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We report a new, pathologically verified Italian case of fatal familial insomnia, whose clinical presentation was characterised by complex behavioural disturbances, suggesting wakefulness/NREM/REM combinations.

Mutations of the presenilin 1 (PS1) gene are the most common cause of early onset familial Alzheimer disease (FAD). PS1 mutations alter the activity of the gamma-secretase on the beta-amyloid precursor protein (APP), leading to selective overproduction of beta-amyloid (Abeta) 42 peptides, the species that forms oligomers that may exert toxic effects on neurons. Here we show that PS1 mutations, expressed both transiently and stably, in non-neuronal and neuronal cell lines increase the expression and the activity of the beta-secretase (BACE1), the rate-limiting step of Abeta production. Also, BACE1 expression and activity are elevated in brains of PS1 mutant knock-in mice compared with wild type littermates as well as in cerebral cortex of FAD cases bearing various PS1 mutations compared with in sporadic AD cases and controls. The up-regulation of BACE1 by PS1 mutations requires the gamma-secretase cleavage of APP and is proportional to the amount of secreted Abeta42. Abeta42, and not AICD (APP intracellular domain), is indeed the APP derivative that mediates the overexpression of BACE1. The effect of PS1 mutations on BACE1 may contribute to determine the wide clinical and pathological phenotype of early onset FAD.

β-Amyloid precursor protein (APP) mutations cause familial Alzheimer's disease with nearly complete penetrance. We found an APP mutation [alanine-673→valine-673 (A673V)] that causes disease only in the homozygous state, whereas heterozygous carriers were unaffected, consistent with a recessive Mendelian trait of inheritance. The A673V mutation affected APP processing, resulting in enhanced β-amyloid (Aβ) production and formation of amyloid fibrils in vitro. Co-incubation of mutated and wild-type peptides conferred instability on Aβ aggregates and inhibited amyloidogenesis and neurotoxicity. The highly amyloidogenic effect of the A673V mutation in the homozygous state and its anti-amyloidogenic effect in the heterozygous state account for the autosomal recessive pattern of inheritance and have implications for genetic screening and the potential treatment of Alzheimer's disease.

A young man, presenting with early onset of personality and behavioural changes followed by slowly progressive cognitive impairment associated with marked bi-parietal cerebral atrophy, was found to carry a novel seven extra-repeat insertional mutation in the prion protein gene (PRNP). In vitro, the mutated recombinant prion protein (PrP) showed biochemical properties that were consistent with pathological PrP variants. Our results further underline the heterogeneity of neurological pictures associated with insertional mutations of PRNP, indicating the diagnostic difficulties of sporadic cases with early-onset atypical dementia.

Objective To describe a new dementia phenotype of Gerstmann-Straussler-Scheinker disease (GSS) in a previously unreported Italian family. Design Longitudinal clinical and neuropsychological assessment, combined with magnetic resonance imaging (MRI), single positron emission tomography (SPECT) and molecular genetic studies. Setting Neuropsychology Laboratory, and Division of Neuropathology and Neurology, “C. Besta” National Neurological Institute. Patients and participants Three members of the family. Measurements and results. Standardised neuropsychological tests were used to determine cognitive patterns. The proband had a history of primary dementia characterised by loss of initiative, planning, behaviour control, awareness, language and memory; the two relatives suffered from progressive ataxia. MRI of the demented patient revealed brain atrophy with a hyperintense signal in the frontal cortex; SPECT revealed decreased perfusion in the left temporal and parietal cortex and left thalamus. The two ataxic patients showed cerebellar atrophy with no signs of altered perfusion. Analysis of the PRNP gene showed a proline/leucine substitution at codon 102 in all three patients, associated with methionine/valine heterozygosity at the polymorphic codon 129. Conclusions Primary dementia with prominent frontotemporal signs is a new phenotypical expression of P102L-related GSS that coexists in the same family with the ataxic form of the disease. This remarkable variability suggests that still unidentified genetic or acquired factors may modulate the manifestations of GSS. Genetic examination of the PRNP should be included in the diagnostic work-up of patients with poorly classifiable dementia.

SummaryA familial form of Creutzfeldt-Jakob disease (CJD) is linked to the D178N/V129 prion protein (PrP) mutation. Tg(CJD) mice expressing the mouse homolog of this mutant PrP synthesize a misfolded form of the mutant protein, which is aggregated and protease resistant. These mice develop clinical and pathological features reminiscent of CJD, including motor dysfunction, memory impairment, cerebral PrP deposition, and gliosis. Tg(CJD) mice also display electroencephalographic abnormalities and severe alterations of sleep-wake patterns strikingly similar to those seen in a human patient carrying the D178N/V129 mutation. Neurons in these mice show swelling of the endoplasmic reticulum (ER) with intracellular retention of mutant PrP, suggesting that ER dysfunction could contribute to the pathology. These results establish a transgenic animal model of a genetic prion disease recapitulating cognitive, motor, and neurophysiological abnormalities of the human disorder. Tg(CJD) mice have the potential for giving greater insight into the spectrum of neuronal dysfunction in prion diseases.

The existence of several prion strains and their capacity of overcoming species barriers seem to point to a high conformational adaptability of the prion protein. To investigate this structural plasticity, we studied here the aggregation pathways of the human prion peptide PrP82-146, a major component of the Gerstmann-Sträussler-Scheinker amyloid disease. By Fourier transform infrared (FT-IR) spectroscopy, electron microscopy, and atomic force microscopy (AFM), we monitored the time course of PrP82-146 fibril formation. After incubation at 37 degrees C, the unfolded peptide was found to aggregate into oligomers characterized by intermolecular beta-sheet infrared bands. At a critical oligomer concentration, the emergence of a new FT-IR band allowed to detect fibril formation. A different intermolecular beta-sheet interaction of the peptides in oligomers and in fibrils is, therefore, detected by FT-IR spectroscopy, which, in addition, suggests a parallel orientation of the cross beta-sheet structures of PrP82-146 fibrils. By AFM, a wide distribution of PrP82-146 oligomer volumes--the smallest ones containing from 5 to 30 peptides--was observed. Interestingly, the statistical analysis of AFM data enabled us to detect a quantization in the oligomer height values differing by steps of approximately 0.5 nm that could reflect an orientation of oligomer beta-strands parallel with the sample surface. Different morphologies were also detected for fibrils that displayed high heterogeneity in their twisting periodicity and a complex hierarchical assembly. Thermal aggregation of PrP82-146 was also investigated by FT-IR spectroscopy, which indicated for these aggregates an intermolecular beta-sheet interaction different from that observed for oligomers and fibrils. Unexpectedly, random aggregates, induced by solvent evaporation, were found to display a significant alpha-helical structure as well as several beta-sheet components. All these results clearly point to a high plasticity of the PrP82-146 peptide, which was found to be capable of undergoing several aggregation pathways, with end products displaying different secondary structures and intermolecular interactions.

There is evidence that Tetracyclines are potentially useful drugs to treat prion disease, the fatal neurodegenerative disease in which cellular prion proteins change in conformation to become a disease-specific species (PrPSc). Based on an in vitro anti-fibrillogenesis test, and using the peptide PrP106-126 in the presence of tetracycline and 14 derivatives, we carried out a three-dimensional quantitative structure-activity relationship (3D-QSAR) study to investigate the stereoelectronic features required for anti-fibrillogenic activity. A preliminary variable reduction technique was used to search for grid points where statistical indexes of interaction potential distributions present local maximum (or minimum) values. Variable selection genetic algorithms were then used to search for the best 3D-QSAR models. A 6-variable model showed the best predictability of the anti-fibrillogenic activity that highlighted the best tetracycline substitution patterns: hydroxyl group presence in positions 5 and 6, electrodonor substituents on the aromatic D-ring, alkylamine substituent at the amidic group in position 2 and non-epi configuration of the NMe2 group. © Springer-Verlag 2008.

A few patients with mutations in the microtubule-associated protein tau gene (MAPT), affected by frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17T), may clinically present with a corticobasal syndrome (CBS). We report a case of apparently sporadic CBS bearing a mutation in the MAPT gene so far associated with frontotemporal dementia (FTD) phenotype. The patient is a 41-year-old man with progressive asymmetric signs of cortical and basal ganglia involvement consistent with CBS. Magnetic resonance imaging showed asymmetric cortical atrophy and unusual corticospinal tract hyperintensity in T2-weighted images. Genetic testing revealed a heterozygous G to C mutation at the first base of codon 389 of the MAPT gene, changing glycine to arginine (G389R), in the patient and his unaffected elderly father. In conclusion, the MAPT G389R mutation shows phenotypic variability resulting in both FTD and CBS. The mutation also demonstrates incomplete penetrance. Corticospinal tract degeneration is an exceptional finding.

Background: The prion diseases are characterized by sleep disruption, with FFI typically characterized also by severe autonomic dysfunction and sympathetic hyperactivity. We report the results of an extensive neurophysiological and autonomic assessment in a CJD patient carrying the D178 mutation with the uncommon homozygosity for valine at codon 129, mutation with long disease duration. Results: A 47years old female presented with a memory impairment followed by progressive cognitive deficits and ataxia. The clinical picture slowly worsened to a state of akinetic mutism in about 2 years, and the patient died six years after the onset of symptoms. Repeated PSG and long-term actigraphic recordings, showed a peculiar, previously undescribed, pattern characterized by conservation of a rudimental circadian and ultradian rhythm, despite dramatic sleep micro-structure deterioration. We also observed a normal autonomic physiological response to orthostatic challenge and normal dynamic autonomic modulation during wake and sleep. The post-mortem brain pathology study, showed that neuronal loss was substantial in the cerebral cortex, diencephalon and thalami, but not in brainstem nuclei. Conclusions: We hypothesize that, despite a dramatic neurological picture (i.e. akinetic mutism) and a severe sleep micro-structural alteration, the persistence of an autonomic modulation and the persistence of a rudimental circadian and ultradian oscillation, are related to the relatively conserved anatomo-functional integrity of foundamental neuronal systems in the brainstem.

Amyloid-β (Aβ) deposits are seen in aged individuals of many mammalian species that possess the same aminoacid sequence as humans. This study describes Aβ deposition in 102 clinically characterized cattle brains from animals aged 0 to 20 years. Extracellular and intracellular Aβ deposition was detected with 4G8 antibody in the cortex, hippocampus, and cerebellum. X-34 staining failed to stain Aβ deposits, indicating the non β-pleated nature of these deposits. Western blot analysis and surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry revealed in Tris, Triton, and formic acid fractions the presence of different Aβ peptides, characterized mainly by C-terminally truncated forms. Exploration of the genetic variability of APOE, PSEN1, and PSEN2 genes involved in Alzheimer's disease pathogenesis revealed several previously unreported polymorphisms. This study demonstrates certain similarities between Aβ deposition patterns exhibited in cattle brains and those in the human brain in early stages of aging. Furthermore, the identification of the same Aβ peptides reported in humans, but unable to form aggregates, supports the hypothesis that cattle may be protected against amyloid plaque formation.

Pathological accumulation of abnormally phosphorylated tau protein in astrocytes is a frequent, but poorly characterized feature of the aging brain. Its etiology is uncertain, but its presence is sufficiently ubiquitous to merit further characterization and classification, which may stimulate clinicopathological studies and research into its pathobiology. This paper aims to harmonize evaluation and nomenclature of aging-related tau astrogliopathy (ARTAG), a term that refers to a morphological spectrum of astroglial pathology detected by tau immunohistochemistry, especially with phosphorylation-dependent and 4R isoform-specific antibodies. ARTAG occurs mainly, but not exclusively, in individuals over 60 years of age. Tau-immunoreactive astrocytes in ARTAG include thorn-shaped astrocytes at the glia limitans and in white matter, as well as solitary or clustered astrocytes with perinuclear cytoplasmic tau immunoreactivity that extends into the astroglial processes as fine fibrillar or granular immunopositivity, typically in gray matter. Various forms of ARTAG may coexist in the same brain and might reflect different pathogenic processes. Based on morphology and anatomical distribution, ARTAG can be distinguished from primary tauopathies, but may be concurrent with primary tauopathies or other disorders. We recommend four steps for evaluation of ARTAG: (1) identification of five types based on the location of either morphologies of tau astrogliopathy: subpial, subependymal, perivascular, white matter, gray matter; (2) documentation of the regional involvement: medial temporal lobe, lobar (frontal, parietal, occipital, lateral temporal), subcortical, brainstem; (3) documentation of the severity of tau astrogliopathy; and (4) description of subregional involvement. Some types of ARTAG may underlie neurological symptoms; however, the clinical significance of ARTAG is currently uncertain and awaits further studies. The goal of this proposal is to raise awareness of astroglial tau pathology in the aged brain, facilitating communication among neuropathologists and researchers, and informing interpretation of clinical biomarkers and imaging studies that focus on tau-related indicators.

A novel technique of quantitative EEG for differentiating patients with early-stage Creutzfeldt–Jakob disease (CJD) from other forms of rapidly progressive dementia (RPD) is proposed. The discrimination is based on the extraction of suitable features from the time-frequency representation of the EEG signals through continuous wavelet transform (CWT). An average measure of complexity of the EEG signal obtained by permutation entropy (PE) is also included. The dimensionality of the feature space is reduced through a multilayer processing system based on the recently emerged deep learning (DL) concept. The DL processor includes a stacked auto-encoder, trained by unsupervised learning techniques, and a classifier whose parameters are determined in a supervised way by associating the known category labels to the reduced vector of high-level features generated by the previous processing blocks. The supervised learning step is carried out by using either support vector machines (SVM) or multilayer neural networks (MLP-NN). A subset of EEG from patients suffering from Alzheimer’s Disease (AD) and healthy controls (HC) is considered for differentiating CJD patients. When fine-tuning the parameters of the global processing system by a supervised learning procedure, the proposed system is able to achieve an average accuracy of 89%, an average sensitivity of 92%, and an average specificity of 89% in differentiating CJD from RPD. Similar results are obtained for CJD versus AD and CJD versus HC.

The wide phenotypic variability of prion diseases is thought to depend on the interaction of a host genotype with prion strains that have self-perpetuating biological properties enciphered in distinct conformations of the misfolded prion protein PrP Sc . This concept is largely based on indirect approaches studying the effect of proteases or denaturing agents on the physicochemical properties of PrP Sc aggregates. Furthermore, most data come from studies on rodent-adapted prion strains, making current understanding of the molecular basis of strains and phenotypic variability in naturally occurring diseases, especially in humans, more limited. To fill this gap, we studied the effects of guanidine hydrochloride (GdnHCl) and heating on PrP Sc aggregates extracted from 60 sporadic Creutzfeldt-Jakob disease (CJD) and 6 variant CJD brains. While denaturation curves obtained after exposure of PrP Sc to increasing GdnHCl concentrations showed similar profiles among the 7 CJD types analyzed, PrP Sc exposure to increasing temperature revealed significantly different and type-specific responses. In particular, MM1 and VV2, the most prevalent and fast-replicating CJD types, showed stable and highly resistant PrP Sc aggregates, whereas VV1, a rare and slowly propagating type, revealed unstable aggregates that easily dissolved at low temperature. Taken together, our results indicate that the molecular interactions mediating the aggregation state of PrP Sc , possibly enciphering strain diversity, are differently targeted by GdnHCl, temperature, and proteases. Furthermore, the detected positive correlation between the thermostability of PrP Sc aggregates and disease transmission efficiency makes inconsistent the proposed hypothesis that a decrease in conformational stability of prions results in an increase in their replication efficiency. IMPORTANCE Prion strains are defined as infectious isolates propagating distinctive phenotypic traits after transmission to syngeneic hosts. Although the molecular basis of prion strains is not fully understood, it is largely accepted that variations in prion protein conformation drive the molecular changes leading to the different phenotypes. In this study, we exposed abnormal prion protein aggregates encompassing the spectrum of human prion strains to both guanidine hydrochloride and thermal unfolding. Remarkably, while exposure to increasing temperature revealed significant strain-specific differences in the denaturation profile of the protein, treatment with guanidine hydrochloride did not. The findings suggest that thermal and chemical denaturation perturb the structure of prion protein aggregates differently. Moreover, since the most thermostable prion protein types were those associated with the most prevalent phenotypes and most rapidly and efficiently transmitting strains, the results suggest a direct correlation between strain replication efficiency and the thermostability of prion protein aggregates.

An atypical case of sporadic Creutzfeldt-Jakob disease (CJD) is described in a 78-year-old woman homozygous for methionine at codon 129 of the prion protein (PrP) gene. The neuropathological signature was the presence of PrP immunoreactive plaque-like deposits in the cerebral cortex, striatum and thalamus. Western blot analysis showed a profile of the pathological form of PrP (PrP(Sc)) previously unrecognised in sporadic CJD, marked by the absence of diglycosylated protease resistant species. These features define a novel neuropathological and molecular CJD phenotype.

Amyloid fibrils in Gerstmann–Sträussler–Scheinker (GSS) disease are composed of a fragment of the prion protein (PrP), the N and C termini of which correspond to ragged residues 81–90 and 144–153. A synthetic peptide spanning the sequence 82–146 (PrP 82–146) polymerizes into protease-resistant fibrils with the tinctorial properties of amyloid. We investigated the biological activity of PrP 82–146 and of two nonamyloidogenic variants of PrP 82–146 with scrambled amino acid sequence 106–126 or 127–146. Cortical neurons prepared from rat and mouse embryos were chronically exposed to the PrP 82–146 peptides (10–50 μm). PrP 82–146 and the partially scrambled peptides induced neuronal death with a similar dose–response pattern, indicating that neurotoxicity was independent of amyloid fibril formation. Neurotoxicity was significantly reduced by coadministration of an anti-oligomer antibody, suggesting that PrP 82–146 oligomers are primarily responsible for triggering cell death. Neurons from PrP knock-out (Prnp0/0) mice were significantly less sensitive to PrP 82–146 toxicity than neurons expressing PrP. The gliotrophic effect of PrP 82–146 was determined by [methyl-3H]-thymidine incorporation in cultured astrocytes. Treatment with PrP 82–146 stimulated [methyl-3H]-thymidine uptake 3.5-fold. This activity was significantly less when the 106–126 or 127–146 regions were disrupted, indicating that PrP 82–146 amyloid activates the gliotrophic response. Prnp0/0 astrocytes were insensitive to the proliferative stimulus of PrP 82–146. These results underline the role of cerebral accumulation of abnormally folded PrP fragments and indicate that cellular PrP governs the pathogenic process.

GRN, the gene coding for the progranulin (PGRN) protein, was recognized as a gene linked to frontotemporal lobar degeneration (FTLD). The first mutations identified were null mutations giving rise to haploinsufficiency. Missense mutations were subsequently detected, but only a small subset has been functionally investigated. We identified missense mutations (C105Y, A199V, and R298H) in FTLD cases with family history and/or with low plasma PGRN levels. The aim of this study was to determine their pathogenicity. We performed functional studies, analyzing PGRN expression, secretion, and cleavage by elastase. GRN C105Y affected both secretion and elastase cleavage, likely representing a pathogenic mutation. GRN A199V did not alter the physiological properties of PGRN and GRN R298H produced only moderate effects on PGRN secretion, indicating that their pathogenicity is uncertain. In the absence of strong segregation data and neuropathological examinations, genetic, biomarker, and functional studies can be applied to an algorithm to assess the likelihood of pathogenicity for a mutation. This information can improve our understanding of the complex mechanisms by which GRN mutations lead to FTLD.

Alzheimer disease (AD) is the most prevalent form of dementia. Loss of hippocampal synapses is the first neurodegenerative event in AD. Synaptic loss has been associated with the accumulation in the brain parenchyma of soluble oligomeric forms of amyloid β peptide (Aβ1-42wt). Clinical observations have shown that a mutation in the APP protein (A673V) causes an early onset AD-type dementia in homozygous carriers while heterozygous carriers are unaffected. This mutation leads to the formation of mutated Aβ peptides (Aβ1-42A2V) in homozygous patients, while in heterozygous subjects both Aβ1-42wt and Aβ1-42A2V are present. To better understand the impact of the A673V mutation in AD, we analyzed the synaptotoxic effect of oligomers formed by aggregation of different Aβ peptides (Aβ1-42wt or Aβ1-42A2V) and the combination of the two Aβ1-42MIX (Aβ1-42wt and Aβ1-42A2V) in an in vitro model of synaptic injury. We showed that Aβ1-42A2V oligomers are more toxic than Aβ1-42wt oligomers in hippocampal neurons, confirming the results previously obtained in cell lines. Furthermore, we reported that oligomers obtained by the combination of both wild type and mutated peptides (Aβ1-42MIX) did not exert synaptic toxicity. We concluded that the combination of Aβ1-42wt and Aβ1-42A2V peptides hinders the toxicity of Aβ1-42A2V and counteracts the manifestation of synaptopathy in vitro. Finally we took advantage of this finding to generate a cell-permeable peptide for clinical application, by fusing the first six residues of the Aβ1-42A2V to the TAT cargo sequence (Aβ1-6A2VTAT(D)). Noteworthy, the treatment with Aβ1-6A2VTAT(D) confers neuroprotection against both in vitro and in vivo synaptopathy models. Therefore Aβ1-6A2VTAT(D) may represent an innovative therapeutic tool to prevent synaptic degeneration in AD.

Frontotemporal lobar degeneration (FTLD) is a group of heterogeneous neurodegenerative diseases which includes tauopathies. In the central nervous system (CNS) tau is the major microtubule-associated protein (MAP) of neurons, promoting assembly and stabilization of microtubules (MTs) required for morphogenesis and axonal transport. Primary tauopathies are characterized by deposition of abnormal fibrils of tau in neuronal and glial cells, leading to neuronal death, brain atrophy and eventually dementia. In genetic tauopathies mutations of tau gene impair the ability of tau to bind to MTs, alter the normal ratio among tau isoforms and favor fibril formation. Recently, additional functions have been ascribed to tau and different pathogenetic mechanisms are then emerging. In fact, a role of tau in DNA protection and genome stability has been reported and chromosome aberrations have been found associated with tau mutations. Furthermore, newly structurally and functionally characterized mutations have suggested novel pathological features, such as a tendency to form oligomeric rather than fibrillar aggregates. Tau mutations affecting axonal transport and plasma membrane interaction have also been described. In this article, we will review the pathogenetic mechanisms underlying tau mutations, focusing in particular on the less common aspects, so far poorly investigated.

Biobanks are important resources for biomarker discovery and assay development. Biomarkers for Alzheimer's and Parkinson's disease (BIOMARKAPD) is a European multicenter study, funded by the EU Joint Programme-Neurodegenerative Disease Research, which aims to improve the clinical use of body fluid markers for the diagnosis and prognosis of Alzheimer's disease (AD) and Parkinson's disease (PD). The objective was to standardize the assessment of existing assays and to validate novel fluid biomarkers for AD and PD. To support the validation of novel biomarkers and assays, a central and a virtual biobank for body fluids and associated data from subjects with neurodegenerative diseases have been established. In the central biobank, cerebrospinal fluid (CSF) and blood samples were collected according to the BIOMARKAPD standardized pre-analytical procedures and stored at Integrated BioBank of Luxembourg. The virtual biobank provides an overview of available CSF, plasma, serum, and DNA samples at each site. Currently, at the central biobank of BIOMARKAPD samples are available from over 400 subjects with normal cognition, mild cognitive impairment (MCI), AD, frontotemporal dementia (FTD), vascular dementia, multiple system atrophy, progressive supranuclear palsy, PD, PD with dementia, and dementia with Lewy bodies. The virtual biobank contains information on over 8,600 subjects with varying diagnoses from 21 local biobanks. A website has been launched to enable sample requests from the central biobank and virtual biobank. © 2015 Reijs, Teunissen, Goncharenko, Betsou, Blennow, Baldeiras, Brosseron, Cavedo, Fladby, Froelich, Gabryelewicz, Gurvit, Kapaki, Koson, Kulic, Lehmann, Lewczuk, Lleó, Maetzler, de Mendonça, Miller, Molinuevo, Mollenhauer, Parnetti, Rot, Schneider, Simonsen, Tagliavini, Tsolaki, Verbeek, Verhey, Zboch, Winblad, Scheltens, Zetterberg and Visser.

Alzheimer's disease (AD) is characterized by amyloid-β (Aβ) accumulation in brain that is paralleled by Aβ(1-42) reduction in cerebrospinal fluid (CSF). We analyzed the pattern of Aβ peptides, including the N- and C-terminal truncated fragments, in brain and CSF from two familial and one sporadic AD cases. We found that (i) each patient is characterized by a distinct Aβ profile in CSF and brain deposits and (ii) the CSF Aβ pattern mirrors the Aβ profile of cerebral amyloid. These results suggest the existence of different molecular AD subtypes which can be recognized by CSF analysis, enabling patient stratification.

Prion diseases are characterized by the accumulation in the brain of abnormal conformers (PrP(Sc)) of the cellular prion protein (PrP(C)). PrP(Sc) immunohistochemistry, currently based on antibodies non-distinguishing between PrP(C) and PrP(Sc), requires pre-treatments of histological sections to eliminate PrP(C) and to denature PrP(Sc). We employed the PrP(Sc)-specific antibody 89-112 PrP motif-grafted IgG on mildly fixed, untreated brain sections from several cases of human prion diseases. The results confirmed specific binding of IgG 89-112 to a structural determinant found exclusively on native disease-associated PrP conformations and lost following tissue denaturation or cross-linking fixation. Importantly, IgG 89-112 demonstrated no reactivity with normal brain tissue or with amyloid deposits in Alzheimer disease brain sections. Thus, immunohistochemical detection of native PrP(Sc) deposits was obtained by means of a PrP(Sc)-specific antibody. Such unique reagent may have many applications in the study of prion biology and in the diagnosis and prevention of prion diseases.

The neuropsychological assessment of non-demented subjects with gene mutation of familial Alzheimer’s disease (AD) provides a model for exploring the early cognitive features of the disease. We evaluated 1 patient and 6 non-demented subjects belonging to a family with AD with M239V mutation of the presenilin 2 gene, aiming to verify the contribution of specific cognitive patterns to the characterization of familial AD. One patient, 3 non-demented subjects with M239V mutation and 3 subjects without mutation from the same family underwent neuropsychological testing. The patient’s cognitive profile was characterized by anosognosia, visuospatial agnosia, apraxia and fluent aphasia. Of the 3 non-demented subjects with mutation, 1 showed no deficits, another constructive apraxia and the third spatial perception and memory deficits. The 3 subjects without mutation showed normal abilities. The cognitive deficits of the non-demented subjects with mutations indicate focal dysfunction of the posterior cortical areas, resembling the more extended parieto-occipito-temporal dysfunction of the demented patient. Such grading of visuospatial, praxis, and language impairments highlights a distinctive pattern related to the M239V mutation of the presenilin 2 gene.

Objective To characterise flash visual evoked potentials (FVEPs) in 20 patients with Creutzfeldt–Jacob disease (CJD), and assess the relationships between spontaneous EEG patterns and the responses to individual stimuli. Methods We analysed the shape and time course of periodic sharp wave complexes (PSWCs) and responses to 1 Hz flashes. In nine patients, we applied an algorithm based on an autoregressive model with exogenous input (ARX) to estimate responses to individual random flashes and their interaction with PSWCs. Results The FVEPs included P1 and N1 components in all patients, and the P2 peak in 18. Eight patients showed giant FVEPs (N1-P2>60 V), all of whom had an MM polymorphism in codon 129 of the prion protein gene; in seven cases, the presence of giant FVEPs correlated with a prominent and almost continuous periodic EEG pattern. Giant N1-P2 abnormally spread on the anterior scalp regions, and had a different waveform distribution from that of the PSWCs. In five patients with a normal or slightly enlarged average N1-P2 amplitude, single sweep (ARX) analysis revealed a period of relative refractoriness following individual PSWCs. In four patients with ‘giant’ FVEPs, the individual responses occurred regardless of the interval between the stimulus and previous PSWC, but their amplitude had an inverse relationship with the interval length. Conclusions Giant responses to flash stimuli are a common finding in CJD patients (40% of our cases). Single sweep ARX analysis showed that PSWCs were followed by a period of partial refractoriness, which prevented most of the individual responses to flashes, but not giant FVEPs. The association between prominent spontaneous paroxysms and giant FVEPs suggests that both are due to a common hyperexcitable change favouring neuronal synchronisation. Significance Our data contribute to clarifying the debated problem of the occurrence of giant FVEPs in CJD and their relationships with the spontaneous periodic EEG pattern.

Prion protein (PrP) amyloid formation is a central feature of genetic and acquired forms of prion disease such as Gerstmann-Sträussler-Scheinker disease (GSS) and variant Creutzfeldt-Jakob disease. The major component of GSS amyloid is a PrP fragment spanning residues approximately 82-146. To investigate the determinants of the physicochemical properties of this fragment, we synthesized PrP-(82-146) and variants thereof, including entirely and partially scrambled peptides. PrP-(82-146) readily formed aggregates that were partially resistant to protease digestion. Peptide assemblies consisted of 9.8-nm-diameter fibrils having a parallel cross-beta-structure. Second derivative of infrared spectra indicated that PrP-(82-146) aggregates are primarily composed of beta-sheet (54%) and turn (24%) which is consistent with their amyloid-like properties. The peptide induced a remarkable increase in plasma membrane microviscosity of primary neurons. Modification of the amino acid sequence 106-126 caused a striking increase in aggregation rate, with formation of large amount of protease-resistant amorphous material and relatively few amyloid fibrils. Alteration of the 127-146 region had even more profound effects, with the inability to generate amyloid fibrils. These data indicate that the intrinsic properties of PrP-(82-146) are dependent upon the integrity of the C-terminal region and account for the massive deposition of PrP amyloid in GSS.

A major prion protein (PrP) mutant that forms amyloid fibrils in the diseased brain of patients with Gerstmann-Sträussler-Scheinker syndrome (GSS) is a fragment of 7 kDa spanning from residues 81-82 to 144-153 of PrP. Analysis of ionic membrane currents, recorded with a libid bilayer technique, revealed that the wild-type fragment PrP(82-146) WT and the partially scrambled PrP(82-146) (127-146) SC are capable of forming heterogenous ion channels that are similar to those channels formed with PrP(106-126). In contrast, PrP(82-146) peptides in which the region from residue 106 to 126 had been scrambled (SC) showed a reduction in interaction with lipid membranes and did not form channels. The PrP(82-146) WT- and PrP(82-146) (127-146) SC-formed cation channels with fast kinetics are Cu2+ sensitive and rifampicin (RIF) insensitive, whereas the time-dependent inactivating channels formed by these same peptides are both Cu2+ and RIF insensitive. The presence of RIF in the solution before the addition of PrP(82-146) WT or PrP(82-146) (127-146) SC affected their incorporation into the lipid bilayers. PrP(82-146) WT and PrP(82-146) (127-146) SC fast cation channels formed in the presence of RIF appeared in an electrically semisilent state or an inactivated state. Increasing [Cd2+] cis enhanced the incorporation of PrP(82-146) WT and PrP(82-146) (127-146) SC channels formed in the presence of RIF. We conclude that the major PrP mutant fragment in the diseased brain of GSS patients is prone to form channels in neuronal membranes, causing their dysfunction. We propose that Cd2+ may accentuate the neurotoxicity of this channel-forming PrP fragment by enhancing its incorporation into the membrane.

Prion diseases are unique in that they comprise sporadic, genetic, and iatrogenically or environmentally acquired forms. When disease is acquired by peripheral route, neuroinvasion occurs via at least two different neural pathways (vague and splanchnic nerves) and is usually preceded by prion propagation in secondary lymphoid organs. Conversely, in the other etiologic forms, PrPSc formation occurs within, and is apparently limited to, the CNS. Longitudinal studies on experimental scrapie indicate that substantial neuropathologic changes (i.e., glial activation and nerve cell degeneration) already are present before the onset of symptoms and are topographically related to PrPSc deposits. Accordingly, any effective intervention should start during the preclinical stage of disease, and be aimed at preventing neuroinvasion or PrPSc propagation in the CNS. Unfortunately, no tests are available currently to detect presymptomatic individuals, except for carriers of pathogenic mutations of the PRNP gene. Inhibition of PrPSc formation can be achieved through (1) abrogation of PrPC synthesis or prevention of its transport to the cell surface; (2) stabilization of the PrPC structure to make its conformational change unfavorable; (3) sequestration of PrPSc; (4) reversion of PrPSc to a protease-sensitive form; or (5) interference with the interaction between PrPC, PrPSc, and other macromolecules that feature in the conversion process. The compounds that have some effectiveness in in vitro, cell culture, or animal models of prion disease seem to operate through one of these mechanisms (see Table 1); however, even the most effective drugs only work when administered at the time of infection or very short thereafter, and these conditions are incurable at present. The heterogeneity and complexity of the etiopathogenesis of prion diseases suggest that various strategies and a combination of several compounds with different modes of actions are likely necessary for prevention and treatment. Major efforts should be focused on the development of preclinical diagnostic tests in conjunction with immunization strategies for diseases acquired by peripheral route and identification of more effective compounds for the other etiological forms.

Although multiple sclerosis (MS) has been classically regarded as a primarily white matter disorder, recent histopathologic studies have shown that the gray matter may be also heavily affected. Subpial demyelination appears as large bands of myelin loss extending from the surface of the cortex into its deeper layers.1 In vivo this change can only be visualized by ultra-high-fields MRI.2 We describe a patient presenting a neurologic disease that rapidly led to spastic paraplegia and death. Plaques of demyelination were absent in the white matter of the brain, but the neuropathologic diagnosis was MS, based on severe and widespread loss of myelin in the spinal cord. Extensive subpial demyelination involved the …

Prions are infectious proteins that possess multiple self-propagating structures. The information for strains and structural specific barriers appears to be contained exclusively in the folding of the pathological isoform, PrPSc. Many recent studies determined that de novo prion strains could be generated in vitro from the structural conversion of recombinant (rec) prion protein (PrP) into amyloidal structures. Our aim was to elucidate the conformational diversity of pathological recPrP amyloids and their biological activities, as well as to gain novel insights in characterizing molecular events involved in mammalian prion conversion and propagation. To this end we generated infectious materials that possess different conformational structures. Our methodology for the prion conversion of recPrP required only purified rec full-length mouse (Mo) PrP and common chemicals. Neither infected brain extracts nor amplified PrPSc were used. Following two different in vitro protocols recMoPrP converted to amyloid fibrils without any seeding factor. Mouse hypothalamic GT1 and neuroblastoma N2a cell lines were infected with these amyloid preparations as fast screening methodology to characterize the infectious materials. Remarkably, a large number of amyloid preparations were able to induce the conformational change of endogenous PrPC to harbor several distinctive proteinase-resistant PrP forms. One such preparation was characterized in vivo habouring a synthetic prion with novel strain specified neuropathological and biochemical properties., Author Summary Prions are infectious proteins capable of acquiring multiple self-propagating structures. The information for strains and structural specific barriers appears to be contained exclusively in the folding of the pathological isoform, designated as PrPSc. During propagation, disease-associated conformer PrPSc coerces the physiological form, denoted as PrPC, to adopt the pathological isoform conformation. We describe here the generation of an array of infectious materials with different structural, morphological, biochemical and cell biological characteristics. After producing purified recombinant prion protein of the wild-type mouse full-length sequence in Escherichia coli, we polymerized the protein into various amyloid fibril conformations based on different amyloid preparations. We also applied a build-in methodology for screening amyloid preparations and generate infectious materials using an amyloid-infected cell culture assay. Some of the amyloid fibrils preparations were able to efficiently amplify in PMCA (Protein Misfolding Cyclic Amplification), and to induce endogenous PrPC to convert into PrPSc in both murine hypothalamic GT1 and neuroblastoma N2a cell lines. One such protocol lead to the generation of a novel synthetic prion strain in mice.

Recently, several studies proposed a physiological role for the cellular prion protein (PrPc) in defense against oxidative stress. Since the pathogenesis of prion disease necessarily involves a disturbance of PrPc homeostasis, we hypothesized that such diseases would be associated with concomitant disturbances in oxidative balance. In support of such a notion, in this study we show increased oxidative damage to nucleic acids in affected brains of patients with Creutzfeldt–Jakob disease. These data suggest that damage by free radicals is a likely cause for neurodegeneration in human prion disease, and antioxidants are a potential therapy for these disorders. Further, our data support the hypothesis that loss of the anti-oxidant function of PrPc plays a key role in the pathogenesis of these disorders.

Gene coding for progranulin, GRN, is a major gene linked to frontotemporal lobar degeneration. While most of pathogenic GRN mutations are null mutations leading to haploinsufficiency, GRN missense mutations do not have an obvious pathogenicity, and only a few have been revealed to act through different pathogenetic mechanisms, such as cytoplasmic missorting, protein degradation, and abnormal cleavage by elastase. The aim of this study was to disclose the pathogenetic mechanisms of the GRN A199V missense mutation, which was previously reported not to alter physiological progranulin features but was associated with a reduced plasma progranulin level. After investigating the family pedigree, we performed genetic and biochemical analysis on its members and performed RNA expression studies. We found that the mutation segregates with the disease and discovered that its pathogenic feature is the alteration of GRN mRNA splicing, actually leading to haploinsufficiency. Thus, when facing with a missense GRN mutation, its pathogenetic effects should be investigated, especially if associated with low plasma progranulin levels, to determine its nature of either benign polymorphism or pathogenic mutation.

Cerebral amyloid angiopathy-related inflammation (CAA-ri), a rare form of vasculitis associated with amyloid-β (Aβ) deposition in vessel walls, has been proposed as a spontaneous human model of the amyloid-related imaging abnormalities (ARIA) occurring after anti-Aβ immunotherapy for the treatment of Alzheimer's disease (AD). We describe a case of a patient with biopsy-proven CAA-ri and prodromal AD, confirmed by means of neuropsychological examination after 20 months follow-up, presenting with ARIA and high levels of cerebrospinal fluid anti-Aβ autoantibodies. This case further supports the analogies between the inflammatory response driven by anti-Aβ immunotherapy and that spontaneously occurring in CAA-ri.

Fatal familial insomnia (FFI) and a genetic form of Creutzfeldt-Jakob disease (CJD178) are clinically different prion disorders linked to the D178N prion protein (PrP) mutation. The disease phenotype is determined by the 129 M/V polymorphism on the mutant allele, which is thought to influence D178N PrP misfolding, leading to the formation of distinctive prion strains with specific neurotoxic properties. However, the mechanism by which misfolded variants of mutant PrP cause different diseases is not known. We generated transgenic (Tg) mice expressing the mouse PrP homolog of the FFI mutation. These mice synthesize a misfolded form of mutant PrP in their brains and develop a neurological illness with severe sleep disruption, highly reminiscent of FFI and different from that of analogously generated Tg(CJD) mice modeling CJD178. No prion infectivity was detectable in Tg(FFI) and Tg(CJD) brains by bioassay or protein misfolding cyclic amplification, indicating that mutant PrP has disease-encoding properties that do not depend on its ability to propagate its misfolded conformation. Tg(FFI) and Tg(CJD) neurons have different patterns of intracellular PrP accumulation associated with distinct morphological abnormalities of the endoplasmic reticulum and Golgi, suggesting that mutation-specific alterations of secretory transport may contribute to the disease phenotype., Author Summary Genetic prion diseases are degenerative brain disorders caused by mutations in the gene encoding the prion protein (PrP). Different PrP mutations cause different diseases, including Creutzfeldt-Jakob disease (CJD) and fatal familial insomnia (FFI). The reason for this variability is not known, but assembly of the mutant PrPs into distinct aggregates that spread in the brain by promoting PrP aggregation may contribute to the disease phenotype. We previously generated transgenic mice modeling genetic CJD, clinically identified by dementia and motor abnormalities. We have now generated transgenic mice carrying the PrP mutation associated with FFI, and found that they develop severe sleep abnormalities and other key features of the human disorder. Thus, transgenic mice recapitulate the phenotypic differences seen in humans. The mutant PrPs in FFI and CJD mice are aggregated but unable to promote PrP aggregation. They accumulate in different intracellular compartments and cause distinct morphological abnormalities of transport organelles. These results indicate that mutant PrP has disease-encoding properties that are independent of its ability to self-propagate, and suggest that the phenotypic heterogeneity may be due to different effects of aggregated PrP on intracellular transport. Our study provides new insights into the mechanisms of selective neuronal dysfunction due to protein aggregation.

BACKGROUND: Prions, the infectious agents responsible for transmissible spongiform encephalopathies, consist mainly of the misfolded prion protein (PrPSc). The unique mechanism of transmission and the appearance of a variant form of Creutzfeldt–Jakob disease, which has been linked to consumption of prion-contaminated cattle meat, have raised concerns about public health. Evidence suggests that variant Creutzfeldt–Jakob disease prions circulate in body fluids from people in whom the disease is silently incubating.METHODS: To investigate whether PrPSc can be detected in the urine of patients with variant Creutzfeldt–Jakob disease, we used the protein misfolding cyclic amplification (PMCA) technique to amplify minute quantities of PrPSc, enabling highly sensitive detection of the protein. We analyzed urine samples from several patients with various transmissible spongiform encephalopathies (variant and sporadic Creutzfeldt–Jakob disease and genetic forms of prion disease), patients with other degenerative or nondegenerative neurologic disorders, and healthy persons. RESULTS: PrPSc was detectable only in the urine of patients with variant Creutzfeldt–Jakob disease and had the typical electrophoretic profile associated with this disease. PrPSc was detected in 13 of 14 urine samples obtained from patients with variant Creutzfeldt–Jakob disease and in none of the 224 urine samples obtained from patients with other neurologic diseases and from healthy controls, resulting in an estimated sensitivity of 92.9% (95% confidence interval [CI], 66.1 to 99.8) and a specificity of 100.0% (95% CI, 98.4 to 100.0). The PrPSc concentration in urine calculated by means of quantitative PMCA was estimated at 1×10−16 g per milliliter, or 3×10−21 mol per milliliter, which extrapolates to approximately 40 to 100 oligomeric particles of PrPSc per milliliter of urine.CONCLUSIONS: Urine samples obtained from patients with variant Creutzfeldt–Jakob disease contained minute quantities of PrPSc. (Funded by the National Institutes of Health and others.)

Frontotemporal lobar degeneration (FTLD) is a very heterogeneous disorder. It is genetically linked to three major genes: microtubule-associated protein tau (MAPT), progranulin (GRN), and C9ORF72. In particular, mutations in GRN account for 5-10% of all cases and give rise to a wide spectrum of clinical phenotypes, ranging from behavioral frontotemporal dementia (bvFTD) to primary progressive aphasia, including progressive non-fluent aphasia (PNFA) and semantic dementia, and corticobasal syndrome (CBS). We studied a family affected by FTLD whose members showed three different phenotypes: bvFTD, PNFA, and CBS. We performed plasma progranulin measurement before any genetic analyses and, due to the low level detected, we sequenced GRN and found the new mutation EX0-5' splice site A > G in the 5'-UTR region, where no pathogenic mutations had been previously demonstrated. Genetic analyses of MAPT and C9ORF72 were normal. GRN mRNA expression showed about 50% reduction caused by this mutation, and similar results were found for progranulin level. Testing of nonsense mediated RNA decay gave negative results, suggesting a different mechanism of mRNA degradation. In summary, the EX0-5' splice site A > G mutation widens the GRN regions affected by null mutations, including the 5'-UTR, and confirms once more the large phenotypic variability linked to GRN mutations.

Diffusion datasets were corrected for motion and eddy current distortions (Smith et al., 2004) and then processed with a Spherical Deconvolution algorithm based on a damped version of the Richardson-Lucy algorithm (Dell’acqua et al., 2010, Dell’Acqua et al., 2013). Tractography was performed following the method described in (Catani et al., 2012). We dissected fiftyfive frontal tracts including U-shaped fibers. For each dissection FA (Basser and Pierpaoli, 1996) and hindrance modulated oriented anisotropy (HMOA) (Dell’Acqua et al., 2013) were extracted as an indirect measure of the tract integrity and correlated with the age of the participants regressing out the level of education. P values are presented after false discovery rate (FDR) correction for multiple comparisons (* p < 0.05 ; ** p < 0.01 ; *** p < 0.001). Results: Aging was significantly associated with a decrease of FA (r1⁄4 0.501*) and OA (r1⁄4 0.508**) in the frontal projections of the corpus callosum. Aging was also associated with a decrease of OA in the right frontal lobe including the SLF I (r 1⁄4 0.401**) and SLF III (r 1⁄4 0.576***) branches of the superior longitudinal fasciculus, inferior fronto-occipital fasciculus (r 1⁄4 0.331*), fronto-thalamic projections (r 1⁄4 0.515***). In the left hemisphere, OA measure also decreased with aging for the frontal inferior longitudinal fasciculus (r1⁄4 0.542***) and the frontal orbito-polar tract (r 1⁄4 0.542***). Results are summarized in Figure 1. Conclusions: We confirmed preliminary evidences reporting reduced integrity in the frontal portion of the corpus callosum associated with aging (Lebel et al., 2010). This commissural decline may explain the increased reaction times associated with aging reported in tasks requiring interhemispheric transfer (Reuter-Lorenz and Stanczak, 2000). Our results also suggest for the first time that aging alters significantly other tracts in the right hemisphere which brings up interesting pathophysiological hypotheses for ageing decline in visuospatial and verbal working memory, memory encoding and retrieval, reward-based associative learning that can be tested in the elderly (Cabeza and Dennis, 2012). IC-P-069 ITALIAN NETWORK FOR AUTOSOMAL DOMINANTALZHEIMER’S DISEASE AND FRONTOTEMPORAL LOBAR DEGENERATION (ITALIANDIAFN) Martina Bocchetta, Michela Pievani, Claudio Babiloni, Amalia C. Bruni, Elio Scarpini, Sandro Sorbi, Fabrizio Tagliavini, Alessandro Padovani, Luisa Benussi, Livia Bernardi, Giuliano Binetti, Barbara Borroni, Giuseppe Di Fede, Emilio Di Maria, Silvia Fostinelli, Daniela Galimberti, Massimo Gennarelli, Roberta Ghidoni, Nicola Marzano, Anna Mega, Benedetta Nacmias, Irene Piaceri, Corinna Porteri, Giacomina Rossi, Silvia Suardi, Fabrizio Vecchio, Giovanni B. Frisoni, IRCCS Centro S. Giovanni di Dio, Fatebenefratelli, Brescia, Italy; IRCCS Fatebenefratelli, Brescia, Italy; 3 University of Rome "La Sapienza", Rome, Italy; 4 Centro Regionale di Neurogenetica, Lamezia Terme (CZ), Italy; 5 Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy; University of Florence, Florence, Italy; IRCCS Foundation "Carlo Besta" Neurological Institute, Milano, Italy; 8 University of Brescia, Brescia, Italy; 9 IRCCS Instituto Centro S. Giovanni di Dio Fatebenefratelli, Brescia, Italy; 10 Centro Regionale di Neurogenetica, Lamezia Terme, Italy; IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy; University of Genova, Genova, Italy; 13 IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy; University of Milan, Ospedale Policlinico, Milan, Italy; IRCCS Centro San Giovanni di Dio, Fatebenefratelli, Brescia, Italy; 16 University of Florence, Florence, Italy; 17 IRCCS Fondazione Instituto Neurologico Carlo Besta, Milano, Italy; 18 IRCCS Fondazione Instituto Neurologico Carlo Besta, Milan, Italy; IRCCS Instituto San Giovanni di Dio Fatebenefratelli, Brecia, Italy. Contact e-mail: mbocchetta@ fatebenefratelli.it

Dear Sir,Most of the rarer causes of chorea have been clarified in thelast decades [1], so that the classic term of ‘‘idiopathicchorea’’ has been critically put into question.A 50-year-old Caucasian woman was referred formarked and progressive generalized chorea. The onset wasabout 1 year before and a depressive syndrome was alsopresent. Past medical and family histories were unre-markable. Slight dysarthria and adiadochokinesia werenoted. Ocular movements were normal. Deep tendonreflexes were diffusely enhanced and plantar response wasin extension bilaterally. Routine serology, ceruloplasmin,tumour markers, HIV serology, onconeural- and auto-antibodies were negative. The anti-streptolysin-O titre wasborderline and careful examination of blood smears failedto demonstrate acanthocytes. A magnetic resonance and a99mTc-ECD SPECT brain scans were not significant. Theneuropsychological assessment evidenced only minorimpairment in selective attention and slight dysexecutivenotes. Genetic testing for Huntigton’s disease (HD, 17/25triplets), DRPLA (150/150), SCA17 (36/37), SCA1 (21/30), SCA2 (23/23), SCA3 (20/22), SCA6 (11/12), SCA7(9/11), and FXTAS (23/23) were negative. Progranulin andPRNP mutations or C9orf72 expansions were absent. Anti-basal ganglia antibodies (ABGA) testing (courtesy ofDr. Giovannoni and Martino, UCL, UK) resulted in a weakpositive binding to pyruvate kinase M1 (60 kDa), while nobinding was shown for both gamma-neuron specific eno-lase, and aldolase C.Since neuroleptics were ineffective, a trial with high-dose IV steroids was attempted, with no immediateimprovement (HD Functional Capacities score: 2/13, stageIV; Folstein Chorea Scale score: 37/57). Three monthslater, only minor changes were noted (HDFCS: 3/13, stageIV; FCS: 27/57). The patient further deteriorated present-ing diffuse spasticity and dystonia. Due to worseningdysphagia the patient was referred for PEG positioning, butshe anyhow died of aspiration pneumonia about 4 yearssince the onset of chorea.The neuropathological study was carried out on forma-lin-fixed sections stained with hematoxylin-eosin, cresylviolet for Nissl substance, Heidenhain-Woelcke for myelin,thioflavine S for amyloid, and silver salts for neurofibrillarychanges (Bodian’s method). Immunohistochemistry wasperformed with antibodies to beta-amyloid (4G8), alpha-synuclein (4D6), ubiquitin (polyclonal), phosphorylated tau(AT8), prion protein (3F4), GFAP (polyclonal), CD3/43,leucocytes common antigen CD45, and MBP (polyclonal).Histopathological examination revealed mild neuronal lossin the cerebral cortex and basal ganglia. Reactive astrogl-iosis and microglia activation were marked in the thalamus,caudate, putamen and substantia nigra (SN) and morepronounced in the brainstem and cerebellum. Slight peri-vascular lymphocytic infiltration was present in the hemi-spheric and cerebellar white matter as well as in thestriatum, thalamus and brainstem. Extracellular deposits orintracellular inclusions were absent but esinophilic, ubiq-uitin-positive inclusions suggestive of Marinesco bodieswere found only in the SN. No clear retrospective corre-lation with imaging data was possible.

We detail the phenotype of a novel form of neuronal ceroid lipofuscinosis due to a homozygous progranulin gene mutation (c.813_816del; CLN11 MIM #614706). The symptoms appeared in two young adult siblings, and included progressive retinopathy, recurrent generalized seizures, moderate ataxia, and subtle cognitive dysfunction. Long-lasting episodes of palinopsia were a recurring symptom and associated with polyphasic visual-evoked potential waveform that suggested hyperexcitability of the occipital cortex. Electroencephalography showed rare spike-wave paroxysms, and magnetic resonance imaging revealed selective cerebellar atrophy. Skin biopsy revealed fingerprint storage and the absence of progranulin protein. Electron microscopy of peripheral blood leukocytes showed fingerprint profiles in 1/100 lymphocytes. These findings define a novel phenotype and provide clues for better understanding of progranulin function. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.