Clinicians caring for patients with brachial plexus and other nerve injuries must possess a clear understanding of the peripheral nervous system's response to trauma. In this article, the authors briefly review peripheral nerve injury (PNI) types, discuss the common injury classification schemes, and describe the dynamic processes of degeneration and reinnervation that characterize the PNI response.
Mark G. Burnett and Eric L. Zager
Sherman C. Stein and Mark G. Burnett
Medical decisions often depend, in part, on cost-effectiveness concerns. Decision analysis is frequently used to help resolve these questions. Unfortunately, this technique has received little attention in neurosurgery. Using an example of moderate head injury, the authors illustrate the utility of this powerful tool in estimating the cost effectiveness of neurosurgical management options.
Mark G. Burnett and Volker K. H. Sonntag
✓ Decisions regarding the return of injured athletes to contact sports after spinal surgery can be complicated. The authors offer a brief overview of the return-to-play guidelines used successfully at their institution for the past two decades when caring for professional and amateur athletes after spinal surgery.
Sherman C. Stein, Neil R. Malhotra and Mark G. Burnett
Matthew C. Cowperthwaite, Deepankar Mohanty and Mark G. Burnett
As their power and utility increase, genome-wide association (GWA) studies are poised to become an important element of the neurosurgeon's toolkit for diagnosing and treating disease. In this paper, the authors review recent findings and discuss issues associated with gathering and analyzing GWA data for the study of neurological diseases and disorders, including those of neurosurgical importance. Their goal is to provide neurosurgeons and other clinicians with a better understanding of the practical and theoretical issues associated with this line of research. A modern GWA study involves testing hundreds of thousands of genetic markers across an entire genome, often in thousands of individuals, for any significant association with a particular disease. The number of markers assayed in a study presents several practical and theoretical issues that must be considered when planning the study. Genome-wide association studies show great promise in our understanding of the genes underlying common neurological diseases and disorders, as well as in leading to a new generation of genetic tests for clinicians.
Sherman C. Stein, Mark G. Burnett and Seema S. Sonnad
The average 65-year-old patient with moderate dementia can look forward to only 1.4 quality-adjusted life years (QALYs), that is, longevity times quality of life. Some of these patients suffer from normal-pressure hydrocephalus (NPH) and respond dramatically to shunt insertion. Currently, however, NPH cannot be diagnosed with certainty. The authors constructed a Markov decision analysis model to predict the outcome in patients with NPH treated with and without shunts.
Transition probabilities and health utilities were obtained from a review of the literature. A sensitivity analysis and Monte Carlo simulation were applied to test outcomes over a wide range of parameters. Using shunt response and complication rates from the literature, the average patient receiving a shunt would gain an additional 1.7 QALYs as a result of automatic shunt insertion. Even if 50% of patients receiving a shunt have complications, the shunt response rate would need to be less than 5% for empirical shunt insertion to do more harm than good. Authors of most studies have reported far better statistics.
In summary, many more patients with suspected NPH should be considered for shunt insertion.
Mark G. Burnett, Seema S. Sonnad and Sherman C. Stein
Many tests have been proposed to help choose candidates for shunt insertion in cases of suspected normal-pressure hydrocephalus (NPH). It is unclear what sensitivity and specificity a prospective test must have to improve outcomes, compared with the results of automatic shunt insertion.
The authors adapted the decision analysis model used in a companion article to allow for application of a screening test. Using the reported sensitivities and specificities of several such tests, they evaluated the effects such tests would have on the expected outcome of an average 65-year-old patient with moderate dementia. They also evaluated the cost-effectiveness of a theoretical screening test with superior sensitivity and specificity.
Although external lumbar drainage comes quite close, none of the screening tests reported to date have sufficient sensitivity and specificity to improve expected outcome in an average candidate, compared with the results of automatic shunt placement in cases of suspected NPH. In addition, even a theoretically improved test would need to be considerably less expensive than prolonged lumbar drainage to be cost-effective in clinical practice.
Mark G. Burnett, Sherman C. Stein and M. Sean Grady
Object. The goal of this study was to create a searchable database of research manuscripts authored by members of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons (AANS/CNS) to describe the nature and character of the research currently being undertaken by neurosurgeons.
Methods. Manuscripts published by all physician members listed in the 2001 AANS/CNS Membership Directory (6921 physicians) were gathered into a database through individual literature searches of the author name for the calendar year 2001. Duplicate publications were purged and the database was reviewed for accuracy. An internal verification of the database revealed a 4% underreporting rate. Statistics from the database were compiled and displayed with information about AANS/CNS members and their clinical activities.
The AANS/CNS members published a total of 2748 research the manuscripts in 479 different journals during 2001. Thirty-eight percent of the manuscripts (1042 of 2748) were authored by US members and 62% (1706 of 2748) by non-US members. The focus of the majority of manuscripts included the areas of brain tumor (26%; 707 of 2748), vascular disease (20%; 558 of 2748), spine (10%; 282 of 2748), and trauma (8%; 233 of 2748). Sixty-nine percent of manuscripts (1897 of 2748) were retrospective and technical clinical studies, and of these 39% (744 of 1897) were case reports. Laboratory investigations made up 15% (414 of 2748) of all manuscripts, whereas prospective randomized clinical trials represented 1% (34 of 2748).
Conclusions. The majority of AANS/CNS member manuscripts are authored by non—US members despite their small AANS/CNS representation. Most research is clinical, based on retrospective data, and includes a large number of case reports. A disparity exists between what neurosurgeons do clinically and both the quantity and subject of their research.
Shabbar F. Danish, Mark G. Burnett and Sherman C. Stein
Deep venous thrombosis (DVT) remains a source of significant morbidity and mortality in patients who undergo craniotomy procedures. Despite several studies in which the safety and efficacy of various prophylactic strategies were examined, there is still no consensus among clinicians. In this paper the authors review the literature with regard to epidemiological and pathophysiological features, screening methods, and prophylactic measures for DVT.