Tau filaments with the chronic traumatic encephalopathy fold in a case of vacuolar tauopathy with VCP mutation D395G.

Dominantly inherited mutation D395G in the gene encoding valosin-containing protein causes vacuolar tauopathy, a type of behavioural-variant frontotemporal dementia, with marked vacuolation and abundant filamentous tau inclusions made of all six brain isoforms. Here we report that tau inclusions were concentrated in layers II/III of the frontotemporal cortex in a case of vacuolar tauopathy. By electron cryomicroscopy, tau filaments had the chronic traumatic encephalopathy (CTE) fold. Tau inclusions of vacuolar tauopathy share this cortical location and the tau fold with CTE, subacute sclerosing panencephalitis and amyotrophic lateral sclerosis/parkinsonism-dementia complex, which are believed to be environmentally induced. Vacuolar tauopathy is the first inherited disease with the CTE tau fold.

Application of Suggestive Biomarkers in Dementia With Lewy Bodies With Masking of Typical Clinical Symptoms by Alzheimer Disease-type Pathology.

Dementia with Lewy bodies (DLB) is strongly associated with Alzheimer disease (AD)-type pathology and tends to mask the core clinical features of DLB. Therefore, there may be cases of undiagnosed DLB without suggestive biomarkers of DLB. We describe the case of a 63-year-old woman who was initially diagnosed as having AD and later diagnosed with DLB based on suggestive biomarkers of DLB. In this case, transient sleep talking with physical movements for several days led to the assessment of suggestive biomarkers for DLB in the absence of the core clinical features of DLB. For clinicians, diagnosing DLB in patients with AD-type pathology is challenging. However, the application of biomarkers suggestive of DLB to all patients with dementia is not realistic. To overcome the difficulties of clinical diagnosis of DLB, further research is needed regarding strategies for the application of suggestive biomarkers for DLB to appropriately diagnose DLB.

Clinicopathological diversity of semantic dementia: Comparisons of patients with early-onset versus late-onset, left-sided versus right-sided temporal atrophy, and TDP-type A versus type C pathology.

Semantic dementia (SD) is a unique clinicopathological entity associated with TDP-type C pathology. We present four cases of SD that illustrate the clinicopathological diversity of TDP-43 pathology, including early-onset cases of TDP-type C with corticospinal tract (CST) and motor neuron pathology and late-onset cases of TDP-type A with combined pathology. Case 1 was a 62-year-old man with semantic variant of primary progressive aphasia (svPPA) with left-predominant temporal atrophy and TDP-type C pathology with low Alzheimer's disease neuropathologic changes (ADNC). Case 2 was a 63-year-old woman with right-predominant temporal atrophy and TDP-type C pathology who had prosopagnosia and personality changes. Phosphorylated(p)-TDP-43-positive long dystrophic neurites (DNs) were observed throughout the cerebral cortex; they were more abundant in the relatively spared cortices and less so in the severely degenerated cortices. We observed CST degeneration with TDP-43 pathology in the upper and lower motor neurons, without apparent motor symptoms, in SD with TDP-type C pathology. Case 3 was a 76-year-old man who had svPPA and personality changes, with left-predominant temporal atrophy and TDP-type A pathology with high ADNC and argyrophilic grain (AG) stage 3. Case 4 was an 82-year-old man who had prosopagnosia and later developed symptoms of dementia with Lewy bodies (DLB) with right-predominant temporal atrophy and TDP-type A pathology with high ADNC, DLB of diffuse neocortical type, and AG stage 3. The distribution of p-TDP-43-positive NCIs and short DNs was localized in the anterior and inferior temporal cortices. An inverse relationship between the extent of TDP pathology and neuronal loss was also observed in SD with TDP-type A pathology. In contrast, the extent of AD, DLB, and AG pathology was greater in severely degenerated regions. CST degeneration was either absent or very mild in SD with TDP-type A. Understanding the clinicopathological diversity of SD will help improve its diagnosis and treatment.

Initial symptoms of early-onset dementia in Japan: nationwide survey.

AIM: The aim of this study was to investigate initial symptoms of early-onset dementia (EOD) for each dementia subtype. METHOD: We conducted a nationwide, population-based EOD prevalence study in Japan. Data were collected through service providers for people with EOD. Initial symptoms were assessed in six domains: loss of memory, difficulty in word generation, irritability, loss of motivation, increased mistakes in the workplace or domestically, and unusual behaviours or attitudes other than those listed. RESULTS: Participants were 770 people with EOD. Characteristic initial symptoms were observed for each EOD subtype. Loss of memory was more common in early-onset Alzheimer's disease (75.7%, P < 0.001), difficulty in word generation was more common in early-onset vascular dementia (41.3%, P < 0.001), and loss of motivation, increased mistakes in the workplace or domestically, and unusual behaviours or attitudes other than those listed were more common in early-onset frontotemporal dementia (34.9%, P < 0.001; 49.4%, P < 0.001; 34.9%, P < 0.001, respectively). In addition, we observed gender differences whereby loss of memory was more common among women and irritability was more common among men. More than half of the participants were employed at symptom onset, and 57.2% of those who were employed at the onset had initial symptoms of increased mistakes in the workplace or domestically. CONCLUSION: This report reveals differences in the frequency of initial symptoms by EOD subtype. The results contribute to increasing public awareness of the initial symptoms of EOD, which will facilitate early diagnosis and social support.

Valosin-containing protein Asp395Gly mutation in a patient with frontotemporal dementia: a case report.

BACKGROUND: Variants in the valosin-containing protein (VCP) gene were identified as one of the causes for inclusion body myopathy associated with Paget disease of the bone and frontotemporal dementia (FTD). Previously identified pathogenic variants in VCP are associated with frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP) pathologically, but p.Asp395Gly VCP was recently reported to cause familial FTD with tauopathy characterized by neurofibrillary tau tangles (NFT) and not FTLD-TDP. We describe the clinical and genetic findings of a patient with p.Asp395Gly valosin-containing protein (VCP), who was diagnosed with FTD without a family history and in the absence of muscle or bone disease comorbidity. CASE PRESENTATION: The patient was a 62-year-old man, who developed atypical depression at the age of 37 years. Subsequently, he presented with self-centered behavior at the age of 45 years. The self-centered behavior intensified from around the age of 50 years, which was accompanied by the development of executive dysfunction; therefore, he visited our hospital at 52 years of age. Magnetic resonance imaging revealed bilateral frontal lobe atrophy. Brain perfusion single-photon emission computed tomography revealed bilateral frontal lobe hypoperfusion. The patient fulfilled the diagnostic criteria for behavioral variant of FTD. Ten years after the diagnosis, computed tomography of the trunk and limbs, muscle biopsy, and bone scintigraphy revealed the absence of concomitant muscle and bone disease. The concentrations of cerebrospinal fluid (CSF) total tau and phosphorylated tau proteins were 389 pg/mL and 53.2 pg/mL (cut-off: 50 pg/mL), respectively. Genetic analyses were performed using the whole-exome and Sanger sequencing methods. We identified p.Asp395Gly VCP in this patient with pure FTD. CONCLUSIONS: p.Asp395Gly VCP was identified in a patient with likely sporadic FTD without concomitant muscle and bone disease. The CSF analysis suggested that our patient may have FTD due to NFT accumulation similar to the familial FTD patients with p.Asp395Gly VCP recently reported. Our findings suggest that a genetic search for the pathogenic variants of VCP should be considered not only for familial FTD, but also for patients with sporadic FTD, even in the absence of comorbid muscle or bone disease.

Clinicopathological heterogeneity of Alzheimer's disease with pure Alzheimer's disease pathology: Cases associated with dementia with Lewy bodies, very early-onset dementia, and primary progressive aphasia.

We report four cases depicting the heterogeneity of Alzheimer's disease (AD) associated with pure AD pathology. Case 1 was a 77-year-old man with a false positive diagnosis of dementia with Lewy bodies with reduced dopamine transporter uptake activity of the striatum but no Lewy body pathology. There were tau deposits in the large neurons in the putamen, which may be related to the development of parkinsonism. Case 2 was an AD patient in his early 30s who presented with a psychotic episode and a cognitive decline, and later developed myoclonus and seizures. He demonstrated considerable amyloid-beta deposits in the cerebral cortex, including cotton wool plaques, basal ganglia, and cerebellum. Tau deposits were also abundant in the cerebral neocortex, hippocampus, basal ganglia, and brain stem. Case 3 was a 60-year-old woman who exhibited typical symptoms characteristic of the logopenic variant of primary progressive aphasia (lvPPA). Case 4 was a 68-year-old man who exhibited the semantic variant of primary progressive aphasia (svPPA) plus repetition impairment, a rare case associated with AD pathology. In addition to tau pathology, astrocytic pathology was prominent in the white matter and cortical layers of the left temporoparietal cortices. While the main AD lesion in case 4 was evaluated by tau accumulation and astrogliosis in the left temporal lobe, that in case 3 in was evaluated by the same points in the left parietal lobe. Within the spectrum of lvPPA, case 4 may be regarded as a temporal variant of lvPPA presenting svPPA. The pathology of PPA associated with AD may have broader clinical manifestations than that in previously described cases. Case 4 also showed pathological features characteristic of cerebral amyloid angiopathy throughout the cerebral cortex. The distribution of tau and astrocytic pathologies in the cerebral cortex, basal ganglia, brain stem, and cerebellum may explain the various symptoms of atypical pure AD patients.

Comparison of the decreases in regional cerebral blood flow in the posterior cingulate cortex, precuneus, and parietal lobe between suspected non-Alzheimer's disease pathophysiology and Alzheimer's disease.

BACKGROUND: Suspected non-Alzheimer's disease pathophysiology (SNAP) shows Alzheimer's disease (AD)-like neurodegeneration; however, amyloid ß, which is a biological marker in AD, remains within normal levels. Since the effectiveness of anti-dementia drugs for AD on SNAP is unknown, it is important to distinguish between patients with SNAP and AD. We aimed to compare decreases in regional cerebral blood flow (rCBF) of the posterior cingulate cortex (PCC), precuneus, and parietal lobe critical to AD between SNAP and AD groups using the easy Z-score imaging system in single-photon emission computed tomography (eZIS-SPECT). METHODS: We retrospectively analysed eZIS-SPECT data of 13 SNAP and 24 AD patients. The three indicators (severity, extent, and ratio) that distinguished AD patients from healthy controls in previous studies were automatically calculated and were compared between the SNAP and AD groups. Receiver operating characteristic curve analysis and the area under the curve (AUC) were used to evaluate the diagnostic performance of the three indicators of eZIS in discriminating between the two groups. RESULTS: The mean values of severity, extent, and ratio were significantly lower in the SNAP group than in the AD group (P = 0.024, P = 0.044, and P = 0.045, respectively). The AUC values for severity, extent, and ratio were 0.668, 0.683, and 0.692, respectively. CONCLUSIONS: The present study suggests that SNAP shows milder reduction of rCBF in the PCC, precuneus, and parietal lobe as compared to AD. However, it may be difficult to distinguish between SNAP and AD with the degrees of decrease in rCBF in these regions.

Effects of the Great East Japan Earthquake and the Fukushima Daiichi Nuclear Power Plant accident on behavioural and psychological symptoms of dementia among patients.

BACKGROUND: The Great East Japan Earthquake triggered accidents at the Fukushima Daiichi Nuclear Power Plant, becoming the first complex disaster that included both a natural and a nuclear power disaster. This study examines how complex disasters affect patients with dementia. METHODS: Participants included the 331 people diagnosed with dementia out of the 2482 new patients (between January 2008 and December 2015) at a psychiatric hospital located in the indoor sheltering zones nearby mandatory evacuation zones. Medical records were retrospectively examined to identify the number of new patients with dementia, the severity, their chief complaints, and the behavioural and psychological symptoms of dementia (BPSD) types. BPSD were classified into the hyperactive BPSD group and the hypoactive BPSD group. The hyperactive BPSD group was further subdivided into the hyperactivity-impulsivity-irritability-disinhibition-aggression-agitation group, which exhibited agitation, disinhibition, and irritability, and the psychosis group, which exhibited delusions and hallucinations. The hypoactive BPSD group included depression, inactivity, apathy, and anxiety. Results were divided into the period before the complex disaster (2008-2010) and after (2012-2015) and were compared. In addition, the post-complex-disaster period was subdivided into the early phase (2012-2013) and the late phase (2014-2015). RESULTS: The proportion of new patients with dementia increased significantly after the disaster. Although there was no change in patients' age and the disease's severity, the proportion of patients whose chief complaint was BPSD increased significantly after the disaster. Furthermore, there was a significant increase in the hyperactivity-impulsivity-irritability-disinhibition-aggression-agitation group in the early post-complex-disaster phase and a significant increase in the psychosis group in the late post-complex-disaster phase. CONCLUSION: This complex disaster caused increased consultations from patients with dementia and increased BPSD. Additionally, it increased participants' symptoms of agitation and irritability in the early post-complex-disaster phase and the proportion of hallucinations and delusions in the late post-complex-disaster phase.

Prevalence and subtype distribution of early-onset dementia in Japan.

AIM: People living with early-onset dementia (EOD) have specific social needs. Epidemiological studies are needed to obtain current information and provide appropriate service planning. This study aimed to clarify the current prevalence and subtype distribution of EOD, as well as the services frequently used by individuals with EOD. METHODS: A multisite, population-based, two-step study was conducted. Questionnaires were sent to 26 416 candidate facilities in 12 areas with a target population of 11 630 322 to inquire whether any individuals with EOD had sought services or stayed during the last 12 months (step 1). When "yes" responses were received, additional questionnaires were sent to the facilities both to complete and to distribute to the target individuals with EOD to obtain more detailed information, including the dementia subtype (step 2). RESULTS: In step 1, valid responses were obtained from 16 848 facilities (63.8%), and 4077 cases were identified. In step 2, detailed information was obtained for 1614 cases (39.6%) from the facilities and 530 cases (13.0%) from the individuals. The national EOD prevalence rate was estimated to be 50.9/100 000 population at risk (95% confidence interval: 43.9-57.9; age range, 18-64 years). The number of individuals with EOD was estimated to be 35 700 as of 2018. Alzheimer-type dementia (52.6%) was the most frequent subtype, followed by vascular dementia (17.1%), frontotemporal dementia (9.4%), dementia due to traumatic brain injury (4.2%), dementia with Lewy bodies/Parkinson's disease dementia (4.1%), and dementia due to alcohol-related disorders (2.8%). Individuals with EOD were most frequently identified at medical centers for dementia. CONCLUSION: The prevalence rate estimated in this study was comparable to those in previous studies in Japan. However, the subtype distribution differed, with Alzheimer-type dementia being the most prominent. Based on the case identification frequencies, medical centers for dementia are expected to continue to function as the primary special health service by providing quality diagnosis and post-diagnostic support for individuals with EOD.

Globular glial tauopathy Type II: Clinicopathological study of two autopsy cases.

Globular glial tauopathies (GGTs) are four-repeat tauopathies characterized by the presence of two types of tau-positive globular glial inclusions (GGIs): globular oligodendrocytic and astrocytic inclusions (GOIs and GAIs). GGTs are classified into three different neuropathological subtypes: Types I, II and III. We report two patients with GGTs - a 76-year-old woman and a 70-year-old man - in whom the disease duration was 5 and 6 years, respectively. Both patients exhibited upper and lower motor neuron signs and involuntary movements, and the latter also had dementia with frontotemporal cerebral atrophy evident on magnetic resonance imaging. Neuropathologically, in both cases, the precentral gyrus was most severely affected, and at the gray-white matter junction there was almost complete loss of Betz cells and occurrence of GOIs and coiled bodies with numerous neuropil threads. Both patients also showed neuronal loss and GGIs (mostly GOIs) in many other central nervous system regions, including the basal ganglia. Apart from the degree of regional severity, the distribution pattern was essentially the same in both cases. However, GAIs were not conspicuous in any of the affected regions. Based on the morphology and distribution pattern of the GGIs, we diagnosed the present two patients as having GGT Type II. Electron microscopic and biochemical findings in the former were consistent with the diagnosis. Type II cases are reported to be characterized by pyramidal features reflecting predominant motor cortex and corticospinal tract degeneration. The present observations suggest that a variety of neurological features, including dementia, can occur in GGT Type II reflecting widespread degeneration beyond the motor neuron system.

Suicide as a result of stereotypic behaviour in a case with semantic dementia.

Semantic dementia (SD) is characterized by semantic aphasia and prosopagnosia, but it may also include behavioural disturbances such as stereotypic behaviour. We report the case of a 50-year-old man with SD accompanied by stereotypic behaviour who committed suicide despite not being in a depressive state. He initially had major depressive disorder accompanied by suicide attempts, but he gradually showed remarkable impairment in single-word semantic comprehension, naming memory, and facial recognition memory. After the diagnosis of SD, his suicidal behaviour by hanging with a cord became stereotypic and lacked seriousness. He repeatedly attempted to hang himself and finally completed suicide. The present report suggests that the risk for suicide in SD is increased not only by the presence of a depressive state, but also by stereotypic behaviour related to suicide attempts before the onset of the disorder.

[18F]THK-5351 PET imaging in early-stage semantic variant primary progressive aphasia: a report of two cases and a literature review.

BACKGROUND: Semantic variant primary progressive aphasia (svPPA) is a subtype of primary progressive aphasia characterized by two-way anomia and disturbance in word comprehension, with focal atrophy in the left temporal lobe. [18F]THK-5351 was originally developed to trace tau protein. However, it has recently been suggested that [18F]THK-5351 binds to monoamine oxidase B in astrocytes, which reflects gliosis. Herein, the authors present two cases involving patients with early-stage svPPA who underwent [18F]THK-5351 positron emission tomography (PET) imaging, and examined whether [18F]THK-5351 PET imaging is more sensitive to neurodegenerative lesions than conventional imaging modalities such as magnetic resonance imaging (MRI) and cerebral blood flow (CBF)-single photon emission computed tomography (SPECT). CASE PRESENTATION: Two patients, 64- and 79-year-old men, without notable medical or family history, exhibited disturbances in word comprehension and mild anomia with fluent speech and spared repetition. In both cases, surface dyslexia was observed but prosopagnosia was absent. Although mild depression was detected in 1 of the 2 patients, no behavioral disorders were present in either case. In both cases, MRI revealed atrophy in the anterior and inferior portions of the left temporal lobe. Technetium-99-ethyl cysteinate dimer ([99mTc]ECD) SPECT revealed hypoperfusion in the left temporal lobe. Alzheimer's disease was ruled out by [11C]Pittsburgh Compound-B (PiB) PET scan. Both patients fulfilled the diagnostic criteria for svPPA. Because of mild language deficits and lack of right temporal atrophy, they were considered to be at an early stage of the disease. In both cases, [18F]THK-5351 retention was observed in bilateral temporal lobes, predominantly on the left side. Comparison of different imaging modalities suggested that [18F]THK-5351 was more sensitive in detecting neurodegenerative change in the right temporal lobe than MRI and [99mTc]ECD SPECT. CONCLUSIONS: [18F]THK-5351 retention was clearly demonstrated at an early stage of svPPA. Results of the present study suggest that [18F]THK-5351 PET imaging may facilitate very early diagnosis of the disease.

Typical and atypical appearance of early-onset Alzheimer's disease: A clinical, neuroimaging and neuropathological study.

The International Working Group (IWG) has classified Alzheimer's disease (AD) as two different types, the typical form and the atypical form, but clinicopathological studies of atypical AD are limited. Because atypical AD cases usually present with early-onset dementia, we investigated 12 patients with early-onset AD, including two patients with typical AD and 10 patients with atypical AD. Of these patients, six had the posterior variant, three had the frontal variant and one had the logopenic variant mixed with semantic dementia. We reported MRI, single-photon emission CT and neuropathological findings in six representative cases. We also described a "left temporal variant" of AD presenting with transcortical cortical sensory aphasia, which has not been reported previously and is another subtype of the posterior variant of AD. We found a significant correlation between regional cerebral blood flow and counts of NFTs in the cerebral cortices. An atypical presentation with focal neuropsychological symptoms roughly correlated with the density of NFTs in the cerebral cortex and more directly related to spongiform changes in the superficial layers of these areas. In contrast, the distribution of amyloid depositions was diffuse and did not necessarily correlate with focal neuropsychological symptoms. Braak staging or ABC score is not necessarily appropriate to evaluate atypical AD, and instead, spongiform changes in addition to tau pathology in the association cortices better explain the diversity of atypical AD. Interestingly, another patient with a posterior variant of AD had a novel type of atypical plaque, which we referred to as "lucent plaque". They were recognizable with HE staining in the circumference and dystrophic neurites were abundant with Gallyas-Braak staining. These plaques demonstrated intense immunoreactivity to both tau AT-8 and amyloid ß (Aß), suggesting a peculiar coexistence pattern of amyloid and tau in these plaques. Clinicopathological studies of atypical AD will provide a new understanding of the pathophysiology of AD.