Fibrillary Gliosis Research Articles

Independent distribution between tauopathy secondary to subacute sclerotic panencephalitis and measles virus: An immunohistochemical analysis in autopsy cases including cases treated with aggressive antiviral therapies.

Subacute sclerotic panencephalitis (SSPE) is a refractory neurological disorder after exposure to measles virus. Recently, SSPE cases have been treated with antiviral therapies, but data on the efficacy are inconclusive. Abnormal tau accumulation has been reported in the brain tissue of SSPE cases, but there are few reports in which this is amply discussed. Five autopsied cases diagnosed as definite SSPE were included in this study. The subject age or disease duration ranged from 7.6 to 40.9 years old or from 0.5 to 20.8 years, respectively. Cases 3 and 4 had been treated with antiviral therapies. All evaluated cases showed marked brain atrophy with cerebral ventricle dilatation; additionally, marked demyelination with fibrillary gliosis were observed in the cerebral white matter. The brainstem, cerebellum, and spinal cord were relatively preserved. Immunoreactivity (IR) against measles virus was seen in the brainstem tegmentum, neocortex, and/or limbic cortex of the untreated cases but was rarely seen in the two treated cases. Activated microglia were broadly observed from the cerebrum to the spinal cord and had no meaningful difference among cases. Neurofibrillary tangles characterized by a combination of 3- and 4-repeat tau were observed mainly in the oculomotor nuclei, locus coeruleus, and limbic cortex. IR against phosphorylated tau was seen mainly in the cingulate gyrus, oculomotor nuclei, and pontine tegmentum, and tended to be observed frequently in cases with long disease durations but also tended to decrease along with neuronal loss, as in Case 5, which had the longest disease duration. Since the distribution of phosphorylated tau was independent from that of measles virus, the tauopathy following SSPE was inferred to be the result of diffuse brain inflammation triggered by measles rather than a direct result of measles virus. Moreover, antiviral therapies seemed to suppress measles virus but not the progression of tauopathy.

Axonal and dendritic swellings on cerebellar Purkinje cells in a cow: a possible age-related change

Dystrophic or swollen axons occur in a variety of neurological disorders. Although the structures are often viewed as an incidental or age-related phenomenon, there are few reports that actually described axonal and dendritic swellings on cerebellar Purkinje cells in domestic animals with no apparent neurological clinical signs. A 12-year-old Holstein-Friesian dairy cow, which exhibited no apparent cerebellar or other significant clinical signs, was culled from old age. On histopathology of the cerebellum, there were Purkinje cell axonal torpedoes and axonal spheroids involving nerve fibers in the folial and medullary white matter, which were identified by Bodian’s silver impregnation technique and anti-neuron-specific enolase (NSE) immunohistochemical stain. Less frequently, dendritic swellings on Purkinje cells were found in the molecular layer. Cell bodies of Purkinje cells appeared otherwise normal and were not accompanied by Bergmann glia proliferation. Immunohistochemistry for glial fibrillary acid protein (GFAP) failed to demonstrate significant fibrillary gliosis. Deposition of lipofuscin pigments was seen in the cortical and medullary neurons and glial cells. Any sites of the cerebellum showed no evidence of neuronal cell degeneration, glial reaction, cellular infiltrates, or vascular lesions. Morphometrically, there was no significant decrease in number of Purkinje cells in comparison with younger control cows (n = 2). Purkinje cell axonal torpedoes or axonal spheroids were absent in the cerebellum of younger control cows (n = 10). The precise mechanism for the development of swollen Purkinje cell axons and dendrites remains to be determined, although an association with advanced age was considered one of the likeliest possibilities.

Hypertrophic Olivary Degeneration and Palatal or Oculopalatal Tremor.

Hypertrophic degeneration of the inferior olive is mainly observed in patients developing palatal tremor (PT) or oculopalatal tremor (OPT). This syndrome manifests as a synchronous tremor of the palate (PT) and/or eyes (OPT) that may also involve other muscles from the branchial arches. It is associated with hypertrophic inferior olivary degeneration that is characterized by enlarged and vacuolated neurons, increased number and size of astrocytes, severe fibrillary gliosis, and demyelination. It appears on MRI as an increased T2/FLAIR signal intensity and enlargement of the inferior olive. There are two main conditions in which hypertrophic degeneration of the inferior olive occurs. The most frequent, studied, and reported condition is the development of PT/OPT and hypertrophic degeneration of the inferior olive in the weeks or months following a structural brainstem or cerebellar lesion. This “symptomatic” condition requires a destructive lesion in the Guillain–Mollaret pathway, which spans from the contralateral dentate nucleus via the brachium conjunctivum and the ipsilateral central tegmental tract innervating the inferior olive. The most frequent etiologies of destructive lesion are stroke (hemorrhagic more often than ischemic), brain trauma, brainstem tumors, and surgical or gamma knife treatment of brainstem cavernoma. The most accepted explanation for this symptomatic PT/OPT is that denervated olivary neurons released from inhibitory inputs enlarge and develop sustained synchronized oscillations. The cerebellum then modulates/accentuates this signal resulting in abnormal motor output in the branchial arches. In a second condition, PT/OPT and progressive cerebellar ataxia occurs in patients without structural brainstem or cerebellar lesion, other than cerebellar atrophy. This syndrome of progressive ataxia and palatal tremor may be sporadic or familial. In the familial form, where hypertrophic degeneration of the inferior olive may not occur (or not reported), the main reported etiologies are Alexander disease, polymerase gamma mutation, and spinocerebellar ataxia type 20. Whether or not these are associated with specific degeneration of the dentato–olivary pathway remain to be determined. The most symptomatic consequence of OPT is eye oscillations. Therapeutic trials suggest gabapentin or memantine as valuable drugs to treat eye oscillations in OPT.

Abstract WP107: Molecular Disorganization of Axons Adjacent to Human Cortical Microinfarcts

Introduction: Ischemic brain lesions are pathologic hallmarks commonly associated with cognitive and cerebrovascular diseases. In particular, cortical microinfarcts are described as microscopically identified wedge shaped ischemic lesions such as cavitations with few remaining macrophages and fibrillary gliosis. These microscopic lesions are observed with high resolution magnetic resonance imaging in aging brains and in patients with cerebrovascular disease (CVD). Recent studies have suggested that strategically located microinfarcts strongly correlate with cognitive deficits, which can contribute to Alzheimer’s Disease (AD) as well as other forms of dementia. Hypothesis: We have recently shown that there is altered axonal molecular organization in white matter areas adjacent to white matter lacunar and microinfarcts. In this study, we hypothesized that similar changes were present in nodal, paranodal, and axon initial segments adjacent to human cortical microinfarcts. Methods: Paraffin-embedded sections of autopsy brain tissue from five patients (post mortem interval range= 4 to 45 h) with cortical microinfarcts reported in their clinical neuropathological examination were immunofluorescently labeled for nodal and paranodal markers including beta-IV spectrin, ankyrin-G, and contactin-associated protein (caspr). High magnification images were generated using confocal microscopy. Results: Cases ranged in age from 73 to 93 years old. Comorbid neuropathologic diagnoses included AD (n=3) and mixed dementia (n=2). Adjacent to cortical microinfarcts, we observed significant elongation of paranodal segments and shortened axon initial segments adjacent to cortical microinfarcts. In adjacent cortical regions without microinfarcts, paranodal segments were less frequently abnormal and axon initial segment length appeared normal. Conclusions: These data indicate that the molecular organization of axons adjacent to human cortical microinfarcts is abnormal providing support for a microinfarct penumbral injury that worsens the effect of these tiny strokes.

Neurohistopathological findings at the electrode-tissue interface in long-term deep brain stimulation: systematic literature review, case report, and assessment of stimulation threshold safety.

Despite the widespread use of deep brain stimulation (DBS) in the treatment of neurologic disorders for over a quarter of a century, there has not been a systematic review and analyses of cases in which long-term postmortem clinic-pathologic data have been collected demonstrating the effects of chronically implanted electrodes and electrical stimulation on human brain tissue. Our objective is to provide a comprehensive systematic review of the literature on clinicopathologic findings of DBS tissue-electrode interface (TEI) and to determine types and prevalences of neuropathological findings among electrode materials and stimulation parameters and to augment this with previously unpublished histopathological data, images, and analyses from a DBS case implanted for 12 years, providing the longest duration histopathological follow-up. A Medline literature review identified DBS cases upon which postmortem clinicopathologic follow-up was performed with adequate characterization of TEI. Direct follow-up with authors augmented this with unpublished data and neuropathological details. We identified 40 cases, mean age 59.1 ± 13.0 (range: 21-88) years, involving 58 implanted DBS electrodes. The mean postmortem histopathological follow-up of the implanted DBS electrodes was 22.2 ± 29.2 (range: 0.067-146) months, including our case with a 12-year follow-up. The following histological changes were identified: fibrous sheaths (5-25 μm thickness) surrounding the electrode (94%), fibrillary gliosis (73%), reactive astrocytes (78%), multinucleated giant cells (75%), mononuclear leukocytes (92%), and macrophages (91%). Microglial activation (60%), axonal spheroids (64%), and neuronal loss (60%) were less common and absent at 12-year follow-up in the index case. This is seventh case reporting T cell presence at the TEI. Neuropathological findings from published cases and our 12-year follow-up index case confirm the long-term safety of neuromodulation and stimulation thresholds and demonstrate persistence of T cells and occasional subclinical focal tissue injury.

Partial Correction of the CNS Lysosomal Storage Defect in a Mouse Model of Juvenile Neuronal Ceroid Lipofuscinosis by Neonatal CNS Administration of an Adeno-Associated Virus Serotype rh.10 Vector Expressing the Human CLN3 Gene

Juvenile neuronal ceroid lipofuscinosis (JNCL or CLN3 disease) is an autosomal recessive lysosomal storage disease resulting from mutations in the CLN3 gene that encodes a lysosomal membrane protein. The disease primarily affects the brain with widespread intralysosomal accumulation of autofluorescent material and fibrillary gliosis, as well as the loss of specific neuronal populations. As an experimental treatment for the CNS manifestations of JNCL, we have developed a serotype rh.10 adeno-associated virus vector expressing the human CLN3 cDNA (AAVrh.10hCLN3). We hypothesized that administration of AAVrh.10hCLN3 to the Cln3(Δex7/8) knock-in mouse model of JNCL would reverse the lysosomal storage defect, as well as have a therapeutic effect on gliosis and neuron loss. Newborn Cln3(Δex7/8) mice were administered 3 × 10(10) genome copies of AAVrh.10hCLN3 to the brain, with control groups including untreated Cln3(Δex7/8) mice and wild-type littermate mice. After 18 months, CLN3 transgene expression was detected in various locations throughout the brain, particularly in the hippocampus and deep anterior cortical regions. Changes in the CNS neuronal lysosomal accumulation of storage material were assessed by immunodetection of subunit C of ATP synthase, luxol fast blue staining, and periodic acid-Schiff staining. For all parameters, Cln3(Δex7/8) mice exhibited abnormal lysosomal accumulation, but AAVrh.10hCLN3 administration resulted in significant reductions in storage material burden. There was also a significant decrease in gliosis in AAVrh.10hCLN3-treated Cln3(Δex7/8) mice, and a trend toward improved neuron counts, compared with their untreated counterparts. These data demonstrate that AAVrh.10 delivery of a wild-type cDNA to the CNS is not harmful and instead provides a partial correction of the neurological lysosomal storage defect of a disease caused by a lysosomal membrane protein, indicating that this may be an effective therapeutic strategy for JNCL and other diseases in this category.

Presence of six different lesion types suggests diverse mechanisms of tissue injury in neuromyelitis optica

Neuromyelitis optica (NMO) is an autoimmune disease targeting aquaporin 4 (AQP4), localized mainly at the astrocytic foot processes. Loss of AQP4 and glial fibrillary acidic protein (GFAP) was reported, but the pathological significance of astrocytopathy is still controversial. Here we show that active lesions in NMO display a wide spectrum of pathology even within a single tissue block of an individual patient. We have distinguished six different lesion types. The first reflects complement deposition at the surface of astrocytes, associated with granulocyte infiltration and astrocyte necrosis and followed by demyelination, global tissue destruction and the formation of cystic, necrotic lesions (lesion type 2). Such destructive lesions lead to Wallerian degeneration in lesion-related tracts (lesion type 3). Around active NMO lesions AQP4 may selectively be lost in the absence of aquaporin 1 (AQP1) loss or other structural damage (lesion type 4). Another pattern is characterized by clasmatodendrosis of astrocytes, defined by cytoplasmic swelling and vacuolation, beading and dissolution of their processes and nuclear alterations resembling apoptosis, which was associated with internalization of AQP4 and AQP1 and astrocyte apoptosis in the absence of complement activation. Such lesions give rise to extensive astrocyte loss, which may occur in part in the absence of any other tissue injury, such as demyelination or axonal degeneration (lesion type 5). Finally, lesions with a variable degree of astrocyte clasmatodendrosis are found, which show plaque-like primary demyelination that is associated with oligodendrocyte apoptosis, but with preservation of axons (lesion type 6). In active multiple sclerosis (MS) lesions astrocytes reveal changes of reactive protoplasmatic or fibrillary gliosis. Only in a subset of lesions, in patients with aggressive disease, loss of AQP4 is observed in the initial stage of their formation, which is associated with retraction of astrocyte processes in the absence of complement deposition, granulocyte infiltration or loss of AQP1 or astrocytes. Our data underline the primary assault of astrocytes in NMO lesions, but also indicate that different mechanisms of tissue injury operate in parallel in the same patient and even within the same lesion.Electronic supplementary materialThe online version of this article (doi:10.1007/s00401-013-1116-7) contains supplementary material, which is available to authorized users.

Spontaneous Thrombosis of a DVA with Subsequent Intracranial Hemorrhage

A 24-year-old man was admitted to the emergency room (er) with impaired consciousness and left-sided hemiplegia. He had suffered from progressive headache and emesis since the day before and had been treated with Acetylsalicylic acid (AsA). The previous medical history was otherwise unremarkable. on admission, a computed tomography (CT) scan demonstrated intraparenchymal hemorrhage in the right temporal and parietal lobe with very marked surrounding hypoattenuation and mass effect (Fig. 1). digital subtraction angiography (dsA) revealed the typical caput medusae aspect of the draining vein in the territory affected by hemorrhage with signs of venous outflow obstruction such as prolonged transition, venous stasis, and a missing central venous collector as a sign for thrombosis of the latter (Fig. 2). The patient was transferred to the neurosurgical or and the hematoma was evacuated via a temporoparietal craniotomy. During the operation, an enlarged superficial vein with obvious signs of thrombosis was found. disproportionate perioperative hemorrhage from the subcortical parenchyma was encountered, but could be controlled by means of resecting a subcortical distended vascular structure, reminiscent of an angioma and connected to the thrombosedcollecting vein (Fig. 3). Histopathological examination revealed a vascular malformation with extensively dilated and thin-walled blood vessels consisting of fibrous tissue; however, lacking a lamina elastica interna. A lamina elastica interna as part of the arterial component would be expected in an arteriovenous malformation (AVM). In this case, the malformated vessels showed only venous characteristics. Its vascular nature was confirmed by immunohistochemical expression of smooth muscle actin, Cd31, and Cd34. Blood vessels were located within a hematoma mainly located in the leptomeninges without evidence for previous hemorrhage. In addition, leptomeningeal blood vessels were attached to fragments of neocortex with reactive astrocytes, fibrillary gliosis, and prominent microglial activation. There was no evidence for an associated cavernoma.

Progressive supranuclear palsy presenting as primary lateral sclerosis but lacking parkinsonism, gaze palsy, aphasia, or dementia

We report an autopsy case of progressive supranuclear palsy (PSP) that clinically showed only slowly progressive and symmetric upper motor neuron syndrome over a disease course of 12years. A female patient initially exhibited dysarthria at the age of 65, followed by gait disturbance and dysphagia. Neurological examination at age 67 disclosed pseudobulbar palsy, spastic gait, hyperreflexia, and presence of bilateral Hoffmann and Babinski signs. However, muscle atrophy, weakness, evidence of denervation on electromyography, vertical gaze palsy, parkinsonism, gait freezing, aphasia, speech apraxia, or dementia was not noted throughout the course. She was clinically diagnosed as having motor neuron disease consistent with so-called primary lateral sclerosis. Pathological examination disclosed histopathological features of PSP, including argyrophilic and tau-positive tufted astrocytes, neurofibrillary tangles, coiled bodies, and thread-like processes in the motor cortex and superior frontal gyrus, and to a lesser degree, in the basal ganglia and brain stem nuclei. In addition, severe fibrillary gliosis was noted in the precentral gyrus and corticospinal tract, being consistent with upper motor neuron syndrome observed in this case. No TAR-DNA binding protein 43-positive lesion, FUS pathology, Bunina body, or Lewy body-like hyaline inclusion was noted in the motor cortex or lower motor neurons. These findings suggest that when tau pathology is prominent in the motor cortex but is minimal in the basal ganglia and brain stem nuclei, a PSP case can lack all classic clinical features of PSP and show only slowly progressive upper motor syndrome, consistent with clinical picture of primary lateral sclerosis.

Hippocampal sclerosis—Origins and imaging

The association between hippocampal sclerosis (HS) and epilepsy has been known for almost two centuries. For many years, HS was studied in postmortem series; however, since the mid-20th century, surgical specimens from temporal lobe resections have provided important new knowledge. HS is the most common pathology underlying drug-resistant mesial temporal lobe epilepsy (MTLE), a syndrome with a characteristic history and seizure semiology. In the early 1990 s, it was recognized that magnetic resonance imaging (MRI) could detect HS. The standard MRI protocol for temporal lobe abnormalities uses coronal slices perpendicular to the long axis of the hippocampus. The MRI features of HS include reduced hippocampal volume, increased signal intensity on T(2)-weighted imaging, and disturbed internal architecture. The histopathologic diagnosis of HS is usually straightforward, with neuronal loss and chronic fibrillary gliosis centered on the pyramidal cell layer. There are several patterns or subtypes of HS recognized from surgical series based on qualitative or quantified assessments of regional neuronal loss. The pathologic changes of HS include granule cell dispersion, mossy fiber sprouting, and alterations to interneurons. There may also be more extensive sclerosis of adjacent structures in the medial temporal lobe, including the amygdala and parahippocampal gyrus. Subtle cortical neuropathologies may accompany HS. The revised classification of dysplasias in epilepsy denotes these as focal cortical dysplasias type IIIa. Sometimes, HS occurs with a second lesion, either in the temporal lobe or extratemporal, most often ipsilateral to the HS. HS on preoperative MRI strongly predicts good seizure outcome following temporal lobe resection (TLR). If adequate MRI shows no structural correlate in patients with MTLE, functional imaging studies are valuable, especially if they are in agreement with ictal electroencephalography (EEG) findings. Focal hypometabolism on 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) ipsilateral to the symptomatic temporal lobe predicts a good surgical outcome; the added value of (11) C-Flumazenil-PET (FMZ-PET) and proton magnetic resonance spectroscopy (MRS) is less clear. Surgical methods have evolved, particularly resecting less tissue, aiming to preserve function without compromising seizure outcome. Around two thirds of patients operated for MTLE with HS obtain seizure freedom. However, the best surgical approach to optimize seizure outcome remains controversial.

Gray matter lesions in Nasu-Hakola disease: A report on three autopsy cases

Nasu-Hakola disease is an autosomal recessively inherited disease characterized by lipomembranous polycystic osteodysplasia and sclerosing leukoencephalopathy. While white matter lesions prominent in the brain have been reported in the literature, gray matter lesions have not received particular attention. In this study, we examined three autopsy cases of Nasu-Hakola disease in order to focus specifically on gray matter lesions. The ages at onset of the three cases were 20, 23 and 29 years, and the disease durations were 29, 19 and 8 years, respectively. In addition to characteristic degeneration in the cerebral white matter, such as demyelination with conspicuous fibrillary gliosis and axonal changes, all three cases showed overt pathology in the gray matter. Neuronal loss with gliosis in the thalamus (particularly in the dorsomedial nucleus and anterior nucleus), caudate nucleus, putamen and substantia nigra was prominent in all cases, and the severity corresponded to the disease duration. The cerebral cortices were relatively preserved in all cases. One case showed neuronal loss and gliosis in the gray matter of the hippocampus, possibly due to repeated episodes of epileptic convulsions. These gray matter pathologies are considered to be responsible for some of the clinical manifestations of the disease, including extrapyramidal symptoms.

Cellular Localization of Sphingosine-1-phosphate Receptor 1 Expression in the Human Central Nervous System

Sphingosine-1-phosphate (S1P), a potent lipid mediator, transduces intracellular signals through the activation of S1P receptors (S1PRs). Although S1PRs have been shown to play an important role in the central nervous system (CNS), accurate localization and the function of S1PR1 in the human CNS are still unclear. In this study, we investigated the localization of S1PR1 in the human CNS of postmortem samples, using a rabbit polyclonal antibody, the specificity of which had been well defined. Immunohistochemical investigation of paraffin-embedded sections revealed diffuse granular staining of the gray matter. The signals of the gray matter were much stronger than those of the white matter. The immunohistochemical expression levels correlated well with the results of quantitative real-time RT-PCR-based analysis and Western blotting. Studies using double immunostaining and immunoelectron microscopy revealed that the antigen was strongly expressed in the membrane of the astrocytic foot processes of glia limitans and astrocytes with radial cytoplasm, but not distributed in neurons. In neurological disorders, hypertrophic astrocytes with strong expression of glial fibrillary acidic protein exhibited significantly decreased expression of S1PR1 in contrast to its strong expression in astrocytes forming fibrillary gliosis. These results indicate that S1PR1 is localized in astrocytes, and its expression level may change during the processes that occur after brain damage.

DISCORDANT CLINICOPATHOLOGIC PHENOTYPES IN A JAPANESE KINDRED OF FATAL FAMILIAL INSOMNIA

The GAC→AAC mutation at codon 178 (D178N) of prion protein (PrP) gene ( PRNP ) results in 2 distinct clinicopathologic phenotypes dependent on codon 129 polymorphism of the mutant allele: fatal familial insomnia (FFI) with methionine encoded in codon 129 and familial Creutzfeldt-Jakob disease (CJD) with valine.1,2 However, some D178N patients who had homozygosity for methionine at codon 129 (D178N-129MM) were reported recently to have the CJD phenotype.3–5 The cause for these clinicopathologic diversities is unclear. We report a Japanese son–mother pair who presented with FFI and CJD phenotypes. ### Case reports. #### Patient 1 (proband). A 54-year-old man, born to nonconsanguineous parents, developed dysphagia and loss of appetite. Later, he showed peculiar movement in sleep, followed by insomnia and hypersomnolence. Diplopia, intention tremor, ataxic gait, sleep apnea, fluctuant low-grade fever, tachycardia, hyperhidrosis, constipation, and impotence also followed. He was admitted to hospital 7 months after the onset of symptoms. Neurologic examination showed mild memory disturbance, cerebellar ataxia, myoclonus, brisk deep tendon reflexes, sleep apnea, and dysautonomia. He did not show akinetic mutism. He moved continuously during sleep. EEG showed no periodic synchronous discharge (PSD), and polysomnography showed loss of deep sleep and marked reduction of REM sleep. Brain MRI showed only mild atrophy. In the cerebral cortex and thalamus, hypoperfusion and hypometabolism were detected by SPECT with 99mTc-ECD and PET with 18F-2-fluorodeoxy-d-glucose. He died 13 months after the onset of symptoms. PRNP analysis, with informed consent, on leukocyte DNA showed D178N-129MM. Histologic examination showed spongiform changes limited to the cingulate gyrus and subiculum, and severe neuronal loss and fibrillary gliosis in the centromedian and dorsomedial nucleus of the thalamus and in the inferior olivary nucleus (figure, A, D, and G). Immunohistochemical analysis showed no pathologic PrP (PrPSc) deposition in the cerebral cortex, thalamus, or inferior olivary nucleus. Western blot analysis (WB) showed very …

Quantum Dot Labeling and Imaging of Glial Fibrillary Acidic Protein Intermediate Filaments and Gliosis in the Rat Neural Retina and Dissociated Astrocytes

The use of antibody and peptide functionalized semiconductor quantum dots holds considerable potential for specific labeling of target antigens and high resolution optical imaging of biological preparations. Despite this potential, their use in neuroscience is not yet widespread; a number of technical and methodological challenges must still be overcome in order to produce reliable and reproducible labeling protocols. We have optimized and used anti-GFAP functionalized quantum dots for specific labeling of intermediate filaments in astrocyte and Müller glial cells in sections of intact rat neural sensory retina and dissociated primary spinal cord astrocytes. These techniques produced stable and robust imaging of retinal astrocytes and Müller cells with minimal non-specific background labeling and intense fluorescence resulting in a high signal to noise ratio. This resulted in clear and efficient labeling of normal levels of GFAP in the retina and the ability to differentiate it from pathologically high levels of GFAP associated with reactive gliosis in a laser induced injury model. Labeling and imaging of dissociated astrocytes demonstrated the presence of what appeared to be highly complex organizations of fine intermediate filaments that spanned between cells to form intricate networks of filamentous intercellular bridges. The presence of these structures in situ and in vivo as well as any potential functions remain to be determined, but their identification should be greatly facilitated by quantum dot labeling protocols.

MELAS with diffuse degeneration of the cerebral white matter: Report of an autopsy case

Up to now diffuse white matter demyelination of the cerebrum has been reported in only a few cases of mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS). Here we document an autopsy case with this rare neuropathology. Most MELAS cases are diagnosed antemortem by A3243G transition of mitochondrial DNA. While cerebral damage including necrotic foci in the cerebral cortex are common findings in MELAS, prominent white matter involvement best characterizes this MELAS case. There were numerous necrotic foci, varying in size and chronological stage, in the cerebral white matter. In the areas of the white matter without necrotic foci, there was diffuse fibrillary gliosis with the loss of axons and oligodendrocytes. The gliosis was dominant in the deep white matter, sparing the U-fiber. The cerebral cortex showed diffuse cortical atrophy with few scattered necrotic foci. Distribution of the cerebral lesions does not coincide with the territory of blood supply. The vascular wall presented only slight to mild hyalinosis. We assumed a common pathogenesis to the cortical lesions and the white matter change. The pathogenesis of the present diffuse cerebral lesions may not be just secondary to circulatory disturbance but partly due to metabolic abnormality.

Diffusely Abnormal White Matter in Chronic Multiple Sclerosis

Diffuse abnormalities in the white matter (WM), ie, the so-called diffusely abnormal WM (DAWM), as observed on magnetic resonance imaging (MRI), may contribute to the development of clinical disability in multiple sclerosis (MS). Underlying pathologic and MRI characteristics of DAWM are largely unknown. To explore and describe the histopathologic and radiologic characteristics of DAWM in chronic MS. An MRI and histopathologic postmortem correlative study. We analyzed 17 formalin-fixed hemispheric brain slices from 10 patients with chronic MS using histopathologic analysis and qualitative and quantitative MRI. A region-of-interest approach was applied to compare radiologically defined DAWM, normal-appearing WM, and focal WM lesions and to correlate quantitative MRI measures with histopathologic findings. The DAWM consisted of extensive axonal loss, decreased myelin density, and chronic fibrillary gliosis, all of which were substantially abnormal compared with normal-appearing WM and significantly different from focal WM lesion pathology. Increased T1- and T2-relaxation times and decreased fractional anisotropy values were found in DAWM regions of interest, in association with extensive axonal loss and reduced myelin density. Increased T1- and T2-relaxation times were associated with chronic gliosis. This study classifies DAWM in chronic MS as an abnormality that is different from normal-appearing WM and focal WM lesions, most likely resulting from the cumulative effects of ongoing inflammation and axonal pathology. As such, DAWM is likely to substantially contribute to disease progression and may prove to be an important new disease marker in clinical trials focusing on the neurodegenerative aspects of MS.

Pyramidal tract degeneration in sporadic Creutzfeldt‐Jakob disease

We investigated the neuropathologic features of pyramidal tract degeneration in 27 cases of sporadic Creutzfeldt-Jakob disease (sCJD). The present study included 13 cases of subacute spongiform encephalopathy (SSE), 13 cases of panencephalopathic-type (PE-type) sCJD and one case of thalamic-type sCJD. Pyramidal tract degeneration was observed in PE-type sCJD cases with disease duration of more than 13 months. Cases of SSE, PE-type sCJD of relatively short duration and thalamic-type sCJD showed no pyramidal tract degeneration. All cases with pyramidal tract degeneration showed severe cerebral neocortical involvement with widespread cerebral white matter degeneration. The loss of myelin and axons and macrophage infiltration and fibrillary gliosis seen in these pyramidal tract lesions is consistent with secondary tract degeneration due to cerebral neocortical involvement. Interestingly, some cases with pyramidal tract degeneration showed a distal-dominant pathology that we believe indicates retrograde degeneration or a "dying-back" phenomenon of the pyramidal tract. Our results indicate that pyramidal tract degeneration is a late pathologic event in sCJD. Investigation of pyramidal tract degeneration may help clarify the mechanisms underlying the development of sCJD white matter pathology, particularly that of PE-type sCJD.

Periodic stupor‐like states in progressive supranuclear palsy

AbstractFour patients with progressive supranuclear palsy presented with various psychiatric symptoms. Periodic stupor‐like states due to fluctuations of consciousness were observed in all four cases. Magnetic resonance imaging showed severe dilatation of the third ventricle suggesting atrophy of the thalami. Neuropathological examination in one of the cases confirmed severe fibrillary gliosis in the intralaminar thalamic nucleus. So far, few studies have focused on periodic stupor‐like states observed in progressive supranuclear palsy patients. From our cases and from the literature, we postulate that the lesions in the intralaminar thalamic nuclei may have close relevance to the stupor‐like states seen in progressive supranuclear palsy patients.

Axo-somatic inhibition of projection neurons in the lateral nucleus of amygdala in human temporal lobe epilepsy: an ultrastructural study

Here, we report ultrastructural alterations in the synaptic circuitry of the human amygdala related to neuronal cell densities in surgical specimens of patients suffering from temporal lobe epilepsy (TLE). The neuronal cell densities quantified in the basolateral complex of amygdala were significantly reduced only in the lateral nucleus (LA) of TLE patients as compared to autopsy or non-Ammon's horn sclerosis (AHS) controls (Nissl staining, immunostaining against the neuronal marker NeuN). For this reason, we focussed on the LA to perform a more detailed quantitative ultrastructural analysis, which revealed an inverse correlation between the number of axo-somatic inhibitory synaptic profiles at the somata of glutamic acid decarboxylase (GAD)-negative projection neurons and the extent of perisomatic fibrillary gliosis. In contrast, the density of GAD-immunoreactive interneurons positively correlated with the number of axo-somatic inhibitory synaptic profiles. The fibrillary material in perisomatic glial cell processes was preferentially labeled by the astroglial marker S100B. In addition, a qualitative study of the dendrites of GAD- and parvalbumin (PARV)-containing interneurons showed that they were often contacted by asymmetrical excitatory synapses. Our results are in line with anatomical data from rodents and cats, which show that amygdalar interneurons form axo-somatic inhibitory synapses on GAD-negative projection neurons, whereas the interneurons themselves receive excitatory input from recurrent collaterals of projection neurons and from cortico- and thalamo-amygdalar afferents. The structural reorganization patterns observed in the GABAergic circuitry are compatible with a reduced feedback or feed forward inhibition of amygdalar projection neurons in human TLE.

Protracted juvenile neuronal ceroid lipofuscinosis—An autopsy report and immunohistochemical analysis

The juvenile form of neuronal ceroid lipofuscinosis (JNCL) is caused by mutations in the CLN3 gene, and is characterized by progressive loss of vision and development of motor deficits. A few patients exhibit a more protracted clinical course and are diagnosed with protracted JNCL (PJNCL). Here, we report the autopsy in a case of PJNCL in a 55-year-old male and immunohistochemical examination of the involvement of oxidative stress and glutamate excitotoxicity in neurodegeneration. The patient was born to consanguineous parents (I assume this means that the parents were related. If not, then the sentence will need to be changed again.) and had brothers with similar neurological disease. He showed mental retardation and visual impairment in the first decade which gradually developed along with motor dysfunction for over 40 years. At autopsy, the cerebral pyramidal neurons revealed deposition of lipopigments, which demonstrated ‘finger print’ and curvilinear profiles on electron microscopy. He also exhibited cerebellar cortical atrophy, fibrillary gliosis in the white matter, and rarefication in the globus pallidus. Immunohistochemically, the number of neurons immunoreactive for advanced glycation end product was elevated in the cerebellar cortex and midbrain. Immunoreactivity for excitatory amino acid transporter 1 was reduced in the cerebellar dentate and inferior olivary nuclei. These findings suggest that oxidative damage to proteins and disturbed glutamate transport can be involved in PJNCL.