[A clinicopathological study of a patient with paraneoplastic limbic encephalitis, myelitis, sensory neuropathy and cerebellar degeneration, associated with a unique antineuronal antibody]

Clinicopathological and immunohistochemical studies were performed in a patient with paraneoplastic limbic encephalitis, myelitis, sensory neuropathy and cerebellar degeneration secondary to small cell lung cancer. A 67-year-old male smoker developed orthostatic dizziness 6 months prior to admission. Over the following months, his wife noticed that he became forgetful and confused. Over the next three weeks, he became unable to sit or stand unaided and admitted to our service. On admission, he was lethargic and disoriented in time and place. Neurological examination revealed marked limb weakness with distal dominant muscle atrophy. A chest radiograph demonstrated a mass in the right middle lobe and a bronchial biopsy revealed a small cell carcinoma. CT scan and MRI of the brain revealed abnormalities in the bilateral medial temporal lobes and putamen. He was treated with anti-cancer chemotherapy, but died of respiratory failure after 13 months illness. Postmortem examination showed a mass in the right middle lobe of the lung. No tumor metastases were noted in the nervous tissue. Microscopical examinations of the nervous system revealed neuronal loss, astrogliosis and perivascular and parenchymatous lymphocytic infiltration in the hippocampus, subiculum, amygdala, putamen, medulla oblongata, spinal cord and dorsal root ganglia. Loss of Purkinje cells was also seen in the cerebellum without lymphocytic infiltration. Immunohistochemical analysis of the patient's serum and CSF by the use of adult rat brain revealed immunoreactivity at the hippocampal pyramidal neurons CA3 and CA4. At the higher dilution, neuronal nuclei were specifically stained.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic catheterization of the epidural space in rabbits: a model for behavioural and histopathological studies. Examination of meptazinol neurotoxicity

A technique of epidural catheterization in rabbits is described. Twelve albino rabbits received a totally implanted epidural catheter system. The system was implanted surgically, and the functioning of the system tested for a period of 3 months. X-ray examinations following epidural contrast injections showed a distribution up to Th4 following 1.5 ml and Th8-9 following 1.0 and 1.25 ml. Epidural injection of lidocaine throughout the study period proved the system to be functioning for all 3 months. Another 12 rabbits were included for the neurotoxicological examinations following epidural catheterization, without any injections (three rabbits), epidural injections of saline (four rabbits) and meptazinol (five rabbits) once a day for 14 days. Histopathological examinations showed a fibrous cocoon, at the tip of the catheter, in all rabbits. In the group of rabbits which did not receive any injections, the cocoon was slightly infiltrated with leukocytes and local depression of the spinal cord was observed in one rabbit. In the saline-injected group this infiltration was more pronounced and in one rabbit it extended into the meninges. Three rabbits showed local depression of the spinal cord and local myelopathy of the white matter in the area adjacent to the cocoon. In the group of rabbits receiving meptazinol, three out of five had local depression and myelopathy of the white matter. In this group these findings were more pronounced. In two rabbits the myelopathy extended transversely through the white matter into the grey matter of the spinal cord. The number of pathological changes in the group receiving meptazinol was significantly higher compared to the control and placebo groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytomegalovirus myelitis in perinatally acquired HIV

A 7 year old child perinatally infected with HIV who died from progressive muscular paralysis and central nervous respiratory failure is described. Cytomegalovirus (CMV) prophylaxis with a special intravenous CMV hyper-immunoglobulin had been successfully conducted for more than four years. Macroscopic and microscopic immunohistochemical examination of the spinal cord revealed a diffuse CMV infiltration of the entire myelon. CMV infected cells were identified as astrocytes, oligodendrocytes, neurons, macrophages, ependymal, endothelial, and Schwann cells. Other organs had no signs of CMV infection. Central nervous spinal CMV infection was most probably due to insufficient penetration of the blood-brain barrier by the CMV hyper-immunoglobulin. In suspicious cases early spinal magnetic resonance imaging (1.5 tesla) combined with an examination of urine and cerebrospinal fluid for CMV is recommended.

Microglia and cytokines in neurological disease, with special reference to AIDS and Alzheimer's disease

Microglia are associated with central nervous system (CNS) pathology of both Alzheimer's disease (AD) and the acquired immunodeficiency syndrome (AIDS). In AD, microglia, especially those associated with amyloid deposits, have a phenotype that is consistent with a state of activation, including immunoreactivity with antibodies to class II major histocompatibility antigens and to inflammatory cytokines (interleukin-1-beta and tumor necrosis factor-alpha). Evidence from other studies in rodents indicate that microglia can be activated by neuronal degeneration. These results suggest that microglial activation in AD may be secondary to neurodegeneration and that, once activated, microglia may participate in a local inflammatory cascade that promotes tissue damage and contributes to amyloid formation. In AIDS, microglia are the primary target of retroviral infection. Both ramified and ameboid microglia, in addition to multinucleated giant cells, are infected by the human immunodeficiency virus (HIV-1). The mechanism of microglial infection is not known since microglia lack CD4, the HIV-1 receptor. Microglia display high affinity receptors for immunoglobulins, which makes antibody-mediated viral uptake a possible mechanism of infection. In AIDS, the extent of active viral infection and cytokine production may be critically dependent upon other factors, such as the presence of coinfecting agents. In the latter circumstance, very severe CNS pathology may emerge, including necrotizing lesions. In other circumstances, HIV infection of microglia probably leads to CNS pathology by indirect mechanisms, including release of viral proteins (gp120) and toxic cytokines. Such a mechanism is the best hypothesis for the pathogenesis of vacuolar myelopathy in adults and the diffuse gliosis that characterizes pediatric AIDS, in which very little viral antigen can be detected.

[Aspergillosis involving the thoracic spinal cord--an autopsy case]

A 63 year old male complained of persistent backache and productive cough. The chest X-ray revealed the fungus ball at the left apical-posterior segment and Aspergillus fumigatus was cultured from the sputum. He was treated on fulconazole and miconazole. Six months later, motor and sensory paralysis below the mamillary level and urinary and stool incontinence developed. A magnetic resonance image disclosed the destruction of the second thoracic spinal vertebra involved by the cavitated fungus ball of the left lung. Continuous peroral administration of antifungal drugs was not successful, and he expired with severe dyspnea. The autopsy revealed an extensive granulomatous and purulent change of the epidural and subdural spaces of the second to fifth thoracic spinal cord. Subdural inflammation extended to the lower thoracic and lower cervical level. Thoracic spinal cord revealed an extensive myelomalacia predominantly involving the left lateral white column, and also anterior and posterior columns. Small areas of the white matter were cystic. The left anterior horn cells revealed severe central chromatolysis. Moderate lymphocytic and plasma cell infiltration was found around the vessels within the cord. A few thrombi were found in the vein near the anterior nerve root. Central nervous system involvement of pulmonary aspergillosis is quite uncommon. However, there are a few reports of patients with paraplegia secondary to the spinal extension by aspergillus infection. Sheth et al. described that epidural and subdural granulomatous change with aspergillus abscesses and spinal cord myelomalacia is comparable to metastatic carcinoma. However, the aspergillus infection in the spinal cord is more extensive and destructive.(ABSTRACT TRUNCATED AT 250 WORDS)

Equine protozoal myelitis in Panamanian horses and isolation of Sarcocystis neurona

Schizonts of Sarcocystis neurona were identified microscopically in hematoxylin-eosin-stained spinal cord sections from 2 native Panamanian horses that exhibited clinical signs of equine protozoal myelitis (EPM). Spinal cord homogenate from a third Panamanian horse with EPM was inoculated onto monolayers of cultured bovine monocytes (M617). Intracytoplasmic schizonts containing merozoites arranged in rosette forms surrounding a central residual body first were observed 13 wk postinoculation. Parasites divided by endopolygeny and lacked rhoptries. Schizonts from each horse reacted with Sarcocystis cruzi antiserum in an immunohistochemical test.

Neuropathology of the spinal cord in the acquired immunodeficiency syndrome

The neuropathologic findings in the spinal cord were reviewed in 138 consecutive autopsies of patients with the acquired immunodeficiency syndrome. In all cases both the brain and spinal cord were examined by conventional histologic techniques, and in 63 cases immunohistochemistry was used to detect human immunodeficiency virus (HIV), Toxoplasma gondii, cytomegalovirus, and JC papovavirus antigens. The most common observation was a normal spinal cord (60%). Vacuolar myelopathy (VM) was observed in 23 (17%) cases. Human immunodeficiency virus myelitis was evident in 8% of cases. Human immunodeficiency virus myelitis was associated with HIV encephalitis in 65% of the cases. Opportunistic infections of the spinal cord were uncommon, consisting of cryptococcosis (five cases), cytomegalovirus (four cases), toxoplasmosis (one case), and progressive multifocal leukoencephalopathy (one case), and almost always were seen with cerebral and/or systemic infection by these agents. Malignant lymphoma rarely involved the spinal cord (four cases); all were B-cell lymphomas and were associated with cerebral and/or systemic lymphoma. Other abnormalities rarely observed were Wallerian degeneration of the corticospinal tracts or posterior columns (6%) and focal microinfarcts. Most cases of VM (78%) were not associated with HIV myelitis, and in the five patients with both VM and HIV myelitis, HIV-infected cells were not found in the regions affected by VM. In contrast, 65% of cases with VM were associated with HIV encephalitis. The pathogenesis of VM remains unknown; it is probably not due to direct infection by HIV.

The effects of a non-competitive NMDA receptor antagonist, MK-801, on behavioral hyperalgesia and dorsal horn neuronal activity in rats with unilateral inflammation

The involvement of NMDA receptors in rats with peripheral inflammation and hyperalgesia was evaluated by administration of the non-competitive NMDA receptor antagonist, MK-801. Inflammation and hyperalgesia was induced by intradermal injection of complete Freund's adjuvant (CFA) or carrageenan into the left hind paw. The latency of paw withdrawal from a thermal stimulus was used as a measure of hyperalgesia in awake rats. MK-801 (1.6 mg/kg, i.p., or 31.5 micrograms, intrathecal) significantly attenuated thermal hyperalgesia and reduced its duration in comparison to saline-injected rats (P less than 0.05). The receptive field size of nociceptive-specific and wide-dynamic-range neurons in the superficial and deep spinal dorsal horn recorded 24 h after injection of CFA was significantly reduced to 73 +/- 6% (P less than 0.05, n = 8) and 74 +/- 4% (P less than 0.05, n = 8) of control values, respectively, by a cumulative dose of 3 mg/kg of MK-801 (i.v.). MK-801 (2 mg/kg) prevented the expansion of the receptive fields of dorsal horn neurons recorded 5 +/- 0.4 h (n = 5) after intradermal injection of CFA as compared to saline-injected rats (P less than 0.05). MK-801 had no significant effect on receptive field size of dorsal horn neurons in rats without CFA-induced inflammation but blocked a transient expansion of the receptive fields induced by 1 Hz, C-fiber intensity electrical stimulation of the sciatic nerve. The background activity and noxious heat-evoked response of dorsal horn neurons in rats with CFA-induced inflammation were primarily inhibited and noxious pinch-evoked activity was both facilitated and inhibited by the administration of MK-801. These results support the hypothesis that NMDA receptors are involved in the dorsal horn neuronal plasticity and behavioral hyperalgesia that follows peripheral tissue inflammation.

[Necrotizing myelopathy associated with neoplasia. A clinico-pathological study of 2 cases and a review of the literature]

Two cases of necrotic myelopathy are presented. This is a very rare paraneoplasic syndrome. One patient had clear cell renal carcinoma and other had lymphatic metastasis of malignant melanoma without filiation of the primary tumor. The complete spinal study (MNR, CT, myelography) proved normal. Diagnosis is possible when all other causes of spinal disease have been discarded. Nowadays, it is possible to diagnose this disease premortem. The international literature reviewed showed 31 cases published since 1903, associated mainly to malignant diseases such as lymphomas, lung cancer, renal carcinoma, breast cancer, leukemias, etc. The differential diagnosis appears in the comments, as well as the presentation and evolution of the cases described up until now.

Necrotizing myelopathy associated with multiple myeloma

A case of progressive necrotizing myelopathy occurring in the context of multiple myeloma is described, and the pathology illustrated. This association has not been previously reported.

Neuropathology of the spinal cord

The neuropathology of the spinal cord is described and illustrated from the viewpoint of a neuropathologist observing at necropsy the many traumas and pathologic diseases affecting the spinal cord. The article provides the clinician with an insight into the disease processes and anatomic derangements underlying the neurologic deficits in paraplegia and quadriplegia. Today, the clinical examination of patients with spinal cord trauma or spinal cord disease is greatly assisted by many anciliary investigations, notably, radiology and the newer imaging techniques now applied to successfully to the spinal cord. Comparison of the patient's neuropathology with the classical neurophathology of the spinal cord, provided in this article, remains important for the clinician.

Herpes zoster myelitis

We studied the clinical (10 patients) and pathological (9 patients) findings in 13 patients with herpes zoster myelitis, all of whom had systemic illnesses associated with immunosuppression. The median interval between the onset of the herpes zoster rash and myelopathic symptoms was 12 days, and the subsequent median interval to maximal deficit was 10.5 days. Presenting neurological symptoms were characteristically ipsilateral to the rash, with motor dysfunction predominating, followed by a spinothalamic and, less often, posterior column sensory deficit. Pathological involvement was most severe in the dorsal root entry zone and posterior horn of the spinal cord segment corresponding to the involved dermatome. There was variable spread both horizontally and vertically in the spinal cord. Direct varicella-zoster virus (VZV) infection of neuroectodermal cells, particularly oligodendrocytes, was demonstrated by immunostaining viral antigens (8 cases), and by the presence of Cowdry type A intranuclear inclusions (7 cases) and often was associated with focal demyelination (6 cases). In 4 patients a VZV vasculitis was associated with leptomeningitis and haemorrhagic necrosis (spinal cord in 1; brainstem or cerebellum in 3). The protracted evolution in many cases and the pathologically documented direct viral infection of the spinal cord provide a rational basis for the use of antiviral therapy in preventing or attenuating the evolving myelopathy.

Multifocal multinucleated giant cell myelitis in an AIDS patient

A 19-year-old male intravenous drug abuser, was admitted to hospital with a one-week history of lower limb weakness and urinary retention. He was known to have been HIV-seropositive for 3 years and had been treated for cerebral toxoplasmosis. Neurological examination confirmed flaccid paraparesis with weak ankle jerks and bilateral extensor plantar responses. There was no obvious sensory deficit. Neurological examination was otherwise normal. CSF contained 63 mg/dl protein and 10 leucocytes/mm3. Myelography was normal. He died 1 month later from septic peritonitis. Neuropathological examination showed chronic lesions of toxoplasmosis in brain. Small necrotic foci with myelin loss, proliferation of microglia, macrophages and multinucleated giant cells (MGC) were disseminated in the whole spinal cord, mostly in the white matter, but the brain was spared. Immunohistochemistry demonstrated p24 and p17 HIV antigens in macrophages, MGC and microglial cells. These lesions resemble those of so called 'multifocal giant cell encephalitis'. The present case demonstrates that HIV-related multifocal inflammatory changes may be restricted to the spinal cord and may be a cause of myelopathy in AIDS patients.

The effect of age on the latency of radiation myelopathy

The latent period to forelimb paresis following photon irradiation of the cervical spinal cord was evaluated in Sprague-Dawley rats ranging in age from 9 days to adulthood. The radiation was administered dorsally in single fractions, and in 15-day-old animals, to different lengths of the rostral cord and in doses ranging from 16 to 38 Gy. The duration of the latent period was found to be directly proportional to the age of the animal at the time of irradiation, and independent of radiation dose or the volume of the cervical cord which was irradiated. In the majority of paretic animals, the irradiated segment of the spinal cord demonstrated white matter necrosis. The results indicate that in the developing rat, the manifestations of radiation myelopathy are delayed by an interval determined in part by the age of the animal at the time of irradiation.

Acute ascending necrotizing myelitis in Okinawa caused by herpes simplex virus type 2

A case of rapidly progressing ascending myelitis was necropsied. Necrosis was present throughout the whole length of the spinal cord and involved both the grey and white matter randomly. The perivascular lymphocytic infiltration in the spinal cord in the present case was more pronounced than that in the previously reported two cases of necrotizing myelopathy associated with malignancy. Using immunoperoxidase staining the presence of herpes simplex virus type 2 (HSV 2) antigen was demonstrated. Electron microscopic examinations revealed large numbers of HSV particles in the spinal cord. HSV 2 may be a common aetiological agent of necrotizing myelopathy and myelitis in Okinawa, an HSV 2 endemic area. In the present case, the necrosis was mainly found in the spinal cord but was also observed, to a very limited extent, in the brain.

[Pathology of inflammatory diseases of the central nervous system--an autopsy analysis 1967-1988]

This paper deals with investigations of CNS-inflammations based on 23,338 autopsies in the period from 1967 to 1988. Inflammatory CNS-findings were observed in 210 cases (0.9 per cent). Their etiology was caused bacterially in 66 per cent and viral infections were found in 20 per cent. Additionally multiple sclerosis appeared in 14 per cent of all CNS-inflammations. The meningitis dominated among the bacterial infections and the leukencephalitis and nekrotizing polioencephalitis of Herpes type among the viral inflammations. The histological classification of the nonbacterial inflammations was difficult or impossible in 9 per cent. A clinical diagnosis was established only in 70 per cent of all cases. Especially babies and patients at the age about 60 or 70 were involved.

Nematode related spinal myelomeningitis and posterior ataxia in muskoxen (Ovibos moschatus)

In the fall of 1988 all five animals in a herd of muskoxen (Ovibos moschatus) developed clinical signs of posterior ataxia. Postmortem investigation revealed inflammatory lesions of the caudal part of the spinal cord, mainly as leptomeningitis. Nematodes were seen in close association with the lesions. Although not identified, the parasites were probably an Elaphostrongylus sp.

Radiologic imaging of intradural pathology

Neuroimaging entails knowing both which modality to use and when in the sequence of clinical evaluation to use a particular modality. This article review the role, both diagnostic and prognostic, of neuroimaging in the various categories of intradural spinal disease and presents the spectrum of neuroimaging modalities.

Myelitis in a cat infected with Toxoplasma gondii and feline immunodeficiency virus

Severe necrotizing myelitis secondary to localization and reactivation of Toxoplasma gondii within the spinal cord of a domestic shorthair cat was diagnosed by use of light and electron microscopy and immunohistochemistry. The cat also was infected with feline immunodeficiency virus. This case may have useful comparative features to T gondii infections in human patients with acquired immunodeficiency syndrome.

Acute myeloradiculitis due to cytomegalovirus as the initial manifestation of AIDS

A 26 year old male intravenous drug abuser presented with rapidly progressive paraplegia and total incontinence. CSF examination showed elevated protein level and pleocytosis. HIV testing was positive. Anti CMV titres were mildly elevated in serum and CSF. Death occurred 26 days after the onset of neurological signs. Necrotic and inflammatory lesions with numerous inclusion bodies characteristic of CMV were found in the roots of the cauda equina, conus terminalis and lumbar segments of the spinal cord. CMV subependymal encephalitis and HIV encephalitis were also present.

Immunohistochemical localization of human immunodeficiency viral antigens in formalin-fixed spinal cords with AIDS myelopathy

Some patients with the acquired immunodeficiency syndrome (AIDS) have long-tract degeneration in the spinal cord. Spinal-cord sections showing degeneration were immunoreactive in 13 of 17 AIDS patients using rabbit antiserum to whole disrupted human immunodeficiency virus (HIV) or a mouse monoclonal antibody to HIV core protein p24. The immunostaining was in a few macrophages, multinucleated cells, gliomesenchymal-cells nodules, glial cells and vascular endothelial cells. Eleven of the positive cases had histopathologic evidence of long-tract vacuolar alterations associated with this immunoreactivity, and the two cases without vacuolar alterations had immunoreactive multinucleated cells and gliomesenchymal-cell nodules. Immunolocalization of HIV in the spinal cord correlated well with clinical signs and symptoms, although concomitant cerebral and systemic infections often obscured the significance of the spinal-cord findings in the clinical setting. HIV vasculitis could lead to myelitis and to the clinical appearance of long-tract signs and symptoms.

Mycobacterial meningomyelitis associated with human immunodeficiency virus infection

A homosexual man, seropositive for human immunodeficiency virus, developed back and leg pain that evolved, over three weeks, into a T-10 anesthetic, areflexic paraplegia. Spinal fluid examination showed lymphocytosis, markedly elevated spinal fluid protein, and hypoglycorrhachia. A spinal cord biopsy specimen disclosed an intramedullary granuloma containing acid-fast bacilli. The patient was treated with antituberculous drugs and had no progression of neurologic deficit. He died, eight months after first becoming ill, of Klebsiella pyelonephritis and septicemia. Mycobacterial meningomyelitis is presently the only known acquired immunodeficiency syndrome-related myelopathy responsive to specific treatment.

Neurologic complications of herpes zoster

Encephalitis, contralateral hemiplegia and postherpetic neuralgia are the most serious neurologic sequelae of herpes zoster infections. Encephalitis occurs more frequently in the presence of cutaneous dissemination and cranial nerve lesions. Contralateral hemiplegia following herpes zoster ophthalmicus results from vasculitic and thrombotic lesions. The combination of a tricyclic antidepressant and a phenothiazine is the most effective medical treatment for postherpetic neuralgia.

Acute ascending necrotizing myelopathy caused by herpes simplex virus type 2

A 57-year-old diabetic man died of a rapidly ascending necrotizing myelitis. Autopsy results proved that the etiologic agent was herpes simplex virus type 2 (HSV2). The clinical findings, autopsy immunohistopathology, and electron-microscopy suggest that either primary HSV2 infection or reactivation of HSV2 infection within dorsal root ganglia was followed by spread to the spinal cord. Viral infection of the CNS occurred by direct extension and led to death by involvement of the brainstem. Although there is only one previous report of HSV2 myelitis in the literature, our findings suggest that HSV2 might be a more common etiologic agent of necrotizing myelitis. Because CSF cultures are usually negative, viral inclusions are not usually seen, and morphologically identifiable virions are exquisitely rare, previous cases were probably descriptively diagnosed as acute ascending necrotizing myelitis without etiologic identification.

Rubella myelitis and encephalitis in childhood. A report of two cases with magnetic resonance imaging

Two children are described with postnatally acquired acute rubella which induced neurological disease. The first patient with restricted transverse myelitis (Th 11-12) was remarkable for the positive result obtained by the magnetic response (MR) technique of the spinal cord. In the second patient the clinical examination demonstrated a circumscribed, however severe, lasting defect in the extrapyramidal motor system with facial muscle dystonia and complete anarthria; in the latter case the CSF contained rubella specific IgM five days after the onset of exanthema. No abnormalities were noticed by MR five weeks after the clinical onset. The possible significance of MR imaging in virus-induced encephalomyelitis is discussed.

A new complication of AIDS: thoracic myelitis caused by herpes simplex virus

Progressive thoracic myelopathy occurred in a patient with AIDS. Concurrent opportunistic infections included disseminated systemic cytomegalovirus, aspergillosis, and cutaneous herpes simplex virus (HSV). At autopsy, immune stains indicated that the myelopathy was caused by HSV type 2 infection of the spinal cord.

Cytomegalovirus and herpes simplex virus ascending myelitis in a patient with acquired immune deficiency syndrome

Progressive ascending myelitis was the presenting feature of the acquired immune deficiency syndrome (AIDS) in a homosexual man who also had Kaposi's sarcoma, Pneumocystis pneumonia, and disseminated cytomegalovirus (CMV) infection. Neuropathological studies showed profuse cytomegalic cells throughout the brain and spinal cord, but no inflammatory response. At postmortem examination, CMV and herpes simplex virus, type 2 (HSV-2), were recovered from multiple sites throughout the central nervous system (CNS). HSV-2 was isolated from the anus, but from no other extraneural site; in contrast, pathology typical of CMV was also seen in the liver, gastrointestinal tract, adrenals, and lungs. Although histopathological evidence suggesting prior CMV infection has been seen in the brains of AIDS patients, the virus has never been cultured from the CNS in these immunosuppressed hosts, nor has it been known to infect the spinal cord. The absence of an inflammatory response suggests that the pathogenesis of CNS viral infections is altered in AIDS patients. Evidence for CMV infection of the CNS in AIDS patients is no longer circumstantial.

Sequential morphological and quantitative changes in blood and bone marrow neutrophils in dogs with acute inflammation

Blood and bone marrow morphology were studied sequentially in dogs during experimental inflammation induced by intramuscular injection of turpentine. Depletion of the bone marrow storage pool of mature neutrophils and an increase in mitotic activity and number of early granulocyte precursors were evident within 24 hours. During the next three days, intense granulocytic hyperplasia resulted in replenishment of the bone marrow storage pool. Neutrophils with foamy vacuolation and increased basophilia of the cytoplasm (toxic neutrophils) were present in the blood by eight hours postinjection. The number of toxic neutrophils paralleled the intensity of clinical signs and changes in rectal temperature but not the number of band neutrophils. This indicates that changes in number of toxic neutrophils in sequential leukograms can be a prognostic indicator in dogs with severe inflammation.

Acute meningoencephalomyelitis in a rabbit infected with Pasteurella multocida

Pasteurella multocida was isolated in pure culture from the optic chiasm of a rabbit that was euthanatized subsequent to acute development of neurological signs. Histopathologically, there was meningoencephalomyelitis, bilateral otitis interna, retrobulbar cellulitis, optic neuritis and iritis. The ocular involvement, severity of the spinal lesions and the lack of otitis media was unusual.

The nervous system in genital herpes simplex virus type 2 infections in mice. Lethal panmyelitis or nonlethal demyelinative myelitis or meningitis

Female mice were inoculated vaginally with the MS strain of herpes simplex virus type 2, and serially positive vaginal cultures were used to confirm infection. The proportion of mice infected and the mortality rate in infected mice decreased with increasing age. In mice 12 weeks old, clinical, neuropathologic, and virologic criteria defined four patterns of disease. Moribund mice had severe genital lesions, hindleg paralysis, and urinary and fecal retention, and most died during the second week of infection. These mice had a panmyelitis with a decreasing gradient of both viral antigen and lesions extending rostrally from the lumbosacral cord into the brain stem. Lesions were about equally distributed in gray and white matter and were characterized by neuronal loss and axonal demyelination, respectively. By contrast, mice with nonfatal infections had mild or no evident genital lesions and a small proportion had mild hindleg weakness. Of these, some mice had demyelinative lesions, particularly in the lower spinal cord but also at higher cord and brain stem levels, whereas others had leptomeningitis. Both of these groups had sacral sensory root abnormalities. A third group of survivors lacked both sensory root and central nervous system abnormalities. This report defines a broader spectrum of disease patterns following infection by a natural route than has been previously appreciated. It provides the first evidence that nonfatal herpes simplex virus type 2 infection by a peripheral route can produce central nervous system demyelination. It indicates that in aseptic meningitis with this agent, the route of virus spread to the central nervous system is neural and not hematogenous. Finally, the antigenic and pathologic observations presented here complement and confirm the virus isolation data and pathologic findings of others that genital herpes simplex virus type 2 infection causes ascending infection in the peripheral and central nervous system.

Endotoxemia-induced diffuse myelitis and extensive patchy necrosis of the liver

An autopsy case with endotoxemia-induced diffuse myelitis and extensive, grossly patchy necrosis of the liver occurring in a 70-year-old female was examined histopathologically and electron microscopically. Leucopenia with prominent leukemoid reaction (myeloblasts 20%) preceded the terminal fulminant hepatitis by two weeks. Soon after the terminal event, bacteremia and endotoxemia were detected and negativity for HB antigen was proved. Diffuse myelitis was characterized by devastation of hyperplastic bone marrow structure mottled with destructed sinus architecture and scattered exudative necrosis, resulting in the loss of mature granulocytes and erythropoiesis. Regenerative clusters of myeloblasts and prominent increase of megakaryocytes were observed. Electron microscopically, the bone marrow contained fibrin and platelets within the exudate of the marrow stroma. Extensive, grossly patchy necrosis of the liver microscopically consisted of well demarcated coagulation necrosis of hepatic parenchyma with scattered fibrin thrombi in the sinusoids at the boundary. There were no definite thrombi but occasional fibrin accumulation in the small blood vessels of the liver. Both extensive diffuse myelitis and extensive, patchy necrosis of the liver seemed to be quite rare in incidence. The pathogenesis of these combined lesions was discussed in relation with endotoxemia.

[Eosinophilic meningomyelitis. Report of a case]

A 31 years old man who developed paraplegia due to a meningomyelitis is reported. Cerebrospinal fluid examination showed 116 white cells with 57% eosinophils. On the 79th day the patient died from pulmonary embolism. On post mortem examination no eosinophilic infiltrations was found. However, a detailed histologic examination was not performed.

Neuronophagia by leukocytes in experimental spinal cord injury

Experimental spinal cord injury was produced in cats by compression trauma. The major histologic features in the first 24 hours following injury included hemorrhagic necrosis, edema, and acute inflammation of gray and white matter. Neutrophilic leukocytes (NL) were apparent in the walls of and adjacent to veins and venules within four hours of injury, but large numbers of NL were not observed in tissue until eight to 24 hours. Acute inflammation was especially prominent in gray matter, and NL frequently surrounded and phagocytized neuronal somata. Large numbers of NL and neuronophagia by leukocytes were evident only in areas of hemorrhage. The role of blood in producing the acute inflammatory response and in generating chemotactic factors responsible for neuronophagia is incompletely understood. Neutrophilic leukocytes, in addition to their response as phagocytes, release histolytic enzymes, reactive species of oxygen, and proinflammatory factors which lead to further tissue necrosis and inflammation.

Density distribution and size of megakaryocytes in inflammatory reactions of the bone marrow (myelitis) and chronic myeloproliferative diseases

Morphometric evaluation was performed on semi-thin sections of core biopsies of the bone marrow and included 20 cases of each group of diseases besides control specimens. (i) Hyperergic myelitis of rheumatic origin. (ii) Chronic granulocytic leukaemia (CGL). (iii) Polycythaemia vera (P. vera). (iv) Chronic megakaryocytic-granulocytic myelosis (CMGM). (v) Myelofibrosis or osteomyelosclerosis (MF/OMS). The following classification of megakaryopoiesis was applied: normal megakaryocytes; giant forms; microforms; intussusceptions; cytoplasmic fragments; naked nuclei. The density distribution shows an increase of megakaryocyte number in those 5 different marrow disorders, ranging from about 13/mm2 in the normal sample up to 65 cells/mm2 in MF/OMS. Microforms are most frequently encountered in CGL, whereas giant megakaryocytes, intussusceptions and many cytoplasmic fragments characterize P. vera, CMGM and MF/OMS. Our measurements suggests 3 distinct categories of bone marrow lesions with corresponding alterations of the megakaryopoiesis: (i) myelitis and CGL; (ii) P. vera; (iii) CMGM and MF/OMS.

Delayed IgG-mediated clearance of herpes simplex virus type 1 from the CNS but not footpad during the early stages of infection: possible result of relative integrity of the blood-brain barrier

Following footpad inoculation in mice, herpes simplex virus type 1 spreads along nerves to the spinal cord where a myelitis causes hind limb paralysis beginning on day 6. Neutralizing antibody effectively prevents this illness only if given within 72 h. We therefore studied the timing of blood-brain barrier (BBB) disruption relative to the appearance of virus and inflammatory cell infiltrates in the spinal cord. Virus was detectable in dorsal root ganglion and spinal cord explants by 48 h. By 72 h, mononuclear cell infiltrates were evident in the spinal cord. By day 4, high titres of virus were demonstrable in the spinal cord. On day 6 125I-labelled IgG tracers penetrated the spinal cord BBB. In addition, using a passive transfer model, mice given neutralizing IgG completely cleared footpad virus within 72 h while brain virus titres were unaffected by IgG treatment up to day 7. These observations indicate that the BBB may prevent IgG-mediated virus clearance during the early stages of infection.

Abnormalities of megakaryocytes in myelitis and chronic myeloproliferative diseases

A planimetric study of megakaryopoiesis in various chronic myeloproliferative diseases (CMPD) was performed and the results compared with those from controls and myelitis of rheumatic origin. Morphometric measurements included at least 200 megakaryocytes in each case observed in Giemsa-stained semithin sections of resin-embedded core biopsies. Twenty specimens were evaluated from the controls and inflammatory disorders and from each of the following CMPD: 1, chronic granulocytic leukaemia (CGL); 2, polycythaemia vera (P. vera); 3, chronic megakaryocytic-granulocytic myelosis without or with minimal increase in reticulin fibre content (CMGM); 4, myelofibrosis or osteomyelosclerosis (MF/OMS). Megakaryocytes were classified as follows: 1, normal megakaryocytes at all stages of maturation; 2, giant forms; 3, microforms; 4, intussusceptions; 5, a-nuclear cytoplasmic fragments; 6, naked nuclei or necrotic forms. The results of this study demonstrate obvious abnormalities of megakaryopoiesis in addition to the increase in absolute numbers of megakaryocytes per marrow area and their different sizes as reported earlier (Thiele et al. 1982). Aberrations are particularly conspicuous when pure granulocytic proliferation or neoplasia of CGL is compared with the so-called mixed cellularity of megakaryocytes and granulocytes in CMGM including MF/OMS. Abnormalities of the giant forms of megakaryocytes are especially evident and comprise irregular cellular and nuclear perimeters (as calculated by a modified shape factor) in the two latter entities (CMGM-MF/OMS). This remarkable feature is associated with a disorganization of nuclear development and/or a disproportionate nuclear-cytoplasmic ratio which has never been observed in CGL previously. In combination with this striking cellular anomaly, which is compatible with an extreme amoeboid shape of giant forms in CMGM and MF, intussuceptions and a-nuclear cytoplasmic fragments are frequently encountered. The final stage of megakaryopoiesis, i.e. naked nuclei, are increased in number in all CMPD, probably because of enhanced proliferation and platelet shedding. Naked nuclei are often small in CGL (as remnants of the frequent micromegakaryocytes) and large in P. vera and CMGM/MF (depending on the high incidence of giant megakaryocytes in these latter disorders).

Primary epiduritis

An infant, born with multiple anomalies of the gastrointestinal tract, required intravenous hyperalimentation for virtually his entire life. His course was characterized by multiple episodes of sepsis or phlebitis, culminating in death five and one-half months after birth. The brain and spinal cord at necropsy were normal on gross inspection. However, microscopic study showed inflammation of the dura surrounding the spinal cord with sparing of the spinal and cerebral subarachnoid spaces.

Visna virus meningoencephalomyelitis in goats

A progressive paresis was encountered in herds of Swedish goats. The symptoms developed during a period of weeks or months, and were initially often seen as a weakness of the hind limbs before the animals became paralytic. The development and the histopathological lesions of the disease in the GNS and the lungs were similar to those of visna in sheep. In vitro grown choroid plexus cells, prepared from affected goats, showed foci of polykaryocytes. Electron microscopy revealed the presence of particles morphologically similar to those of sheep visna virus (SVV). Goats experimentally infected with the goat visna virus (GVV) developed GNS lesions similar to those of visna in sheep and became seropositive to SVV. The results of complement fixation tests, carried out on sera from 11 goat herds, showed a coincidence between seropositiveness and the occurrence of disease in one and the same herd. Using the ELISA method, an average of 80 % of the goats in 5 herds were found to be seropositive to GVV.

Pathology of rabies: a light- and electron-microscopical study with particular reference to the changes in cases with prolonged survival

Light- and electron-microscopical studies were conducted on necropsy material from six cases of rabies encephalitis including three with the unusual feature of surviving for over 14 days as a result of intensive medical care. This included administration of antiviral agents and interferon inducers and prevention of hypoxia by intermittent positive pressure ventilation. In all these cases, typical Negri bodies were demonstrated. Inflammatory reaction was absent or minimal. Unlike the cases with short survival where Negri bodies were infrequently seen and restricted mostly to the hippocampus, in cases with prolonged survival, they were present in large number, widely distributed throughout the grey matter of the brain. The associated inflammatory reaction in these cases, however, did not keep pace with the increase in number of inclusion bodies. Peripheral neuritis was observed in two of these cases, which also showed myelitis involving the cervical region and inflammation of dorsal root ganglia. One of them showed necrosis and severe inflammation of the lower cervical sympathetic ganglion. An electron-microscopical study conducted in four cases showed three forms of the inclusion body in the cytoplasm of neurons.

Chronic, relapsing myelitis in hamsters associated with experimental measles virus infection

Chronic, relapsing myelitis has been induced in golden Syrian hamsters by the intracerebral inoculation of measles virus when the animals were less than 1 day old. No acute illness was seen in animals that developed myelitis, and the onset of the myelitis was at 5 to 50 weeks after infection. In most animals the illness was slowly progressive, with hindquarter myoclonus being the most common clinical sign. Occasionally the disease involved episodic limb paresis with nearly total recovery of limb function between periods of paralysis. In most animals pathologic changes were confined to the spinal cord and involved mononuclear cell infiltration, marked gliosis, widespread demyelination, and necrosis. Virus could not be isolated from nervous tissue by cocultivation techniques, and virus-specific immunofluorescence could not be detected. The strain of virus used was distinctive in that it contained high levels of a naturally occurring viral variant that differs from typical measles virus in several distinctive ways.