Search

Immunohistochemisty with RD3, a monoclonal antibody specific for three-repeat (3R) tau, is sometimes hampered by diffuse neuronal staining on formalin-fixed, paraffin-embedded sections pretreated with formic acid and heating. Additional pretreatment with potassium permanganate followed by oxalic acid completely eliminated this diffuse RD3-immunoreactivity (IR) in neurons. Furthermore, this additional pretreatment uniformly enhanced RD3-IR, as well as RD4-IR, a monoclonal antibody specific for four-repeat (4R) tau, on pathological deposits with tau IR. This enhanced sensitivity and specificity may allow more reliable identification of 3R and 4R tau in pathological deposits, which may be variable dependent on disease and regions. Cerebral cortex and midbrain from 8 patients [5 progressive supranuclear palsy (PSP) and 3 corticobasal degeneration (CBD)] were screened for RD3- and RD4-IR with this improved procedure. In addition to RD4-positive structures found both in cerebral cortex and brainstem, RD3-positive neurofibrillary tangles (NFTs) were also found in midbrain in 7 of these 8 cases but not in the cortex. Multi-labeling study demonstrated that most of RD3-negative neurons were positive for RD4. This reliable demonstration of pathological 3R tau deposits in the brainstem of PSP/CBD, so far presumably characterized by deposition of 4R tau, is useful to map tau-positive lesions according to their biochemical composition.

Progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are neurodegenerative diseases that are characterized by intracytoplasmic aggregates of hyperphosphorylated tau with four microtubule-binding repeats. Although PSP and CBD have distinctive pathological features, no biochemical difference in aggregated tau has been identified. In this study, we examined the brains of eight patients with PSP, six patients with CBD, and one atypical case with pathological features of both CBD and PSP. On immunoblots of sarkosyl-insoluble brain extracts, a 33kDa band predominated in the low molecular weight tau fragments in PSP, whereas two closely related bands of approximately 37kDa predominated in CBD. Immunoblots of the atypical case showed both the 33kDa band and the 37kDa doublet. Protein sequencing and immunochemical analyses showed that the 33kDa band and the 37kDa doublet consisted of the carboxyl half of tau with different amino termini. These results suggest that, despite the identical composition of tau isoforms, different proteolytic processing of abnormal tau takes place in these two diseases. Such a biochemical divergence may be related to the neuropathological features of these diseases.

The microtubule-associated protein tau accumulates as cytoplasmic inclusions in Alzheimer's disease (AD), Pick's disease (PiD), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). We investigated the immunoreactivity of tau-positive structures using a panel of antibodies to epitopes spanning the entire length of the tau molecule. In ethanol-fixed brain tissues, most antibodies to the microtubule-binding domain (MBD) required formic acid (FA) treatment to stain tau inclusions in PSP and CBD. This is in contrast with the intense labeling of neurofibrillary tangles in AD without FA treatment. Pick bodies (PiB) in PiD showed an intermediate pattern with respect to the immunoreactivity of the MBD because accumulated tau in PiB mostly lacks the insertion of exon 10, and the proportion of tau phosphorylated at Ser262 is smaller than in other abnormal tau structures. Such immunohistochemical profiles appeared to correlate with the occurrence of the smeared tau on immunoblot analysis of brain homogenate. The smeared tau was more abundant in AD and PiD than in PSP and CBD. Since the smeared tau was N-terminally truncated and was characteristic of advanced forms of modified tau, these findings suggest that tau accumulated in AD and PiD was processed more markedly than that in PSP and CBD. The MBD of tau may be masked in the presence of the intact N terminus and require FA treatment for antibody recognition in tissue sections. Advanced modification may expose the MBD in brain tissues of AD and PiD. It is suggested that the processing of abnormally accumulated tau characterizes the pathophysiology of each tauopathy.

Corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) are sporadic neurodegenerative diseases with intracytoplasmic aggregates of the microtubule-associated protein, tau, in neurons and glial cells. Immunoblot analysis of detergent-insoluble brain extracts of patients with CBD and PSP shows distinctive patterns of tau fragments. These results suggest differing intracellular processing of aggregated tau in these two diseases despite an identical composition of tau isoforms. Such biochemical differences may be related to the neuropathological features of these diseases.

We investigated isoform composition of aggregated tau protein in brains with Pick's disease (PiD), corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) by immunoblot analysis of sarkosyl-insoluble fractions of brain homogenates. We also examined the adjacent brain tissues immunohistochemically with a rabbit antibody, Ex10, which specifically recognizes exon 10 of tau. The Ex10 recognizes tau isoforms with four microtubule-binding repeats (4Rtau) but not those with three microtubule-binding repeats (3Rtau). Sarkosyl-insoluble tau from the brains of patients with CBD and PSP consisted of 4Rtau. Insoluble tau from the PiD brains contained both 3Rtau and 4Rtau, where 3Rtau predominated over 4Rtau. In brain tissues of CBD and PSP, Ex10 immunostained all neuronal and glial tau-positive structures. They included pre-tangles, astrocytic plaques, tuft-shaped astrocytes, and oligodendroglial coiled bodies. In PiD brains, astrocytic inclusions were also positive for 4Rtau. However, the majority of, if not all, Pick bodies and oligodendroglial tau inclusions were negative for 4Rtau. Such results suggest that, in neurons and oligodendroglia, tau isoforms involved in the pathological processes differ between CBD/PSP and PiD, and are thus disease specific. This contrasts with the astrocytic tau isoforms that accumulate similarly in all three disorders.

Corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) are characterized by their unique clinical features and neuronal pathology. Although astrocytic plaques and tufts of abnormal fibers have been suggested to be specific histopathologic markers, recent studies have revealed significant clinicopathologic overlap between CBD and PSP. Based on the distinctive camera lucida profile of astrocytic inclusions on Gallyas-Braak silver staining, we found that astrocytic plaques and tufts of abnormal fibers did not coexist in the same patient among 30 cases of clinically diagnosed CBD, PSP and atypical Parkinson's disease. Using Tau immunohistochemistry it was difficult to verify the absence of tufts of abnormal fibers. A morphometric analysis revealed that the two groups classified by the presence or absence of astrocytic plaques and tufts of abnormal fibers exhibited significant differences in the density of ballooned neurons and neurofibrillary tangles and degeneration of the subcortical nuclei. Assessment using the NINDS neuropathologic criteria revealed that the cases with astrocytic plaques and tufts of abnormal fibers closely correspond to CBD and typical PSP, respectively. In addition, the cases lacking either of these two astrocytic inclusions had atypical PSP according to the NINDS criteria, and were associated with novel tau-positive astrocytes (spiny astrocytes). We thus conclude that astrocytic plaques and tufts of abnormal fibers are highly characteristic structures for CBD and typical PSP, respectively. We emphasize the importance of strict differentiation between different astrocytic inclusions not only for diagnosis, but also for further studies for elucidation of their role in the disease mechanisms of CBD and PSP.

Progressive supranuclear palsy (PSP) is known to have tau-positive cytoskeletal abnormalities in astrocytes and oligodendroglia as well as neurons. Astrocytic tau-positive structures (tuft-shaped astrocytes; Tu-SA) were studied to elucidate their proper significance in the neuropathological diagnosis of PSP. The distribution and incidence of Tu-SA were examined in 26 cases of PSP. The disease specificity of Tu-SA was demonstrated by comparison with diseases accompanied by neurofibrillary tangles (NFTs) and those with or without cytoskeletal abnormalities other than NFTs. In PSP, Tu-SA appeared prominently in the precentral and premotor cortex (areas 4 and 6) of the superior and middle frontal gyri, but were quite scare in the temporal lobe and limbic area. In the subcortical nuclei, they appeared preferentially in the putamen and were also scattered in other degenerating regions. In the cerebrum the Tu-SA and NFTs were distributed in quite different regions. The assessment of the incidence of Tu-SA in area 6 revealed that only 5 of 26 PSP cases lacked Tu-SA in the examined fields. In contrast, in the control diseases, Tu-SA were found only rarely in cases of corticobasal degeneration in the cerebral cortex among other frequent tau-positive structures. One case of Pick's disease showed occasional Tu-SA but only in the hippocampal region and not in the frontal lobe or putamen. In summary, although the absence of Tu-SA does not necessarily exclude the possibility of PSP, Tu-SA in the frontal lobe and putamen is highly suggestive for PSP. Thus, detection of Tu-SA and the ranking of the characteristic distribution of NFTs contribute to the neuropathological diagnosis of PSP.

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.

Cerebellar torpedoes can be induced by direct damage to Purkinje cell axons. This raises the possibility that the loss of dentate nucleus neurons (DNNs) may also cause torpedo formation through synaptic detachment between DNNs and Purkinje cell axon terminals. To investigate this possibility, we conducted a morphometric study with an image analyzer in progressive supranuclear palsy (PSP) and dentatorubro-pallidoluysian atrophy (DRPLA). Using horizontal and sagittal sections of the cerebellar hemispheres containing the greatest proportion of the dentate nucleus, we determined the line densities of torpedoes, Purkinje cells, and DNNs. In PSP and DRPLA, the densities of DNNs were significantly lower, and the densities of torpedoes much greater than in controls, while those of Purkinje cells were normal in both diseases. In addition, the torpedo densities in PSP and DRPLA showed a strong negative correlation with the DNN densities. Thus, this study clearly demonstrated that torpedoes are formed in association with the loss of DNNs, suggesting that they may occur in consequence of synaptic disconnection of Purkinje cells from DNNs.

Hypertrophic changes in the inferior olivary nuclei have been occasionally described in patients with progressive supranuclear palsy (PSP). To elucidate the incidence of olivary hypertrophy, we investigated morphologically the olives and their associated pathways in 20 autopsied cases: 11 cases of PSP, 3 cases of Machado-Joseph disease and 6 cases of dentatorubropallidoluysian atrophy (DRPLA) as control diseases that usually exhibited lesions of the cerebellofugal pathway. Olivary hypertrophy was observed in 5 of 11 PSP cases, but not in the other diseases, except for 1 case of DRPLA with an old infarct in the dentate nucleus. In the olivopetal pathway, grumose degeneration of the dentate nucleus and mild neuronal loss in the red nucleus were observed in all patients with PSP and in the control subjects. Atrophy and fibrillary gliosis of the tegmentum of the pons, including that of the bilateral central tegmental tracts, were observed in all patients with PSP, more severe in the cases with hypertrophic neurons in the olives. We speculate that a lesion that involves the central tegmental tracts may play a major role in inducing hypertrophy of the olives in patients with PSP.

Using Gallyas-Braak's silver stain, neuropil threads (NTs) in Alzheimer's disease (AD), corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) were analyzed morphologically and morphometrically. The NT density was highest in the cerebral cortical layer V in AD and CBD, and in the subcortical white matter in PSP. An overlaid, two-dimensional, camera lucida drawing revealed differences in the fine profile of NTs among these three disease groups. The differences were confirmed by computerized feature analysis which revealed differences in maximum length, breadth, Feret's angle and orientation of the NTs. Unlike a previous assumption that all NTs have a similar appearance, our study revealed that NTs in AD, CBD and PSP were distinctively different with respect to their morphology.

Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease which shows several psychiatric and neurologic symptoms: pseudobulbar palsy, supranuclear ocular palsy, extrapyramidal rigidity, gait ataxia, and dementia. Almost all cases seem to be sporadic; therefore, the elucidation of risk factors is important to clarify the pathological mechanism. Apolipoprotein E4 (ApoE4) is now well established as a risk factor of Alzheimer's disease (AD). Here we report the ApoE allele frequency in PSP, which shares pathological findings such as neurofibrillary tangle (NFT) with AD. NFT is an important sign for the derangement of normal cytoskeletons in degenerating neurons. Although there was no significant increase in epsilon 4 allele frequency in the present series of PSP cases compared with that in the Japanese controls, there was a significant increase in the epsilon 2 allele frequency in PSP compared to controls.

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.

We report an autopsy case of progressive supranuclear palsy (PSP) with a five-year clinical course. A 67-year-old man was suffering from a gait disturbance and mental deterioration. Neurological examination at the age of 71 revealed pseudobulbar palsy, horizontal ophthalmoplegia, and truncal dystonia, and a diagnosis of PSP was made. Mental deterioration including forgetfulness and character change was also noted, and the patient sometimes exhibited intermittent stuporous states. Cranial computed tomography and magnetic resonance images revealed moderate brain atrophy, predominantly in the frontal lobes. The patient died of bronchopneumonia at the age of 71. Neuropathological examination confirmed typical pathological changes of PSP, such as neuronal loss, neurofibrillary tangles, and fibrillary gliosis in the subcortical nuclei. Gallyas-Braak silver impregnation revealed neurofibrillary tangles, silver-positive glia and thread-like structures in degenerating subcortical nuclei. In addition to these classical lesions, the argentophilic structures were detected in the cerebral cortex, cortical white matter and cerebellar white matter. In the cerebral cortex, they were abundant mostly in the precentral gyrus and subcortical white matter. Immunohistochemical studies revealed that most silver-positive structures were also tau 2 antibody-positive. Thus, these argentophilic structures seemed to be closely related to abnormal tau protein. Their distribution in this case implies that lesions related to abnormal tau protein may occur more extensively in the brains of PSP than expected.

This report is to investigate neuropathological changes of the thalamus observed in progressive supranuclear palsy. Six autopsy cases were examined. They were 5 males and a female, whose age was between 57 and 72 years old. They developed dementia in various degrees and three of the cases showed periodic stuporous state and akinetic mutism in the last stage. The paraffined thin-sections were stained with hematoxylin-eosin, luxol-fast-blue, Holzer, modified Bielschowsky, Gallyas and anti-tau stainings. The histological changes were evaluated in the aspects of neuronal loss, fibrillary gliosis and neurofibrillary tangles. In conclusion, there were three types in six cases. The first was seen in two cases and that there appeared many Alzheimer's neurofibrillary tangles (NFTs) in medial nuclei, lateral and ventral nuclei as well as zona incerta and reticular nucleus. The second was observed in two cases and that the loss of nerve cells was severe, especially in medial nuclei and the dorsal part of lateral and ventral nuclei and fibrillary gliosis was observed beyond the lesions of neuronal loss. The third was that the appearance of NFTs was moderate in number and neuronal loss was minimal. Moreover, neuronal loss and NFTs of zona incerta were common in these cases. Argentophilic fibrillary inclusions were observed in the neuropil and astrocytes in all cases. It is important to investigate the correlations between neuropathological changes and clinical manifestations, especially in the peculiar type of dementia observed in PSP. The thalamic changes of PSP may play an important role in causing stuporous state and akinetic mutism as well as subcortical dementia.

Progressive supranuclear palsy (PSP) is characterized by symptoms of disturbance of eye movement, nuchal rigidity, parkinsonism and subcortical dementia. Its pathology reveals that Alzheimer's neurofibrillary tangles (NFTs) are situated especially in the nuclei of basal ganglia and brainstem. It has been pointed out that NFTs observed in PSP are composed of straight tubules, the width of which is about 15 nm. This report is to reappraise the ultrastructure of NFTs observed in three cases of PSP. They are case 1; 69-year-old male, case 2; 62-year-old female and case 3; 65-year-old male. The clinical features of three cases were characterized by above-mentioned symptoms. Many NFTs were observed in brainstem of case 1 and 3. NFTs seen in brainstem of case 2 were in a small amount. In case 1 and 2, there were many NFTs in cerebral cortex, especially in parahippocampal gyri and other limbic areas. We examined the portions of frontal cerebral cortex, parahippocampal cortex, the basal nucleus of Meynert, oculomotor nucleus, substantia nigra, pontine nuclei and locus caeruleus of case 1, substantia nigra, red nucleus and inferior olivary nucleus of case 2, and Ammon's horn, globus pallidum, subthalamic nucleus, substantia nigra, oculomotor nucleus, pontine nuclei, locus ceruleus and inferior olivary nucleus of case 3. Ultrastructurally, NFTs of frontal cortex of case 1 consisted of twisted tubules and those of hippocampal and parahippocampal cortices of case 1 consisted of straight and twisted tubules, being observed separately in neurons. The NFTs of brainstem of case 1 and 2 were mainly composed of 12-17 nm straight tubules, and twisted tubules occasionally intermingled with straight components. In locus ceruleus of case 1, a single straight tubule could be seen in the bundles of twisted tubules. NFTs of case 3 were composed of only straight tubules, the width of which was about 15 nm. Twisted components were not observed in neurons of each nuclei of case 3. The characteristic ultrastructure of NFTs in PSP has been an appearance of straight tubules, however, twisted tubules were occasionally observed in this study. There are several case reports which demonstrated an appearance of both straight and twisted components. It is easily presumed that the process of aging takes part in the accumulation of twisted fibrils. However, it is now under consideration why twisted tubules are also observed in PSP. To summarize this study, the cases with many NFTs observed in widespread cerebral cortex may have a tendency to show both straight and twisted tubules.