Otogenic lateral sinus thrombosis in children

INTRODUCTION

The clinical picture of lateral sinus thrombosis (LST) has changed with the advent of antibiotics, as have the utility of various diagnostic tests. LST may appear in children as a complication of acute otitis media, but nowadays it is more frequently encountered in adults with long-standing chronic ear disease.

METHOD

A retrospective study of all the pediatric patients with LST between 1982 and 1997.

RESULTS

Thirteen cases of LST were diagnosed and treated by our department. In six cases, LST was due to acute otitis media and in the remaining cases it was due to chronic otitis media. Headache, fever, aural discharge and mastoid tenderness were the most frequent findings in these patients and four patients were initially diagnosed with meningitis. In the majority of the patients, LST was accompanied with other intracranial complications, such as perisinus abscess, brain abscess and meningitis. One patient with multiple brain abscesses, unresponsive to several drainage procedures, died. The other patients recovered and have since been followed-up as out-patients.

CONCLUSION

LST may be difficult to diagnose due to previous antibiotic treatment and to the overlap of clinical findings with other entities such as meningitis. Despite the value of modern imaging techniques in the investigation of the disease, a high index of suspicion based on the clinical picture is warranted. Our results are consistent with those of other recent studies, who found that mortality of LST has dropped below 10%.

Acute cerebellitis caused by Coxiella burnetii

We report a childhood case of severe acute cerebellitis caused by Coxiella burnetii. After 10 days of fever and headache, the patient fell into a drowsy state. Examination of the cerebrospinal fluid (CSF) revealed pleocytosis, an increased level of protein, and negative results in bacterial and viral studies. Magnetic resonance imaging demonstrated a herniated tonsil compressed by the swollen vermis. Administration of minocycline relieved the patient's clinical symptoms. C. burnetii was isolated from the CSF obtained during convalescence.

[Cerebral abscess of otogenic origin located simultaneously in the temporal and cerebellar regions]

A 28-year-old male was seen for chronic left ear disease. A brain abscess appeared in the left temporal lobe and later spread to the cerebellum. Diagnosis was clinical and radiological. Intravenous antibiotic treatment resulted in resolution of the temporal abscess on CT. However, a new abscess that appeared in the left cerebellar hemisphere required neurosurgical debridement. The patient's microbiological cultures and history suggested an otological origin. Brain abscess is a serious complication of ear disease that requires early diagnosis and treatment.

Nitric oxide and prostaglandin E2 formation parallels blood-brain barrier disruption in an experimental rat model of bacterial meningitis

During meningitis, the host produces a plethora of signaling agents as part of a coordinated defense mechanism against invading pathogens. Nitric oxide (NO) and prostaglandin E2 (PGE2) are two such inflammatory mediators produced in response to bacterial endotoxins. Disruption of the blood-brain barrier (BBB) is one of many pathophysiological consequences of meningitis. The present objective was to examine the time-course of NO and PGE2 production in relationship to BBB permeability alterations during experimentally-induced meningitis. Meningeal inflammation was elicited by intracisternal administration of the bacterial endotoxin, lipopolysaccharides (LPS; 200 microg), and NO, PGE2, and BBB integrity were monitored over the next 24 h. Meningeal NO production was assessed by headspace chemiluminescence; cerebrospinal fluid PGE2 was determined by enzyme-linked immunosorbent assay (ELISA) immunoassay; and BBB integrity was determined by the brain accumulation of 14C-sucrose. Similar time-course profiles for NO and PGE2 were observed, with a peak effect for both inflammatory mediators observed within 6-8 h after intracisternal LPS dosing. Statistically significant (p < 0.05) disruption of the BBB was observed in various brain regions. Strikingly similar temporal relationships were observed for NO and PGE2 production and BBB disruption. These results suggest the hypothesis that NO and PGE2 may act in conjunction to disrupt the BBB during experimental meningitis.

Central nervous system abscesses due to Coccidioides species

Meningitis occurs in one-third to one-half of patients with disseminated coccidioidomycosis, but mass lesions have rarely been described; these lesions are usually found at autopsy. We report six cases of disseminated coccidioidomycosis with central nervous system (CNS) abscesses. Four patients had cerebellar involvement, and two had spinal cord involvement. Four patients were diabetic, and two subsequently died. Review of the literature on CNS coccidioidomycosis indicated that parenchymal brain involvement occurs in 1%-33% of cases, and < 40 cases with mass lesions have been reported since 1905. Almost all patients were male and had other active disseminated foci of coccidioidomycosis. In approximately one-third of all cases, meningitis was absent. Brain lesions may be superficial or deep and multiple or single. In the absence of meningitis, serology of cerebrospinal fluid is negative. Hematogenous origin appears to be more common than direct extension from the meninges. Spinal cord involvement is rare. Diabetes was present in several cases, thus suggesting a vascular predisposition. We hope our experience will increase awareness of this entity, which appears to be more common than previously appreciated, and will facilitate diagnosis.

Myeloencephalitis associated with a viridans group Streptococcus in a colony of Japanese macaques (Macaca fuscata)

Five weaned immature Japanese macaques (Macaca fuscata), bred in captivity, showed nervous signs over a 12-month period. Hemorrhagic cerebral infarcts with vasculitis were detected in four necropsied animals. The distribution and nature of the lesions were consistent with bacterial embolism, and a Streptococcus isolate, biochemically similar to S. salivarius, was recovered from the cerebral lesions from three of the four necropsied macaques. Treatment with antibacterial agents (enrofloxacin) improved the clinical condition of the surviving affected animal. These observations strongly suggest that this Streptococcus spp., member of the viridans group, is responsible for this outbreak. Dental pulpitis, present in two of the four macaques, probably served as the entry for this bacterium.

[Cerebellar abscess by Nocardia: a case report]

The authors describe a case of cerebellar abscess by Nocardia in a patient with the acquired immunodeficiency syndrome (AIDS) that was submitted to a posterior fossa craniectomy for diagnosis and treatment. Pathological and neuroimage findings are discussed as well as the surgical approach taking into account literature data on the subject.

Teratogenic effects of neonatal arenavirus infection on the developing rat cerebellum are abrogated by passive immunotherapy

The effects of viral infection on the developing nervous system and the potential of passive immunotherapy to protect against infection were examined. When 4-day-old Lewis rats were injected intracerebrally with lymphocytic choriomeningitis virus (LCMV) the majority of stem cells within the external granular layer of the developing cerebellum became infected. The infection progressed to the molecular layer, internal granular layer, and the Purkinje cells. By 15 days postinfection the molecular and internal granular layers of LCMV-infected cerebella were noticeably thinner than those in the controls and the individual folia were smaller. Neurons remained infected for up to 40 days as determined by immunohistochemistry. However, in rats treated with rat monoclonal anti-LCMV antibodies the staining was limited to the cells of ependyma and choroid plexus and was not detectable by 15 days postinfection. Macroscopically the infection resulted in pronounced hypoplasia, with the cerebella of 21-day-old LCMV-infected rats weighing 52 +/- 10 mg compared with 159 +/- 30 mg for control rats. Antibody-treated rats exhibited normal cerebellar size and development. Neutralizing antibodies specific for the viral GP-1 glycoprotein were protective but nucleoprotein-specific antibodies were not. Furthermore, suckling rat pups born of and nursed by LCMV-immune mothers were spared from cerebellar disease following neonatal infection. These results suggest that passive immunotherapy of neonates can provide effective protection against teratogenic effects of neonatal viral infection on the developing CNS.

Intracerebral hemorrhages and syncytium formation induced by endothelial cell infection with a murine leukemia virus

The mechanisms of endothelial cell damage that lead to cerebral hemorrhage are not completely understood. In this study, a cloned murine retrovirus, TR1.3, that uniformly induced stroke in neonatal BALB/c mice is described. Restriction digest mapping suggests that TR1.3 is part of the Friend murine leukemia virus (FMuLV) family. However, unlike mice exposed to other FMuLVs, mice infected with TR1.3 virus developed tremors and seizures within 8 to 18 days postinoculation. This was uniformly followed by paralysis and death within 1 to 2 days. Postmortem examination of TR1.3-inoculated mice revealed edematous brain tissue with large areas of intracerebral hemorrhage. Histologic analysis revealed prominent small vessel pathology including syncytium formation of endothelial cells. Immunohistochemical analysis of frozen brain sections using double fluorescence staining demonstrated that TR1.3 virus specifically infected small vessel endothelial cells. Although infection of vessel endothelial cells was detected in several organs, only brain endothelial cells displayed viral infection associated with hemorrhage. The primary determinant of TR1.3-induced neuropathogenicity was found to reside within a 3.0-kb fragment containing the 3' end of the pol gene, the env gene, and the U3 region of the long terminal repeat. The restricted tropism and acute pathogenicity of this cloned murine retrovirus provide a model for studying virus-induced stroke and for elucidating the mechanisms involved in syncytium formation by retroviruses in vivo.

SSPE in Slovakia: immunocytochemical study

In a retrospective study of two patients from Slovakia with clinical, virological and histopathological diagnosis of subacute sclerosing panencephalitis (SSPE), measles virus antigen was detected by immunocytochemical labelling studies. The formalin fixed, paraffin-embedded thin brain sections labelled with anti-measles antibodies and avidin-biotin complex peroxidase were counterstained with haematoxylin. Only a single area of brain was examined in each patient: cerebellum and parietal lobe. Viral antigen positive reaction was identified within Purkinje cells and extending along dendritic processes in cerebellum, and also in oligodendrocytes of subparietal white matter.

Brain vascular endothelial cells express JC virus large tumor antigen in immunocompetent and cyclophosphamide-treated hamsters

When injected intracerebrally into newborn hamsters, the human polyomavirus JC virus (JCV) establishes a nonproductive infection resulting in brain tumor formation. Using immunostaining methods to detect the JCV regulatory protein, large tumor antigen (T antigen), we have now demonstrated JCV infection of brain vascular endothelial cells (EC) in infected hamsters. JCV T antigen was detected in lectin-labeled EC as well as in von Willebrand factor-expressing EC in both cyclophosphamide-treated and nonimmunosuppressed hamster brains 16, 21, and 31 days after birth. Cyclophosphamide-treated hamsters exhibited a greater number of JCV-infected EC, whereas T-antigen expression in nonvascular cells was not affected. The influence of cyclophosphamide was most pronounced in the cerebellum where increased numbers of JCV-infected EC were located predominantly at the internal granular layer-white matter junction, also a prominent location for T-antigen-expressing neoplastic foci. The hamster model demonstrates in vivo infection of EC by a human polyomavirus and directs interest toward the role of these cells in human JCV infection.

Molecular characterization of a JC virus (Sap-1) clone derived from a cerebellar form of progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease caused by polyomavirus JC (JCV). In the majority of cases of PML the cerebrum is mainly affected (cerebral PML) but on rare occasions lesions are restricted to the cerebellum and brain stem (cerebellar PML). We report a rare cerebellar PML case which occurred in a Japanese patient undergoing prolonged hemodialysis treatment. To understand the molecular basis of the viral tissue tropism, we molecularly cloned JCV DNA and compared it with those of cerebral PML. Of ten clones analyzed nine showed identical fragment patterns after digestion with various restriction endonucleases, and we designated these clones Sap-1. It could be shown that the basic structures of the regulatory regions are similar between Sap-1 and isolates from cerebral PML. Restriction endonuclease mapping analysis was used to examine the genetic relationship between Sap-1 and urine-derived isolates containing the archetypal regulatory sequence. We found that Sap-1 was genetically related to an archetypal JCV isolate in Japan.

Borna disease: association with a maturation defect in the cellular immune response

Borna disease virus (BDV) is a negative-strand RNA virus which produces persistent infection in a variety of experimental animals. In the rat, the presence or absence of clinical signs of Borna disease, a characteristic, biphasic neurobehavioral illness, depends on host-related factors. A window of opportunity exists after birth wherein inoculation with BDV produces a persistently infected rat without signs of Borna disease or encephalitis (persistent, tolerant infection-newborn [PTI-NB] rat). Although immunopathological destruction of the nervous system does not occur in the PTI-NB rat, significant alterations in the development of the nervous system were noted, including site-specific lysis of neurons. Unlike the case with other pharmacologically produced, persistent, tolerant BDV infections, adoptive transfer of spleen cells from BDV-infected rats did not produce disease in the PTI-NB rats. PTI-NB rats developed Borna disease after being connected by parabiosis to rats with Borna disease. Bone marrow transplantation experiments revealed that bone marrow cells from PTI-NB rats produced Borna disease in lethally irradiated, BDV-infected recipient rats. Bone marrow from PTI-NB rats contained a complement of inflammatory cells capable of inducing Borna disease. Thus, the loss of BDV-specific cellular immunity appeared to occur after the release of cells from the bone marrow.

Natural scrapie: detection of fibrils in extracts from the central nervous system of sheep

Extracts from the cervical spinal cord and from the medulla, thalamus, cerebellum and cerebral cortex of the brains of 10 sheep, histopathologically confirmed as cases of scrapie, were examined by electron microscopy for the presence of scrapie-associated fibrils. Characteristic fibrils were observed in all the extracts except for that from the thalamus of one sheep. No fibrils were found in any extracts from three control sheep. A comparison of these results with a similar study of 22 cases of bovine spongiform encephalopathy (BSE) suggests that in cases of scrapie the area of the brain chosen for the detection of fibrils is less critical than in cases of BSE, in which fibrils are more readily extracted from areas of the brain stem.

South American blastomycosis: ophthalmic and oculomotor nerve lesions

A case of South American blastomycosis began with an oropharyngeal lesion which was followed by a granulomatous uveitis. The patient was treated with Amphotericin B and showed a clinical regression. Four months later, he developed a right 3rd cranial nerve palsy, aggravating the clinical aspect with a severe generalized involvement of the central nervous system and death. Necropsy showed blastomycotic meningoencephalitis.

Incubation periods and histopathological changes in mice injected stereotaxically in different brain areas with the 87V scrapie strain

After stereotaxic injection into five different brain areas (cortex, caudate nucleus, substantia nigra, thalamus and cerebellum) of IM mice with the 87V scrapie strain, the cerebellum had the shortest incubation period. The vacuolation pattern was similar regardless of the area injected with extensive vacuolation in the thalamus, mesencephalon and hypothalamus. The pattern of amyloid plaques differed markedly depending on the area injected. In particular, no plaques were seen anywhere in the brain after injection into intact cerebellum, whereas injection into the four cerebral areas yielded plaques in the forebrain but not in the cerebellum. The incubation period after injection into bisected cerebella was much longer than after injection into intact cerebella. Mice injected on one side of bisected cerebellum had amyloid plaques in the forebrain but not in the cerebellum. There is a discussion of the finding that, although no plaques and virtually no vacuolation were seen in the cerebellum, the shortest incubation period occurred after injection into intact cerebellum.

Ultrastructural and biochemical findings in brain cell cultures infected with canine distemper virus

To study the pathomechanism of demyelination in canine distemper (CD), dog brain cell cultures were infected with virulent A75/17-CD virus (CDV) and examined ultrastructurally. Special attention was paid to the oligodendrocytes, which were specifically immunolabelled. In addition, cerebroside sulfotransferase (CST), an enzyme specific for oligodendrocyte activity was assayed during the course of the infection. Infection and maturation as well as CDV-induced changes were found in astrocytes and brain macrophages. Infection of oligodendrocytes was rarely seen, although CST activity of the culture markedly decreased and vacuolar degeneration of these cells occurred, resulting in their complete disappearance. We concluded that the degeneration of oligodendrocytes and demyelination is not due to direct virus-oligodendrocyte interaction, but due to CDV-induced events in other glial cells.

Pathogenesis and pathology of scrapie after stereotactic injection of strain 22L in intact and bisected cerebella

The mechanisms involved in the spread of scrapie within the brain remain unclear. To examine this issue the 22L scrapie strain was injected in one side of the cerebellum of mice in which the cerebellum had been bisected prior to injection. Another group of animals received the same injection into intact cerebella, i.e. without prior bisection. We found that bisection of the cerebella delayed the spread of scrapie agent from the injection site to the contralateral side of the cerebellum and that the occurrence of vacuolization was not as extensive and was markedly delayed in the uninjected side compared to its occurrence after injection in the intact cerebellum. Replication of agent in an area preceded the development of vacuolization in that area by several weeks. There was marked loss of Purkinje cells on the injected side of bisected cerebella, with no loss seen on the uninjected side. The incubation period of scrapie disease in mice injected after cerebellar bisection was significantly longer than after the injection of intact cerebella. The results in this study suggest that the scrapie agent spreads along intact nerve cell tracts, probably by axonal transport.

In ovo infection with the avian retrovirus RAV-1 leads to persistent infection of the central nervous system

The ability of an avian retrovirus to cause central nervous system (CNS) disease was investigated in chickens infected in ovo with Rous associated virus-1. Viral envelope and core proteins and mature virions were found throughout CNS parenchyma, with the highest amounts localized in the granular layer of the cerebellum, in blood vessel endothelium, and the choroid plexus. This distribution was established by the time of hatching and persisted throughout the 14 weeks of observation. The highest levels of integrated proviral DNA and viral mRNA, were present in the cerebellum, consistent with the distribution of viral antigens. Mononuclear cell infiltrates were evident throughout the CNS, consistent with an inflammatory process. However, demyelination or vacuolar changes, as observed in other retroviral-induced CNS diseases, were not detected. Clinical symptoms of progressive neurologic dysfunction, i.e., weakness or paralysis of the hindlimbs, imbalance, and ataxia, were present in 7 of 38 infected chickens before termination of the experiment at 14 weeks posthatch. Viral antigens or lymphocyte infiltration were not detected in peripheral nerves. These findings suggest that the avian system may provide a valuable model to analyze the mechanisms governing retroviral induced CNS disease.

Differences in virulence between two strains of Streptococcus suis type II after experimentally induced infection of newborn germ-free pigs

Fifteen newborn germ-free pigs were inoculated with 2 strains, D-282 and T-15, of Streptococcus suis type II. Some pigs also were preinoculated with Bordetella bronchiseptica, which successfully predisposed them to S suis infection. The 2 streptococcal strains were differentiated by muramidase treatment, which released certain high molecular-weight proteins, termed muramidase-released proteins (MRP), from the cell wall of strain D-282, but not from the cell wall of strain T-15. Only strain D-282 (MRP-positive) induced clinical signs of disease and markedly increased neutrophil numbers in pigs. Streptococci were more frequently isolated from fecal swab specimens obtained from pigs inoculated with strain D-282 (MRP-positive) than from specimens obtained from pigs inoculated with strain T-15 (MRP-negative). Both strains were isolated from nasal swab specimens obtained from all infected pigs. Postmortem examination revealed fibrinopurulent meningitis, polyserositis, and polyarthritis in pigs inoculated with strain D-282; this strain was isolated from the CNS, serosae, visceral organs, heart, and joints. Whereas strains D-282 caused several pathologic changes, strain T-15, isolated from the lungs, caused only pneumonia. Both strains were isolated from the tonsils of all pigs. Virulence differed distinctly between the MRP-positive and the MRP-negative strains.

Viral antigen distribution in the central nervous system of cattle persistently infected with bovine viral diarrhea virus

Distribution of viral antigens in the central nervous system of 25 cattle with a persistent bovine viral diarrhea virus (BVDV) infection was studied. Using a polyclonal antiserum produced in pigs and the direct immunofluorescence and immunoperoxidase technique, BVDV antigen was located exclusively in neurons. Predilection sites for viral persistence were cerebral cortex and hippocampus; in other areas of brain and spinal cord, viral antigens were in single neurons or small groups of neurons. There was no morphological evidence of cellular alteration due to viral persistence. Perivascular lymphocytic infiltrations were in affected nervous tissue. It is concluded that the central nervous system is an important location for persistence of BVDV.

Contrasting patterns of virus spread and neuropathology following microinjection of herpes simplex virus into the hippocampus or cerebellum of mice

Two strains of herpes simplex virus type 1 (HSV) were microinjected into either the hippocampus or cerebellum of two different mouse strains. Immunoperoxidase staining revealed rapid and extensive spread of virus within the hippocampus and certain of its afferent connections. In contrast, only scattered peroxidase positive cells were observed following cerebellar inoculation. Extensive lesions were observed only in animals surviving intrahippocampal inoculations. These results suggest that localization of the pathological process in HSV encephalitis is due in part to a selective vulnerability of telencephalic or limbic structures.

Ultrastructural changes associated with retroviral replication in central nervous system capillary endothelial cells

Widespread ultrastructural alterations in the vascular basal lamina were found in the central nervous system of symptomatic mice infected with three different neuropathogenic murine leukemia viruses. These changes appeared to progress in frequency and severity in parallel with the progression of spongiform lesions and clinical symptoms. Accumulations of pleomorphic, apparently degenerating, virions were frequently seen within areas that showed marked aberrations from the normal basal lamina ultrastructure. We suggest that the observed retrovirus-associated ultrastructural changes in the endothelial basal lamina may alter normal physiologic functions and thus play a primary role in the pathogenesis of retrovirus-induced spongiform disease.