[Experiences with assessment of frontobasal defects, a diagnostic concept]

Spontaneous sphenoid sinus cerebrospinal fluid leak and meningoencephalocele - are they due to patent Sternberg's canal?

Sternberg's canal is a congenital bony defect in the lateral wall of the sphenoid sinus. If it persists to adulthood, it may become a source of spontaneous cerebrospinal fluid leak (CSF) and meningoencephalocele. The aim of the study was to describe the authors' experience and review articles related to spontaneous sphenoid sinus CSF leaks and Sternberg's canal. We analysed patients managed surgicallly due to sphenoid sinus CSF leak and performed a PubMed database search. Two female patients with spontaneous CSF leak of sphenoid origin were found. Both patients underwent surgery with the endoscopic endonasal approach, and the defect was closed using the multi-layer technique. Twelve articles related to CSF leaks of sphenoid origin (due to Sternberg's canal) were found in the PubMed database. Lines of lesser resistance within sphenoid bone may underlie CSF leak pathology together with intracranial hypertension. The endoscopic transnasal approach to the sphenoid sinus is an excellent alternative to standard transcranial procedures.

Nontraumatic skull base defects with spontaneous CSF rhinorrhea and arachnoid herniation: imaging findings and correlation with endoscopic sinus surgery in 27 patients

BACKGROUND AND PURPOSE

Defects at the skull base leading to spontaneous CSF rhinorrhea are rare lesions. The purpose of our study was to correlate CT and MR findings regarding the location and content of CSF leaks in 27 patients with endoscopic sinus surgery observations.

MATERIALS AND METHODS

Imaging studies in 27 patients with intermittent CSF rhinorrhea (CT in every patient including 10 examinations with intrathecal contrast, plain CT in 2 patients, and MR in 15 patients) were analyzed and were retrospectively blinded to intraoperative findings.

RESULTS

CT depicted a small endoscopy-confirmed osseous defect in 3 different locations: 1) within the ethmoid in 15 instances (53.6% of defects) most commonly at the level of the anterior ethmoid artery (8/15); 2) adjacent to the inferolateral recess of the sphenoid sinus in 7 patients including one patient with bilateral lesions (8/28 defects, 28.6%); 3) within the midline sphenoid sinus in 5 of 28 instances (17.9%). Lateral sphenoid defects (3.5 +/- 0.80 mm) were larger than those in ethmoid (2.7 +/- 0.77 mm, P < or = 0.029) or midsphenoid location (2.4 +/- 0.65 mm, P < or = 0.026). With endoscopy proven arachnoid herniation in 24 instances as reference, MR was correct in 14 of 15 instances (93.3%), CT cisternography in 5 of 8 instances (62.5%). Plain CT in 1 patient was negative.

CONCLUSION

In patients with a history of spontaneous CSF rhinorrhea, CT was required to detect osseous defects at specific sites of predilection. MR enabled differentiating the contents of herniated tissue and allowed identification of arachnoid tissue as a previously hardly recognized imaging finding.

Combined HRCT and MRI in the detection of CSF rhinorrhea

Cerebrospinal fluid (CSF) rhinorrhea is a potentially dangerous problem. Accurate preoperative localization of the site of leakage is mandatory. The standard diagnostic technique is computed tomography (CT) cisternography. Because of its related risks, however, various alternatives have been suggested. High-resolution CT (HRCT) provides good bony details, but fluid is poorly detected. In contrast, T2-weighted magnetic resonance imaging (MRI) shows CSF as a bright signal, but spatial resolution is poor as is the depiction of bony details. To overcome the shortcomings of both techniques, we superimposed the images obtained from each modality and used the result to plan surgical explorations. The sensitivity of HRCT was 88.25%. Fat-suppressed T2-weighted MRI detected a CSF-like density in 18 cases (90%) with a sensitivity of 88.88%. Superimposing the CTs and MRIs accurately localized the site of CSF leakage in 17 of 19 cases with a sensitivity of 89.74%. This finding compares favorably with the results of other techniques. We thus recommend this technique as the primary diagnostic method of choice for the investigation of patients with CSF rhinorrhea.

Comprehensive Algorithm for Skull Base Dural Lesion and Cerebrospinal Fluid Fistula Diagnosis

OBJECTIVES/HYPOTHESIS

Skull base dural lesions and cerebrospinal fluid (CSF) fistulas are potentially vital conditions whose diagnosis can be challenging. The authors' aim was to compose a comprehensive algorithm that combines the most modern diagnostic tools in easily applicable patterns to indicate a possible dural lesion or CSF fistula.

STUDY DESIGN

Prospective clinical study.

METHODS

The authors collected the data of all patients with suspicion of CSF fistula or dural lesion, or both, between January 1999 and December 2002. Beta-trace protein, beta2-transferrin, and endoscopic and laboratory sodium fluorescein tests; high-resolution computed tomography; and magnetic resonance cisternography were used according to the symptoms and etiological factors. The results of the diagnostic tools that were used and intraoperative findings (in case of an operative treatment) were reviewed.

RESULTS

From 1999 to 2002, 236 patients were evaluated because of suspicion of dural lesion or CSF fistula, mostly after head trauma. Pattern I of the algorithm was applied for head trauma in dural lesion or CSF leak assessment, pattern II for postoperative CSF leaks, pattern III for evaluation of spontaneous CSF rhinorrhea, and pattern IV for the assessment of recurrent pneumococcal meningitis related to dural lesions without CSF fistula. By applying the patterns of this algorithm, a dural lesion or CSF leak that was also confirmed intraoperatively was detected in 48 patients.

CONCLUSION

The four patterns of the new diagnostic algorithm described in the present study enable physicians to reliably clarify suspicions of dural lesions and CSF fistulas and aim to help them choose the best possible management. Each pattern uses the optimal combination of CSF tests and radiological imaging to reach a synergistic effect for precisely detecting dural lesions or CSF fistulas. Accordingly, this improves surgical decision-making when necessary.

Predictive values of beta-trace protein (prostaglandin D synthase) by use of laser-nephelometry assay for the identification of cerebrospinal fluid

OBJECTIVE

beta-Trace protein (beta-TP) is an immunological marker for the detection of cerebrospinal fluid traces. The aim of the study was to evaluate the predictive values of a new research assay for beta-TP.

METHODS

A total of 154 specimens from patients with otorrhea or rhinorrhea were investigated for cerebrospinal fluid (CSF) by use of a laser-nephelometric assay for beta-TP. Samples were obtained between January 1994 and November 2000. A sample was reported to be positive for CSF when the beta-TP concentration was more than 6 mg/L. Case evaluations were performed retrospectively and tabulated for indication, clinical course, additional investigations, surgical procedure, and follow-up.

RESULTS

beta-TP was detected in 16 specimens; 138 samples were negative for beta-TP with a value less than 3 mg/L. One sample was suggestive of CSF traces at 4.6 mg/L. In correlation with the clinical course, the intraoperative findings, intraoperative visualization with sodium fluorescein, high-resolution computed tomography of the paranasal sinuses or the petrous bone, computed tomographic cisternography, magnetic resonance imaging, and radionuclide cisternography, there was no false-positive result. On four occasions, false-negative results occurred, with an overall accuracy of 0.974. The beta-TP test had a negative predictive value of 0.971 and a positive predictive value of 1.

CONCLUSION

Analysis of betas-TP via the nephelometric assay is a valuable and reliable test in cranial base surgery for the identification of CSF.

Clinical experience with beta-trace protein as a marker for cerebrospinal fluid

beta-Trace protein is an immunological marker for the detection of cerebrospinal fluid traces. The aim of the study was to evaluate the predictive value of the beta-trace protein test. We investigated 145 specimens for cerebrospinal fluid using beta-trace protein. All case notes were retrospectively reviewed and tabulated for indication and procedure with focus on outcome. The specimens were analyzed by immunoelectrophoresis. beta-Trace protein was detected in 62 specimens and was absent in 83. In correlation with the clinical course, the clinical findings, the results of high-resolution computed tomography of the paranasal sinuses or petrous bone, computed tomographic cisternography, magnetic resonance imaging, indium 111-pentetic acid radionuclide cisternography, intraoperative findings, and visualization using sodium-fluorescein, there were no false-positive results. In 6 cases, a false-negative result occurred. The overall accuracy was 95.68%. The beta-trace test has a specificity of near 100% and a sensitivity of 91.17%. Analysis of beta-trace protein is a valuable test and has some advantages in comparison with the beta2-transferrin assay.

Outcomes of a population-based asthma management program: quality of life, absenteeism, and utilization

BACKGROUND

Despite the availability of the National Asthma Education Program (NAEP) guidelines since 1991, asthma remains inadequately managed. To improve quality of life, functional status, and self-management behavior of asthma patients, a large health maintenance organization (HMO) in California implemented an asthma management program in 1996.

OBJECTIVE

To evaluate the effectiveness of an asthma management program in an HMO setting.

DESIGN AND SETTING

Prospective study. Survey data from members who participated in the intervention program and data from members who received usual care were analyzed using propensity score technique.

RESULTS

A total of 1,043 asthma patients who responded both baseline and follow-up survey were included in the analysis. From baseline to followup, participants in the in-home intervention program reported significant improvement in functional status (improvements range from 0.2 to 7.2), daily use of steroid inhaler (+4.1%), daily peak flow meter use (+6.4%), self-reported knowledge of what to do for an asthma attack (+12.4%), and feeling that their asthma was under control (+10.8%). Absenteeism (-11.8%) and hospitalization due to asthma (-3.5%) were significantly reduced from baseline to follow-up. Participants did not report significant changes in overuse of beta2-agonists and emergency room visits due to asthma. In comparison with the asthmatic patients who received usual care (non-participants), participants had significantly greater improvement on daily use of steroid inhaler (+4.0% versus -6.0%), daily use of home peak flow meter (+6.4% versus 1.9%) and self-reported knowledge on what to do for an asthma attack (+12.4% versus +5.4%).

CONCLUSION

These findings suggest that population-based programs can improve functional status, increase self-monitoring and knowledge about asthma, and decrease absenteeism and hospitalization for asthma by directly providing asthmatic patients with educational materials and self-monitoring tools. Such "direct-to-consumer" outreach programs may help bridge the gap between NAEPs 1991 practice guidelines and the reality of current asthma management.