Cross-sectional imaging of primary osseous hemangiopericytoma.

The aim of this study was to assess cross-sectional imaging features and the value of CT and MRI in primary hemangiopericytoma of bone. In five patients with histologically proven primary osseous hemangiopericytoma CT and MR scans were evaluated retrospectively. Both CT and MRI were available in four patients each. In three patients both imaging techniques were available. On CT primary hemangiopericytoma of bone presents as an expansive lytic lesion with bone destruction and inhomogeneous contrast enhancement. Magnetic resonance imaging depicts osseous hemangiopericytoma as hyperintense lesion on T2-weighted images with intermediate signal intensity on T1-weighted images. Curvilinear tubular structures of signal void in the tumor matrix on T1-weighted images and corresponding hyperintense structures on T2-weighted and on fat-suppressed short tau inversion recovery images were present in three patients. Although cross-sectional imaging findings are non-specific, they add to the diagnosis and provide valuable information about the extent of bone destruction and local tumor spread in patients with primary osseous hemangiopericytoma. While CT demonstrates the extent of bone destruction best, MRI better visualizes medullary and soft tissue extension of the tumor. Curvilinear signal abnormalities support the diagnosis of hemangiopericytoma of bone. This imaging pattern is best visualized on fat-suppressed or contrast enhanced T1-weighted MR images.

Use of hydroxyapatite bone cement to prevent cerebrospinal fluid leakage through the frontal sinus: technical report.

OBJECTIVE: To test the efficacy of a simple technique of frontal sinus obliteration during low frontal craniotomy using hydroxyapatite cement instead of more traditional methods, such as pericranial flaps, free muscle or adipose grafts, lumbar drainage, or fibrin glue. METHODS: Eight patients undergoing low frontal craniotomy for intradural surgery had the frontal sinus obliterated by careful removal of mucosa followed by filling of the sinus with hydroxyapatite bone cement. No other adjuncts for preventing cerebrospinal fluid leakage through the sinus were used. RESULTS: At an average follow-up of 9 months, there were no cerebrospinal fluid leaks, infections, instances of resorption, or cosmetic deformities. CONCLUSION: Hydroxyapatite bone cement seems to be a simple and effective method for frontal sinus obliteration and prevention of cerebrospinal fluid leakage.

Treatment of the epileptic patient in the dental office.

Epilepsy is a relatively common problem in children, adults and the elderly. Dentists need to be familiar with the various manifestations of the disease, the anticonvulsant medications (AEDs) the patients are taking, and the complications and side effects of these drugs. In this article the types of seizures and AEDs in common use are described. Guidelines for treatment planning are given. Recommendations are made for managing the patient who has a seizure in the dental office.

Report of congenital anaplastic astrocytoma discovered in a newborn.

Reports of congenital anaplastic astrocytoma have been rare, representing less than 2% of all brain tumors. We present a case of a congenital anaplastic astrocytoma discovered during the first 24 hours after delivery. A recent literature review found 12 additional cases since 1972. The presenting signs, most common findings on neuroimaging, treatment, and outcome are examined.

Assessing short-term recognition memory with forced-choice psychophysical methods.

The rationale and methodology for using computer-controlled forced-choice psychophysical methods to assess short-term recognition memory in human subjects are presented. Here, we use non-verbal computer-synthesized auditory and visual stimuli with an adaptive psychophysical procedure. Sequence-length thresholds (SLTs, span lengths) for randomly generated binary auditory and visual-sequential patterns and simultaneous visual-spatial patterns are determined to assess short-term memory capacity. The SLTs can also be used to equate for initial retention level for delayed matching-to-sample (DMS) or delayed matching-to-non-sample (DMNS) tasks which assess memory decay. The DMS/DMNS tasks have also been modified for use with the forced-choice paradigm. In contrast to many verbal paradigms requiring immediate ordered recall, non-verbal stimuli in a forced-choice paradigm provide a more direct measure of sensory memory because long-term memory, complex encoding/decoding processes, and motor-sequencing factors are minimized or avoided. Furthermore, the forced-choice recognition memory tasks are applicable over a broad age range, are less sensitive to socio-economic factors and educational level, and avoid complex instructions. Taken together, these factors enhance the applicability of these tasks in children and adults with CNS lesions, particularly where cognitive status may be compromised.

Intraspinal hematomas in hemophilia.

We report herein a case of a intraspinal hematoma in a 9-year-old boy with factor IX deficiency. Replacement of factor IX resulted in resolution of symptoms. The most frequent presentations of intraspinal hematomas are neck or back pain, paresis, sensory impairment, and urinary retention. Intraspinal hematomas may have devastating sequelae, including hemiplegia and quadriplegia. The occurrence or development of sequelae are related to the length of time between onset of symptoms and factor replacement. Whenever the physician suspects intraspinal hematoma, immediate replacement should be given to obtain levels of 80-100% prior to any imaging studies. Factor levels should be maintained at 30-50% for 10-14 days while the patient is monitored closely with serial neurological examinations. Most patients respond to factor replacement, but laminectomy should be considered for intractable or progressive cases.

The beginnings of urban ambulance service in the United States and England.

Urban ambulance systems emerged in the second half of the 19th century as an outgrowth of military experiences in both Europe and America. Developing first in cities such as Cleveland and New York, these systems quickly adapted to the urban environment, and modifications in ambulance construction and procedures soon followed. Since first-aid texts for urban ambulances were rare, military texts on battlefield medicine were adapted to emergency medicine in civilian accidents.

Trench foot--a study in military-medical responsiveness in the Great War, 1914-1918.

Along the nearly 15,000 miles of trenches on the western front in the Great War of 1914-1918, a condition known as "trench foot" caused serious attrition among the fighting troops and resulted in swollen limbs, impaired sensory nerves, inflammation, and even loss of tissue through gangrene. Physicians, sanitarians, and military officers explored numerous theories regarding etiology and treatment before focusing on a combined regimen of common-sense hygiene and strict military discipline.