using a substance that can be used instead of bovine blood. In addition, the characteristics of oxygen transfer were estimated using empirical formulas and the reliability of the equations was ascertained by comparing their output with an experiment performed using bovine blood. The dimensionless function was derived using distilled water and bovine blood to estimate the oxygen transfer rate. Using the derived equations, the calculated oxygen transfer rates for bovine blood and distilled water were similar for Reynolds numbers ranging from 0.7 to 7.0. Therefore, it is possible to estimate the oxygen transfer rate in bovine blood, which is a non-Newtonian fluid, using distilled water, which is a Newtonian fluid. Moreover, it was possible to verify the related equations because the oxygen transfer rate could be estimated using the derived equations, according to the diameters of the various device modules.     

The effect of MS-818, a pyrimidine compound,on the regeneration of peripheral nerve fibers of mice after a crush injury

One of the pyrimidine compounds, 2-piperadino-6-methyl-5-oxo-5,6-dihydro(7H)pyrrolo[3,4-d]pyrimidine (MS-818), has neurotropic effects in vitro. Therefore, we studied the effect of MS-818 on the regeneration of the peroneal nerve in C57BL/6J mice after a crush injury. Two test groups, which received a daily intraperitoneal injection of 5 mg/kg or 10 mg/kg MS-818, respectively, were compared with controls, which received daily intraperitoneal injections of physiological saline, over a 14-day period. The maximum foot-width ratio (crushed side/uncrushed side) was obtained on days 1, 8 and 14 after the crush injury, and the various morphometric parameters were evaluated at both 5 and 10 mm distal to the proximal portion of the crush site. The significant effects of MS-818 included a larger maximum foot width (P<0.04) and a greater number of unmyelinated axons per nerve at both levels (P<0.003) in both test groups than in controls. MS-818 had no significant effects on body weight, the increase of total transverse fascicular area after the crush injury, the total number of myelinated fibers with their size distributions, or the number of nuclei of Schwann cells and macrophages. Therefore, we conclude that MS-818 promotes axonal sprouting and elongation after a crush injury in mice.     

Sensory axonopathy in hereditary distal spinal muscular atrophy

A girl of 14 year is presented with a distal spinal muscular atrophy (SMA) with autosomal recessive inheritance. The technical findings are in agreement with the diagnosis. Light microscopical examination of sural nerve biopsy, including teased fiber studies and morphometry, showed no abnormalities. Electron microscopical investigation however demonstrated axonal pathology. The question arises if distal SMA is a distal axonopathy mainly of motor nerves, but to some extent also of sensory nerves.     

甲状腺切除术中喉返神经损伤的预防

目的：探讨降低喉返神经损伤的方法。方法：2005年9月-2007年1月共有375例甲状腺手术患者，对其喉返神经损伤进行分析。结果：375例病人中有5例喉返神经损伤，其中甲状腺腺瘤3例，桥本甲状腺炎1例，甲状腺癌1例，损伤后立即行喉镜检查示声带处于外展位。给予营养神经治疗，15 d-3个月后完全恢复，喉镜检查示声带正常。结论：喉返神经损伤可以预防，关键是术者应熟悉喉返神经的解剖结构和变异，熟悉其与周围组织及血管的关系，要有手术区域的组织结构特别是喉返神经走行的“立体影像”。     

Needle electromyography

Physiologic assessment of diseases of the motor unit from the anterior horn cells to the muscles relies on a combination of needle electromyography (EMG) and nerve conduction studies (NCS). Both require a unique combination of knowledge of peripheral nervous system anatomy, physiology, pathophysiology, diseases, techniques, and electricity is necessary. Successful, high‐quality, reproducible EMG depends on the skills of a clinician in patient interaction during the physical insertion and movement of the needle while recording the electrical signals. These must be combined with the skill of analyzing electric signals recorded from muscle by auditory pattern recognition and semiquantitation. 10 , 52 This monograph reviews the techniques of needle EMG and waveform analysis and describes the types of EMG waveforms recorded during needle EMG. © 2009 Wiley Periodicals, Inc. Muscle Nerve 39: 244–270, 2009     

Are the same phoneme and lexical layers used in speech production and comprehension? A case-series test of model of aphasic speech production

In this paper, we investigate the claim that although the same lexical units are involved in speech production and comprehension, there are separate input and output phoneme layers (Foygel and Dell, 2000). Data from a case series of aphasic patients are used to test this claim by examining the relationship between performance on a test of picture naming and performance on tests of phonological input. Estimates of each patient's semantic-lexical and phonological impairments in speech production were derived from Foygel and Dell's computational model of picture naming. It was found that the strength of the semantic-lexical impairments in speech production was significantly correlated with performance on auditory comprehension tests. This finding is consistent with the claim that the same lexical units are involved in speech comprehension and production. Conversely, the correlations between the strength of the phonological lesions in speech production and performance on tests of phonological input were non-significant, consistent with Foygel and Dell's claim that there are distinct input and output phoneme layers.