Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Thangam Venkatesan is active.

Publication


Featured researches published by Thangam Venkatesan.


Neurogastroenterology and Motility | 2010

Autonomic nerve function in adults with cyclic vomiting syndrome: a prospective study.

Thangam Venkatesan; Thomas Prieto; Alexandru Barboi; B. U. K. Li; Abigail Schroeder; Walter J. Hogan; Ashwin N. Ananthakrishnan; Safwan Jaradeh

Background  Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder that is characterized by recurrent episodes of intense vomiting. There are several postulated mechanisms involved in its pathogenesis and one potential explanation for this disorder may be linked to autonomic dysfunction. The aim of our study was to evaluate autonomic nerve function in patients with CVS prospectively.


BMC Gastroenterology | 2012

Cyclic Vomiting Syndrome (CVS): is there a difference based on onset of symptoms - pediatric versus adult?

Nilay Kumar; Qumseya Bashar; V. Naveen Reddy; Jyotirmoy Sengupta; Ashwin N. Ananthakrishnan; Abigail Schroeder; Walter J. Hogan; Thangam Venkatesan

BackgroundCyclic Vomiting Syndrome (CVS) is a well-recognized functional gastrointestinal disorder in children but its presentation is poorly understood in adults. Genetic differences in pediatric-onset (presentation before age 18) and adult-onset CVS have been reported recently but their clinical features and possible differences in response to therapy have not been well studied.MethodsThis was a retrospective review of 101 CVS patients seen at the Medical College of Wisconsin between 2006 and 2008. Rome III criteria were utilized to make the diagnosis of CVS.ResultsOur study population comprised of 29(29%) pediatric-onset and 72 (71%) adult-onset CVS patients. Pediatric-onset CVS patients were more likely to be female (86% vs. 57%, p = 0.005) and had a higher prevalence of CVS plus (CVS + neurocognitive disorders) as compared to adult-onset CVS patients (14% vs. 3%, p = 0.05). There was a longer delay in diagnosis (10 ± 7 years) in the pediatric-onset group when compared to (5 ± 7 years) adult-onset CVS group (p = 0.001). Chronic opiate use was less frequent in the pediatric-onset group compared to adult-onset patients (0% vs. 23%, p = 0.004). Aside from these differences, the two groups were similar with regards to their clinical features and the time of onset of symptoms did not predict response to standard treatment. The majority of patients (86%) responded to treatment with tricyclic antidepressants, anticonvulsants (topiramate), coenzyme Q-10, and L-carnitine. Non-response to therapy was associated with coalescence of symptoms, chronic opiate use and more severe disease as characterized by longer episodes, greater number of emergency department visits in the year prior to presentation, presence of disability and non-compliance on univariate analysis. On multivariate analysis, only compliance to therapy was associated with a response. (88% vs. 38%, Odds Ratio, OR 9.6; 95% Confidence Interval [CI], 1.18-77.05).ConclusionDespite reported genetic differences, the clinical features and response to standard therapy in pediatric- and adult-onset CVS were mostly similar. Most patients (86%) responded to therapy and compliance was the only factor associated with a response.


BMC Emergency Medicine | 2010

A survey of emergency department use in patients with cyclic vomiting syndrome

Thangam Venkatesan; Sally Tarbell; Kathleen Adams; Jennifer McKanry; Trish Barribeau; Kathleen R. Beckmann; Walter J. Hogan; Nilay Kumar; B. U. K. Li

BackgroundCyclic vomiting syndrome (CVS), a chronic disorder characterized by recurrent episodes of vomiting, is frequently unrecognized and is associated with high utilization of emergency department (ED) services.MethodsA web-based survey was posted on the Cyclic Vomiting Syndrome Association (CVSA) website to assess utilization of ED services in patients with CVS.ResultsOf 251 respondents, 104 (41.4%) were adult CVS patients and 147 (58.6%) were caregivers of pediatric and adult patients. In the adult group, the median number of ED visits for CVS symptoms was 15(range 1 - 200), with a median of 7 ED visits prior to a diagnosis of CVS (range 0 - 150). In the caregiver group, the median number of ED visits was 10 (range 1 - 175) and the median number of ED visits prior to a diagnosis of CVS was 5 (range 0 - 65). CVS was not diagnosed in the ED in 89/104 (93%) adults and 119/147 (93%) patients in the caregiver group. CVS was not recognized in the ED in 84/95 (88%) of adults and 97/122 (80%) of patients in the caregiver group, despite an established diagnosis of CVS.ConclusionThere is a sub-group of adult and pediatric CVS patients who are high utilizers of ED services and CVS is not recognized in the ED in the majority of patients. Improved efforts to educate ED physicians are indicated to optimize treatment of patients with CVS and to decrease potential overuse of ED services.


The American Journal of Gastroenterology | 1999

Prevalence and predictors of severe acute pancreatitis in patients with acquired immune deficiency syndrome (AIDS)

Anuj Paul Manocha; Michael Sossenheimer; Stephen P. Martin; Kenneth E. Sherman; Thangam Venkatesan; David C. Whitcomb; Charles D. Ulrich

OBJECTIVE:Recent case control data suggested that a severe course of acute pancreatitis in HIV+ patients was 1) common (50% of cases), 2) poorly predicted by Ransons criteria (sensitivity 41%), and 3) accurately predicted by a diagnosis of AIDS (positive predictive value 67%). However, the definition of severity included length of stay in hospital and excluded commonly accepted markers (local complications, systemic complications, and need for surgery). The aim of this study was to determine 1) the prevalence of severity and 2) the value of these predictors with regard to severity, as defined by commonly accepted standardized criteria in patients with AIDS and acute pancreatitis.METHODS:A retrospective review identified 50 patients with AIDS exhibiting clinical, laboratory, and/or radiological features of acute pancreatitis.RESULTS:Only five patients followed a severe course as defined by accepted markers. Of these patients, 29 had values available for at least nine of 11 of Ransons criteria (sensitivity 80%, specificity 54%). Points were awarded most commonly for decreased serum Ca2+ (n = 14) and elevated serum LDH (n = 7).CONCLUSIONS:In patients with AIDS and acute pancreatitis at our institutions, 1) the prevalence of severity and 2) the sensitivity of Ransons criteria with regard to severity is comparable to that reported in large historical case series of immunocompetent patients. Pseudohypocalcemia and/or elevation in LDH are frequent, likely due to the catabolic infectious disease state.


Pancreas | 2003

Prevalence and Predictors of Severity as Defined by Atlanta Criteria Among Patients Presenting with Acute Pancreatitis

Thangam Venkatesan; Jonathan S. Moulton; Charles D. Ulrich; Stephen P. Martin

Introduction Effective triage of patients with acute pancreatitis is dependent on the ability to accurately predict a severe course. Predictors (e.g., APACHE II score of >8) have been tested against wide-ranging definitions of severity (prevalence, 15%–40%). To ensure uniformity in defining a severe course of acute pancreatitis, the Atlanta symposium of 1992 adopted all-encompassing criteria (local complications, systemic complications, need for surgery, or death). Aims To assess the prevalence of each Atlanta criteria for severe acute pancreatitis and to determine the sensitivity, specificity, and positive and negative predictive values of the APACHE II score as a predictor of these criteria for severe acute pancreatitis. Methodology We reviewed records of patients admitted to the University of Cincinnati Medical Center (Cincinnati, OH, U.S.A.) between 1994 and 1998 with acute pancreatitis. Exclusion criteria included referral from an outside hospital, immunocompromised state, and chronic pancreatitis. Results Seventy-four consecutive patients met our inclusion criteria. Ten patients (13.5%) had a severe course. Seven patients developed only local complications. Three patients had systemic complications. Pancreatic surgical intervention was required in four patients. No deaths occurred. An APACHE II score of >8 exhibited 50% sensitivity and 69% specificity (positive predictive value, 20%; negative predictive value, 89%). All patients with systemic complications and two of seven patients with only local complications had an APACHE II score of >8. Conclusions The prevalence of severity among our nonreferred patients with acute pancreatitis was less than previously reported. The APACHE II scoring system exhibited reasonable sensitivity in predicting systemic complications and/or the need for surgery, with a low positive predictive value. This most certainly is a function of the low pretest probability of severe pancreatitis. Future studies attempting to identify predictive systems that triage patients in a more cost-effective manner should restrict their analysis to Atlanta criteria other than local complications.


Neurogastroenterology and Motility | 2016

Endocannabinoid-related lipids are increased during an episode of cyclic vomiting syndrome

Thangam Venkatesan; Y Zadvornova; Hershel Raff; Cecilia J. Hillard

The endocannabinoid system and the hypothalamic–pituitary–adrenal axis are important neuromodulators of nausea and vomiting. This led us to hypothesize that patients with cyclic vomiting syndrome (CVS) have lower serum endocannabinoids (eCBs) and higher salivary cortisol and alpha amylase.


The American Journal of Gastroenterology | 2017

Cannabinoid Receptor Type 1 and mu-Opioid Receptor Polymorphisms Are Associated With Cyclic Vomiting Syndrome

Andrzej Wasilewski; Urszula Lewandowska; Paula Mosińska; Cezary Watala; Martin Storr; Jakub Fichna; Thangam Venkatesan

Objectives:Cyclic vomiting syndrome (CVS) is a disorder defined by recurrent, unexplained episodes of severe nausea and vomiting. Our aim was to investigate whether CVS and pathophysiological mechanisms underlying this condition are associated with selected variations in genes encoding the components of the endogenous cannabinoid and opioid systems.Methods:This case–control study included 65 patients with CVS-16 male and 49 female, and 1,092 healthy controls-525 male and 567 female from the 1000 Genomes Project. CVS subjects filled out study-specific questionnaires. Single-nucleotide polymorphisms (SNPs) in genes encoding cannabinoid receptors (CNR1 and CNR2), fatty acid amide hydrolase (FAAH) and mu-opioid receptor (OPRM1) were analyzed using the TaqMan SNP genotyping assay. Correlations between SNP’s and clinical characteristics of CVS were ascertained.Results:Our study disclosed an increased risk of CVS among individuals with AG and GG genotypes of CNR1 rs806380 (P<0.01), whereas the CC genotype of CNR1 rs806368 and AG and GG genotypes of OPRM1 rs1799971 were associated with a decreased risk of CVS (P<0.05). In addition, AG and GG genotypes of OPRM1 rs1799971 were correlated with migraine episodes, AG and GG of OPRM1 rs1799971, and CT and CC of CNR1 rs806368 with a family history of migraines (second degree relatives), and CT and CC of CNR1 rs2023239 with a positive response to therapy.Conclusions:Our results show for the first time that the variations in CNR1 and OPRM1 genes are associated with CVS and that different genotypes may contribute to the risk of CVS.


Current Treatment Options in Gastroenterology | 2016

Novel Treatments for Cyclic Vomiting Syndrome: Beyond Ondansetron and Amitriptyline

Sanjay Bhandari; Thangam Venkatesan

Opinion statementCyclic vomiting syndrome (CVS) is a chronic functional gastrointestinal disorder that is characterized by episodic nausea and vomiting. Initially thought to only affect children, CVS in adults was often misdiagnosed with significant delays in therapy. Over the last decade, there has been a considerable increase in recognition of CVS in adults but there continues to be a lack of knowledge about management of this disorder. This paper seeks to provide best practices in the treatment of CVS and also highlight some novel therapies that have the potential in better treating this disorder in the future. Due to the absence of randomized control trials, we provide recommendations based on review of the available literature and expert consensus on the therapy of CVS. This paper will discuss prophylactic and abortive therapy and general measures used to treat an episode of CVS and also discuss pathophysiology as it pertains to novel therapy. Recent recognition of the association of chronic marijuana use with cyclic vomiting has led to the possibility of a new diagnosis called “Cannabinoid Hyperemesis Syndrome,” which is indistinguishable from CVS. The treatment for this purported condition is abstinence from marijuana despite scant evidence that marijuana use is causative. Hence, this review will also discuss emerging data on the role for the endocannabinoid system in CVS and therapeutic agents targeting the endocannabinoid system, which offer the potential of transforming the care of these patients.


Psychology Health & Medicine | 2007

Objective risk, subjective risk, and colorectal cancer screening among a clinic sample

B. Alex Matthews; Ann B. Nattinger; Thangam Venkatesan; Reza Shaker; Ruric Anderson

Abstract Among cancers, colorectal (CRC) is the third most incident and the second most lethal. Although screening for the disease has been shown to be effective in reducing morbidity and mortality, screening rates remain low. Risk of disease has been shown to increase screening uptake, but different types of risk may influence intent to screen, screening in a timely manner, or participating in screening at all. A cross-sectional design was used to select a diverse sample of CRC asymptomatic patients 50 or more years of age (N = 104) visiting one of three Midwestern medical clinics. Results showed a positive relationship between receipt of CRC screening and planning to screen for CRC in the future. Objective risk factors (personal/family history and having a primary care physician) were associated with CRC screening uptake and screening within the time intervals recommended by professional screening guidelines, but subjective risk did not obtain significance for screening participation. Both objective (primary care physician) and subjective risk (long-term comparative risk, knowledge) were associated with future plans to screen. Findings suggest that CRC screening behaviors may be differentially influenced by type of risk.


Clinical Autonomic Research | 2018

Cyclic vomiting syndrome: epidemiology, diagnosis, and treatment

Sanjay Bhandari; Pinky Jha; Abhishek Thakur; Abhipsa Kar; Harrison Gerdes; Thangam Venkatesan

Cyclic-vomiting syndrome (CVS) is a chronic functional gastrointestinal disorder characterized by recurrent episodes of nausea and vomiting. Although once thought to be a pediatric disorder, there has been a considerable increase in recognition of CVS in adults. The exact pathogenesis is unknown and several theories have been proposed. Migraine and CVS share a similar pathophysiology as suggested by several studies. Since there are no specific biomarkers available for this disorder, physicians should rely on Rome criteria for the diagnosis. Due to the lack of randomized control trials, the treatment of CVS is primarily empirical.

Collaboration


Dive into the Thangam Venkatesan's collaboration.

Top Co-Authors

Avatar

Reza Shaker

Medical College of Wisconsin

View shared research outputs
Top Co-Authors

Avatar

Erica A. Samuel

Medical College of Wisconsin

View shared research outputs
Top Co-Authors

Avatar

Arash Babaei

Medical College of Wisconsin

View shared research outputs
Top Co-Authors

Avatar

Walter J. Hogan

Medical College of Wisconsin

View shared research outputs
Top Co-Authors

Avatar

Abigail Schroeder

Medical College of Wisconsin

View shared research outputs
Top Co-Authors

Avatar

Jyotirmoy Sengupta

Medical College of Wisconsin

View shared research outputs
Top Co-Authors

Avatar

Nilay Kumar

Cambridge Health Alliance

View shared research outputs
Top Co-Authors

Avatar

Robert M. Siwiec

Advocate Lutheran General Hospital

View shared research outputs
Top Co-Authors

Avatar

Sanjay Bhandari

Medical College of Wisconsin

View shared research outputs
Top Co-Authors

Avatar

B. U. K. Li

Medical College of Wisconsin

View shared research outputs
Researchain Logo
Decentralizing Knowledge