Meningeal Lesions Research Articles

A dosimetric model for intrathecal treatment with 131I AND 67GA

Purpose : Calculations were performed of absorbed dose distributions of the β-emitter 131I and the Auger emitter 67Ga for intrathecal administration. Methods and Materials : The proposed dosimetric model accounts for the macroscopic distribution of the activity, by means of a Medical Internal Radiation Dose Committee approach, and for the microscopic distribution of activity, by means of a point kernel technique. This point kernel approach was used in combination with a distance histogram technique, to study in more detail the absorbed dose distribution in the cerebro-spinal fluid, in the surface of the central nervous system, and in tumor sites. We simulated decreased uptake, as well as highly selective uptake in free-floating tumor cells and in meningeal lesions (1–16 cells thick). Results : In case of limited access to lesions adherent to the pia mater, the β-emitter 131I provides crossfire from the CSF, resulting in a higher absorbed dose (Gy/MBq) in these lesions as compared with the Auger emitter 67Ga. In case of increasing radionuclide uptake, the increment of the absorbed dose in the adherent lesions and the free floating cells from 67Ga is considerable because of the local deposition of energy by this radionuclide. Conclusions : The model might be useful to select the optimal emission characteristics of radionuclides applicable for intrathecal therapy, which is demonstrated in a comparison of the Auger emitter 67Ga and the β-emitter 131I.

Diseases of the intracranial meninges: MR imaging features.

Although the meninges are often thought of simplistically as a connective tissue sac that contains the CSF and the contents of the CNS, they are far more complex. Anatomically, they comprise several layers. Pathologically, numerous disease processes may affect the meninges; different processes may even involve different areas of the meninges. These factors all influence the MR imaging characteristics of meningeal lesions. This review briefly discusses the anatomy of the meninges, the MR imaging technique when meningeal disease is suspected, and the appearance of the normal meninges. It then focuses on tumors, infections, cysts, and other lesions that primarily involve the meninges, excluding lesions that secondarily involve the meninges.

An extended outbreak of infectious peritonitis in a closed colony of european wildcats ( Felis silvestris)

SummaryFeline infectious peritonitis is a multisystemic disease of domestic and exotic cats caused by a coronavirus. An outbreak of feline infectious peritonitis was investigated in a closed colony of European wildcats (Felis silvestris) at a zoological garden. Over a six-year period, a putative fading kitten syndrome occurred in six of 11 litters born and severe lesions of infectious peritonitis occurred in five of the eight wildcats retained in the colony during this period. Lesions were more acute in the early stages of the outbreak and included perivascular pyogranulomatous inflammation with exudative serositis. Lesions occurred only in males. Vascular lesions were common in the liver of all affected wildcats, serositis occurred in the abdominal and thoracic cavities in most cases and meningeal lesions were present in two cases. Immunohistochemistry with specific antisera detected viral antigen within macrophages in all lesions. This outbreak demonstrates that the lesions of feline infectious peritonitis can become modified over time and that the virus can persist in a closed colony, possibly via carrier wildcats.

An Autopsy Case of Purulent Mycobacterial Meningitis in AIDS

The patient was a 46-year-old male hemophiliac who died of acute mycobacterial meningitis associated with AIDS (acquired immune deficiency syndrome). Autopsy revealed severe basal meningitis which was characterized by an infiltration of numerous polymorphonuclear leukocytes. Severe mural inflammation of the subarachnoid arteries was noted, and innumerable acid-fast bacilli were demonstrated. Epithelioid cell granulomas were not found in the meningeal lesion. The lungs, liver, spleen, and bone marrow contained many epithelioid cell granulomas with caseous necrosis. Massive proliferation of swollen histiocytes could not be identified in any organ. The absence of epithelioid cell granulomas in the meningeal lesion indicate a severe impairment of cell-mediated immunity in the patient; this anergic type of lesion is one of the characteristics of tuberculosis occurring in association with terminal AIDS.

Meningeal mesenchymal chondrosarcoma of the spine: A case report

Primary soft-tissue chondrosarcomas are most often of the mesenchymal variety. When affecting the central nervous system, these tumors usually arise from the intracranial meninges. Intraspinal meningeal lesions are much less common but may be considered, especially in the pediatric age group, when clinical or radiologic presentation is atypical. The author presents a case report including MR imaging studies of a 7-year-old girl with intraspinal dural chondrosarcoma.

Prominent meningeal enhancement adjacent to meningioma on Gd-DTPA-enhanced MR images: histopathologic correlation.

To assess tissue changes responsible for enhancement of the meninges adjacent to meningiomas on magnetic resonance (MR) images, the authors correlated the MR imaging characteristics of meningeal lesions seen before and after administration of gadolinium diethylenetriamine-pentaacetic acid (DTPA) with the appearance of these lesions on contrast material-enhanced computed tomographic (CT) images and with histopathologic findings in four patients. Histopathologic examination of meninges showed increased loose connective tissue, hypervascularity, and dilated vessels. There was neoplastic infiltration of the dura mater in two patients but it was restricted to the immediate junction of neoplasm and dura mater, with maximum peripheral extension within 1 mm of the tumor margin. In both patients the meninges were enhanced far beyond the neoplastic infiltration. The other two patients showed no infiltration of dura mater. These findings suggest that pathologic enhancement of meninges adjacent to meningioma after administration of Gd-DTPA mainly represents reactive changes to the neoplasm and does not necessarily indicate neoplastic involvement.

Epidural abscess, vertebral destruction, and paraplegia caused by extending infection from an aspergilloma

An aspergilloma developed in a lung cyst in a 53-year-old man. Aspergillus infection then contiguously spread to the spidural space, causing an abscess, vertebral destruction, and paraplegia at the level of T 4. Chronic alcoholism, liver cirrhosis, and corticosterold treatment may have been predisposing factors In this patient. Although Aspergillus epidural abscess has been described Infrequently, this complication has not been described in association with an aspergilloma. Symptoms, signs, or roentgenographic or laboratory findings suggestive of vertebral or meningeal pathologic lesions In patients with aspergilloma should alert the physician to the possibility of contiguous spread of Infection.

Neuro-ophthalmologic signs in the angiitic form of neurosarcoidosis.

We studied eight patients with CNS sarcoidosis, including two patients with postmortem evidence of sarcoid granulomatous angiitis. Neuro-ophthalmologic findings included perivenular sheathing of retinal veins resembling the dripping of candle wax, vitreous cells, anterior uveitis, optic disk edema or granulomas, and conjunctival granulomas. Perivenous sheathing in the retina and the perivascular meningeal lesions in sarcoid angiitis were identical.

The immune system and the nervous system.

The immune system may interfere with brain function. The central nervous system may also influence the activity of the immune system. The central nervous system is functionally protected by the blood-brain barrier. The central nervous system is functionally protected by the blood-brain barrier. The endothelial cells of the brain capillaries are linked by tight junctions, resulting in an almost continuous interior wall which restricts the transfer of plasma proteins. The barrier function is modified by inflammatory meningeal lesions, stroke and epileptic seizures. Antigenic material may penetrate the barrier and enter the nerve tissue. The phagocytic cells in the central nervous system are mainly of haematogenous origin. The number of such cells in the brain is very low. There are also few lymphocytes under normal circumstances. These cells circulate from the blood, through the vessel walls and into the perivascular spaces, along the perivascular channels and to the CSF and back to the blood. This circulation may increase enormously during inflammatory conditions. In multiple sclerosis, the number of T-lymphocytes in the CSF is increased, corresponding to a preponderance of T-lymphocytes in the perivascular cell infiltrates in and around the lesions. Thus, the individual elements of the immune system are all present in the brain, which is only partially immunologically privileged. The mechanisms underlying the brain's immunological privilege may be of a non-immunological nature. As yet there are only few data which indicate that auto-immunity is a prominent feature in diseases of the human brain. The central nervous system also exerts a modulating influence upon the immune response. This may take place both by secretion of hormones and by a nervous/neurotransmitter influence upon the immune system.

Postnatal mortality, bodyweight gain and wool production to two years of age of lambs surviving caesarean or stressful vaginal birth.

SUMMARY This experiment tested the hypothesis that prolonged, stressful vaginal birth in sheep results in injury to the fetal CNS manifest by meningeal haemorhage, thereby causing increased neonatal mortality or depressed production of affected survivors. Mortality, bodyweight gain and wool production to 740 days of age were measured in single‐reared Merino lambs surviving caesarean (caesarean group) or artificially prolonged vaginal birth (delayed group). Total mortality of live births in the delayed group was higher than that in the caesarean group (38.7% v. 23.7%, p < 0.025). Virtually all the difference was due to higher neonatal mortality in the delayed group within 7 days of birth compared to the caesarean group (34.2% v. 17.1%, p < 0.01). As meningeal haemorrhage was detected at autopsy of the delayed group only, the additional mortality was attributed to birth injury to the fetal CNS. Fifty‐three per cent were affected, at prevalences relative to time of death after birth strongly suggestive of a dose‐response to varying levels of birth injury. Meningeal lesions were present in all lambs dying within 3 hours of delivery and in 32% of those dying over the next 7 days. In the latter the lesions were associated invariably with evidence of starvation and cold injury, implying a causal relationship between the presence of meningeal haemorrhage and impaired feeding activity and cold injury. Although stressful birth and presumed sub‐lethal injury to the fetal CNS had no permanent adverse effect on the growth and wool production of survivors, there was equivocal evidence of a birth related temporary residual handicap, as the mean growth rate of the delayed group born in 1973 was significantly lower than that of the caesarean group during a three‐monthly period of pasture shortage.Stressful vaginal birth clearly increased the level of neonatal mortality. The results also demonstrated the pathological significance of meningeal haemorrhage as an index of stressful birth and presumed damage to the fetal CNS, and strongly suggested the probable role of such injury in the pathogenesis of the starvation‐mismothering‐exposure complex.

Experimental cryptococcal-induced myocarditis.

Rabbits and Wistar rats developed myocarditis after intracardiac inoculation with Cryptococcus neoformans. Myocardial lesions were observed on the 1st, 2nd, 3rd and 4th weeks after this inoculation in all animals. The cardiac lesions consisted of focal necrosis with mononuclear inflammatory cells infiltration in the myocardium. Cryptococcus neoformans itself was found by PAS stain and indirect immunofluorescence stain by the 2nd week after the inoculation. Maximal cardiac lesions were observed in the 2nd week and thereafter, the lesions showed progressive scarring. In the 9th week, there were fibrotic lesions and we were not able to demonstrate cryptococcal antigens in these lesions. Fungemia and antibody for Cryptococcus neoformans were not found over the entire period. Cryptococcal meningeal lesions were observed in all animals. In the animals given an intracardiac administration of saline. Pseudomonas aeruginosa, and Serratia marcescens, there were no myocardial lesions. The relationship of this experimental fungal myocarditis and fungal endocarditis in human is discussed.

Experimental cryptococcal myocarditis.

Rabbits and Wistar rats developed myocarditis after intramyocardial inoculation with Cryptococcus neoformans. Myocardial lesions were observed on the 1st, 2nd, 3rd, and 4th week after the inoculation in all animals. The cardiac lesion consisted of focal necrosis with accompanying lymphocytes, macrophages, and rare fibroblasts in the myocardium. Cryptococcus neoformans itself was found by PAS stain and indirect immunofluorescence stain by the 2nd week after the inoculation. Maximal cardiac lesions were observed in the 2nd week and thereafter, the lesions showed progressive scarring. In the 9th week there were fibrotic lesions, and we were not able to demonstrated cryptococcal antigens in these lesions. Fungemia and antibody for Cryptococcus neoformans were not found over the entire period. Cryptococcal meningeal lesions were observed in all animals. In the animals given an intramyocardial inoculation of saline, Pseudomonas aeruginosa, and Serratia marcescens there were no myocardial lesions. The relationship of this experimental cryptococcal myocarditis and fungal endocarditis in humans is discussed.

The role of birth in the pathogenesis of meningeal haemorrhage and congestion in newborn lambs.

SUMMARY: In a controlled experiment, term lambs born of caesarean sacrifice, normal or artificially prolonged birth were examined at autopsy to determine the role of vaginal birth in the pathogenesis of presumed birth injury to the fetal CNS characterised by subdural and extradural haemorrhage, subarachnoid haemorrhage and congestion, and blood‐stained cerebrospinal fluid in and around the cranial and spinal meninges of lambs dying during or within 7 days of birth. Additional material, comprising near‐term fetuses, was examined at an abattoir to determine the prevalence of meningeal lesions in unborn fetuses.Mean durations of parturition in the caesarean‐born controls, natural and artifically‐delayed vaginal deliveries were 0 min., 56 min., and 185 min. respectively. The experimental treatments influenced the frequency of cranial lesions only. Single lambs were more prone to injury than twin lambs. The incidence of affected lambs in delayed births was 8.9 times higher than that in caesarean births and 1.7 times higher than that in normal births. Within the delayed group the incidence of affected single lambs in the subgroups was similar despite wide differences in the nature of parturition. It was concluded that the induced lesions resembled those associated with the perinatal mortality of livestock and infants and that pathogenetic variables included interactions between the duration and the vigour of the birth process. Repeated stretching and relaxation of the rostral fetal cranio‐vertebral skeleton during Stage 2 labour may be involved in pathogenesis. At that stage of delivery, the fetus is relatively fixed because the chest and shoulders have firmly engaged the pelvic inlet, while the head and neck are exposed to the lower pressure of the vagina and atmosphere. Intrafetal pressure is hydrostatically continuous with intrauterine pressure which is higher than atmospheric pressure. Rises in intrauterine pressure due to labour are probably transmitted hydraululically to the fetal cranio‐vertebral canal leading to stretching of the head and neck. Because the fetal CNS is firmly anchored to the cranio‐vertebral skeleton such movement may set up the shearing action necessary to rupture small vessels in the cranial and cervical meninges.

Disseminated Cryptococcosis with Ocular Involvement

A case of disseminated cryptococcosis with extensive ocular involvement is reported. The patient had pulmonary, meningeal, cerebral, cutaneous, lymph node, renal, adrenal and thyroid lesions, as well as granulomatous endophthalmitis.

Bacterial meningitis in farmed rainbow trout Salmo gairdneri Richardson affected with chronic pancreatic necrosis

Abstract. Chronic mortalities associated with meningeal and pancreatic lesions are described, from two trout farms in Scotland. Histopathological and microbiological studies suggested that bacterial infection with strains of Pseudomonas fluorescens of low pathogenicity was developing in fish already affected by the lesions of chronic infectious pancreatic necrosis virus infection (IPN). Antibiotic therapy reduced losses temporarily; eradication of the virus resulted in complete elimination of the condition.

Malignant melanoma metastatic to the central nervous system.

The CT appearance of metastatic malignant melanoma is varied, but it can show features suggesting the correct diagnosis. Intracerebral hemorrhage alone, associated with an adjacent tumor nodule or mixed diffusely with a tumor, occurred in 10 of 33 patients. Identification of a tumor nodule is important, since it may be the site of recurrent hemorrhage if not removed completely at surgery. Unusual presentations such as meningeal carcinomatosis and lesions simulating primary gliomas also occurred.

Computer Assisted Tomography Findings in Cerebral and Meningeal Lesions Caused by Cryptococcus neoformans

(Diagnostic Radiology Department, Clinical Center, National Institutes of Health, Bethesda, Maryland).

Meningeal haemorrhage and congestion associated with the perinatal mortality of foals

A high frequency of meningeal lesions was found at autopsy in foals dying perinatally. Such lesions are considered an index of injury to the fetal central nervous system, from trauma and/or hypoxia during birth. Their incidence in the sample examined (26 foals) is similar to that observed in the perinatal mortality of lambs and calves.

Myeloma cells in the cerebrospinal fluid in plasma cell neoplasia.

Myeloma cells were detected in the cerebrospinal fluid of two patients with plasma cell neoplasia during the myelographic studies of 38 patients whose myeloma was associated with extensive neurological complications. The myeloma cells were looked for in Wright stained centrifuged deposit of 2-5 ml samples of the cerebrospinal fluid obtained during myelography. The possibility that occult traumatic lumbar puncture had allowed entry of circulating myeloma cells from the peripheral blood into the subarachnoid space was excluded by the absence of myeloma cells in smears of peripheral blood and its buffy coat. Up to the end stages of the disease the meningeal myeloma lesions remained microscopical and no signs of raised intracranial tension were manifested by either patient.

Neurologic disease in wapiti naturally infected with meningeal worms.

Four wapiti (Cervus canadensis) from Oklahoma which had shown clinical signs of neurologic disease were submitted for pathological examination. Both mature female and larval meningeal worms (Parelaphostrongylus tenuis Pryadko and Boev, 1971) were either observed in or recovered from the meninges and parenchyma of the brains. Lesions found in the brain of each wapiti included focal meningitis, perivascular cuffing, and focal gliosis; frequently these were associated with the meningeal worms. There appeared to be a direct correlation between the presence of meningeal worms and lesions observed histologically which resulted in neurologic disturbances in the wapiti.