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J Miklossy

Publications and source records attributed to J Miklossy.

At least 37 records · Page 2Linked to original sources
PubMed1997

HIV-I induced destruction of neocortical extracellular matrix components in AIDS victims.

Neurological dysfunction is not uncommon in patients suffering from acquired immunodeficiency syndrome (AIDS) and, when manifested, intimates involvement of the central nervous system. Here, the human immunodeficiency virus (HIV) infects preferentially microglial cells, which thereby release substances known to interfere with neuronal function. One class of agents set free in this manner are proteases; these degrade certain components within, and thereby undermine the integrity of, the extracellular matrix (ECM) compartment, which plays a vital role in cell-to-cell communication. We wished to ascertain whether the ECM compartment is indeed disrupted in the brains of AIDS victims. We examined the neocortical areas of 27 AIDS autopsy cases, including 9 with diagnosed HIV-encephalopathy (HIVE); 8 HIV-seronegative cases with various types of brain lesion, including viral infections, were also included in this study. HIV-antigens and DNA were identified by use of immunohistochemistry and in situ hybridization, and ECM components by lectin staining and immunohistochemistry. Of the 27 AIDS cases examined, each of the 9 with HIVE was completely devoid of labeled ECM components; 8 of the 18 without HIVE had incurred substantial losses, and only 2 manifested a normal complement of constituents within this compartment. With respect to stratal and topographic variations, layers II and III were less affected than layers V to VII, as was the frontal cortex relative to other areas. These findings confirmed our expectations of the brain's ECM undergoing degradation following HIV infection, and these changes may well underlie the neurological disturbances manifested in AIDS patients.

AIDS Dementia Complex↗
PubMed1994

Further ultrastructural evidence that spirochaetes may play a role in the aetiology of Alzheimer's disease.

Recently it was reported that, at autopsy, in neuropathologically confirmed cases of Alzheimer's disease spirochaetes were found in blood and cerebrospinal fluid using dark-field microscopy. Moreover, the spirochaetes were isolated and cultured from brain tissue. We now show, using scanning electron microscopy and atomic force microscopy that the helically shaped microorganisms isolated and cultured from the Alzheimer brains possess axial filaments. This indicates that these microorganisms taxonomically indeed belong to the order Spirochaetales. A morphometric analysis reinforces this notion.

Alzheimer Disease↗
PubMed1994

[Range of neuromuscular involvement in 47 patients infected with the human immunodeficiency virus].

Over a 30 month period, 47 out of 749 patients infected with the human immunodeficiency virus had various neuromuscular symptoms. Based on clinical and electrophysiological data, 47% had distal symmetric polyneuropathy, 11% chronic inflammatory demyelinating polyneuropathy (CIDP), 8.5% toxic neuropathy related to 2-3-dideoxyinosine (DDI), 8.5% cranial neuropathy, 8.5% mononeuropathy multiplex or isolated focal neuropathy, 8.5% progressive lumbosacral polyradiculopathy, and 8.5% myopathy. Half of the patients exhibited previous or concomitant signs of central nervous system involvement and 18 patients died during the study period. CIDP and cranial neuropathies usually appeared early in the course of the disease and consequently showed neurological improvement. Nerve conduction studies of DDI related toxic neuropathies showed distal axono-myelinic sensitivo-motor neuropathy, differing from CIDP by the absence of a conduction block. Distal symmetric polyneuropathies, frequent in the advanced systemic illness, do not systematically require an extended workup, but more unusual peripheral neuropathies which might be treatable necessitate further investigations (electromyography, radiology, serological blood tests; protein chemistry and routine workup of the cerebrospinal fluid). For example, progressive lumbosacral polyradiculopathies responded to early treatment, with a better outcome in one case of herpetic origin than in another case due to cytomegalovirus infection. Our observations suggest that myopathies in HIV infected patients should first be tackled by temporary interruption of virostatic medication, followed by muscle biopsy if the symptoms persist.

AIDS Dementia Complex↗
PubMed1993

Early symptoms and outcome of Listeria monocytogenes rhombencephalitis: 14 adult cases.

Listeria monocytogenes rhombencephalitis has never been studied in a significant group of patients. We describe 14 adult cases who were seen over a 10-year period. A biphasic illness was characteristic: (1) prodromes (5-15 days) with malaise, fatigue, headache, nausea or vomiting, and fever; (2) cranial nerve palsy with facial palsy, diplopia, dysphagia, dysarthria, usually multiple. Meningism and hemi- or tetraparesis were present in 11 patients and cerebellar dysfunction in 9 patients. In 4 cases, CT showed widening of the brain stem with disappearance of the surrounding cisterns. The cerebrospinal fluid was abnormal in all patients in whom this investigation was done (pleocytosis, elevation in protein content). The patients received antibiotic therapy for 2-6 weeks. In the 9 patients who recovered, the neurological dysfunction improved within 2 days to 1 week of the initiation of therapy. There were 5 deaths. At autopsy in 2 cases, there was severe purulent meningitis and rhombencephalitis with predominantly polymorphonuclear cellular infiltration in 1 case, while numerous microabscesses in the midbrain, pons and medulla were observed in the other. We conclude that L. monocytogenes infection should be considered in patients who develop fever and focal neurological signs particularly localized to the brain stem.

Adult↗
PubMed1993

Alzheimer's disease--a spirochetosis?

The aetiology of Alzheimer's disease (AD), which affects a large proportion of the aged population is unknown and the treatment unresolved. The role of beta amyloid protein (beta A4), derived from a larger amyloid precursor protein (APP) in AD is the subject of intense research. Here I report observations that in 14 autopsy cases with histopathologically confirmed AD, spirochetes were found in blood and cerebrospinal fluid and, moreover, could be isolated from brain tissue. Thirteen age-matched control cases were without spirochetes. Reference strains of spirochetes and those isolated from brains of AD patients, showed positive immunoreaction with monoclonal antibody against the beta amyloid precursor protein. These observations suggest that spirochetes may be one of the causes of AD and that they may be the source of the beta amyloid deposited in the AD brain.

Aged↗
PubMed1991

Borrelia rhombencephalomyelopathy.

Three patients, in whom the diagnosis of Borrelia burgdorferi infection was unknown for several years, developed a biphasic involvement of the central nervous system: an acute brain-stem dysfunction was followed up, in two patients, by a progressive, disabling myelitis and, in one patient, by further relapsing-remitting episodes of severe multifocal rhombencephalitis. The most consistent cerebrospinal fluid abnormalities in the analysis of sequential specimens were elevated total IgM levels that normalized after penicillin therapy. The neuropathologic findings in one patient showed microgliosis and meningovascular involvement of the central nervous system, resulting in two ischemic infarcts in the myelencephalon. Few spirochetes were localized in the leptomeninges and around subependymal vessels of the fourth ventricle. The vascular element consisted of an obliterative inflammatory vasculopathy in the medullary parenchyma. This study (1) provides pathologic evidence that a vascular disease induced by B burgdorferi is a pathogenetic mechanism for cerebrovascular diseases, and (2) emphasizes the similarities between neuroborreliosis and neurosyphilis.

Adult↗
PubMed1991

Acute fatal myeloencephalopathy after combined intrathecal chemotherapy in a child with acute lymphoblastic leukemia.

We report a case of a fatal toxic encephalomyelopathy in a 12-year-old girl due to prophylactic intrathecal injection of methotrexate and cytosine arabinoside, with a characteristic progressive symptomatology leading to death after 28 days. The location and type of neuropathological changes support the hypothesis of a direct toxic effect of methotrexate and/or cytosine arabinoside on structures directly exposed to the cerebrospinal fluid.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

The long-distance effects of brain lesions: visualization of myelinated pathways in the human brain using polarizing and fluorescence microscopy.

We describe several new possibilities for the study of degenerated myelinated tracts in the human central nervous system (CNS). The methods are based on the visualization of myelin breakdown products that show birefringence in polarized light and, when stained with Nile blue and benzpyrene-3,4, exhibit fluorescence. Even after lengthy formalin fixation, the methods permit the localization of anterogradely degenerated tracts in a variety of fiber systems in the brains of patients who died between five and 20 months after the onset of neurological symptoms. Particularly the polarizing technique, because of its simplicity, can be added to the usual neuropathological methods for demonstrating the long-distance effects of a brain lesion. As research tools, these methods would also aid in the study of the anatomical substrate of human neurological symptomatology.

Birefringence↗
PubMed1991

The long distance effects of brain lesions: visualization of axonal pathways and their terminations in the human brain by the Nauta method.

This study aims at determining the reliability and the optimal post-injury survival time for the application of the Nauta technique to the analysis of the human brain. The Nauta method reveals the degeneration not only of nerve fibers, myelinated and unmyelinated, but also of their terminations. Immunohistochemical and ultrastructural observations appear to prove that the Nauta technique indeed stains axons in human autopsy material. The optimal survival time for the use of the Nauta method was found to be between nine days and five months. In cases with longer survival times--up to 20 months--the Nauta technique and a previously proposed polarizing technique (showing birefringent breakdown products of myelin) can be used as complementary methods. Applying these techniques to the human brain may help define the anatomical basis of neurological and neuropsychological symptoms important for man.

Axons↗
PubMed1990

Occipital cortex in man: organization of callosal connections, related myelo- and cytoarchitecture, and putative boundaries of functional visual areas.

Human area 17 is known to contain a single (the primary) visual area, whereas areas 18 and 19 are believed to contain multiple visual areas (defined as individual representations of the contralateral visual hemifield). This is known to be the case in monkeys, where several boundaries between visual areas are characterized by bands of callosal afferents and/or by changes in myeloarchitecture. We here describe the pattern of callosal afferents in (human) areas 17, 18, and 19 as well as their cortical architecture and we infer the position of some visual areas. Sections from occipital lobes of 6 human brains with unilateral occipital infarctions have been silver-impregnated for degenerating axons, thereby revealing callosal afferents to the intact occipital cortex. Their tangential distribution is discontinuous, even in cases with large lesions. A band of callosal afferents straddles the area 17/18 boundary, whereas the remainder of area 17 and a 15-45 mm wide stripe of area 18 adjacent to the callosal band along the 17/18 border are free of them. Patches of callosal afferents alternate with callosal-free regions more laterally in area 18 and in area 19. We conclude that, in man, a second visual area (analogue of V2) lies in area 18, horseshoe-shaped around area 17, and includes the inner part of the acallosal stripe adjacent to the callosal band along the 17/18 boundary. The outer part of this acallosal stripe belongs to a third visual area, which may contain dorsally the analogue of V3 and ventrally that of VP. Thus the lower parts of the second and third visual areas lie on the lingual gyrus, whereas the analogue of the macaque's fourth visual area probably lies on the fusiform gyrus. Although the proposed subdivision of the occipital cortex relies largely on the pattern of callosal afferents, some putative human visual areas appear to have distinct architectonic features. The analogue of V2 is rather heavily myelinated and its layer III contains large pyramidal neurons. Its upper part is not well delimited laterally since adjacent "V" has similar architecture. Its lower part, however, differs clearly from the adjacent "VP," which is lightly myelinated and lacks the large pyramids in layer III. The cortex lateral to "VP" is heavily myelinated and contains fairly large pyramids in layers III and V. The myeloarchitecture of the lateral part of the occipital cortex is not uniform; a very heavily myelinated region stands out in the lateral part of area 19, near the occipito-temporal junction.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1990

[Nervous system pathology in AIDS: results of a collaborative autopsy study from Switzerland].

Neuropathological lesions were studied in a consecutive autopsy series of 206 cases, comprising 61% of all patients who died of Aids in Switzerland between April 1981 and December 1988. Central nervous system involvement was found in 84% of the patients, and 17% showed multiple concomitant intracerebral lesions. Among the non-viral opportunistic infections, cerebral toxoplasmosis was most frequent (24%), whilst among the viral opportunistic infections, cytomegalovirus (CMV) encephalitis was most frequent (7%). A nodular encephalitis consisting of disseminated microglial nodules without morphological or immunocytochemical evidence of CMV occurred in 13.5% of the patients. The majority of these cases showed evidence of extracerebral CMV infection. Progressive multifocal leukoencephalopathy (PML) was observed in 6% of the patients and was associated with widespread tissue destruction and cyst formation. HIV encephalopathy occurred in 38 patients (18%) and showed two characteristic morphological patterns: progressive diffuse leukoencephalopathy (PDL) and multifocal giant cell encephalitis (MGCE). PDL was observed in 22 patients and was characterized by a diffuse demyelination and gliosis of the white matter with little inflammatory infiltrates and scattered multinucleated giant cells which were immunoreactive to HIV antigens. MGCE was found in 16 patients and was characterized by clusters of macrophages, lymphocytes, and HIV-immunoreactive multi-nucleated giant cells. In our view, PDL and MGCE represent two opposite variants of HIV-induced encephalopathies with numerous intermediate manifestations.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Meningovascular form of neuroborreliosis: similarities between neuropathological findings in a case of Lyme disease and those occurring in tertiary neurosyphilis.

Recent observations have delineated the neurological manifestations of Lyme disease, but, to our knowledge, no detailed neuropathological study from autopsy cases has been reported. In this report we describe the neuropathological findings in a case of Lyme neuroborreliosis. The chronic meningitis, the occlusive meningovascular and secondary parenchymal changes that we found are similar to those occurring in the meningovascular form of neurosyphilis. Thus, we suggest that the case described here represents the meningovascular form of tertiary Lyme neuroborreliosis.

Humans↗
PubMed1990

Vertical gaze palsy and selective unilateral infarction of the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF).

We report a clinico-pathological correlation study in a patient with basilar artery thrombosis, who developed tetraplegia and combined up- and downgaze palsy involving voluntary saccades and visually-guided movements, but sparing the oculocephalic responses. At necropsy, apart from bilateral infarction in the basis pontis, there was a single unilateral infarct selectively destroying the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) on the right. The posterior commissure and its nucleus, the nucleus of Cajal, the nucleus of Darkschewitsch and the pontine tegmentum were spared. We suggest that the unilateral riMLF lesion may have disrupted bilateral upgaze excitatory and inhibitory inputs and unilateral downgaze excitatory inputs. The functional anatomy of inhibitory and excitatory vertical gaze circuitry, which remains speculative, may explain why a unilateral lesion of the upper midbrain tegmentum may be sufficient to generate an upgaze palsy or a combined up- and downgaze palsy, while an isolated downgaze palsy requires bilateral lesions.

Brain Stem↗
PubMed1989

[Cachexia, pain and muscle weakness in a 69-year-old woman].

The case is reported of a 69-year-old woman who for the last 2 years of her life had severe muscle weakness (with elevated muscular enzymes), thyroid abnormalities (autoantibodies and increase in TSH) and a slowly growing mass in the anterior mediastinum. She died in cardiogenic shock. The diagnosis of "nodular polymyositis" (painful nodules palpable in the muscles) with heart involvement was strongly suspected. The thyroid abnormalities were considered to be "biological thyroiditis" i.e. a "disease" frequent in normal females (5-10%) and, after differential diagnosis of anterior mediastinal masses, the diagnosis of thymoma was adopted in view of its frequent association with autoimmune diseases. Moreover, in rare cases of thymoma associated with polymyositis, histology has disclosed "giant cell polymyositis". Autopsy revealed giant cell polymyositis, a thymoma and lymphocytic infiltration of the thyroid.

Aged↗
PubMed1989

Neuropathology of the acquired immune deficiency syndrome (AIDS): a report of 135 consecutive autopsy cases from Switzerland.

Neuropathological changes were studied in a consecutive autopsy series of 135 cases, comprising 73% of all patients who died of AIDS in Switzerland between April 1981 and December 1987. Central nervous system involvement was found in 119 patients (88%), 19 of which had multiple concomitant intracerebral lesions. Among the non-viral opportunistic infections, encephalitis due to Toxoplasma gondii was most frequent and occurred in 35 patients (26%), followed by central nervous system infection with Cryptococcus neoformans, which was found in five patients (4%). Cytomegalovirus (CMV) encephalitis was present in 14 patients (10%). Disseminated microglial nodules without morphological or immunocytochemical evidence of CMV was encountered in 18 patients (13%). However, in all but two of these patients there was evidence of extracerebral CMV infection, suggesting that CMV was responsible for these nodular encephalitides. Nine patients (7%) had progressive multifocal leukoencephalopathy (PML); in five of these, demyelination was associated with extensive tissue destruction and cyst formation. HIV-associated encephalopathy was observed in 21 patients (16%) and showed two characteristic morphological patterns: progressive diffuse leukoencephalopathy (PDL) and multifocal giant cell encephalitis (MGCE). PDL was observed in 13 cases and characterized by diffuse pallor and gliosis of the cerebral and cerebellar white matter with scattered multinucleated giant cells, but without significant inflammatory response. MGCE was found in eight patients and characterized by clusters of numerous multinucleated giant cells, rod cells, macrophages, lymphocytic infiltrates and occasional necroses. In our view, PDL and MGCE represent the two opposite variants of HIV-induced encephalopathies, with overlapping intermediate manifestations.

Acquired Immunodeficiency Syndrome↗