Evaluation of CSF leaks: high-resolution CT compared with contrast-enhanced CT and radionuclide cisternography. (1/55)

BACKGROUND AND PURPOSE: Radiologic evaluation of CSF leaks is a diagnostic challenge that often involves multiple imaging studies with the associated expense and patient discomfort. We evaluated the use of screening noncontrast high-resolution CT in identifying the presence and site of CSF rhinorrhea and otorrhea and compared it with contrast-enhanced CT cisternography and radionuclide cisternography. METHODS: We retrospectively reviewed the imaging studies and medical records of all patients who were evaluated for CSF leak during a 7-year period. Forty-two patients with rhinorrhea and/or otorrhea underwent high-resolution CT of the face or temporal bone and then had CT cisternography and radionuclide cisternography via lumbar puncture. The results of the three studies were compared and correlated with the surgical findings in 21 patients. RESULTS: High-resolution CT showed bone defects in 30 of 42 patients (71%) with CSF leak. High-resolution, radionuclide cisternography and CT cisternography did not show bone defects or CSF leak for 12 patients (29%) who had clinical evidence of CSF leak. Among the 30 patients with bone defects, 20 (66%) had positive results of their radionuclide cisternography and/or CT cisternography. For the 21 patients who underwent surgical exploration and repair, intraoperative findings correlated with the defects revealed by high-resolution CT in all cases. High-resolution CT identified significantly more patients with CSF leak than did radionuclide cisternography and CT cisternography, with a moderate degree of agreement. CONCLUSION: Noncontrast high-resolution CT showed a defect in 70% of the patients with CSF leak. No radionuclide cisternography or CT cisternography study produced positive results without previous visualization of a defect on high-resolution CT. CT cisternography and radionuclide cisternography may be reserved for patients in whom initial high-resolution CT does not identify a bone defect or for patients with multiple fractures or postoperative defects.  (+info)

Advanced glycation end products in human optic nerve head. (2/55)

AIMS: To localise advanced glycation end products (AGEs) in human optic nerve head. METHODS: Optic nerve samples from 13 elderly individuals (seven diabetics and six non-diabetics) were obtained at necropsy. Pyrraline, an advanced glycation end product, was immunohistochemically localised in the optic nerve heads. RESULTS: In the diabetic subjects, moderate to intense immunoreactivity for pyrraline was detected in sclera, pia mater, cribriform plates, connective tissues in the optic nerve, and around vessels in the optic nerve and pia mater. Immunoreactivity for pyrraline was also detected around retinal vessels. In the non-diabetic subjects, slight or no immunoreactivity for pyrraline was found in cribriform plates and around the optic nerve vessels. CONCLUSION: Accumulation of AGEs in cribriform plates and around vessels in the optic nerve may contribute to the development of optic neuropathy in diabetic patients.  (+info)

A critical evaluation of the pitchfork analysis. (3/55)

The pitchfork analysis has gained increasing acceptance among researchers and clinicians to evaluate the effects of orthodontic treatment that can be measured on lateral cephalometric radiographs. It is primarily used in Class II cases to distinguish between the skeletal and dental effects of such treatments. The aim of this study was to conduct an objective evaluation of the pitchfork analysis by comparing cephalometric data obtained by that method with those using the more conventional and established method of Bjork. The pitchfork analysis consistently provided an overestimation of the skeletal effects and an under-estimation of the dental changes. These results indicate that the pitchfork analysis is not sufficiently sensitive to distinguish between the skeletal and dental effects of orthodontic treatment.  (+info)

Epignathus: always a simple teratoma? Report of an exceptional case with two additional fetiforme bodies. (4/55)

We report on a case of a fetal epignathus combined with two fetus-like structures resembling acardius acranius. The anomaly was detected at 23 weeks of gestation and led to termination of pregnancy at 24 weeks. This is the first description of epignathus with parasitic fetuses detected prenatally. It shows that the boundary between fetal teratoma and multiple pregnancy in special cases may be difficult to define.  (+info)

Morphological relationship between the cranial base and dentofacial complex obtained by reconstructive computer tomographic images. (5/55)

The aims of this study were to investigate the relationships between the cranial base, including the glenoid fossa and maxillofacial morphology, obtained by three-dimensional (3D) computed tomography (CT). The specimens were 45 Skeletal I and Skeletal II dry skulls of modern Japanese males without marked crowding, anterior crossbite, or maxillofacial asymmetry, which had been preserved in the Tokyo University Museum. To examine the differences in the cranial base and maxilla between two groups classified by the median value of N line-A [N defined as a perpendicular line to Frankfort horizontal (FH) through point N, and N line-A as the distance between N and point A]. The specimens with an N-A line less than 1.5 mm were classified as the small group, and those with an N line-A more than 1.5 mm as the large group. Correlation coefficients showed that S-SE was positively related to N-Ba, S-N, S-Ba, and angleFH to S-Ba, and negatively related to SE-N. Ba-X, Ba-Y and Gf-X showed positive correlation with S-Ba and angleFH to S-Ba. For the small group S-SE was longer, angleFH to S-Ba was larger, and Ba-X, Gf-X, A-X, ANS-X, and PNS-X located more posterior and in addition more inferior in ANS-Y. The evidence suggests that S-SE, which is a main component factor of the anterior cranial base, and the antero-posterior position of glenoid fossa, is related to the position of the maxilla. The length and inclination of the posterior cranial base, which is related to Ba, influenced the position of the glenoid fossa.  (+info)

THE PATHOGENESIS OF HERPES VIRUS ENCEPHALITIS. I. VIRUS PATHWAYS TO THE NERVOUS SYSTEM OF SUCKLING MICE DEMONSTRATED BY FLUORESCENT ANTIBODY STAINING. (6/55)

The pathogenesis of herpes simplex virus encephalitis and myelitis was studied in suckling mice using routine titration procedures and fluorescent antibody staining for the identification of infected cells. After intracerebral inoculation virus was shown to disperse rapidly in the cerebrospinal fluid (CSF), multiply in meninges and ependyma, and then invade the underlying parenchyma infecting both neurons and glia. Following extraneural inoculation virus gained access to the central nervous system (CNS) by both hematogenous and neural pathways. After intraperitoneal and intranasal inoculation virus was found to multiply in viscera and produce viremia; foci of CNS infection then developed around small cerebral vessels. After subcutaneous and intranasal inoculation neural spread of virus was demonstrated along corresponding peripheral and cranial nerves. This spread resulted from the centripetal infection of endoneural cells (Schwann cells and fibroblasts). Antigen was not found in axons even after infection of the corresponding ganglion cell perikaryon. Subsequent spread within the CNS was unrelated to neural tracts, and there was no evidence of axonal spread of virus in the host-virus system studied. These findings are discussed in relation to previous and current theories of the viral "blood-brain barrier" and neural pathways of infection.  (+info)

Penetration of telithromycin into the nasal mucosa and ethmoid bone of patients undergoing rhinosurgery for chronic sinusitis. (7/55)

OBJECTIVES: Telithromycin has a broad spectrum of activity against respiratory tract pathogens including penicillin- and macrolide-resistant streptococci. The aim of the study was to investigate the penetration of telithromycin into nasal tissue following a single oral dose of 800 mg. PATIENTS AND METHODS: A total of 29 patients undergoing rhinosurgery for chronic sinusitis were evaluated. Samples of blood, nasal mucus, nasal mucosa and ethmoid bone were collected during surgery in groups of 5-6 patients after 3, 6, 9, 15 and 24 h following a single oral dose of 800 mg telithromycin. Drug concentrations were determined by HPLC with fluorimetric detection. RESULTS: The highest telithromycin concentrations were observed after 3 h in plasma as well as in all tissues sampled. The mean plasma concentrations were 0.73 mg/L in the 3 h group and 0.02 mg/L in the 24 h group. The concomitant tissue concentrations were higher. The tissue penetration, expressed by the ratio of the area under the concentration-time curve in tissue versus plasma, was 1.0 for nasal mucus, 5.9 for nasal mucosa and 1.6 for ethmoid bone. CONCLUSIONS: Telithromycin achieved tissue concentrations that were generally above the MIC(90) for common pathogens in upper respiratory tract infections. These results indicate that telithromycin diffuses rapidly into the nasal tissues and achieves high and prolonged concentrations in nasal mucosa and ethmoid bone.  (+info)

Nasal dermoid with intracranial extension. (8/55)

Nasal dermoids are rare congenital anomalies, which usually present in early childhood as a midline nasal mass that requires surgical management. It is important to rule out any intracranial extension before subjecting the patient to surgery. We describe a case of nasal dermoid with intracranial extension. The embryology of the formation of the nasal dermoid, cyst and sinus, with the role of CT scan and MRI in diagnosing intracranial extension, and its management are discussed.  (+info)