No abstract

This 8-year-old boy presented with a rare case of epidural hematoma of the clivus and atlantoaxial dislocation caused by a hyperflexion injury sustained in a traffic accident. Magnetic resonance (MR) imaging demonstrated an epidural hematoma in the posterior fossa that compressed the pons and medulla. On admission, the patient was confused and had bilateral abducens palsy. He was treated conservatively, and 6 months after admission, the epidural hematoma on the clivus had disappeared on MR imaging and the bilateral abducens palsy was cured. Only two such cases have been reported in the literature. In this report, the authors discuss the mechanism of hematoma formation in this region of the brain.

Abstract.This report presents a unique case of corticotroph cell adenoma in a 30-year-old man without acromegaly or features typical of Cushing's disease, who developed cavernous sinus syndrome following pituitary apoplexy. Magnetic resonance imaging revealed a large intrasellar/suprasellar mass with pituitary hemorrhage and extension of a hematoma to the anterior base of the skull. Urgent transnasal pituitary surgery revealed an acidophilic pituitary adenoma, with immunoreactivity for ACTH and GH and expression of proopiomelanocortin (POMC) and GH messenger ribonucleic acid (mRNA) demonstrated by in situ hybridization.To our knowledge, a silent corticotroph cell adenoma with GH production has never been reported.This type of adenoma may potentially enlarge and develop tumoral hemorrhage because it is free of endocrinological symptoms.

Summary: Myelinated nerve fibers of the human abducent nerve were analyzed with a new staining method that permits simultaneous observation of the axon and surrounding myelin sheath. The following equipment was employed for the measurements: an image-analyzing digitizer, a microscope equipped with a drawing tube (or camera lucida), and a computer for data storage and statistical analysis. The numbers, transverse areas, and circularity ratios of axons were measured in 10 human abducent nerves. The average number was 1,997 with a definite decrease with age, and the Several studies on the number and size of fibers in the human abducent nerve have been conducted, but to our knowledge, these studies have not dealt with age-related changes in the abducent nerve. The aim of the present study was precisely to investigate these changes through an analysis of transverse area, number and shape of axons. Material and MethodsSmall sections of the abducent nerve situated in the subarachnoid space were removed from 10 human cadavers (4 males and 6 females) aged 63-88 years (average age: 74.7 years). The causes of death had no direct or indirect influence on the nervous system, so the abducent nerves were considered to be normal.Fixation: The fixation procedure consisted of two steps as follows: (1) Primary fixation: the material was kept in 3.7% formaldehyde for at least one week. (2) Secondary fixation: the material was immersed in a mixture of 5% potassium dichromate and 5% potassium chromate (1:4 in volume) for three weeks (two weeks at room temperature, and a further week at 37 °C). The volume of fixative was at least ten times the volume of the specimen.Washing: After fixation, tissue blocks fitted with a nylon-mesh bag or a plastic tissue-basket were washed in running water with siphon-operated automatic pipette washer for several hours.Dehydration and celloidin embedding: The tissue blocks were dehydrated with ethanol at 50%, 70%, 90%, 95% and pure, and were then embedded in celloidin. The shrinkage of nerve tissue sections during fixation and embedding amounted to approximately 10% in length.Sections: The blocks were sectioned transversely into 20 p.m thick slices.Staining: The sections were stained with LPH triple stain (Luxol fast blue-periodic acid-Schiffhematoxylin staining). For more details, see the reference section (Goto, 19875)).Morphometry: The systemic sampling method was employed for the measurement of axons. A sampling site at the center of the abducent nerve Correspondence to:

Summary: Unmyelinated nerve fibers of the abducent nerve have occasionally been observed with electron microscopes, but, to our knowledge, they have never been evaluated from the morphometric point of view. We analyzed the aging process of the unmyelinated nerve fibers in the human abducent nerve with the help of a new staining method suitable for morphometric research on the nervous system. We studied numbers and transverse areas of unmyelinated fibers of the abducent nerve in 10 cadavers. Our findings were that (1) these fibers were distributed diffusely, (2) their number decreased with age, and (3) the mean transverse area did not change with age. Most of the unmyelinated axons were thinner than the myelinated axons. These results may be important for analysis of clinical signs in relation to aging and ophthalmologic functions.