James W. Forsen

Tutorials in Clinical Research: Part IV: Recognizing and Controlling Bias

Objective This is the fourth of a series of Tutorials in Clinical Research. 1–3 The objectives of this article are to heighten reader awareness of biases and of methods to reduce their impact and to provide an easy reference document for the reader during future journal reading.

Intracranial complications of pediatric frontal rhinosinusitis

Background The aim of this study was to review the presentation and management of children admitted for intracranial complications arising from frontal rhinosinusitis. We performed a retrospective case series review at two academic tertiary care childrens hospitals. Methods This study consisted of children <18 years old who presented with intracranial complications from frontal rhinosinusitis between January 1, 1990 and December 31, 2002. Relevant literature was reviewed with the assistance of Medline. Presentation, type of intracranial complication, radiographic evaluations, response to treatment, and prognosis were evaluated. Results Sixteen patients were identified with intracranial complications due to frontal rhinosinusitis. Patients were usually older (mean age, 14 years and 3 months), of male gender (M/F, 4.3:1.0), and African American (AA/W, 3.0:1.0). Headache, nasal congestion, and visual changes were the most common early symptoms and neurological findings indicated advanced disease. Subdural (56%), epidural (44%), and cerebral abscesses (19%) were the most common complications. Meningitis alone was identified in 13% and was associated with another intracranial complication in 6%. Multiple intracranial complications were noted in 31%. Polymicrobial cultures were obtained in 50% of patients. Although CT was excellent in identifying orbital pathology, MRI was superior for characterization of intracranial disease. Conclusion Intracranial complications of frontal rhinosinusitis are rare in children. Early symptoms often are nonspecific, with neurological findings more commonly seen in advanced disease. Adolescent African American male patients were found to be at highest risk for intracranial complications from frontal rhinosinusitis. Headache and orbital complaints associated with rhinosinusitis in older children failing to respond to initial therapy should prompt an aggressive evaluation including MRI.

Tutorials in clinical research, Part VIII: Creating a Journal club

Objective The present report is the eighth in a series of sequential tutorials entitled “Tutorials in Clinical Research.” The objective of the report is to provide the reader with information to create or refine a journal club.

Tutorials in clinical research: VII. Understanding comparative statistics (contrast)—part B: Application of T‐test, Mann‐Whitney U, and Chi‐Square

Objective: This tutorial on comparative statistics has been written in two complementary segments. The first paper (part A) focused on explaining the general concepts of the null hypothesis and statistical significance. This second article (part B) addresses the application of three specific statistical tests. These two articles should be read sequentially and the first article should be available for reference while one reads the second. Study Design: Tutorial. Methods: The authors met weekly for 10 months to discuss clinical research articles and the applied statistics. The difficulty was not the material but the effort to make it easy to read and as short as possible. Results: The article discusses the application of three common statistical indexes of contrast, χ 2 , Mann‐Whitney U, and Student t‐test and other concepts, such as sample size, degrees of freedom, errors, power, and confidence intervals. Conclusions: Statistical tests generate a number known as a statistic (χ 2 , U, t), which is sometimes called a “critical ratio” because it helps us to make a decision. This number is then associated with a probability, or P value. Sample size is a crucial element in the initial design of a research project and in the subsequent ability of the results to show statistical significance if the difference is clinically important. The example data used in this paper demonstrate the application of the three specific tests and illustrate the effect of sample size on the results.

Visual loss in a child due to allergic fungal sinusitis of the sphenoid.

Acute blindness due to allergic fungal sinusitis (AFS) is rare and, to our knowledge, has not been previously reported in a child. We present a pediatric case of acute, complete unilateral vision loss related to AFS involving the sphenoid sinus. An otherwise healthy, 11-year-old female presented to St. Louis Children’s Hospital with acute left-sided blindness after a 6-week history of nasal congestion with headaches, photophobia, and right infraorbital hypesthesia occurring the week prior to admission. When the patient noted intermittent blurriness in the vision of her left eye, she was evaluated by her pediatrician and diagnosed with migraine headaches after normal sinus and chest x rays were obtained. Treated symptomatically, her headaches improved but her left-sided visual changes became more pronounced and persistent, with her contralateral vision also becoming blurry. The morning of admission, the patient reported no vision in her left eye, prompting her parents to seek emergent treatment. No pupillary response to light or to accommodation was noted in the left eye and her visual acuity was 20/40 in the right eye. Mild proptosis was noted bilaterally, but no limitations in extraocular muscle motion were identified. Hypesthesia in the distribution of the right infraorbital nerve was also confirmed. The rest of her physical examination was normal. An orbital CT scan was obtained, which demonstrated an expansile lesion involving the sphenoid and posterior ethmoid sinuses bilaterally. Numerous calcifications within the sphenoid sinus were noted and both orbital apices appeared compressed by lateral bony remodeling. (Fig 1). The patient was started on high-dose corticosteroids and

Desmoplastic fibroma of the mandible in an infant

We report the CT and MR imaging findings of a case of a desmoplastic fibroma of the mandible in a 6-month-old girl who presented with a rapidly enlarging facial mass and who represents one of the youngest reported children with this rare tumor. Although imaging is non-specific and these lesions are best distinguished histologically, the desmoplastic fibroma should be considered when there is an occurrence of any bubbly or cystic expansile mandibular lesion presenting in childhood.

Hair relaxer ingestion: a new trend.

Although the health care system has done much to reduce the incidence of ingestion of such alkalis as drain and oven cleaners, in recent years we have seen an overwhelming increase in the incidence of hair relaxer ingestion. In a 5-year review (1987 to 1992) of 48 cases of caustic ingestion, 15 cases involved alkaline hair-relaxing agents. This retrospective study was undertaken to evaluate the agents ingested, the presenting signs and symptoms, the diagnostic procedures, and the outcomes in those 15 cases. Oral cavity and lip burns were common in these children, but none of the 15 had significant esophageal burns. Education of the medical and lay community about the risk of hair relaxer ingestion should be undertaken to reverse this worrisome trend.

Tutorials in Clinical research, part VI: Descriptive statistics

OBJECTIVES This is the sixth in a series of Tutorials in Clinical Research. The objectives of this tutorial are to produce a brief, step-by-step, user-friendly atlas with clinical scenarios and illustrative examples to serve as ready references and, it is hoped, to open an inviting door to understanding statistics. STUDY DESIGN Tutorial. METHODS The authors met weekly for 6 months discussing clinical research articles and the applied statistics. Liberal use of reference texts and discussion focused on constructing a tutorial that is factual as well as easy to read and understand. RESULTS The tutorial is organized into five sections: Overview, Key to Descriptive Summaries, Steps in Summarizing Descriptive Data, Understanding the Summaries of Specific Data Types, and Understanding Scope or Dispersion of Data. CONCLUSIONS Assessing the validity of medical studies requires a working knowledge of statistics; however, obtaining this knowledge need not be beyond the ability of the busy surgeon. Desire is the only limiting factor. We have tried to construct an accurate, basic, easy-to-read-and-apply introduction to the task of summarizing the characteristics of a single variable. This is known as descriptive statistics.

Tutorials in clinical research : Part III. Selecting a research approach to best answer a clinical question

Objective This is the third in a series of sequential “Tutorials in Clinical Research.” 1,2 The objectives of this specific report are to enable the reader to rapidly dissect a clinical question or article to efficiently determine what critical mass of information is required to answer the question and what study design is likely to produce the answer.

Free Jejunal Graft: Effects of Longitudinal Myotomy:

Pharyngoesophageal reconstruction using the free vascularized jejunal graft results in dysphagia in approximately 20% to 40% of patients. This may be caused by graft contractility, and we therefore developed this canine model to assess the functional effects of myotomy on transplanted jejunum. Nine female dogs underwent microvascular transposition of jejunum to the neck, the bowel being placed subcutaneously with two end jejunostomies. Baseline functional manometry was performed. Five animals then underwent complete longitudinal myotomy and four animals underwent a sham procedure. Graft function was then reevaluated after complete wound healing. Contraction frequency, contraction amplitude, and total work done by the graft were recorded; all grafts demonstrated activity and were more active postrecovery than at the time of operation. Although myotomy animals showed a within-group trend to decreased contractility postintervention, this was not statistically significant. Furthermore, there was no significant postintervention difference between the sham and myotomy groups. We conclude that our model is effective for the study of activity in the free jejunal graft and that longitudinal myotomy does not significantly reduce, let alone ablate contraction.