Primary meningeal lymphoma in a horse

Primary meningeal lymphoma was diagnosed in an 18-year-old Morgan gelding. The horse was examined because of a 3-day history of progressive ataxia and weakness. The gait abnormalities were worse on the left side, and the pelvic limbs were more affected than the thoracic limbs. Additional findings included signs of depression, miosis of the left pupil, ptosis of the left upper eyelid, and areas of muscle atrophy on the left side of the neck and over the dorsal aspect of the left scapula. Inflammatory changes were evident in the CSF. At necropsy, there was diffuse and irregular thickening of the dura mater along the entire spinal cord. Histologic examination revealed infiltration of the leptomeninges with neoplastic lymphocytes.     

Ruptured de novo aneurysm induced by ethyl 2-cyanoacrylate: case report

OBJECTIVE AND IMPORTANCE: We report a rare case of a ruptured de novo aneurysm induced by ethyl 2-cyanoacrylate. CLINICAL PRESENTATION: A 44-year-old woman had undergone microvascular decompression for a right-sided facial spasm. The preoperative vertebral angiogram did not show any aneurysmal dilation. The right anteroinferior cerebellar artery, which was compressing the exit zone of the facial nerve, was detached and fixed to the dura mater with ethyl 2-cyanoacrylate. Nine years later, the patient suffered a subarachnoid hemorrhage caused by the rupture of a newly developed aneurysm of the right anteroinferior cerebellar artery. INTERVENTION: The aneurysm was clipped 2 days after onset of the subarachnoid hemorrhage. It consisted of two bulges in the arterial wall on the proximal side of the meatal loop. One bulge was stuck to the dura mater of the pyramis by ethyl 2-cyanoacrylate, which had been used in the microvascular decompression 9 years previously. CONCLUSION: This is the first reported clinical case of a de novo aneurysm induced by a cyanoacrylate adhesive. Ethyl 2-cyanoacrylate can damage the arterial wall and induce a de novo aneurysm.     

Infantile myofibromatosis located in the temporal bone

Infantile myofibromatosis (IM) is a proliferative disorder of infancy and early childhood characterized by the nodular or diffuse growth of lesions that are comprised of a mixture of mesenchymal elements. Intracranial involvement is reportedly rare, only eight such patients having been reported to our knowledge. We report on a 4-year-old boy with intracranial IM with a mass in his left temporal bone. A previous report on intracranial IM proposed that the underlying dura mater should be resected because of the possibility of early recurrence. At surgery in this case, the tumor was noted to be located in the bone itself and did not arise from the underlying dura. Therefore, the underlying dura mater and venous sinus were preserved. The follow-up MRI showed no sign of recurrences. It may not to be necessary to resect the dura mater in patients with intracranial IM.     

Does the subdural space exist?

A potential space between the dura mater and the arachnoides is thought to exist, occupied by a serous fluid and called the subdural space. Recent studies may change this classical concept, however. The dura-arachnoid complex from the epidural to the arachnoid space is formed by morphologically distinct layers: the dura mater, the subdural compartment and the arachnoid mater, which are made up of different cell types. The dura mater consists of greater and lesser laminae formed mainly of collagen fibers aligned differently. The subdural compartment is formed by a number of so-called "neurothelial cells", which are in close contact with the inner dural layers. These cells are flat and have long interlaced branches. The arachnoides are made of cells grouped in three different layers. The outer layer is the "barrier arachnoid layer". Located just inside the anterior cell plane, this layer is made of less flattened cells that form an epithelial-type tissue, with complex cell-cell junctures surrounded by collagen fibers. The middle layer is the reticular arachnoid, composed of irregularly interlaced cells alternating with collagen fibers and intercellular gaps of varying sizes. The innermost layer, the trabecular arachnoid, is in direct contact with the subarachnoid space. The cells of this layer form strands that contribute to the weblike pattern found in the subarachnoid space. Recently, special techniques for fixing and preparing samples, preserving in situ the anatomical relations between the arachnoides and the dura mater, have allowed us to examine the normal configuration of the subdural space. All samples examined revealed the presence of a cellular plane between the dura mater and the arachnoides, with no evidence of the classically described space. The zone of least resistance in the dura-arachnoid complex was the subdural compartment, which could be torn mainly along intercellular spaces, though cell rupture was also observed, affecting the cytoplasmic membranes of adjacent cells. The subdural space is opened by tearing the subdural compartment between neurothelial cells alongside the collagen fibers of the dura mater. Such a tear can be caused mechanically by injecting air or contrast media, which exert pressure on a laminar structure that tends to separate because it is weaker than neighboring ones.     

Inhibition by dexamethasone of human neutrophil apoptosis in vitro

The efficacy of collagen-sponge to reduce postoperative scar formation was investigated in 65 Japanese white rabbits that received laminectomy in the 7th and 8th thoracic vertebra. The defect after laminectomy was filled by collagen-sponge in 25 rabbits, by free fat in 20 rabbits, and by nothing in 20 rabbits as controls. The animals were sacrificed 2, 4, 8 and 12 weeks and additional 5 rabbits of which defects were filled with collagen-sponge were sacrificed after 24 weeks. All the defects were examined histologically. At 4 weeks after laminectomy, the defects filled by collagen-sponge showed that fibrous tissue had invaded into the sponge, but there was no remarkable adhesion to the dura mater. At 8 weeks, the defect with collagen sponge showed foaming cells, and no thickening of the dura mater was observed. At 12 weeks, the grouping of foaming cells was partially replaced by fat cells. At 24 weeks, most of the foaming cells were replaced by fat cells, and the defect was then similar to that filled by free fat at 12 weeks. In contrast, the defect with no interposed membrane was already filled with fibrous tissue at 4 weeks, and adhesion to the dura mater was observed. Although the free-fat graft at 12 weeks postoperatively showed no remarkable adhesion around the dura mater, infiltration of fat tissue into the spinal canal was observed in 2 of 5 rabbits. These results indicated that collagen-sponge can be utilized as a new biomaterial to effectively prevent scar formation after laminectomy.     

Sudden deafness and facial palsy from metastatic bronchogenic carcinoma

A 52-year-old man developed sudden total bilateral deafness, and unilateral facial palsy, without other symptoms and findings. He died two months later of of bronchogenic carcinoma metastatic to dura, brainstem, pons, carebellopontine angle, cerebellum and cranial nerves III, VI, VII and VIII. There was bilateral internal auditory canal erosion. Tumour replaced right facial, acoustic and vestibular nerves. Tumour infiltrated spiral ganglion, cochlear nerve, cochlear aqueduct, and destroyed nearly all facial nerve fibres to the level of the stapedius muscle. No tumour cells were found on the left, but few fibres of facial, acoustic and vestibular nerves survived. Both ears showed some cochlear outer hair cell destruction. Metastatic tumour to temporal bone or dura should be considered when loss of peripheral VIIth or VIIIth nerve function occurs.     

Sensorineural hearing loss caused by NSAID-induced aseptic meningitis

Aseptic meningitis is a rare complication of nonsteroidal anti-inflammatory drug (NSAID) use. Otologic symptoms may include sensorineural hearing loss and tinnitus. A 66-year-old woman sought the care of an otologist for sudden bilateral sensorineural hearing loss and a substantial increase in baseline tinnitus. The patient had previously undergone a left tympanoplasty secondary to cholesteatoma and had been treated for atypical face pain with ibuprofen taken every six hours for three months. Magnetic resonance imaging (MRI) with gadolinium demonstrated abnormal enhancement of the dura mater and the surrounding basal cisterns, with extension of enhancing dura mater into the internal auditory canals. Cerebrospinal fluid examination revealed evidence of aseptic meningitis. An audiogram confirmed new bilateral sensorineural hearing loss. Hearing loss and tinnitus resolved and no abnormalities were observed with MRI when nonsteroidal anti-inflammatory medication was discontinued. Otolaryngologists are well aware of the otologic sequelae in patients with meningitis. However, NSAIDs need to be considered as possible causal agents in the evaluation of meningitis with otologic symptoms.     

The polarization microscopy characteristics of collagen in dura mater transplants

In order to establish the polarizing microscopical characteristics of collagen in preserved dura mater transplants and in controls, a study was performed. Attempt was made for an intrpretation of velocity of collagen rehydratation by means of data of total anisotropy. The results show a faster rehydratation of collagen fibrils in control (unpreserved) dura mater. Changes in the velocity of rehydratation of collagen fibrils in lyophilized dura mater were connected with structural changes during lyophilization. The most appropriate period of time for rehydratation of lyophilized dura mater transplant was determined from the results of the polarizing microscopical study.     

Studies on microbial genome

We treated a 6-year-old child for hyperteleorbitism. We performed a facial bipartition steel wire osteosynthesis of the frontal bone. After 7 years we observed two episodes of pneumococcal meningitis, which were treated with intravenous antibiotic, resulting in a prompt recovery. The computed tomographic scan and nuclear magnetic resonance image showed the steel wire included in the frontal sinus and in contact with the dura mater. Removal of the wire and suture of the dura allowed prompt recovery.     

The neuropathology of South American mummies

Few studies of intracranial mummified brain tissue have been undertaken. This is because of the infrequency in which preserved human central nervous system tissue is encountered and the scarcity of available mummies from different parts of the world. This study undertook a systematic analysis of 15 naturally mummified human brains from 1000 B.C. to 1500 A.D. excavated from the deserts of northern Chile. Gross examination revealed relatively well-preserved dura mater, cerebral hemispheres, cerebellum, and spinal cord in several cases. Five cases showed evidence of intracranial disease. Three cases had evidence of external injury. One case revealed subarachnoid and one case revealed intracerebral hemorrhage. Samples of central nervous system tissues were taken for further analysis. The samples were rehydrated and processed for structural analysis by light and electron microscopy. Light microscopy of the brain parenchyma revealed an eosinophilic staining background with vascular structures but few cellular elements present. The dura mater demonstrated normal dural architecture consisting of collagen fibrils. Electron microscopy did not clearly demonstrate individual neurons or axonal processes. Bundles of collagen fibrils with typical periodicity were clearly seen in the dura mater. The examination of ancient human central nervous system tissues reveals normal and abnormal neuroanatomy.     

Release of immunoreactive substance P in the trigeminal brain stem nuclear complex evoked by chemical stimulation of the nasal mucosa and the dura mater encephali--a study with antibody microprobes

In order to study a possible involvement of substance P in the processing of chemonociceptive input from the nasal mucosa and the dura mater encephali in the spinal trigeminal, the release of immunoreactive substance P was measured in the trigeminal brain stem nuclear complex in anaesthetized rats. Microprobes coated with antibody to substance P were inserted into the lateral area of the brain stem up to 1 mm posterior to the obex corresponding to the trigeminal subnucleus caudalis. When the nasal mucosa was stimulated by topical administration of mustard oil (1% and 5%) into the nostrils, immunoreactive substance P was mainly detected in the dorsal region of the trigeminal brain stem nuclear complex with a maximum in the superficial gray matter. When the dura mater encephali was stimulated by topical administration of Tyrode's solution (pH 6.2), immunoreactive substance P was mainly released in the ventral region of the trigeminal brain stem nuclear complex; with pH 5.5 the release was more diffuse extending from the ventral to the dorsal part of the spinal trigeminal nucleus. Release was maximal rather after than during the administration of the stimuli, and it considerably outlasted the stimulation periods. These data suggest that substance P plays an important role in the processing of chemonociceptive inputs from the nasal mucosa and the dura mater encephali in the trigeminal brain stem nuclear complex. Substance P may be important, therefore, in the generation of those headaches that are caused by affections of the nasal mucosa and the dura mater encephali. Since enhanced levels of immunoreactive substance P were present for considerable time periods beyond the administration of the stimuli, substance P and neurokinin-1 receptors may be involved in long-lasting neuronal events following noxious stimulation.     

Cranial sutures require tissue interactions with dura mater to resist osseous obliteration in vitro

A chemically defined serum-free medium, which supports the development of bones and fibrous tissues of rat calvaria from nonmineralized mesenchymal precursor tissues, was employed to investigate tissue interactions between the dura matter and overlying tissues. Fetal calvarial rudiments from stages prior to bone and suture morphogenesis (fetal days 19 and 20) and neonatal calvarial rudiments with formed sutures (day 1) were cultured with and without associated dura mater. Removal of calvaria for in vitro culture allowed the examination of suture morphogenesis in the absence of tensional forces exerted on the sutures via fiber tracts in the dura mater originating in the cranial base. Ossification of frontal and parietal bones proceeded in a fashion comparable to development in vivo, but the cranial (coronal) sutures--primary sites for subsequent skull growth--were obliterated by osseous tissue union in the absence of dura mater. Bony fusion did not occur when rudiments were cocultured with dura mater on the opposite sides of 0.45 microns polycarbonate transwell filters, suggesting that the influence of dura mater on sutural obliteration was mediated by soluble factors rather than cell-cell or cell-matrix interactions. These results indicate that cell signaling mechanisms rather than biomechanical tensional forces are required for morphogenesis of the calvaria.     

Bulging fontanelle as presenting sign in cystic fibrosis. Vitamin A metabolism and effect on cerebrospinal fluid pressure

A 51/2-month-old infant had the single problem of a bulging fontanelle. A diagnosis of cystic fibrosis with secondary hypovitaminosis A was made by the findings of high sweat chloride values and a low serum carotene level. A greatly accelerated rate of weight gain following the addition of pancreatic enzyme supplements confirmed the presence of malabsorption. The infant developed characteristic fibrosis pulmonary disease at 20 months of age. Animal studies have shown vitamin A deficiency to be associated with increased cerebrospinal fluid (CSF) pressure, diminished absorption of CSF, and pathological findings of thickening and infiltration with mucopolysaccharides of the dura mater around the arachnoid villi.     

A case of idiopathic spinal cord herniation

The authors experienced a case of idiopathic spinal cord herniation with duplicated dura mater. A 63-year-old woman presented right dominant slowly progressive spastic paraplegia and dissociated sensory disturbance. Magnetic resonance imaging (MRI) demonstrated an enlarged dorsal arachnoid space associated with an apparently focally narrowed thoracic cord. The cord was kinked towards the anterior and closely applied to vertebral body at the level of Th3-4. Computed tomographic myelography (CTM) revealed homogeneous filling at dorsal arachnoid space immediately after injection and no defects. At operation multilocular arachnoid cyst and duplicated dura mater was respectively observed dorsally, and ventrally. From defected area of the inner layer, a ventral part of the spinal cord was incarcerated between the two dural layers. After rejection of arachnoid cyst and inner layer was performed, the patient recovered neurologically. Idiopathic spinal cord herniation is a rare disease that shows slowly progressive myelopathy at middle age. The herniations were observed at ventral thoracic cord in all reported cases. The mechanism of this disease is still uncertain. But at least three successive factors seem to be necessary for formation of herniation, 1) abnormal structure of the dura mater such as defect, diverticulum and duplication; 2) adhesion between the cord and the destructive dura mater, and 3) continuous cerebrospinal fluid (CSF) pressure pushing the cord outward from subdural space. In the thoracic spine, mobility is limited compared with the cervical and lumbar spine, and because of physiological curvature the cord situates rather ventrally. For these reasons the incidence of adhesion might be higher at ventral thoracic spine. Although neuroradiological imagings especially MRI and CTM were useful, operative findings were necessary for definitive diagnosis in many reported cases. Considering the effectiveness of surgical treatment, study of the ventral side of the cord should be important to avoid misdiagnosis.     

A case report: CD8 expression in B-cell chronic lymphocytic leukemia (B-CLL). Prognostic significance of the aberrant CD8 expression

We report on a 13-year old girl with severe aplastic anemia and hypertrophic cranial pachymeningitis. She was admitted to our hospital with severe headache and vomiting. A computerized tomographic (CT) scan of the brain on the third day of symptoms showed a hyperdense area in the tentorial region. Magnetic resonance imaging (MRI) showed iso-intensity in the same tentorial region in T1- and T2-weighted images, and gadolinium enhancement of this region suggested a thickened dura mater. Initially, a diagnosis of subdural or subarachnoid hemorrhage was made. Since her platelet count was low (3000/microl) making the patient a poor-risk candidate for surgery, and the area was limited to the dura mater, conservative therapy, including glycerol administration and platelet transfusion, was carried out. Despite clinical improvement 10 days after admission without specific therapy, the iso-intense region on the left side of the tentorial region remained unchanged on MRI. On the other hand, the iso-intense area on the right side of the tentorial region became hyperdense on T1-weighted MRI images and was also enhanced by gadolinium. Cerebrospinal fluid findings were normal except for slightly elevated protein at 62 mg/dl. A diagnosis of hypertrophic cranial pachymeningitis of the tentorial dura mater with hemorrhage on the right side was made. Although hypertrophic cranial pachymeningitis is a rare disease, it must be considered in the differential diagnosis of severe headache in a case of aplastic anemia.     

A case of rapidly progressive T cell type malignant lymphoma which started with multiple cranial neuropathy

A 35-year-old man had suffered from recurrent right trigeminal nerve palsy and flaccid paraparesis for about five months. Cerebrospinal fluid (CSF) showed a marked increase of protein (400 mg/dl) and mononuclear cells (146/mm3), but there were no malignant cells. Antibiotic therapy remitted his inguinal and mediastinal lymph nodes swelling, and trigeminal nerve palsy had recovered spontaneously. Then he developed left trigeminal and facial nerve palsy, mononeuropathy multiplex, and cauda equina syndrome. Nerve conduction studies revealed delayed velocity and reduction of amplitude. Enhanced magnetic resonance imaging showed increased signal intensity in bilateral trigeminal nerves, left internal auditory meatus, and meninges of the basal cistern. Also, there were two mass lesions in cauda equina. They were operated by orthopedist, and were not malignant. After that, CSF cells of malignant lymphoma were elevated and revealed T cell type (large cell). Then the patient exacerbated in bulbar palsy and died. When there is lymph node swelling with multiple neurological deficits, despite remission of lesions and signs, biopsies should be positively pursued early in the patient's clinical course.     

Atractyloside-induced release of cathepsin B, a protease with caspase-processing activity

Craniosynostosis, the premature osseous obliteration of cranial vault sutures, can result from mutations in genes encoding components of growth factor signaling systems or the extracellular matrix (ECM). Little is known of the capacity of osteoprogenitor cells of the cranial sutures to divide or to synthesize ECM in situ. Osteoblasts derived from patients with prematurely fused sutures were reported to express alkaline phosphatase and osteocalcin at elevated levels, while proliferating at a rate comparable to control cells [DePollack et al., JBMR, 1996]; however, the suture osteoprogenitors, the population most likely to show proliferative abnormalities, were not present in the fused sutures used for this study. A model in which rat coronal sutures and associated bones develop normally in vitro, but in which sutures can be induced to fuse in the absence of dura mater, was used to examine cell proliferation and total protein synthesis in unfused sutures cultured in the presence of dura mater or in sutures induced to fuse in the absence of dura mater. Significantly increased cell proliferation was seen in suture cells prior to sutural obliteration, which returned to control levels as sutural fusion proceeded. Collagen synthesis in fusing sutures was elevated compared to non-fusing sutures and comparable to that seen in bone. Results indicated that in the absence of intercellular signals provided by the dura mater, suture cell proliferation increased initially, followed by increased synthesis of collagenous ECM within the suture and subsequent osseous obliteration of the suture. Thus factors originating in the dura mater affected suture cell proliferation and ECM production and were required for the maintenance of suture patency.     

FGF-, BMP- and Shh-mediated signalling pathways in the regulation of cranial suture morphogenesis and calvarial bone development

The development of calvarial bones is tightly co-ordinated with the growth of the brain and needs harmonious interactions between different tissues within the calvarial sutures. Premature fusion of cranial sutures, known as craniosynostosis, presumably involves disturbance of these interactions. Mutations in the homeobox gene Msx2 as well as the FGF receptors cause human craniosynostosis syndromes. Our histological analysis of mouse calvarial development demonstrated morphological differences in the sagittal suture between embryonic and postnatal stages. In vitro culture of mouse calvaria showed that embryonic, but not postnatal, dura mater regulated suture patency. We next analysed by in situ hybridisation the expression of several genes, which are known to act in conserved signalling pathways, in the sagittal suture during embryonic (E15-E18) and postnatal stages (P1-P6). Msx1 and Msx2 were expressed in the sutural mesenchyme and the dura mater. FGFR2(BEK), as well as Bmp2 and Bmp4, were intensely expressed in the osteogenic fronts and Bmp4 also in the mesenchyme of the sagittal suture and in the dura mater. Fgf9 was expressed throughout the calvarial mesenchyme, the dura mater, the developing bones and the overlying skin, but Fgf4 was not detected in these tissues. Interestingly, Shh and Ptc started to be expressed in patched pattern along the osteogenic fronts at the end of embryonic development and, at this time, the expression of Bmp4 and sequentially those of Msx2 and Bmp2 were reduced, and they also acquired patched expression patterns. The expression of Msx2 in the dura mater disappeared after birth. FGF and BMP signalling pathways were further examined in vitro, in E15 mouse calvarial explants. Interestingly, beads soaked in FGF4 accelerated sutural closure when placed on the osteogenic fronts, but had no such effect when placed on the mid-sutural mesenchyme. BMP4 beads caused an increase in tissue volume both when placed on the osteogenic fronts and on the mid-sutural area, but did not effect suture closure. BMP4 induced the expression of both Msx1 and Msx2 genes in sutural tissue, while FGF4 induced only Msx1. We suggest that the local application of FGF on the osteogenic fronts accelerating suture closure in vitro, mimics the pathogenesis of human craniosynostosis syndromes in which mutations in the FGF receptor genes apparently cause constitutive activation of the receptors. Taken together, our data suggest that conserved signalling pathways regulate tissue interactions during suture morphogenesis and intramembranous bone formation of the calvaria and that morphogenesis of mouse sagittal suture is controlled by different molecular mechanisms during the embryonic and postnatal stages. Signals from the dura mater may regulate the maintenance of sutural patency prenatally, whereas signals in the osteogenic fronts dominate after birth.     

Extracerebral metastases of a glioblastoma, in the absence of surgery

A 50 y.o. male presented with a right parietal tumor which was a glioblastoma on stereotactic biopsy. He was treated by radiation and steroids, with clinical improvement. Four months later, he presented with a left preauricular mass and cervical lymphadenopathy. CT scan showed destruction of the left mastoid and filling of the left tympanic cavity. One month later, he suffered progressive dyspnea. Chest X ray showed a mediastinal mass on the right side and numerous bilateral interstitial opacities in the lungs. A bronchial biopsy was inconclusive. His general condition worsened, and he died. Postmortem showed continuous neoplastic infiltration of the left part of the base of skull, extending into the neck. Numerous metastases were present in mediastinal lymph nodes, lung parenchyma, pleura and pleural aspect of the diaphragm. There were no subdiaphragmatic metastases. Neuropathological examination confirmed a poorly differentiated highly malignant glioblastoma with severe necrosis involving the internal part of the parietal lobe extending to the dura mater of the convexity and falx cerebri with invasion of the superior longitudinal sinus which was entirely occluded. The biopsy scar was not infiltrated. Visceral tumors were morphologically identical to the brain tumor. They were strongly GFAP positive and cytokeratin negative. Extraneural metastases of glioblastoma in the absence of surgery are uncommon in adults. Involvement of the dura mater and/or superior longitudinal sinus is an almost constant feature. In our case, this may have led to invasion of the base of skull and secondary regional, lymphatic, and hematogenous spread.     

Linoleic acid desaturation activity of liver microsomes of essential fatty acid deficient and sufficient rats

By employing fluorescent histochemistry and spectrofluorimetry the influence of an original psychotropic substance -- carbidine on the level, localization and accumulation of the adrenergic mediator in Vas deferens, dura mater and the kidney capsule was studied "in vivo" and "in vitro". Carbidine was shown to capable of liberating the adrenergic mediator from the sympathetic nerve fibres of the peripheral tissues without affecting the capture and accumulation of exogenous norepinephrine by adrenergic nerve fibres.