Ultrastructure of neurofibrillary tangles in progressive supranuclear palsy

Tau-positive glial inclusions in progressive supranuclear palsy, corticobasal degeneration and Pick's disease

The presence of tau-positive glial inclusions has been recently found a consistent feature in the brains of patients with progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and Pick's disease (PiD). These inclusions are classified based on cellular origin as tau-positive astrocytes, presumably either fibrillary or protoplasmic, coiled bodies and glial threads. Immunohistochemically, their major structural component is abnormal tau proteins, similar to those found in Alzheimer's disease. Nevertheless, their morphology, including ultrastructural profile, has been suggested to be distinctive for each disease. The profile and extent of particular glial inclusions correlate well with disease phenotype. Highly characteristic correlations include tufts of abnormal fibers in PSP, astrocytic plaques and dense glial threads in CBD and ramified astrocytes and small Pick body-like inclusions in PiD. The significance of the inclusions in disease pathogenesis and their biochemical characteristics remain to be clarified. Nevertheless, these distinctive glial lesions most likely reflect fundamental alterations in isoform composition of tau as well as its specific cellular and regional expression in sporadic tauopathies.

Abnormal tau-containing filaments in neurodegenerative diseases

It has been known for some time that the neurofibrillary pathology in Alzheimer's disease consists of so-called paired helical and straight filaments made up of the microtubule-associated protein tau. The degree of dementia observed in the disease correlates better with the extent of neurofibrillary pathology than with the Abeta amyloid deposits, the other characteristic defining pathological fibrous deposit in Alzheimer's disease. However, no familial cases of Alzheimer's disease have been genetically linked to the tau protein locus. Recently a group of frontotemporal dementias with parkinsonism linked to chromosome 17 has been shown to be caused by mutations in the tau gene. Some are missense mutations giving altered tau proteins, whereas others affect the splicing of the pre-mRNA and change the balance between different tau isoforms. Histologically these diseases are all characterised by various kinds of filamentous tau protein deposits, mostly in the complete absence of Abeta deposits. The abnormal tau filaments show different morphologies, depending on the nature of the tau mutation. These diseases show that tau mutations can be a prime cause of inherited dementing illness and may throw some light on the pathological process in the much larger number of sporadic cases of Alzheimer's disease.

Neuropathologic differentiation of progressive supranuclear palsy and corticobasal degeneration

Progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are usually sporadic multi-system degenerations associated with filamentous tau inclusions in neurons and glia. As such they can be considered sporadic tauopathies in contrast to familial tauopathies linked to mutations in the tau gene. Mutations have not been found in the tau gene in either PSP or CBD. The clinical syndromes and neuroimaging of typical cases of PSP and CBD are distinct; however, atypical cases are described that have overlapping clinical and pathologic features. Both PSP and CBD have similar biochemical alterations in the tau protein, with the abnormal tau protein containing predominantly four-repeat tau. While there is overlap in the pathology in PSP and CBD, there are sufficient differences to continue the present day trend to consider these separate disorders. Several important pathologic features differentiate PSP from CBD. Ballooned neurons are frequent and nearly a sine qua non for CBD, but they are found in PSP at a frequency similar to that of other neurodegenerative diseases, such as Alzheimer's disease. Astrocytic lesions are different, with tufted astrocytes found in motor cortex and striatum in PSP and astrocytic plaques in focal atrophic cortices in CBD. The most characteristic neuronal tau pathology in CBD is wispy, fine filamentous inclusions within neuronal cell bodies, while affected neurons in PSP have compact, dense filamentous aggregates characteristic of globose neurofibrillary tangles. Thread-like processes in gray and white matter are much more numerous and widespread in CBD than in PSP. The brunt of the pathology in CBD is in the cerebrum, while the basal ganglia, diencephalon and brainstem are the targets of PSP. Further clinicopathologic studies will refine our understanding of these disorders and open the possibility that common etiologic factors may be identified for these unusual sporadic tauopathies.

Regional quantitative analysis of tau-positive neurons in progressive supranuclear palsy: comparison with Alzheimer's disease

In patients with progressive supranuclear palsy (PSP), various tau-positive abnormal structures are found in the cerebral cortex as well as in the subcortical nuclei. Similar tau-positive abnormalities are also identified in cortico-basal degeneration (CBD). It is therefore questionable as to whether PSP can be neuropathologically differentiated from CBD. It also remains nuclear whether neurofibrillary tangles (NFT) in the cerebral cortex of PSP patients consist of PSP-NFT or concomitant Alzheimer's disease (AD)-NFT, although there have been some reports suggesting that PSP- and AD-NFT are different with respect to distribution pattern and biochemical character. In this study, a regional quantitative analysis of the distribution and antigenicity of tau-positive neurons (TPN) was performed in PSP cases and compared with that in AD cases. TPN consisted of NFT with tangle-formation and pretangle neurons (PN) without tangle-formation. In addition, NFT were subdivided into mature and immature NFT according to the difference of staining properties with anti-tau-related antibodies. The comparison of the TPN of the PSP cases with those of the AD cases revealed that the degree of tangle-formation in the TPN of AD was similar in all of the examined regions, while that in the TPN of PSP varied according to the region and case. Moreover, the NFT in the PSP and AD cases had different distributions according to the cortical layer and subnucleus, even in the common predilection sites of PSP and AD, suggesting that NFT in these regions of the PSP cases consist mainly of PSP-NFT. In addition, the PSP cases could be divided into two groups according to the difference of the tangle-formation of TPN; group I with typical PSP pathology and group II with atypical PSP pathology similar to CBD. This suggests that there is a continuity between PSP and CBD with respect to the distribution and antigenicity of TPN.

Corticobasal degeneration: widespread argentophilic threads and glia in addition to neurofibrillary tangles. Similarities of cytoskeletal abnormalities in corticobasal degeneration and progressive supranuclear palsy

A 57-year-old man had exhibited cortical sensory disturbance, rigidity, spasticity, dementia, alien hand, grasp reflex, supranuclear ophthalmoplegia, pseudobulbar palsy, and neck dystonia for 4 years. Histological examination of autopsied specimens revealed neuronal loss in the cerebral cortex, with ballooned neurons, subthalamic nucleus, substantia nigra, basal ganglia, midbrain tegmentum, and the thalamus. There were neurofibrillary tangles in the subthalamic nucleus and the substantia nigra. Gallyas-Braak silver impregnation demonstrated numerous argentophilic tangles, threads, and a few argentophilic glia in the cerebral cortex, subcortical white matter, particularly in the precentral gyrus, subcortical nuclei, and the brainstem. These argentophilic structures were largely positive for tau, and negative for ubiquitin, paired helical filaments, and phosphorylated neurofilament. Ultrastructurally, 15-nm-wide straight tubules were observed in the neurons of the substantia nigra, globus pallidus, and the precentral cortex, coexisting with a few twisted tubules periodically constricted at 160- to 230-nm intervals. It was conclusively shown that Gallyas- and tau-positive cytoskeletal abnormalities occurred widely in brain of corticobasal degeneration. Both distribution and morphology of abnormal phosphorylated tau protein in corticobasal degeneration appear to resemble these features in progressive supranuclear palsy. These findings suggest a common cytoskeletal etiopathological significance in corticobasal degeneration and progressive supranuclear palsy.

Distribution of tangles and threads in the cerebral cortex in progressive supranuclear palsy

Recent studies have described silver- and tau-positive glia and threads in the degenerating lesions of progressive supranuclear palsy. In this study, Gallyas-Braak silver impregnation and several immunohistochemical techniques were employed to examine the distribution of tangles, abnormal glia and threads in the cerebral cortex of nine cases of progressive supranuclear palsy. In addition to neurofibrillary tangles, argentophilic glia and threads were impregnated exclusively by Gallyas-Braak technique. This technique demonstrated two types of glia profiles: tightly coiled intra-cytoplasmic profiles surrounding nuclei (coiled profiles) and thorn-like profiles with radial ramifications (thorn-like profiles). Thorn-like profiles are possibly in astrocytes and were detected in the cerebral cortex, while coiled profiles are possibly in oligodendroglia and were detected both in the cerebral cortex and subcortical white matter. Topographically, many neurofibrillary tangles were constantly seen in the frontal cortex and in the pre-central gyrus. Numerous neurofibrillary tangles were detected in the entorhinal cortex of the two brains. Argentophilic glia and threads were also frequent both in the frontal cortex and the precentral gyrus; however, they were more frequent in the pre-central gyrus that in the frontal cortex in four of the eight cases examined. In two brains, argentophilic threads were distributed widely in the cerebral cortex and white matter except for the temporal cortex. In immunohistochemical studies, argentophilic glia and threads were mostly positive for Tau 2, and a small number of them were weakly positive for ubiquitin and paired helical filament protein. The immunoproperties of these abnormal glia and threads seemed to be virtually identical to those of neurofibrillary tangles.(ABSTRACT TRUNCATED AT 250 WORDS)

Corticonigral degeneration with neuronal achromasia presenting with primary progressive aphasia: ultrastructural and immunocytochemical studies

We describe a clinico-pathological variant of a degenerative disorder involving Broca's, Wernicke's, and supplementary motor areas, which presented as primary progressive aphasia, dysarthria, bucco-facial apraxia, and hearing loss as initial symptoms, followed by organic personality changes. Postmortem examination revealed severe focal atrophy of the cerebral convolutions in the frontal operculum, superior frontal gyrus, and superior and transverse temporal gyri in addition to diffuse atrophy of the frontal and temporal lobes in both hemispheres. Microscopical examination revealed argyrophilic neuronal inclusions (ANIs) in the neuronal perikarya and presynaptic terminal throughout the central nervous system, as well as neuronal loss and swollen chromatolytic neurons in the affected cortices. Neocortical ANIs showed a positive immunoreaction with an anti-tau antibody but only a weak reaction with an anti-ubiquitin antibody immunohistochemically. Ultrastructurally, neocortical ANIs consisted of 15-nm thick smooth-surfaced tubules and tubules with constrictions at 120-150-nm intervals; thus they were different from the typical paired helical filaments of the 80-nm interval constrictions observed in the subiculum. ANIs were also found in the basal ganglia, brain stem nuclei, and cervical cord. Accordingly, ANIs appear distinct from neurofibrillary tangles (NFTs) of progressive supranuclear palsy, NFTs of Alzheimer-type dementia, and Pick bodies. The authors consider that this case fits the histopathological criteria of corticonigral degeneration with neuronal achromasia except for the unusual extension to the temporal lobes.

Subcortical neurofibrillary degeneration presenting as Steele-Richardson-Olszewski and other related syndromes: a review of 90 pathologically verified cases

We have reviewed 90 patients from the literature with histopathological features compatible with currently accepted criteria for the diagnosis of the Steele-Richardson-Olszewski syndrome (SROS). Only 62 patients (69%) had clinically definite SROS based on the criteria of Maher and Lees. Neurofibrillary degeneration of subcortical structures with involvement of the internal pallidum, the subthalamic nucleus, and substantia nigra was considered essential for the pathological diagnosis. Thirty-six cases (40%) had neocortical neurofibrillary change that bore no clear relationship to the degree of cognitive impairment (chi 2 = 9.293; p < 0.4107). Grumose degeneration of the dentate nucleus was present in 25 cases (28%), and occasionally there were other, less usual, findings such as Pick bodies and Lewy bodies.

Morphological investigation of neurofibrillary tangles in Alzheimer's disease

There are two types of neurofibrillary tangles, namely, a twisted tubule and a straight or uniform tubule in the same cell in the brain with Alzheimer's disease. However, in some parts of the same fibril, both the twisted and straight tubules clearly could be seen as a continuation of each other. This finding suggests that both of the tubules have a deep relation to each other, especially at the molecular level. This might also suggest the possibility of both tubules which mutually transform into each other.

The neuropathology of progressive supranuclear palsy

The macroscopical, histological, ultrastructural and immunocytochemical features of progressive supranuclear palsy (PSP) are reviewed. Recent investigations have revealed important differences in the distribution, ultrastructure and immunocytochemical profile of neurofibrillary tangles in PSP and in Alzheimer's disease. Cortical involvement, as demonstrated by the presence of tangles and neuropil threads has extended the neuropathological spectrum of PSP. Quantitative assessments of neuronal populations show neuronal loss, not only in various nuclei of the brainstem, diencephalon and cerebellum, but also in other areas, including the nucleus basalis of Meynert, substantia nigra and neostriatum. A new classification, based on neuropathological criteria, is suggested in order to take into consideration the phenotypic heterogeneity of PSP. This new classification distinguishes three types: typical, atypical and combined cases. Typical (Type 1) cases conform to the original definition of PSP. Type 2, atypical cases are variants of the histological changes characteristic of PSP: either the severity or the distribution of abnormalities, or both of these deviate from the typical pattern. Cases with combined pathology belong to type 3 group: in these the typical pathology of PSP is accompanied by lesions characteristic of another neurodegenerative or vascular disease.

Cortical tangles in progressive supranuclear palsy

Ten cases of PSP were examined for the presence of neocortical and hippocampal lesions. Samples from 10 cortical areas were stained by Bodian's method and by tau, ubiquitin and beta A4 immunocytochemistry. For the sake of comparison, 5 Alzheimer's cases were studied with the same techniques. Neocortical tangles, star-like tufts of fibers, and neuropil threads were seen in all the cases of PSP. They were stained by Bodian's technique and labelled by an anti-tau, but not by a polyclonal anti-ubiquitin antibody. Senile plaques (Bodian's technique), diffuse or focal amyloid deposits (beta-A4 immunohistochemistry) were rare or absent. The density of tangles was the highest in area 4 and the lowest in area 17. In area 4, the tangles were mainly located in layers V-VI. By contrast, the Alzheimer's tangles had a bimodal distribution (layers III and V-VI). These results favor the specificity of cortical alterations in PSP.

Neurofibrillary tangles in the neurons of spinal dorsal root ganglia of patients with progressive supranuclear palsy

Neurofibrillary tangles (NFTs) occur in neurons of human central nervous system (CNS) both in aged subjects and patients with several degenerative diseases, with a certain topographical predilection. In surveying the NFT distribution in nervous tissue of patients with progressive supranuclear palsy (PSP), we found silver-positive fibrillary tangles in the neurons of dorsal root ganglia (DRG) in two of five patients. By immunohistochemistry, these tangles were stained with antibodies to human tau protein, paired helical filaments (PHFs) and ubiquitin. Electron microscopy revealed that they were mainly composed of PHFs that were morphologically indistinguishable from PHFs in the NFTs of CNS typically seen in Alzheimer's disease brains. Our data demonstrate for the first time that the neurons of DRG produce NFTs in PSP and suggest that the pathological process(es) leading to tangle formation can occur in the neurons of the peripheral nervous system in this disease condition.

Immunohistochemical, ultrastructural and immunoelectron microscopic studies of spinal cord neurofibrillary tangles in progressive supranuclear palsy

Immunohistochemical, ultrastructural and immunoelectron microscopic studies of spinal cord neurofibrillary tangles (NFTs) in progressive supranuclear palsy (PSP) were performed. The spinal cord NFTs reacted with antibodies to tau protein (tau-2), ubiquitin and Alzheimer neurofibrillary tangles (ANTs, Ab 39). Ultrastructurally, the NFTs consisted of bundles of straight fibrils. In longitudinal sections, the individual NFT fibrils appeared as straight fibrils with a diameter of approximately 15 nm. In cross sections, circular structures approximately 15 nm in diameter were seen, and some had a central density. Electron microscopic examination of specimens stained with the antibodies and by the modified Bielschowsky method revealed the products of the tau, ubiquitin and ANTs immunoreactions and silver deposits on the NFT fibrils. This is the first demonstration of the ultrastructure of spinal cord NFTs in PSP.

Presenile dementia with progressive supranuclear palsy tangles and Pick bodies: an unusual degenerative disorder involving the cerebral cortex, cerebral nuclei, and brain stem nuclei

Degeneration of heterogeneous systems in the central nervous system, with widespread distribution of argyrophilic neuronal fibrillary inclusions, was found in a patient with presenile dementia. Atrophy was circumscribed in the frontal and temporal lobes. Neuronal loss was severe in the basal ganglia, subthalamic nucleus, and substantia nigra. Immunocytochemical study using anti-phosphorylated tau and anti-ubiquitin antibodies in conjunction with ultrastructural observations revealed two types of inclusions: neurofibrillary tangles (NFTs) of progressive supranuclear palsy (PSP) in the Edinger-Westphal nucleus, locus coeruleus, cerebellar dentate nucleus, inferior olivary nucleus, and posterior horn of the spinal cord; and Pick bodies (PBs) in the atrophied cerebral cortex and red nucleus. PSP-type NFTs and PBs have been demonstrated in a single case for the first time. Despite their pathognomonic significance in certain disorders, we suggest that these inclusions may reflect a form of cytoskeletal disorganization, which is not entirely restricted to a single disease entity.

Immunohistochemical study of a case with progressive supranuclear palsy without ophthalmoplegia

A case of progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome; PSP) with parkinsonism and absence of gaze palsy or mental changes is reported. Neuropathological examination, apart from typical changes, showed, lack of midbrain tegmentum demyelination, marked loss of Purkinje cells and presence of hyalin-like bodies in individual neurons of the substantia nigra. Immunostaining against tau-1 protein revealed the prevalence of a diffuse reaction in locus coeruleus neurons; reflecting either different ability of these cells to accumulate straight filaments, or a various time sequence of neurofibrillary tangles formation. Ferritin immunohistochemistry demonstrated widespread microglial cell proliferation, confirming further the generalized character of CNS pathology in PSP.

Distribution of cortical neurofibrillary tangles in progressive supranuclear palsy: a quantitative analysis of six cases

Progressive supranuclear palsy is characterized neuropathologically by the presence of high densities of neurofibrillary tangles in several subcortical structures. In some cases, neurofibrillary tangles have also been described in the cerebral cortex. We performed a quantitative regional and laminar analysis of the distribution of these lesions in six cases of progressive supranuclear palsy. We observed that the neurofibrillary tangle distribution in the cerebral cortex was largely confined to the hippocampal formation. In particular, in all the cases neurofibrillary tangles were observed in the granule cell layer of the dentate gyrus. In the prefrontal and inferior temporal cortex, neurofibrillary tangles were predominantly distributed in layers II and III. In addition, there were moderate-to-high neurofibrillary tangle densities in the primary motor cortex. This localization pattern contrasts with the neurofibrillary tangle distribution observed in the cerebral cortex of Alzheimer's disease cases, where tangles are denser in layer V than in layer III, and where the primary motor cortex and the dentate gyrus are usually not involved. These results suggest that specific elements of the cortical circuitry might be differentially vulnerable in progressive supranuclear palsy as compared to Alzheimer's disease.

Straight and paired helical filaments in Alzheimer disease have a common structural unit

The presence of abundant neurofibrillary tangles in certain areas of the brain constitutes one of the defining pathological characteristics of Alzheimer disease. The predominant component of the tangle is an abnormal fibrous assembly known as the paired helical filament (PHF). The PHF is formed by a twisted double-helical ribbon of subunits that gives rise to an image alternating in width between 8 nm and 20 nm with a cross-over spacing of 80 nm. Also found in tangles is the straight filament (SF), a different kind of abnormal filament, about 15 nm wide, that does not exhibit the marked modulation in width shown by the PHF. It is reported herein that PHFs and SFs form hybrid filaments displaying both morphologies, that PHFs and SFs share surface epitopes, and that computed maps reveal a similar C-shaped morphological unit in PHFs and SFs, though differing in relative arrangement in the two types of filament. The observations imply that the SF is a structural variant of the PHF and establish a common unit of assembly for these two pathological filaments.

Occurrence of 15-nm-wide straight tubules in neocortical neurons in progressive supranuclear palsy

Ultrastructural investigations were carried out on the cerebral neocortex in two cases of progressive supranuclear palsy. In both cases, characteristic 15-nm-wide straight tubules were observed in the neurons. The numbers of cells containing the straight tubules and of tubules in individual cells were small. However, the occurrence of the tubules strongly suggests that the cerebral neocortex is also exposed to the disease process in progressive supranuclear palsy.

Neurofibrillary tangles in Alzheimer's disease and progressive supranuclear palsy: antigenic similarities and differences. Microtubule-associated protein tau antigenicity is prominent in all types of tangles

The antigenic profile of neurofibrillary tangles (NFT) in Alzheimer's disease (AD), senile dementia of Alzheimer type (SDAT), progressive supranuclear palsy (PSP) and in non-demented aged humans was investigated by light and electron microscopic immunocytochemistry using antisera and monoclonal antibodies to tubulin, microtubule-associated proteins (MAP1, MAP2 and tau), neurofilament proteins and determinants unique to Alzheimer paired helical filaments (PHF). Antibodies to tau proteins labeled NFT in all cases investigated (AD, SDAT, PSP and non-demented aged humans). However, one monoclonal antibody to PHF recognized numerous tangles in AD/SDAT, but only a small minority of the PSP tangles. Antibodies to tubulin, MAP1, MAP2 and neurofilament proteins did not selectively stain NFT. Whereas pretreatment of sections with phosphatase was required for the detection of tangles with Tau-1 monoclonal antibody, digestion of sections with either phosphatase or pronase had no significant effect on the staining pattern obtained with the other antibodies. Our studies show that, as previously described for AD/SDAT, phosphorylated tau polypeptides are also a major antigenic determinant of tangles in PSP, indicating that tangle formation may follow a common pathogenetic pathway in neurofibrillary degenerations. There is, however, at least one epitope in AD/SDAT tangles which seems to be absent on, or at least inaccessible in, the 15-nm straight fibrils of PSP.

Cytoskeletal protein abnormalities in neurodegenerative diseases

The nervous system is a rich source of filamentous proteins that assume critical roles in determining and maintaining neuronal form and function. Neurons contain three major classes of these cytoskeletal organelles: microtubules, intermediate filaments, and microfilaments. They also contain a variety of proteins that organize them and serve to connect them with each other. Such major neurodegenerative diseases as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, as well as a variety of toxic neuropathies, are characterized pathologically by intraneuronal filamentous inclusions. Recent studies using biochemical and immunocytochemical techniques have established that these abnormalities represent disorganized states of the neuronal cytoskeleton and have determined some of the specific molecular constituents of these inclusions. This knowledge has led to new ways of thinking about their origins.

Atypical presentation of progressive supranuclear palsy

Four pathologically documented cases of progressive supranuclear palsy are reported. Two patients exhibited severe dementia and 2 parkinsonism; none had the classic ophthalmoplegia. On retrospective analysis, clues to the diagnosis included early prominent gait disturbance, apraxia of eyelid opening in 1 patient, lack of tremor, poor response to levodopa-carbidopa, and severe rigidity with a posture of neck extension terminally in 1 patient. The clinical presentation of progressive supranuclear palsy, therefore, is not as stereotyped as previously thought, and the diagnosis can be overlooked if one adheres rigidly to the classic diagnostic criteria.

Progressive supranuclear palsy--20 years later

Reviewing the literature since recognition of progressive supranuclear palsy (PSP) as a clinicopathological entity 20 years ago, the present state of knowledge is delineated. The etiology of PSP is still unknown. The clinical hallmarks are supranuclear palsy of vertical gaze, axial dystonia in extension and pseudobulbar palsy with marked dysarthria and dysphagia. Accessory features include subcortical dementia, mental, extrapyramidal, pyramidal and cerebellar symptoms. PSP is a disease of the presenium (average age at onset, 59.6 years) with a male preponderance (60% men). The onset is insidious with vague complaints of dysequilibrium (60%), mental changes (46%) and disturbed vision (21%), often preceding abnormal neurological findings. The important borderland and main differential diagnosis is parkinsonism. However, in PSP, responsiveness to antiparkinsonian agents is poor and progression is rapid and fatal within few years (average survival time, 5.7 years). Promising diagnostic tools at present include CT-scanning and neuro-otologic and -ophthalmologic examination. Neuropathological findings, confined to specific diencephalic, brainstem and cerebellar nuclei, include neurofibrillary tangles (ultrastructurally different from those seen in other CNS disorders), neuron loss and gliosis. The importance of research on neurocytochemistry, brain ultrastructure and immunology in the current investigation of PSP is outlined.

Substructure of 20 nm filaments of progressive supranuclear palsy

In contrast to the ultrastructure of Alzheimer's neurofibrillary tangles (NFT), which has been well characterized as accumulations of paired helical 10-nm filaments (PHF) with 80-nm regular constrictions, the morphology of the neurofibrillary changes of PSP remains ill-defined. Until recently, the fine structure of PSP tangles was generally accepted as 15-nm straight filaments or tubules, although many reports describing different electron-microscopic findings have appeared in the literature. In this report, we present morphological data indicating a protofilamentous substructure present in straight filaments of PSP which has some points of similarity with the protofilamentous architectures which have been reported for paired helical filaments of Alzheimer's disease. The straight filaments were found to be composed of six or more helically symmetric 2-5-nm protofilaments. We conclude that despite the varied morphology of filaments in neurofibrillary tangles observed in PSP there may be some underlying identity at the molecular level with the PHF of neurofibrillary tangles of Alzheimer's disease.

A quantitative and ultrastructural study of substantia nigra and nucleus centralis superior in Alzheimer's disease

In four patients with presenile Alzheimer's disease (AD) and three age-matched controls a quantitative study of neurons and neurofibrillary tangles (NFT) in the substantia nigra (SN) and nucleus centralis superior (NCS) was performed. A significant neuronal loss, similar in both nuclei, was found in AD cases, while the incidence of NFT was remarkably higher in NCS. Moreover, no significant correlation between neuronal loss and number of NFT was detected. An electron-microscopic study revealed that the subcortical NFT in NCS are made up of paired helical filaments in spite of their globose round shape.

Immunohistochemical localization of neurofilament protein in neuronal degenerations

The immunohistochemical localization of human neurofilament proteins was studied in a variety of neuronal changes by the peroxidase-antiperoxidase method using antisera raised against each of the subunit proteins of human neurofilament. Torpedoes of the cerebellum, axonal spheroids of amyotrophic lateral sclerosis as well as of infantile neuroaxonal dystrophy, and neurofibrillary changes in a case of Pick's disease were consistently immunostained. Occasionally, a positive immunoreactivity was also observed in Lewy bodies, in neurofibrillary tangles of progressive supranuclear palsy, and in neuritic processes of senile plaques. Neurofibrillary tangles of Alzheimer type and Pick's bodies, however, did not react with the antisera. These data indicate that the human neurofilament does not share major antigenic determinants of its subunit protein with either Alzheimer's neurofibrillary tangles or Pick's bodies.

Progressive supranuclear palsy: clinical features and response to treatment in 16 patients

Among 415 patients with parkinsonism, 16 (3.9%) had findings of progressive supranuclear palsy (PSP). This report reviews the clinical features and response to drug therapy in those 16 patients. Anticholinergic drugs failed to benefit any of the 5 patients treated, while presynaptic dopaminergic drugs (Sinemet or amantadine) were beneficial in only 5 of 22 patient trials. Alternatively, dopamine agonists (bromocriptine and pergolide) caused improvement in 9 of 14 patient trials despite the fact that all but 1 of these patients had previously failed to respond to presynaptic dopaminergic drugs. Dopamine agonists such as bromocriptine and pergolide may be useful in some patients with PSP.

Immunocytochemical comparison of neurofibrillary tangles in senile dementia of Alzheimer type, progressive supranuclear palsy, and postencephalitic parkinsonism

Antiserum raised against a two-cycle-purified human brain microtubule fraction that binds specifically to tangles of senile dementia of the Alzheimer type was tested on the subthalamus, basis pontis, and midbrain sections of two patients with progressive supranuclear palsy. Tangles composed of 15 nm straight fibers in these areas showed positive immunolabeling with the antiserum. The labeling tangles appeared as a fibrous meshwork in neuronal cell bodies and occasionally in short segments of axons. Corresponding sections of brains obtained from patients with idiopathic parkinsonism, striatonigral degeneration, and olivopontocerebellar atrophy treated with the same antiserum did not display peroxidase products. Only in the elderly subjects and patients with postencephalitic parkinsonism did the periaqueductal gray and median raphe show occasional cells that reacted positively with the antiserum. Tangles in the substantia nigra of patients with postencephalitic parkinsonism were also recognized by the antiserum. The results suggest that the two morphologically distinct neurofibrillary tangles share their immunological properties with components present in microtubule fractions of normal brain.

Progressive supranuclear palsy

Progressive supranuclear palsy has been recognized as a distinct nosological entity for about three decades now. Typically, this progressive neurological disease manifests itself late in the sixth decade with a terminal course of approximately four to six years. Well over one hundred cases have been described in the literature and the heterogeneous nature of progressive supranuclear palsy includes the characteristic vertical ophthalmoplegia, frequent falling and a profound nuchal rigidity. Other features are similar in many respects to those found in Parkinson's disease. The present article reviews the literature on progressive supranuclear palsy with particular reference to its clinical manifestations including the ophthalmoplegia, characteristic sleep disturbances and unique dementia. Also addressed, are neuropathological and epidemiological findings. Finally, conclusions and recommendations for further investigation are offered especially with regard to the neuropsychological nature of this neurological disorder.

Reappraisal of the fine structure of Alzheimer's neurofibrillary tangles

Alzheimer's neurofibrillary tangles were studied by electron microscopy. The study includes four cases of Alzheimer's disease, two cases of atypical senile dementia, and one case of progressive supranuclear palsy. In Alzheimer's disease the tangles were composed of either straight filaments or paired helical filaments. In progressive supranuclear palsy the tangles were composed of 15 nm straight filaments or helical filaments. A few straight filaments were mixed with paired helical filaments. In atypical senile dementia, both straight and paired helical filaments comprised the tangles and one type of filaments appeared to intermingle with the other in the same neurons.

The fine structure of neurofibrillary tangles in a case of atypical presenile dementia

The neurofibrillary tangles in a case of atypical presenile dementia were studied by electron microscopy. The tangles consisted of 2 types of tubule: one straight, measuring about 15--20 nm in width, the other twisted. Both types of tubule appeared separately in each neuron; however, occasionally twisted tubules seemed to be distributed among the straight tubules. The implications of these findings are briefly discussed.

Neurofibrillary pathology in progressive supranuclear palsy

We describe the fine structure of the subcortical neurofibrillary tangles (NFT) in 2 cases of progressive supranuclear palsy (PSP). In case 1 (69-year-old man) about one half of the NFT in the midbrain and pons examined were composed of 13-16 nm straight filaments and the other were made up of paired helical filaments (PHF) of Alzheimer type. The NFT in case 2 consisted of straight tubules with infrequent segments of unusual twisted fibril of unknown nature. The simultaneous occurrence of straight and PHF in one of these cases suggests that the NFT in PSP may be similar to those of Alzheimer type occurring in various conditions.