Role Of Diagnostic Tests Research Articles

Tuberculous Meningitis in a Healthy Young Woman: Case Report and Review of Literature (P03.250)

Objective: To present an unusual case of an immune-competent young woman with CNS tuberculosis (CNSTB) Background CNSTB comprises 0.5%-1% of encephalitis cases. Eighty percent of CNSTB patients have foreign travel or other exposure to TB. Many reported cases of CNSTB are notable for immune-compromise. Early disease presentation includes symptoms of progressive head/neck pain, pyrexia, and anorexia. Disease progression results in meningeal inflammation, vasculitis, hydrocephalus and elevated ICP. Late clinical presentation includes confusion, hemiparesis, cranial nerve palsy and visual deficits. Without intervention these cases progress to blindness, coma and death making early recognition imperative for optimal outcome. Design/Methods: We present an immune-competent 26 year-old woman without TB exposure history with unusual presentation of CNSTB and rapid decline. We have searched the literature, identifying cases of CNSTB with attention to details of disease risk factors, presentation & progression, the role of diagnostic testing and outcome data relative to timing of treatment initiation. Results: A 26 year old immune-competent woman with CNSTB and unusual presentation of thunderclap headache. Diagnostic TB studies were initially negative. CSF with high WBC/protein, low glucose. MRI with meningeal and diffuse nodular enhancement. Clinical progression was consistent with CNSTB and empiric therapy was initiated but ineffective. The patient progressed to herniation despite optimal management. Literature review revealed 4 cases of laboratory confirmed immune-competent individuals with CNSTB. Significant literature exists on HIV patients with TB, 40% eventually developing CNSTB. Early confirmatory testing is often negative. In HIV early empiric therapy improves outcomes. No consensus exists when to start treatment in immune-competent individuals. Conclusions: Our case has several unique characteristics: she had no exposure history and was immune-competent. Her presentation was quite fulminant and atypical for CNSTB. Her decline and expiration occurred prior to confirmatory labs. CNSTB and early empiric therapy should always be considered, even in immune-competent patients, presenting with acute onset hydrocephalus to optimize outcomes. Disclosure: Dr. Mutgi has nothing to disclose. Dr. Greene-Chandos has nothing to disclose. Dr. Torbey has nothing to disclose. Dr. Behrouz has nothing to disclose.

A questionnaire study on parasite control practices on UK breeding Thoroughbred studs

Improved education of veterinarians and equine owners/managers is essential in implementing parasite control strategies that are less reliant on chemicals. This questionnaire study, conducted on 61 UK Thoroughbred (TB) establishments during 2009 and 2010, was designed to obtain an understanding of current helminth control practices on studs. To our knowledge, this is the first occasion that statements obtained from TB studs via questionnaire have been supported by statistical analysis. Despite many respondents indicating high levels of concern regarding anthelmintic resistance, 56% of these establishments that received visiting equines co-grazed these animals with permanent stock and <74% administered anthelmintics prior to integration. In the 12 months preceding the study, most respondents administered frequent macrocyclic lactone (ML) treatments, with none appearing to leave any animals in groups untreated at each administration. Indiscriminate whole group treatments with MLs and movement of animals to 'clean grazing' post treatment (reported by >25% of respondents), indicates that many stud owners/managers are not aware of the strong risk factors for the development of anthelmintic resistance. Few studs had conducted faecal egg count (FEC) analysis in the past and only 22% indicated that they considered this form of analysis beneficial in determining anthelmintic choice. The challenge now is to convince stud owners/managers to deviate from their current practices to control strategies that are more likely to preserve anthelmintic efficacy. Veterinarians need to get more involved in implementing these control strategies, with better emphasis placed on the role of diagnostic tests in facilitating targeted treatments and in investigating anthelmintic sensitivity in the associated nematode populations.

Role of Diagnostic Testing in Schistosomiasis Control Programs in Rural Ghana

Background: Schistosomiasis affects an estimated 200-300 million people worldwide. Construction of dams has contributed to the high prevalence of urinary schistosomiasis in Ghana. To assist rural villages downstream from the Barekese dam in schistosomiasis control programs, this study evaluated possible detection methods of schistosomiasis. Methods: A cross-sectional survey of volunteers was conducted in a rural setting of Ghana. Five hundred and thirty four (534) volunteers provided symptom information and urine samples for urinalysis. Microscopic egg count of 341 random samples was used to determine prevalence of disease and to analyze effectiveness of urinalysis and symptom information for diagnosing schistosomiasis. Results: Schistosomiasis prevalence was 41.1 % for the village. The highest prevalence was in the 10-14 age groups (71.1 %). Sensitivity and specificity for hematuria was 76.1 and 77.7 % respectively, and proteinuria was 58.2 & 68.7 % respectively. The positive predictive value was highest for hematuria (71.1 %). The highest negative predictive value was among positive proteinuria or hematuria (84.0 %). From urinary symptom information, reporting pain and dark urine yielded the highest positive predictive value (72.0 %). Reporting pain, difficulty, or dark urine yielded the highest negative predictive value (75.8 %). Discussion: The positive and negative predictive values of urine analysis and symptom information may be an inexpensive tool for diagnosing schistosomiasis in areas of high prevalence.

The Future of Neurology

Yogi Berra, the former New York Yankees baseball manager, known for his interesting phraseology, famously once said, “It's tough to make predictions, especially about the future.” While this has become somewhat of a tired cliche, there is an inherent validity to the argument that makes us somewhat cautious and humble in any discussion regarding the future of Neurology. At the risk of fumbling our way toward the truth, we remind ourselves that in order to find the truth, we need to ask the right questions. Other colleagues have written eloquently about the changing role of neurologists (Engstrom and Hauser, 1994; Bradley, 2000; Freeman and Vatz, 2010), and the fundamental changes facing Child Neurology (Ridel and Gilbert, 2010). A continuous stream of advances in basic neuroscience research, gene identification, neurogenomics, cutting-edge genetic techniques, neurodiagnostic tools including advanced neuroimaging technologies (Masdeu and Bakshi, 2005), and longitudinal biomarkers, coupled with new treatment modalities and paradigms for neurologic disease, suggests increased demands on available practitioners. In view of the growing aging population, associated with declines in infant mortality and treatment of infectious disease, more people will suffer from age related neurologic disorders such as stroke, dementia, Parkinson's disease, epilepsy, and autoimmune disorders (Engstrom and Hauser, 1994; Bradley, 2000; Freeman and Vatz, 2010; Weiner, 2007). In the past, a neurologist was recognized particularly for skilled diagnoses using clues derived from a thorough and elaborate history and physical examination, but treatment options were limited. Colloquially, the neurologist would “diagnose and adios.” With the advent of advanced neuroimaging and laboratory techniques, there has been much lament about the disappearance of the neurologists’ much vaunted skill in clinical diagnosis. And yet, the various tests, coupled with advanced treatment techniques, have certainly led to an explosion of opportunity, with both increased demand for neurologists and an increased number of people interested in the field. In the near future, the role of diagnostic testing in clinical neurology (as in all of medicine) will only further accelerate. There will be some value to the diagnostic prowess of neurologists in determining the appropriateness and meaning of complex and potentially unnecessary tests and procedures. As noted by Gooch and Amato (2010), in a discussion of the utility of anti-ganglioside antibodies in the diagnosis of multifocal motor neuropathy: “In this era of limited resources, the judicious exercise of sound clinical judgment in crafting a logical and efficient diagnostic evaluation has never been more important. Careful selection of the best path to the final diagnosis will not only most benefit our patients but will also as health reform continues to advance, insure that our precious (and finite) medical resources are not necessarily wasted” (Gooch and Amato, 2010). Still, academicians simply become Luddites if they lament how testing has superseded the neurologic history and physical examination which were never as accurate as we cared to admit. We respectfully suggest that the future of neurology will be critically dependent on harmonizing the tensions between clinical skills and an over-reliance on testing paradigms. The future of Neurology will also be reflected in the greater opportunities to develop therapeutic interventions, delay, or ideally prevent progressive neurodegenerative diseases, and the roles to be played by the new breed of neurologists in providing these interventions. There will likely be explosive growth in potential medical therapies including novel drugs, human pluripotent stem cell technology and gene therapies, and new immunosuppressant modalities in the near future (Mallarkey, 2008). There will also be an increased role for neurologists in interventional fields such as stroke, pain, neurostimulation, and even neuroregeneration. There will also be a continued separation between the practice of intensive and hospital-based neurology and office-based general and specialty neurology. The parallels with Cardiology/Internal Medicine combined with the growth of procedural non-surgical focused specialists in these fields are both obvious and inevitable given the profound shift toward a treatment oriented focus for neurology in the near future. The challenge for neurology will be whether we can satisfy the need for neurologic expertise in providing these treatments or whether others will pick up the slack for this pent-up demand for aggressive treatment of neurologic disease. The field of neurology remains one of the most dynamic areas of medicine, with advances on many fronts. Frontiers in Neurology offers an unprecedented opportunity for a more accessible, more manageable, and more useful dynamic interactive seminal exchange between the world community of neurologists and neuroscientists striving toward a common goal of excellence. Only by sharing your expertise and knowledge with the neurological community, can we achieve our ultimate goal of improving the quality of life and outcomes for patients with neurological disorders.

Legal Developments and Practical Implications of Gene Patenting on Targeted Drug Discovery and Development

The use of genetic information to design and guide therapies creates novel patent issues. Gene patents have been integral to the introduction of new biologics, but their role in diagnostic testing is controversial. Genotype-phenotype associations are at the heart of personalized medicine. The intellectual property rules by which these biological relationships are governed have profound implications for the growth of this field. Several cases currently before the courts may add reason and clarity to the law in this area.

Quality care: a link between clinical and public health approaches to HIV infection in developing countries

As the importance of quality in health care provision is increasingly recognised, it is opportune to consider quality care as a key link between clinical and public health approaches to human immunodeficiency virus (HIV) infection in developing countries, especially in sub-Saharan Africa. This region has the lion's share of the global epidemic and the least resources to respond. Looking at health problems using a 'quality lens' may help bridge the gaps between clinical care and public health, the current and desired standard of care, and prevention and treatment. Quality care, with prompt diagnosis and effective treatment, of people with HIV infection is crucial for good individual health outcomes, public health outcomes (in terms of decreased HIV transmission) and societal outcomes (increased productivity and decreased costs of health provision for HIV-related care). A spotlight on quality care can bring clinicians and public health practitioners together in working towards universal access to quality HIV care and prevention - one of the greatest health challenges faced in developing countries in Africa today.

Pathology question time - Testing for anaemia

In the first of a series of case studies, Barry Hill introduces the role of diagnostic testing in primary care practice.

An Evidence-Based Systematic Review on the Management of Irritable Bowel Syndrome

An Evidence-Based Systematic Review on the Management of Irritable Bowel Syndrome

Utility of Magnetic Resonance Imaging in Small Bowel Crohn’s Disease

Small bowel involvement in Crohn’s disease (CD) occurs in 70% of patients with CD, and exclusive small bowel involvement is seen in approximately 30% of CD patients. Although endoscopy and histologic examination have served as the gold standard for the diagnosis of CD, diagnosing lesions in the small bowel from the distal duodenum to the terminal ileum has been a challenge. Critically important pathologic observations in CD are that (1) submucosal and serosal-mesenteric involvement is common and commonly involves the processes of fibrosis and/or inflammation and (2) mucosa has a high capacity for repair and evaluation of the mucosa alone may under represent the extent and activity of disease. Because disease management depends on appreciating the degree of active inflammatory disease, and the presence or absence of fistulae, the role of diagnostic tests should primarily be to provide an accurate assessment of these pathologic features. Herein we present the use of magnetic resonance imaging (MRI) as a powerful diagnostic modality for assessing the severity of the submucosa and serosa of small bowel in CD. We present the technical basis of a standard MRI study, and describe the range of MRI features of mild to severe and active in

Thoracic Outlet Syndrome: A 50-Year Experience

"Thoracic Outlet Syndrome: A 50-Year Experience." Baylor University Medical Center Proceedings, 20(3), p. 256

Headache related to brain tumors

Headache is one of the most common somatic complaints of patients seeking medical care. Most headaches are not of serious cause and can be diagnosed easily with a good history and physical examination. The challenges to the physician are to determine when underlying intracranial pathology may be causing the symptoms and signs, and to identify the few patients in whom a tumor is the cause of the headache. The subject of headache in patients with brain tumors has been reviewed in neurologic textbooks and in several investigations before, as well as after, modern imaging diagnostic techniques became available. Headache can also manifest as an acute or chronic complication of radiation treatment and/or chemotherapy in patients with intracranial neoplasm, but there are few data in the literature specifically addressing this subject. This article provides an overview of headache in patients with primary and secondary brain tumor, including headache characteristics, the putative mechanism for these headaches, the role of diagnostic testing, and the general principles of management.

Human Parainfluenza Virus 4 Outbreak and the Role of Diagnostic Tests

Owing to the difficulties in isolating the virus and the lack of routine surveillance, the clinical significance of human parainfluenza virus 4 (HPIV-4) is less well defined than that of the other human parainfluenza viruses. We describe the first outbreak of HPIV-4 infection in a developmental disabilities unit, involving 38 institutionalized children and three staff members, during a 3-week period in autumn 2004. Most subjects had upper respiratory tract infections (URTI), while lower respiratory tract infections (LRTI) occurred in three children (7%), one complicated by respiratory failure requiring ventilation support. All patients recovered. Nasopharyngeal aspirates tested for HPIV-4 were positive by reverse transcriptase PCR (RT-PCR) in all 41 cases (100%), by direct immunofluorescence in 29 of 39 tested cases (74%), and by cell cultures in 6 of 37 cases (16%), and serum was positive for antibodies against HPIV-4 in all 35 cases (100%) with serum samples available. In addition, RT-PCR detected HPIV-4 in four children (three LRTI and one URTI) out of 115 patients with community-acquired respiratory tract infection. Molecular analysis of the 1,198-bp phosphoprotein sequences showed that HPIV-4 isolates among the cases were genetically similar, whereas the community controls were more genetically distant, supporting nosocomial transmission of a single HPIV-4 genotype during the outbreak. Moreover, the HPIV-4 causing the outbreak is more closely related to HPIV-4A than HPIV-4B. HPIV-4 may be an important cause of more severe respiratory illness in children. The present RT-PCR assay is a sensitive, specific, and rapid method for the diagnosing HPIV-4 infection. To better define the epidemiology and clinical spectrum of disease of HPIV-4 infections, HPIV-4 should be included in the routine panels of respiratory virus detection on respiratory specimens.

The brugada syndrome

The diagnostic and therapeutic aspects of Brugada syndrome, one of the important genetic arrhythmias which causes sudden cardiac death in young people, and the relevance of this diagnostic entity to the paediatric population are briefly summarised. The role of diagnostic testing (genetic, pharmacologic and invasive electrophysiologic) for establishing the diagnosis and for risk stratification are discussed. Finally, while the implantable defibrillator is the only therapy of proven effectiveness in preventing sudden cardiac death, alternative therapies which are being considered (pharmacologic, hormonal and catheter ablation) are overviewed. The aim of this manuscript is to raise the awareness among doctors caring for young patients to the possibility of Brugada syndrome in patients presenting with potentially life-threatening symptoms of syncope or near-miss sudden death, and in index patients with a similar family history.

Testing for Helicobacter pylori in the clinical setting.

There are a variety of tests available to identify Helicobacter pylori infection. These tests can be divided into those that do not require and those that do require endoscopy. This review provides a detailed discussion of the available diagnostic tests for H. pylori infection. Special attention is paid to the role of diagnostic testing in the management of patients with H. pylori-related disease. The potential advantages and disadvantages of various tests and the role of testing to confirm eradication after treatment for H. pylori is also discussed.

The Diagnosis of Deep-Vein Thrombosis: An Application of Decision Analysis

Using information from the medical literature on the accuracy and complications of diagnostic tests and therapy, a decision-analysis model is developed and used to evaluate alternative diagnostic strategies for deep-vein thrombosis. With the help of an integrated computer-software package, the probability of death or major complication of different diagnostic strategies is computed, and the strategies exhibiting the least morbidity and mortality are identified. The sensitivity of the results to changes in the parameters of the model are explored. The work provides surprising insights into the role of diagnostic tests.

The Hazards of Bedside Bayes

Those who advocate the use of Bayesian or decision-analysis approaches to solve clinical problems often assume that data on the sensitivities and specificities of diagnostic tests are readily obtainable and reliable. For the most part, however, there is little information currently available on the sensitivities and specificities of common tests. A critical review of the literature was performed for seven commonly used tests. This study showed that there is significant variability among the reported results of five of these tests. Such variability was not expected but is one more factor that any quantitative approach must consider. Two tests, the rapid-sequence excretory urogram and the thallous chloride TI 201 cardiac stress test, did not, however, show significant variation among the reported sensitivities and specificities. These findings have relevance to clinicians attempting to diagnose disease, to advocates of quantitative decision making, and to researchers seeking to clarify the nature and role of diagnostic tests.

Role of diagnostic tests in esophageal evaluation

In the evaluation of esophageal disease, the appropriate question must be asked before the correct tests can be selected. Reflux can be demonstrated by radiologic methods, pH testing or radioisotopic techniques. Esophageal mucosal damage is best evaluated by x-ray, endoscopy or biopsy. Chest pain is demonstrated by acid infusion or by manometry. Two algorithms are presented for the evaluation of chest pain and reflux symptoms.

Experiences with the technique and complications of meglumine iothalamate (Conray) ventriculography.

The development of contrast ventriculography is outlined and an experience with 40 meglumine iothalamate ventriculograms in 37 patients is described. The details of the procedure, hazards, value, and indications are discussed.