• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.445-452
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• 2015

Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers a low-intensity direct current to the cortical areas, thereby facilitating or inhibiting spontaneous neuronal activity. This study was designed to examine the changes in various sensory functions after tDCS. A single-center, single-blinded, randomized trial was conducted to determine the effect of a single session (August 4 to August 29) of tDCS with the current perception threshold (CPT) in 50 healthy volunteers. Nerve conduction studies (NCS) were performed in relation to the median sensory and motor nerves on the dominant hand to discriminate peripheral nerve lesions. The subjects received anodal tDCS with 1mA for 15 minutes under two different conditions, with 25 subjects in each group. The conditions were as follows: tDCS on the dorsolateral prefrontal cortex (DLPFC) and sham tDCS on DLPFC. The parameters of the CPT was recorded with a Neurometer$^{(R)}$ at frequencies of 2000, 250 and 5 Hz in the dominant index finger to assess the tactile sense, fast pain and slow pain, respectively. In the test to measure the CPT values of the DLPFC in the anodal tDCS group, the values increased significantly in all of 250 and 5 Hz. All CPT values decreased for the sham tDCS. These results showed that DLPFC anodal tDCS can modulate the sensory perception and pain thresholds in healthy adult volunteers. This study suggests that tDCS may be a useful strategy for treating central neurogenic pain in rehabilitation medicine.

• Annals of Clinical Neurophysiology
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• v.12 no.1
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• pp.21-26
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• 2010

Background: Although quantitative sensory test (QST) is being used with increasing frequency for measuring sensory thresholds in clinical practice and epidemiologic studies, there has been no age-matched normative data in Korean adults. The objective of this study is to evaluate the value of QST in diabetic polyneuropathy with normal range in Korean adults. Methods: The Computer Aided Sensory Examination IV 4,2 (WR Medical Electronics Co., Stillwater, Minnesota, U.S.A.), with 4,2,1 stepping algorithm was used to determine vibration and cold perception threshold in 70 normal controls and 19 patients with diabetic polyneuropathy aged from 21 to 79 years. The data were used to define age-matched upper and lower normal limits and normal range of side to side difference. We also evaluated the duration of diabetes, serum HbA1C level, and findings of nerve conduction study (NCS) and QST in patients with diabetic polyneuropathy. Results: In normal adults, sensory thresholds slightly increased with age, and a slight side-to-side difference was observed. The diagnostic sensitivity of QST was not higher than NCS in patients with diabetic polyneuropathy (36.8% vs. 42.1%, p=0.716), especially among elderly patients. Conclusions: QST might be used as a complementary test for NCS in the diagnosis of diabetic polyneuropathy. Although the QST is a simple method for the evaluation of peripheral nerve function, there are some limitations. Most of all, because the QST measuring is dependent on the subjective response of patients, the degree of concentration and cooperation of the patients can significantly affect the result. And thus, attention should be paid during the interpretation of QST results in patients with peripheral neuropathy.

• Journal of Community Nutrition
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• v.8 no.4
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• pp.185-192
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• 2006

This study was performed to investigate factors affecting sensitivity and preference for salty tastes of Korean adult females. Sensitivity and preference for salty tastes were determined as detection threshold concentration of NaCl solution and the optimally-preferred NaCl concentration of the bean sprout soup, respectively. A self-administered questionnaire was used to obtain the information regarding general characteristics, self diagnosis of stress, health-related lifestyle practices, dietary habits and food preferences. Dietary intake using 24-hours recall and blood pressure were measured. Salty taste detection thresholds and optimally-preferred NaCl concentrations were 0.0197% and 0.357%, respectively. There was a significant positive correlation between the optimally-preferred salt concentration and age, despite no significant correlation between either sensitivity or preference for salty taste and sodium intake, which was 3,605mg/day. Those who had bread or cereal with milk as breakfast instead of a traditional Korean meal and those who preferred jjigae to soup had significantly higher NaCl preferences for bean sprout soup. Going to bed after midnight and skipping meals (${\geq}3/week$) decreased salty taste sensitivity without reaching statistical significance. Self awareness of one's own health, recent weight changes, family history of hypertension, sleep quality, getting-up time, rate of eating and other food preferences did not affect either perception. Stress level, TV watching, BMI and sodium intake did not have significant correlation to sensitivity or preference. Further research including a large number of well-controlled subjects and more accurate measurement of sodium intake should be directed to find other factors affecting salt preference and sensitivity in order to decrease Na intake and related diseases.

• Journal of Audiology & Otology
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• v.25 no.2
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• pp.65-71
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• 2021

Background and Objectives: In masking level difference (MLD), the masked detection threshold for a signal is determined as a function of the relative interaural differences between the signal and the masker. Study 1 analyzed the results of school-aged children with good school performance in the MLD test, and study 2 compared their results with those of a group of children with poor academic performance. Subjects and Methods: Study 1 was conducted with 47 school-aged children with good academic performance (GI) and study 2 was carried out with 32 school-aged children with poor academic performance (GII). The inclusion criteria adopted for both studies were hearing thresholds within normal limits in basic audiological evaluation. Study 1 also considered normal performance in the central auditory processing test battery and absence of auditory complaints and/or of attention, language or speech issues. The MLD test was administered with a pure pulsatile tone of 500 Hz, in a binaural mode and intensity of 50 dBSL, using a CD player and audiometer. Results: In study 1, no significant correlation was observed, considering the influence of the variables age and sex in relation to the results obtained in homophase (SoNo), antiphase (SπNo) and MLD threshold conditions. The final mean MLD threshold was 13.66 dB. In study 2, the variables did not influence the test performance either. There was a significant difference between test results in SπNo conditions of the two groups, while no differences were found both in SoNo conditions and the final result of MLD. Conclusions: In study 1, the cut-off criterion of school-aged children in the MLD test was 9.3 dB. The variables (sex and age) did not interfere with the MLD results. In study 2, school performance did not differ in the MLD results. GII group showed inferior results than GI group, only in SπNo condition.

• Korean Journal of Audiology
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• v.25 no.2
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• pp.65-71
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• 2021

Background and Objectives: In masking level difference (MLD), the masked detection threshold for a signal is determined as a function of the relative interaural differences between the signal and the masker. Study 1 analyzed the results of school-aged children with good school performance in the MLD test, and study 2 compared their results with those of a group of children with poor academic performance. Subjects and Methods: Study 1 was conducted with 47 school-aged children with good academic performance (GI) and study 2 was carried out with 32 school-aged children with poor academic performance (GII). The inclusion criteria adopted for both studies were hearing thresholds within normal limits in basic audiological evaluation. Study 1 also considered normal performance in the central auditory processing test battery and absence of auditory complaints and/or of attention, language or speech issues. The MLD test was administered with a pure pulsatile tone of 500 Hz, in a binaural mode and intensity of 50 dBSL, using a CD player and audiometer. Results: In study 1, no significant correlation was observed, considering the influence of the variables age and sex in relation to the results obtained in homophase (SoNo), antiphase (SπNo) and MLD threshold conditions. The final mean MLD threshold was 13.66 dB. In study 2, the variables did not influence the test performance either. There was a significant difference between test results in SπNo conditions of the two groups, while no differences were found both in SoNo conditions and the final result of MLD. Conclusions: In study 1, the cut-off criterion of school-aged children in the MLD test was 9.3 dB. The variables (sex and age) did not interfere with the MLD results. In study 2, school performance did not differ in the MLD results. GII group showed inferior results than GI group, only in SπNo condition.

• The Korean Journal of Pain
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• v.35 no.3
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• pp.240-249
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• 2022

Background: Widespread pain partially depends upon sensitization of central pain mechanisms. However, mechanisms controlling pain distribution are not completely known. The present study sought to assess skin temperature variations in the area of experimentally-induced pain and potential sex differences. Methods: Pressure-pain thresholds (PPTs) were measured on the right infraspinatus muscle. At the end of Day 0, all participants performed an eccentric exercise of the shoulder external rotators to induce muscle soreness 24 hours after. On Day 1, participants indicated on a body chart the area of pain induced by 60 seconds of suprathreshold pressure stimulation (STPS; PPT + 20%) on the right infraspinatus muscle. Skin temperature variations in the area of referred pain were recorded with an infrared thermography camera, immediately before and after the STPS. Results: Twenty healthy, pain-free individuals (10 females) participated. On Day 0, the pre-STPS temperature was higher than the post-STPS temperature on the arm (P = 0.001) and forearm (P = 0.003). On Day 1, the pre-STPS temperature was higher than the post-STPS temperature on the shoulder (P = 0.015), arm (P = 0.001), and forearm (P = 0.010). On Day 0, the temperature decrease after STPS in females was greater than in males on the forearm (P = 0.039). On Day 1, a greater temperature decrease was found amongst females compared with males at the shoulder (P = 0.018), arm (P = 0.046), and forearm (P = 0.005). Conclusions: These findings indicate that sympathetic vasomotor responses contribute to expand pressure-induced referred pain, especially among females.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.347-362
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• 2022

Current vibration serviceability assessment criteria for wind-induced vibrations in tall buildings are based largely on human 'perception' thresholds which are shown not to be directly translatable to human 'acceptability' of vibrations. There is also a considerable debate about both the metrics and criteria for vibration acceptability, such as frequency of occurrence or peak vs mean vibration, and how these might vary with the nature of the vibration. Furthermore, the design criteria are necessarily simplified for ease of application so cannot account for a range of environmental, situational and human factors that may enhance or diminish the impact of vibrations on serviceability. The dual-site VSimulators facility was created specifically to provide an experimental platform to address gaps in understanding of human response to building vibration. This paper considers how VSimulators can be used to inform general design guidance and support design of specific buildings for habitability, in terms of vibration, which allow engineers and clients to make informed decisions with regard to sustainable design, in terms of energy and financial cost. This paper first provides a brief overview of current vibration serviceability assessment guidelines, and the current understanding and limitations of occupants' acceptability of wind-induced motion in tall buildings. It then describes how the dual-site VSimulators facility at the Universities of Bath and Exeter can be used to assess the effects of motion and environment on human comfort, wellbeing and productivity with examples of how the facility capabilities have been used to provide new, human experience based experimental research approaches.

• The Korean Journal of Pain
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• v.36 no.2
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• pp.173-183
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• 2023

Background: Understanding the stability of quantitative sensory tests (QSTs) over time is important to aid clinicians in selecting a battery of tests for assessing and monitoring patients. This study evaluated the short- and long-term reliability of selected QSTs. Methods: Twenty healthy women participated in three experimental sessions: Baseline, 2 weeks, and 6 months. Measurements included pressure pain thresholds (PPT) in the neck, upper back, and leg; Pressure-cuff pain tolerance around the upper-arm; conditioned pain modulation during a pressure-cuff stimulus; and referred pain following a suprathreshold pressure stimulation. Intraclass correlation coefficients (ICC) and minimum detectable change (MDC) were calculated. Results: Reliability for PPT was excellent for all sites at 2 weeks (ICC, 0.96-0.99; MDC, 22-55 kPa) and from good to excellent at 6 months (ICC, 0.88-0.95; MDC, 47-91 kPa). ICC for pressure-cuff pain tolerance indicated excellent reliability at both times (0.91-0.97). For conditioned pain modulation, reliability was moderate for all sites at 2 weeks (ICC, 0.57-0.74; MDC, 24%-35%), while it was moderate at the neck (ICC, 0.54; MDC, 27%) and poor at the upper back and leg at 6 months. ICC for referred pain areas was excellent at 2 weeks (0.90) and good at 6 months (0.86). Conclusions: PPT, pressure pain tolerance, and pressure-induced referred pain should be considered reliable procedures to assess the pain-sensory profile over time. In contrast, conditioned pain modulation was shown to be unstable. Future studies prospectively analyzing the pain-sensory profile will be able to better calculate appropriate sample sizes.

• Journal of Preventive Medicine and Public Health
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• v.28 no.4 s.51
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• pp.765-771
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• 1995

This study was performed to investigate the possibility of temporary threshold shift (TTS) of vibration sense could induced by exposure to high-frequency vibration or by work position taking by dentists in drilling or polishing. The vibratory perception thresholds (VPT) of 28 healthy men were measured on the index fingertip pulp of dominant hand at 250 Hz. The vibrating tool used in test was a low-speed handpiece of 34,000 rpm. For the TTS test, the dominant hand was exposed to high-frequency vibration and to work position for five minutes, respectively. The VPTs before and after vibratory exposure were $23.5{\pm}3.5dB,\;30.8{\pm}4.2dB$, respectively and VPT after work position was $23.7{\pm}4.6dB$. The difference between before and after vibartory exposure was statistically significant (p<0.001). The correlation of height, weight and BMI with baseline VPTs was not statistically significant. Also, there was no difference of VPTs by smoking. These results suggest that high-frequency vibration from dental handpieces might cause the impairment of vibration sensation.

• Journal of Oral Medicine and Pain
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• v.36 no.2
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• pp.131-137
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• 2011

Current Perception Threshold (CPT) using Neurometer($Neurometer^{(R)}$ CPT/C) is thought as one of easy and noninvasive QST(qunatitative sensory testing) tools for A${\beta}$, A${\delta}$ and C fibers within a relatively short time. However, conflicts about its reliability still exist. This study aimed to evaluate the reliability of CPTs evaluation and find a way to increase its reliability. Two examiners separately tested CPTs at each side of the mandibluar nerve areas for ten healthy male adults (average age of 22.4 years) three times with an intervals of a week during three weeks. Mean CPTs were compared between the right and left sides of the mandibular nerve area and between the three examinations on the each side. While CPTs at 2000 Hz(A${\beta}$ fiber) showed statistically significant side differences in all three examinations (p<0.05), significant side difference was found in only one examination at 250 Hz(A${\delta}$ fiber) and no difference at 5 Hz(C fiber). Comparing CPTs on the each side of the mandibular nerve area, all examinations at all sensory nerve fibers showed the least CPTs at the 1st examinations. CPTs at 250 Hz(A${\delta}$ fiber) and 5 Hz(C fiber) were significantly different between the first and the following examinations (p<0.05) and there was no significant difference between 2nd and 3rd examinations. The results of this study indicated that CPTs at 250 Hz(A${\delta}$ fiber) and 5 Hz(C fiber) are reliable but CPTs at 2000 Hz(A${\beta}$ fiber) is not appropriate for evaluation of side differences in the mandibular nerve area. In addition, it is suggested that repeated examination be helpful to increase reliability of the CPT evaluation.