A case of malignant glioma associated with verbal recent memory disturbance due to left hippocampal atrophy; case report]

Verbal recent memory disturbance was observed in a patient with a malignant glioma associated with left hippocampal atrophy. A 25 year-old male was admitted because of seizures. CT scan and MRI showed enhanced mass lesions in the left temporal lobe associated with ipsilateral hippocampal atrophy. Neurological examination disclosed right homonymous hemianopsia, word amnesia, alexia, agraphia and acalculia. Neuropsychological examination disclosed verbal recent memory disturbance, which consisted of impaired recall of the precisely memorized words after some interruption. Although hippocampal lesions are known to be often associated with cerebrovascular disease, hippocampal atrophy due to brain tumor is quite unusual. This case suggested that the left hippocampus is closely related to verbal recent memory. Hippocampal atrophy in this case conceivably derived from the decreased arterial flow due to perifocal edema or obstructive hydrocephalus.     

Pericallosal lipomas: MR features

We report on six cases of pericallosal lipomas. The T1-weighted sagittal images best demonstrated the relationship between the lipoma and the corpus callosum. In four cases the lipomas surrounded the splenium of the corpus callosum and in two cases the tumors were situated posteriorly and caudally to the splenium. In no case did we encounter an exclusively dorsal pericallosal localization.     

MRI evaluation of the diaphragmal opening: using MRI parallel to the transsphenoidal surgical approach.

Twenty-six adult diaphragma sellae and infundibulae were examined by MRI parallel to the transsphenonidal surgical plane with attention given to the diaphragmal opening. The diaphragmal opening was observed in 11 cases (42.3%). The anteroposterior diame ter of the opening ranged from 4.0 to 14.0 mm (mean 8.8 mm), and the lateral diameter ranged from 6.0 to 14.0 mm (mean 9.5 mm). In the cases of open diaphragma sellae, the infundibulum tended to be located in the posterior part of the diaphragma sellae but this was not statisticallysignificant. On MRI parallel to the transsphenoidal surgical approach, the anatomy of the dia phragma sellae was well evaluated.     

Gliosarcoma of the posterior cranial fossa: MRI findings

We report the MR findings of a biopsyproven gliosarcoma of the posterior cranial fossa. Multiple homogeneously enhancing lesions had shaggy margins and broad-based dural attachments, which may reflect the gliomatous and sarcomatous element of this tumour.     

Why do bridging veins rupture into the virtual subdural space?

Electron microscopic data on human bridging veins show thin walls of variable thickness, circumferential arrangement of collagen fibres and a lack of outer reinforcement by arachnoid trabecules, all contributory to the subdural portion of the vein being more fragile than its subarachnoid portion. These features explain the laceration of veins and the subdural location of resultant haematomas.     

The origin of inner membranes in chronic subdural hematomas

Summary Electron-microscopic findings of inner membranes of chronic subdural hematomas showed multilayered tiers of flattened cells. The basis characteristics of these cells were similar to dural border cells in the human dura-arachnoid interface layer. The cells covering the hematoma surface had indented nuclei with a prominent nucleolus and were abundant in enlarged rough ER, glycogen granules, lipid droplets, and caveolae. The cells in the intermediate layer had thin cytoplasmic extensions containing tonofilaments, which were oriented almost parallel to the long axis of inner membranes. The cells facing the arachnoid surface sometimes showed disintegration of cellular organelles and dissolution of nuclear chromatin. Between these cells and the tiers was an increased amount of extracellular substance, such as collagen fibrils, clastins, and finely granular material, which were often intermingled with blood pigments or fibrins, especially toward the arachnoid surface. In two of the ten cases studied, there was a syncytial mass of arachnoid cells which reinforced the arachnoid surface of inner membranes. Conceivably, a primary extravasation of blood within the dura-arachnoid interface layer may cleave a few tiers of dural border cells, which envelope the inner surface of the hematoma, proliferate, and later on form inner membranes.     

MRI findings on healing process of vertebral fracture in osteoporosis

The healing process of vertebral fracture was investigated in 37 senile osteoporotic patients on serial magnetic resonance imagings (MRIs), including enhancement study with gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA). The healing process was classified retrospectively into six categories in terms of the changes and recovery of T1 and T2 signal intensity and in terms of the local vascularity. Two types of damage foci were identified, and, in each type, three patterns of healing were noted. In the partial collapse type, the focus of damage in the fractured vertebral body was located near the cranial or caudal endplates; in the total collapse type, the focus was located at the center of the body. In each of these two types, fracture healing was smooth, belated, or resulted in nonunion. In the partial collapse type, vertebral fractures healed smoothly (smooth pattern) in 8 cases, belatedly (belated pattern) in 11, and resulted in nonunion (nonunion pattern) in 5. In the total collapse type, vertebral fractures healed smoothly (smooth pattern) in 6 cases, belatedly (belated pattern) in 4, and resulted in nonunion (nonunion pattern) in 3. The percent height of the anterior wall, central portion, and posterior wall was defined to allow accurate calculatation of the collapse of the fractured vertebral body. Chronological changes in the vertebral body height were investigated. Progressive collapse of the vertebral body was minimal in the smooth pattern cases, and most severe in the nonunion pattern cases. Statistical analysis indicated that prediction of the course of the fracture was difficult only with the height of the fractured vertebral body in acute phase. Enhancement study with Gd-DTPA showed that, in fractures with favorable prognosis, the ischemic area in the body tended to be smaller from the beginning, and restoration of vascularity was prompt. On the contrary, in fractures with unfavorable prognosis, the ischemic area was wider, and restoration of vascularity was poor.     

Ultrastructural study of calcification process in the ligamentum flavum of the cervical spine

The ultrastructure of the formation of calcified nodules in three cases of symptomatic calcification of the cervical ligamentum flavum were studied. In some areas of the ligament, extracellular plasma membrane-invested matrix vesicles and thick wall-bound matrix giant bodies with or without mineralized deposits were present. These calcified vesicles and bodies were also encountered in the wide mineralized areas among the collagen and elastic fibers in the ligament. The mineralization process of the calcified nodules in the ligamentum flavum implies that matrix vesicles and matrix giant bodies acquire mineralized precipitates; then some gather in clusters. Calcified deposits may spread to collagen and elastic fibers contiguous with the calcified vesicles and bodies, and some eventually coalesce to make a calcified nodule.