A point mutation in GPI-attachment signal peptide accelerates the development of prion disease.

A missense variant from methionine to arginine at codon 232 (M232R) of the prion protein gene accounts for ~ 15% of Japanese patients with genetic prion diseases. However, pathogenic roles of the M232R substitution for the induction of prion disease have remained elusive because family history is usually absent in patients with M232R. In addition, the clinicopathologic phenotypes of patients with M232R are indistinguishable from those of sporadic Creutzfeldt-Jakob disease patients. Furthermore, the M232R substitution is located in the glycosylphosphatidylinositol (GPI)-attachment signal peptide that is cleaved off during the maturation of prion proteins. Therefore, there has been an argument that the M232R substitution might be an uncommon polymorphism rather than a pathogenic mutation. To unveil the role of the M232R substitution in the GPI-attachment signal peptide of prion protein in the pathogenesis of prion disease, here we generated a mouse model expressing human prion proteins with M232R and investigated the susceptibility to prion disease. The M232R substitution accelerates the development of prion disease in a prion strain-dependent manner, without affecting prion strain-specific histopathologic and biochemical features. The M232R substitution did not alter the attachment of GPI nor GPI-attachment site. Instead, the substitution altered endoplasmic reticulum translocation pathway of prion proteins by reducing the hydrophobicity of the GPI-attachment signal peptide, resulting in the reduction of N-linked glycosylation and GPI glycosylation of prion proteins. To the best of our knowledge, this is the first time to show a direct relationship between a point mutation in the GPI-attachment signal peptide and the development of disease.

An autopsy case of variably protease-sensitive prionopathy with Met/Met homogeneity at codon 129.

The typical clinical manifestations of sporadic Creutzfeldt-Jakob disease (sCJD) are rapid-progressive dementia and myoclonus. However, the diagnosis of atypical sCJD can be challenging due to its wide phenotypic variations. We report an autopsy case of variably protease-sensitive prionopathy (VPSPr) with Met/Met homogeneity at codon 129. An 81-year-old woman presented with memory loss without motor symptoms. Seventeen months after the onset, her spontaneous language production almost disappeared. Diffusion-weighted images (DWI) showed hyperintensity in the cerebral cortex while electroencephalogram (EEG) showed nonspecific change. 14-3-3 protein and real-time qualing-induced conversion (RT-QuIC) of cerebrospinal fluid were negative. She died at age 85, 3.5 years after the onset. Pathological investigation revealed spongiform change, severe neuronal loss, and gliosis in the cerebral cortex. Mild to moderate neuronal loss and gliosis were observed in the basal ganglia. PrP immunostaining revealed plaque-like, dotlike, and synaptic structures in the cerebral cortex and small plaque-like structures in the molecular layer of the cerebellum. Analysis of PRNP showed no pathogenic mutations, and Western blot examination revealed the lack of a diglycosylated band consistent with VPSPr. The present case, which is the first report on a VPSPr case in Japan, supports previously published evidence that VPSPr cases can present variable and nonspecific clinical presentations. Because a small number of VPSPr cases can show typical magnetic resonance imaging (MRI) change in sCJD. We should investigate the possibility of VPSPr in a differential diagnosis with atypical dementia that presented DWIs of high intensity in the cortex, even though 14-3-3 proteins and RT-QuIC are both negative. In addition, VPSPr cases can take a longer clinical course compared to that of sCJD, and long-term follow-up is important.

V180I genetic Creutzfeldt-Jakob disease: Severe degeneration of the inferior olivary nucleus in an autopsied patient with identification of the M2T prion strain.

Genetic Creutzfeldt-Jakob disease (gCJD) with a V180I mutation (V180I gCJD) is the most common type of gCJD in Japan, characterized by an older age at onset, slower progression, and moderate to severe cortical degeneration with spongiform changes and sparing of the brainstem and cerebellum. Degeneration of the inferior olivary nucleus (IO) is rarely observed in patients with CJD but is known to occur in fatal familial insomnia (FFI) and MM2-thalamic-type sporadic CJD (sCJD-MM2T) involving type 2 prion protein (M2T prion). Here we report on an 81-year-old Japanese woman who initially developed depressive symptoms followed by progressive cognitive impairment, myoclonus, and hallucinations and died after a clinical course of 23 months. Insomnia was not evident. Genetic analysis of the prion protein (PrP) identified a V180I mutation with methionine/valine heterozygosity at codon 129. Pathologic analysis demonstrated extensive spongiform degeneration, neuronal loss in the cortices, and weak synaptic-type PrP deposition. Except for IO degeneration, the clinicopathologic features and Western blotting PrP band pattern were compatible with those of previously reported V180I gCJD cases. Quantitative analysis revealed that the neuronal density of the IO, especially in the dorsal area, was considerably reduced to the same extent as that of a patient with sCJD-MM2T but preserved in other patients with V180I gCJD and sCJD-MM1 (this patient, 2.3 ± 0.53/mm2 ; a patient with sCJD-MM2T, 4.2 ± 2; a patient with V180I gCJD, 60.5 ± 9.3; and a patient with sCJD-MM1, 84.5 ± 17.9). Use of the protein misfolding cyclic amplification (PMCA) method confirmed the presence of the M2T prion strain, suggesting that the latter might be associated with IO degeneration in V180I gCJD. Autopsy studies are necessary to better understand the nature of CJD, since even if patients present with the common clinical picture, pathologic analysis might provide new insights, as was the case here.

Methionine homozygosity for PRNP polymorphism and susceptibility to human prion diseases.

BACKGROUND: No studies have assessed the independent association of methionine homozygosity at codon 129 with the susceptibility to prion diseases, controlling for the effects of the codon 219 polymorphisms and other potential confounders, using a large-scale population-based dataset. METHODS: We conducted a case-control study using a Japanese nationwide surveillance database for prion diseases. The main exposure was methionine homozygosity at codon 129, and the outcome was development of prion diseases. Multivariable logistic regression models were employed for specific disease subtypes (sporadic Creutzfeldt-Jakob disease (CJD), genetic CJD and Gerstmann-Sträussler-Scheinker disease (GSS)). RESULTS: Of 5461 patients registered in the database, 2440 cases and 796 controls remained for the analysis. The cases comprised 1676 patients with sporadic CJD (69%), 649 with genetic CJD (27%) and 115 with GSS (5%). For patients with methionine homozygosity, potential risk for occurring prion diseases: adjusted OR (95% CI) was 2.21 (1.46 to 3.34) in sporadic CJD, 0.47 (0.32 to 0.68) in genetic CJD and 0.3 (0.17 to 0.55) in GSS. Among patients with specific prion protein abnormalities, the potential risk was 0.27 (0.17 to 0.41) in genetic CJD with 180 Val/Ile, 1.66 (0.65 to 5.58) in genetic CJD with 200 Glu/Lys, 3.97 (1.2 to 24.62) in genetic CJD with 232 Met/Arg and 0.71 (0.34 to 1.67) in GSS with 102 Pro/Leu. CONCLUSIONS: Methionine homozygosity at codon 129 was predisposing to sporadic CJD, but protective against genetic CJD and GSS, after adjustment for codon 219 polymorphism effect. However, the impacts differed completely among patients with specific prion protein abnormalities.

An autopsy case of MV2K-type sporadic Creutzfeldt-Jakob disease presenting with characteristic clinical, radiological, and neuropathological findings.

In Japan, because MV2-type sporadic Creutzfeldt-Jakob disease (CJD) is rare, little is known about its clinical and neuropathological characteristics. An autopsy case of MV2K-type sporadic CJD is presented, and the characteristic clinical, radiological, and neuropathological findings are discussed. The patient was a Japanese woman who died at the age of 72 years. Her initial symptom was rapidly progressive dementia. She then developed truncal ataxia and delusions. Approximately nine months after onset, she exhibited akinetic mutism. The total clinical course was 11 months. Magnetic resonance imaging revealed hyperintensity areas in the basal ganglia, thalamus, and hippocampus on diffusion-weighted images. In the cerebral cortex, this finding was slight and inconspicuous. Electroencephalography revealed no periodic sharp wave complexes. Prion protein (PrP) gene analysis revealed no mutations, and polymorphic codon 129 exhibited methionine and valine heterozygosity. In the cerebrospinal fluid, levels of both total tau and 14-3-3 proteins were elevated. Grossly, the brain weighed 1050 g before fixation and exhibited diffuse cortical atrophy. On histopathological examination, extensive fine vacuole-type spongiform degeneration was noted in the cerebral cortex. Numerous kuru plaques were observed in the cerebellum. PrP immunohistochemistry revealed extensive diffuse synaptic- and perineuronal-type PrP deposits in the cerebral cortex. Kuru plaques were strongly immunoreactive for PrP. Western blot analysis of brain tissue samples revealed mixed type 2 and intermediate type. Systematic and comprehensive investigations of both clinical and neuropathological aspects are required for accurate diagnosis.

α2,3 linkage of sialic acid to a GPI anchor and an unpredicted GPI attachment site in human prion protein.

Prion diseases are transmissible, lethal neurodegenerative disorders caused by accumulation of the aggregated scrapie form of the prion protein (PrPSc) after conversion of the cellular prion protein (PrPC). The glycosylphosphatidylinositol (GPI) anchor of PrPC is involved in prion disease pathogenesis, and especially sialic acid in a GPI side chain reportedly affects PrPC conversion. Thus, it is important to define the location and structure of the GPI anchor in human PrPC Moreover, the sialic acid linkage type in the GPI side chain has not been determined for any GPI-anchored protein. Here we report GPI glycan structures of human PrPC isolated from human brains and from brains of a knock-in mouse model in which the mouse prion protein (Prnp) gene was replaced with the human PRNP gene. LC-electrospray ionization-MS analysis of human PrPC from both biological sources indicated that Gly229 is the ω site in PrPC to which GPI is attached. Gly229 in human PrPC does not correspond to Ser231, the previously reported ω site of Syrian hamster PrPC We found that ∼41% and 28% of GPI anchors in human PrPCs from human and knock-in mouse brains, respectively, have N-acetylneuraminic acid in the side chain. Using a sialic acid linkage-specific alkylamidation method to discriminate α2,3 linkage from α2,6 linkage, we found that N-acetylneuraminic acid in PrPC's GPI side chain is linked to galactose through an α2,3 linkage. In summary, we report the GPI glycan structure of human PrPC, including the ω-site amino acid for GPI attachment and the sialic acid linkage type.

Potential for transmission of sporadic Creutzfeldt-Jakob disease through peripheral routes.

Five sporadic Creutzfeldt-Jakob disease (CJD) strains have been identified to date, based on differences in clinicopathological features of the patients, the biochemical properties of abnormal prion proteins, and transmission properties. Recent advances in our knowledge about iatrogenic transmission of sporadic CJD have raised the possibility that the infectivity of sporadic CJD strains through peripheral routes is different from that of intracranial infection. To test this possibility, here we assessed systematically the infectivity of sporadic CJD strains through the peripheral route for the first time using a mouse model expressing human prion protein. Although the infectivity of the V2 and M1 sporadic CJD strains is almost the same in intracerebral transmission studies, the V2 strain infected more efficiently than the M1 strain through the peripheral route. The other sporadic CJD strains examined lacked infectivity. Of note, both the V2 and M1 strains showed preference for mice with the valine homozygosity at the PRNP polymorphic codon. These results indicate that the V2 strain is the most infectious sporadic CJD strain for infection through peripheral routes. In addition, these findings raise the possibility that individuals with the valine homozygosity at the PRNP polymorphic codon might have higher risks of infection through peripheral routes compared with the methionine homozygotes. Thus, preventive measures against the transmission of the V2 sporadic CJD strain will be important for the eradication of iatrogenic CJD transmission through peripheral routes.

Detection of cutaneous prion protein deposits could help diagnose GPI-anchorless prion disease with neuropathy.

BACKGROUND AND PURPOSE: To investigate prion protein (PrP) deposits in cutaneous tissues of patients of glycosylphosphatidylinositol (GPI)-anchorless prion diseases with neuropathy. METHODS: Cutaneous tissue samples from three patients with GPI-anchorless prion diseases were obtained, two cutaneous biopsy samples from the lower leg of Case 1 (Y162X) and Case 3 (D178fs25), and a cutaneous sample taken from the abdomen during an autopsy of Case 2 (D178fs25). We performed immunohistochemistry for PrP to look for abnormal PrP deposits. RESULTS: PrP deposits were observed in the dermal papilla, the sweat glands, the hair follicles, the arrector pili muscles, and peripheral nerves of all examined cases of GPI-anchorless prion disease with neuropathy. The abnormal PrP accumulation was frequently localized at the basement membrane, and colocalized with laminin. CONCLUSION: Immunohistochemical detection of PrP in cutaneous samples could be used to definitively diagnose GPI-anchorless PrP disease with neuropathy.

Genetic Creutzfeldt-Jakob disease-M232R with the cooccurrence of multiple prion strains, M1 + M2C + M2T: Report of an autopsy case.

Genetic Creutzfeldt-Jakob disease (gCJD) with a methionine to arginine substitution at codon 232 of the prion protein gene (gCJD-M232R) is rare and has only been reported in Japan. We report an autopsy case of gCJD-M232R showing alleles of codon 129 that were homozygous for methionine and the presence of multiple strains of the protease-resistant, abnormal isoform of prion protein (PrPSc ), M1 + M2C + M2T. The patient, a 54-year-old Japanese man, died after a clinical course of 21 months characterized by slowly progressive dementia and sleep disturbance. At autopsy, the neuropil of the cerebral neocortex showed a widespread and severe spongiform change. Grape-like clusters of large confluent vacuoles were admixed with fine vacuoles. Neuronal loss was moderate, but reactive astrocytosis was mild. The dorsomedial nucleus of the thalamus and the inferior olivary nucleus showed moderate and severe neuronal loss, respectively. Many amyloid plaques were present in the cerebellar molecular layer. PrPSc deposition pattern was predominantly the synaptic type in the cerebrum and corresponded to the plaques in the cerebellum. Perivacuolar deposition was also seen. Western blot analysis of PrPSc revealed the predominance of type 2. Moreover, by employing Western blot analysis in combination with the protein misfolding cyclic amplification (PMCA) method, which selectively amplifies the minor M2T prion strain, we demonstrated the presence of M2T, in addition to M1 and M2C strains, in the brain of the patient. PMCA was a powerful method for demonstrating the presence of the M2T strain, although the amount is often small and the transmission is difficult.

Characterization of Sporadic Creutzfeldt-Jakob Disease and History of Neurosurgery to Identify Potential Iatrogenic Cases.

We previously reported a phenotype of Creutzfeldt-Jakob disease (CJD), CJD-MMiK, that could help identify iatrogenic CJD. To find cases mimicking CJD-MMiK, we investigated clinical features and pathology of 1,155 patients with diagnosed sporadic CJD or unclassified CJD with and without history of neurosurgery. Patients with history of neurosurgery more frequently had an absence of periodic sharp-wave complexes on electroencephalogram than patients without a history of neurosurgery. Among 27 patients with history of neurosurgery, 5 had no periodic sharp-wave complexes on electroencephalogram. We confirmed 1 case of CJD-MMiK and suspected another. Both had methionine homozygosity at codon 129 of the prion protein gene and hyperintensity lesions in the thalamus on magnetic resonance images of the brain, which might be a clinical marker of CJD-MMiK. A subgroup with a history of neurosurgery and clinical features mimicking dura mater graft-associated CJD might have been infected during neurosurgery and had symptoms develop after many years.

Eliminating transmissibility of bovine spongiform encephalopathy by dry-heat treatment.

Bovine spongiform encephalopathy (BSE) prion is more resistant to heat inactivation compared to other prions, but the effect of heat inactivation has been reported to differ depending on the BSE-contaminated tissue state or heating type. We aimed to evaluate the secure level of inactivation of original BSE transmissibility by dry-heating. Cattle tissues affected with BSE were subjected to dry-heat treatment for 20 min at various temperatures ranging from 150 to 1000 °C. To assess the inactivation effect, we conducted protein misfolding cyclic amplification (PMCA) and follicular dendritic cell (FDC) assays in transgenic mice expressing bovine prion protein genes. Under dry-heating at 600 °C or higher, BSE cattle tissues lost their transmissibility in transgenic mice. In contrast, transmissibility was detected in the cattle tissues treated at temperatures of 400 °C or lower through the FDC assay combined with PMCA. In this study, we confirmed that transmissibility was eliminated in BSE-affected cattle tissues by dry-heating at 600 °C or higher.

Ganglioside Synthase Knockout Reduces Prion Disease Incubation Time in Mouse Models.

Localization of the abnormal and normal isoforms of prion proteins to detergent-resistant membrane microdomains, lipid rafts, is important for the conformational conversion. Lipid rafts are enriched in sialic acid-containing glycosphingolipids (namely, gangliosides). Alteration in the ganglioside composition of lipid rafts can affect the localization of lipid raft-associated proteins. To investigate the role of gangliosides in the pathogenesis of prion diseases, we performed intracerebral transmission study of a scrapie prion strain Chandler and a Gerstmann-Sträussler-Scheinker syndrome prion strain Fukuoka-1 using various knockout mouse strains ablated with ganglioside synthase gene (ie, GD2/GM2 synthase, GD3 synthase, or GM3 synthase). After challenge with the Chandler strain, GD2/GM2 synthase knockout mice showed 20% reduction of incubation time, reduced prion protein deposition in the brain with attenuated glial reactions, and reduced localization of prion proteins to lipid rafts. These results raise the possibility that the gangliosides may have an important role in prion disease pathogenesis by affecting the localization of prion proteins to lipid rafts.

A Novel Combination of Prion Strain Co-Occurrence in Patients with Sporadic Creutzfeldt-Jakob Disease.

Six subgroups of sporadic Creutzfeldt-Jakob disease have been identified by distinctive clinicopathologic features, genotype at polymorphic codon 129 [methionine (M)/valine (V)] of the PRNP gene, and type of abnormal prion proteins (type 1 or 2). In addition to the pure subgroups, mixed neuropathologic features and the coexistence of two types of abnormal prion proteins in the same patient also have been reported. Here, we found that a portion of the patients previously diagnosed as MM1 had neuropathologic characteristics of the MM2 thalamic form (ie, neuronal loss of the inferior olivary nucleus of the medulla). Furthermore, coexistence of biochemical features of the MM2 thalamic form also was confirmed in the identified cases. In addition, in transmission experiments using prion protein-humanized mice, the brain material from the identified case showed weak infectivity and generated characteristic abnormal prion proteins in the inoculated mice resembling those after inoculation with brain material of MM2 thalamic form. Taken together, these results show that the co-occurrence of MM1 and MM2 thalamic form is a novel entity of sporadic Creutzfeldt-Jakob disease prion strain co-occurrence. The present study raises the possibility that the co-occurrence of the MM2 thalamic form might have been overlooked so far because of the scarcity of abnormal prion protein accumulation and restricted neuropathology.

Identification of intracerebral hemorrhage in the early-phase of MM1+2C-type sporadic Creutzfeldt-Jakob disease: A case report.

We report a case of early-phase sporadic Creutzfeldt-Jakob disease (sCJD) complicated by intracerebral hemorrhage (ICH), classified as MM1 + 2C-type based on autopsy. A 61-year-old Japanese man presented to our hospital with speaking difficulties including repeated usage of the same words. He was hospitalized on the seventh day after symptom onset, and diffusion-weighted images on magnetic resonance imaging showed hyperintense regions in the frontal cortex and caudate nucleus. On the 11th day after symptom onset, head computed tomography revealed ICH in the right occipital and parietal lobes. Routine laboratory evaluations and angiography revealed no cause of ICH. Myoclonus of the extremities and drowsiness were observed on the 15th day after symptom onset. He reached the state of akinetic mutism approximately two months after symptom onset. The cerebrospinal fluid test revealed positive real-time quaking-induced conversion and 14-3-3 protein. Electroencephalography revealed periodic sharp wave complexes. A clinical diagnosis of probable Creutzfeldt-Jakob disease was made according to the diagnostic criteria. After a relapse of pneumonia, he passed away on the 103rd day after symptom onset. Postmortem examination revealed ICH in the right posterior cingulate gyrus. No pathological change that might have caused ICH was obtained. Although the effect of sCJD on the onset of ICH is undeniable, the cause of ICH was unknown. Prion protein immunohistochemistry revealed the following results: (1) weak synaptic-type deposits in the tissue rarefacted by ICH; (2) synaptic-type deposits in the cerebral cortex, which showed fine vacuoles; and (3) perivacuolar-type deposits in the inferior temporal gyrus and lingual gyrus, which showed frequent large confluent vacuoles. Although it could be considered MM1-type sCJD clinically, this case was neuropathologically diagnosed as having MM1 + 2C-type sCJD. It was shown that ICH may occur in early-phase sCJD. To improve sCJD prognosis, treatment of complications and careful follow up are important. Furthermore, pathological diagnosis is indispensable for sCJD type diagnosis.

Autopsied case of sporadic Creutzfeldt-Jakob disease classified as MM1+2C-type.

We encountered an autopsy case of sporadic Creutzfeldt-Jakob disease (CJD) pathologically classified as MM1+2C-type, where Western blot analysis of prion protein (PrP) mainly showed type-1 scrapie PrP (PrPSc ) but also, partially, mixed type-2 PrPSc . A Japanese woman complained of visual disorder at the age of 86 years and then showed disorientation and memory disturbances. Magnetic resonance imaging (MRI) showed cerebral cortical hyperintensity on diffusion-weighted images. The patient died 2 months after the onset of symptoms; her condition did not reach the akinetic mutism state and periodic sharp-wave complexes on electroencephalography and myoclonus were not recognized. The brain weighed 1100 g and neuropathological examination showed extensive fine vacuole-type spongiform changes in the cerebral cortex. In some cortical regions, large confluent vacuole-type spongiform changes were also present. Gliosis and hypertrophic astrocytosis were generally mild, and tissue rarefaction of the neuropil and neuronal loss were not apparent. PrP immunostaining showed diffuse synaptic-type PrP deposition in the cerebral gray matter, but some regions with large confluent vacuoles showed perivacuolar-type deposition. We speculated, based on the clinicopathological findings and previous reports, that most MM1-type sporadic CJD cases may be associated with type-2 PrPSc , at least partially, within certain regions of the cerebrum.

Autopsy case of MV2K-type sporadic Creutzfeldt-Jakob disease with spongiform changes of the cerebral cortex.

Comprehensive analysis is required for the accurate diagnosis of MV2-type sporadic Creutzfeldt-Jakob disease (sCJD) because it shows a wide clinicopathological spectrum. Here, we describe the clinical findings and neuropathologic observations of an autopsy-confirmed MV2K-type sCJD case with extensive spongiform changes of the cerebral cortex. In the early disease stages, the patient exhibited gait disturbance with ataxia and gradually showed cognitive dysfunction. Diffusion-weighted magnetic resonance images revealed hyperintense regions in the cerebral cortex, basal ganglia, and particularly in the thalamus. Prion protein (PrP) gene analysis revealed no mutations, and polymorphic codon 129 exhibited methionine and valine heterozygosity. During the course of the disease, a startle reaction was observed, whereas myoclonus was not observed. Electroencephalography showed no periodic sharp wave complexes. The patient died at age 61 years with 13 months total disease duration and did not reach the akinetic mutism state. Pathologic investigation revealed extensive fine vacuole-type spongiform change in the cerebral cortex, and the appearance of vacuolation tended to be more pronounced in the deeper layers. Numerous kuru plaques were observed in the cerebellum. PrP immunostaining revealed extensive diffuse synaptic-type PrP deposition in the cerebral cortex, and the finding was prominent in the deeper layer with perineuronal-type PrP deposition. In the limbic system, basal ganglia, and thalamus, mixed small plaque-type PrP with synaptic-type PrP deposition was observed. In the cerebellar cortex, diffuse synaptic-type PrP depositions were observed with numerous strongly immunopositive plaques. Western blot analysis of examined brain samples revealed mixed type 2 PrPSc (scrapie type) and intermediate-type PrPSc .

Biochemical features of genetic Creutzfeldt-Jakob disease with valine-to-isoleucine substitution at codon 180 on the prion protein gene.

Valine-to-isoleucine substitution at codon 180 of the prion protein gene is only observed in patients with Creutzfeldt-Jakob disease and accounts for approximately half of all cases of genetic prion disease in Japan. In the present study, we investigated the biochemical characteristics of valine-to-isoleucine substitution at codon 180 in the prion protein gene, using samples obtained from the autopsied brains of seven patients with genetic Creutzfeldt-Jakob disease exhibiting this mutation (diagnoses confirmed via neuropathological examination). Among these patients, we observed an absence of diglycosylated and monoglycosylated forms of PrPres at codon 181. Our findings further indicated that the abnormal prion proteins were composed of at least three components, although smaller carboxyl-terminal fragments were predominant. Western blot analyses revealed large amounts of PrPres in the cerebral neocortices, where neuropathological examination revealed marked spongiosis. Relatively smaller amounts of PrPres were detected in the hippocampus, where milder spongiosis was observed, than in the cerebral neocortex. These findings indicate that abnormal prion proteins in the neocortex are associated with severe toxicity, resulting in severe spongiosis. Our findings further indicate that the valine-to-isoleucine substitution is not a polymorphism, but rather an authentic pathogenic mutation associated with specific biochemical characteristics that differ from those observed in sporadic Creutzfeldt-Jakob disease.

Creutzfeldt-Jakob disease with Alzheimer pathology, presenting with status epilepticus following repeated partial seizures: a case report and literature review.

BACKGROUND: Creutzfeldt-Jakob disease (CJD) is a fatal neurodegenerative disease. Common first symptoms are dementia, cerebellar ataxia, visual disturbance, and psychiatric symptoms. Seizure as the first symptom of CJD is a very rare finding. CASE PRESENTATION: We experienced an elderly woman who presented initially with status epilepticus following repeated partial seizures in the course of Alzheimer disease (AD) dementia. Anti-convulsive therapy had no effect. Autopsy revealed definite CJD with AD pathology. COCLUSIONS: This is the first reported CJD case presenting with status epilepticus in the course of AD dementia.

Autopsied case of non-plaque-type dura mater graft-associated Creutzfeldt-Jakob disease presenting with extensive amyloid-ß deposition.

We present an autopsied case of non-plaque-type dura mater graft-associated Creutzfeldt-Jakob disease (dCJD) with extensive amyloid-ß (Aß) deposition in the brain. A 39-year-old Japanese woman presented with memory disturbance and abnormal behavior. The patient had a history of craniotomy with dura matter-graft transplant for a head injury which occurred when she was 19 years old. Magnetic resonance imaging (MRI) showed hyperintensities in the cerebral cortex and striatum on diffusion-weighted images, particularly on the dura mater-grafted right side. Her clinical symptoms, including rapidly progressing cognitive impairment, myoclonus, and periodic sharp wave complexes on electroencephalogram, could not be distinguished from typical sporadic CJD cases. The patient died 11 months after symptom onset, and pathological investigations showed extensive spongiform degeneration with prion protein (PrP) deposition without Kuru plaques; these observations were essentially the same as those of typical sporadic CJD cases. Furthermore, Aß immunohistochemistry showed extensive diffuse staining in the cerebral neocortex, plaque-type deposition, positive staining in the pia mater, and cerebral amyloid angiopathy. Although the MRI findings suggested that the pathological involvement originated from the dura mater-grafted right side, the PrP and Aß depositions showed no apparent regionalization and laterality. Tau-pathology including neurofibrillary tangles was hardly identified. The proteins phosphorylated α-synuclein and phosphorylated transactivation response DNA-binding protein 43 kDa were not detected on immunostaining. Although this report describes only one case, various speculations were made based on detailed clinical and pathological observations in conjunction with previous reports of dCJD. In particular, this report provides significant insight into the characteristics and progression of dCJD pathology and its relationship with Aß pathology.