• Korean Journal of Bronchoesophagology
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• v.3 no.1
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• pp.79-83
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• 1997

The term laryngopharyngeal reflux (LPR) refers to the backflow of food or stomach acid back up into the larynx (the voice box) or the pharynx (the throat). Esophagopharyngeal reflux is suggested as an etiologic factor in laryngeal disease. To examine a possible esophageal basis for laryngopharyngeal symptoms, we studied 48 patients with persistent laryngopharyngeal symptoms, and 12 relative control subjects. Patients were evaluated for cervical symptoms by questionnaire and underwent gastrofiberoscopy, fiberoptic laryngoscopy, esophageal manometry and 24-hour ambulatory double-probe pH monitoring. We found LPR in fourteen out of 48 patients with cervical symptoms (29%). The LPR group consisted of nine men and five women. The symptoms that LPR patients complained were throat lump sensation, hoareness, sore throat, throat clearing, chronic coughing and dysphagia in order of frequency, and they were not different significantly from non-LPR patients. The laryngoscopic findings in LPR patients were posterior erythema, laryngeal edema and diffuse erythema, and there was also no significant difference between LPR group and non-LPR group. There was statistically significant correlation between LPR and gastroesophageal reflux (GER). We concluded that there is no pathognomonic symptoms or laryngoscopic findings in diagnosis of LPR, and 24-hour ambulatory double-probe pH monitoring is an essential diagnostic tool in LPR.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.27 no.2
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• pp.78-83
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• 2016

Laryngopharyngeal reflux (LPR) disease is an extraoesophageal variant of gastro-esophageal reflux disease that can affect the larynx and pharynx. LPR is associated with symptoms of laryngeal irritation such as throat clearing, coughing, and hoarseness. The main diagnostic methods currently used are laryngoscopy and pH monitoring. The most common laryngoscopic signs are redness and swelling of the throat. However, these findings are not specific of LPR and may be related to other causes or can even be found in healthy individuals. Furthermore, the role of pH monitoring in the diagnosis of LPR is controversial. A therapeutic trial with proton pump inhibitors (PPIs) has been suggested to be cost-effective and useful for the diagnosis of LPR. However, the recommendations of PPI therapy for patients with a suspicion of LPR are based on the results of uncontrolled studies, and high placebo response rates suggest a much more complex and multifactorial pathophysiology of LPR than simple acid reflux. Laryngoscopy and pH monitoring have failed as reliable tests for the diagnosis of LPR. Empirical therapy with PPIs is widely accepted as a diagnostic test and for the treatment of LPR. However, further research is needed to develop a definitive diagnostic test for LPR.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.9 no.2
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• pp.115-127
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• 1998

Laryngopharyngeal reflux(LPR) is one firm of the gastroesophageal reflux diseases(GERD). It is known to cause various kinds of otolaryngologic symptoms such as hoarseness, foreign body sensation in throat, chronic throat clearing, chronic cough, etc. Disease entities diagnosed by otolaryngologists as posterior laryngitis, globus pharyngeus should be suspected as LPR-related diseases. In this multi-center trial, we tried to evaluate the effect of cisapride(10mg tid) on LPR-related symptoms as the part I study(CIS-KOR-051) in 19 centers, and as the part II study(CIS-KOR-052) comparative evaluation of effect between cisapride(10mg tid) and ranitidine(150mg bid) on LPR-related symptoms in 4 centers. In part I study, efficacy of cisapride on LPR-related symptoms after 4 weeks was 53.5% and that of after 8weeks was 77.9% in per protocol(PPA) analysis group. In part II study, efficacy of the cisapride was much better than that of ranitidine not only from 8 weeks trial(p<0.001) but also from 4 weeks trial(p<0.021) in PPA group. In the multiple logistic regression analysis among the parameters which affect the efficacy of the treatment, cisapride prescribed group showed 10 times greater than that of ranitidine prescribed group(p<0.0001, Odds ratio : 10) in PPA group. LPR was proved by 24Hr double probe pHmetry in 13 patients out of 19 patients tested(68.4%). Thus these results indicated that inducing the improvement of motility functions could affect the amelioration of the LPR-related symptoms much better than reducing acid secretion from the stomach. And maybe it suggests that LPR-related symptoms mainly developed by the reduced motility functions of the esophagus and/or delayed gastric emptying.

• Korean Journal of Bronchoesophagology
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• v.16 no.2
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• pp.97-104
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• 2010

Gastroesophageal reflux disease (GERD) is a common disorder caused by the reflux of gastric contents into the esophagus. According to the recent classification, GERD can elicit esophageal and extraesophageal syndromes. Laryngopharyngeal reflux (LPR) is defined as laryngeal symptoms with laryngeal inflammation caused by the acid reflux. The prevalence of GERD and LPR is increasing during the past decades in Korea and management of GERD and LPR is a challenging issue in clinical practice. Proton pump inhibitor is the most effective drug in the treatment of GERD. Most patients with LPR are given a 2-month trial of a proton pump inhibitor (PPI), however, there is still little evidence on the diagnosis or the treatment of LPR. During the last years concern have been raised regarding the risk of averse events related to long-term use of PPI. We review the recent update on medical treatment of GERD/LPR.

• Korean Journal of Bronchoesophagology
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• v.9 no.1
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• pp.67-74
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• 2003

Larygopharyngeal reflux(LPR) is one form of the Gastroesophageal Reflux Diseases(GERD). It is known to cause various kinds of otolaryngologic symptoms such as hoarseness, globus sensation in throat, chronic throat clearing, and chronic cough, Disease entities diagnosed by otolaryngologists as posterior laryngitis, globus pharyngeus and reflux laryngitis should be suspected as LPR-related diseases. The nizatidine(AXID), as a Histamine H2-receptor antagonist, reduces gastric acid secretion and improves gastric motility function. Objectives : The effect of nizatidine using 150mg b.i.d was evaluated for symptom relief and improvement of laryngoscopic findings in patients with LPR. Materials and Methods : In 30 multicenter, observational trial performed nationalwidely in Korea. 308 patients with LPR symptom were observed to evaluate their symptoms and larygnoscopic findings after 4weeks, 8weeks, 12weeks of treatment with nizatidine. Results : The symptoms of LPR including globus sensation, chronic throat clearing and hoarseness, are reduced significantly after 4 weeks, 8weeks, and 12weeks of treatment(p<0.05). The laryngoscopic findings including diffuse erythema, edema and granulation are improved after nizatidine treatment(p<0.05). and the efficacy of nizatidine on LPR-related sympoms after 4 weeks is 88.6%, and those of after 8 weeks and 12weeks were 92.6%, and 99.1% in ITT(Intent To Treatment) group(p<0.05). And PPA(Per Protocol Analysis)group showed 93.7%, 97.3%, and 99.1% of efficacy after 4, 8, and 12 weeks of nizatidine treatment(p<0.05). Conclusion : These results indicate that in patient with LPR, nizatidine 150mg b.i.d treatment very effectively reduces LPR symptoms and improves laryngoscopic findings as well as reduces gastric acid secretion and improves gastric motility function.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.1
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• pp.87-97
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• 2000

One week survey to investigate the prevalence rate and clinical characteristics of laryngopharyngeal reflux symptoms in Korea. The subject(n=7,704 patients) was newly enrolled patients at the out patient clinic in 90 ENT departments of resident training hospitals and 11 local clinics, which were voluntarily participated in the study 1) Twenty five percent of all enrolled patients has LPR-related symptoms or clinical findings from the examination by ENT specialists. 2) Among e name of LPR-related diagnosis, globus syndrome was e most common, and follows by reflux laryngitis, and chronic laryngitis. 3) Women was more prevalent than men, and it is common in 5th, 6th, and 7th decades, which seems to be related with aging process. 4) Most popular symtoms of LPR. were globus sensation, conic throat clearing, and hoarseness of unknown origin. 5) Aggravating factors of LPR-related symptoms were tiredness, mental stress, drink alcohol, cigarettes smoking, spicy food, and drinking coffee. 6) LPR-related symptoms were more common in professional voice users. 7) In past medical history, diseases of stomach and tonsillitis were most common.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.2
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• pp.113-117
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• 2007

Although the prevalence of laryngopharyngeal reflux (LPR) is presumed to be very high, basic researches on LPR have not been active so far. This is a review of present status and prospect of researches on LPR to help readers' understanding of current trend on LPR research. In vitro and in vivo researches on acid/pepsin, intercellular junctions, bile juice, carbonic anhydrase, cytokines, and Helicobacter pylori were discussed. Considering that quality of life is getting more important in accordance with longer life span and that a fair proportion of LPR patients do not respond to conventional therapy, researches on pathogenesis and pathophysiology of treatment measures are necessary and it is anticipated for more and more researchers to concern themselves in basic research on LPR in the future.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.4
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• pp.85-94
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• 2021

The LPR system's trigger sensor makes problem occasionally due to the heave weight of vehicle or the obsolescence equipment. If we replace the hardware sensor to the deep-learning based software sensor in order to generate the trigger signal, LPR system maintenance would be a lot easier. In this paper we proposed the deep-learning sliding window based object detection and tracking algorithm for the LPR system's trigger signal generation. The gate passing vehicle's license plate recognition results are combined into the normal tracking algorithm to catch the position of the vehicle on the trigger line. The experimental results show that the deep learning sliding window based trigger signal generating performance was 100% for the gate passing vehicles including the 5.5% trigger signal position errors due to the minimum bounding box location errors in the vehicle detection process.

• Corrosion Science and Technology
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• v.15 no.5
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• pp.217-225
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• 2016

Linear polarization resistance (LPR) testing of soils has been used extensively by a number of water utilities across Australia for many years now to determine the condition of buried ferrous water mains. The LPR test itself is a relatively simple, inexpensive test that serves as a substitute for actual exhumation and physical inspection of buried water mains to determine corrosion losses. LPR testing results (and the corresponding pit depth estimates) in combination with proprietary pipe failure algorithms can provideauseful predictive tool in determiningthe current and future conditions of an asset. Anumber of LPR tests have been developed on soil by various researchers over the years1), but few have gained widespread commercial use, partly due to the difficulty in replicating the results. This author developed an electrochemical cell that was suitable for LPR soil testing and utilized this cell to test a series of soil samples obtained through an extensive program of field exhumations. The objective of this testing was to examine the relationship between short-term electrochemical testing and long-term in-situ corrosion of buried water mains, utilizing an LPR test that could be robustly replicated. Forty-one soil samples and related corrosion data were obtained from ad hoc condition assessments of buried water mains located throughout the Hunter region of New South Wales, Australia. Each sample was subjected to the electrochemical test developed by the author, and the resulting polarization data were compared with long-term pitting data obtained from each water main. The results of this testing program enabled the author to undertake a comprehensive review of the LPR technique as it is applied to soils and to examine whether correlations can be made between LPR testing results and long-term field corrosion.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.123-129
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• 2016

This study investigates the relationship between dysphonia severity index(DSI) and voice handicap index(VHI). Seventeen patients with a vocal nodule and twenty patients with laryngopharyngeal reflux(LPR) patients participated in this study. Results showed that there is no significant difference in either DSI or VHI between vocal nodule and LPR patients, with a weak negative correlation between DSI and VHI. Results also showed that there is significant difference only in both MPT and Fhi of all DSI parameters between vocal nodule and LPR patients. These results suggest that voice evaluation should be conducted both objectively in terms of acoustical and aerodynamic parameters and subjectively in terms of GRBAS and VHI.