Structural aging of human neurons is opposite of the changes in schizophrenia.

Human mentality develops with age and is altered in psychiatric disorders, though their underlying mechanism is unknown. In this study, we analyzed nanometer-scale three-dimensional structures of brain tissues of the anterior cingulate cortex from eight schizophrenia and eight control cases. The distribution profiles of neurite curvature of the control cases showed a trend depending on their age, resulting in an age-correlated decrease in the standard deviation of neurite curvature (Pearson's r = -0.80, p = 0.018). In contrast to the control cases, the schizophrenia cases deviate upward from this correlation, exhibiting a 60% higher neurite curvature compared with the controls (p = 7.8 × 10-4). The neurite curvature also showed a correlation with a hallucination score (Pearson's r = 0.80, p = 1.8 × 10-4), indicating that neurite structure is relevant to brain function. This report is based on our 3D analysis of human brain tissues over a decade and is unprecedented in terms of the number of cases. We suggest that neurite curvature plays a pivotal role in brain aging and can be used as a hallmark to exploit a novel treatment of schizophrenia.

Possible association of limbic tau pathology with psychosis or behavioral disturbances: Studies of two autopsied psychiatric patients.

Tauopathies, including Alzheimer's disease and primary age-related tauopathy (PART), present heterogeneous clinico-pathological phenotypes that include dementia, aphasia, motor neuron diseases, and psychiatric symptoms. PART is neuropathologically characterized by the presence of neurofibrillary tangles in limbic regions without significant Aß deposition, but its clinical features have not yet been fully established. Here, we present two patients with distinct psychosis and behavioral symptoms. At autopsy, these patients showed tau pathologies that could not be classified as typical PART, although PART-like neurofibrillary tangles were present in limbic regions. Clinically, both patients were admitted to mental hospitals due to severe delusions or other neuropsychiatric/behavioral symptoms. The first case presented with hallucination, delusion, and apathy at age 70, and died of pancreatic cancer at age 75. He had neuronal cytoplasmic inclusions with selective accumulation of 3Rtau in the striatum and thorn-shaped astrocytes in the amygdala. The second case, who presented with abnormal behaviors such as wandering, agitation and disinhibition, exhibited limbic neurodegeneration with massive 4R tau-positive oligodendroglial inclusions in the medial temporal white matter. His age at onset was 73, and the duration of disease was 15 years. These findings support the notion that distinct limbic tau pathology with concomitant degeneration of the related neural circuits might induce specific psychosis and behavioral symptoms. This underlines the importance of neuropathological evaluation for both clinical education and practice in the fields of neuropathology and neuropsychiatry.

Neuropathological investigation of patients with prolonged anorexia nervosa.

OBJECTIVES: Recent neuroimaging studies have indicated that the mesolimbic pathway, known to work as reward neuronal circuitry, regulates cognitive-behavioral flexibility in prolonged anorexia nervosa (AN). Although AN is associated with the highest mortality rate among psychiatric disorders, there have been few neuropathological studies on this topic. This study aims to identify alterations of the reward circuitry regions, especially in the nucleus accumbens (NAcc), using AN brain tissues. METHODS: The neuronal networks in AN cases and controls were examined by immunohistochemistry directed at tyrosine hydroxylase (TH; dopaminergic neuron marker) and glial fibrillary acidic protein (GFAP; astrocyte marker). We also immunochemically analyzed frozen samples presenting astrogliosis, especially in the NAcc and striatum. RESULTS: Histologically, neuronal deformation with cytoplasmic shrinkage was seen in reward-related brain regions, such as the orbitofrontal cortex/anterior cingulate cortex. The NAcc showed massive GFAP-positive astrocytes and dot-like protrusions of astrocytes in the shell compartment. In the shell, TH and GFAP immunoreactivities revealed prominent astrogliosis within striosomes, which receive projection from the ventral tegmental area (VTA). The numbers of GFAP-positive astrocytes in the NAcc (P = 0.0079) and VTA (P = 0.0025) of AN cases were significantly higher than those of controls. Strongly immunoreactive 18 to 25 kDa bands, which might represent degradation products, were detected only in the NAcc of AN cases. Clinically, all cases presented cognitive rigidity, which might reflect a deficit of the reward pathway. CONCLUSION: Our findings suggest impaired dopaminergic innervation between the NAcc and VTA in AN. Functional dysconnectivity in the reward-related network might induce neuropsychiatric symptoms associated with AN.

AKR1A1 Variant Associated With Schizophrenia Causes Exon Skipping, Leading to Loss of Enzymatic Activity.

Schizophrenia is a heterogeneous psychiatric disorder characterized by positive symptoms such as hallucinations and delusions, negative symptoms such as anhedonia and flat affect, and cognitive impairment. Recently, glucuronate (GlucA) levels were reported to be significantly higher in serum of patients with schizophrenia than those in healthy controls. The accumulation of GlucA is known to be related to treatment-resistant schizophrenia, since GlucA is known to promote drug excretion by forming conjugates with drugs. However, the cause of GlucA accumulation remains unclear. Aldo-keto reductase family one member A1 (AKR1A1) is an oxidoreductase that catalyzes the reduction of GlucA. Genetic loss of AKR1A1 function is known to result in the accumulation of GlucA in rodents. Here, we aimed to explore genetic defects in AKR1A1 in patients with schizophrenia, which may result in the accumulation of GlucA. We identified 28 variants of AKR1A1 in patients with schizophrenia and control subjects. In particular, we identified a silent c.753G > A (rs745484618, p. Arg251Arg) variant located at the first position of exon 8 to be associated with schizophrenia. Using a minigene assay, we found that the c.753G > A variant induced exon 8 skipping in AKR1A1, resulting in a frameshift mutation, which in turn led to truncation of the AKR1A1 protein. Using the recombinant protein, we demonstrated that the truncated AKR1A1 completely lost its activity. Furthermore, we showed that AKR1A1 mRNA expression in the whole blood cells of individuals with the c.753G > A variant tended to be lower than that in those without the variants, leading to lower AKR activity. Our findings suggest that AKR1A1 carrying the c.753G > A variant induces exon skipping, leading to a loss of gene expression and enzymatic activity. Thus, GlucA patients with schizophrenia with the c.753G > A variant may show higher GlucA levels, leading to drug-resistant schizophrenia, since drug excretion by GlucA is enhanced.

Brain capillary structures of schizophrenia cases and controls show a correlation with their neuron structures.

Brain blood vessels constitute a micrometer-scale vascular network responsible for supply of oxygen and nutrition. In this study, we analyzed cerebral tissues of the anterior cingulate cortex and superior temporal gyrus of schizophrenia cases and age/gender-matched controls by using synchrotron radiation microtomography or micro-CT in order to examine the three-dimensional structure of cerebral vessels. Over 1 m of cerebral blood vessels was traced to build Cartesian-coordinate models, which were then used for calculating structural parameters including the diameter and curvature of the vessels. The distribution of vessel outer diameters showed a peak at 7-9 µm, corresponding to the diameter of the capillaries. Mean curvatures of the capillary vessels showed a significant correlation to the mean curvatures of neurites, while the mean capillary diameter was almost constant, independent of the cases. Our previous studies indicated that the neurites of schizophrenia cases are thin and tortuous compared to controls. The curved capillaries with a constant diameter should occupy a nearly constant volume, while neurons suffering from neurite thinning should have reduced volumes, resulting in a volumetric imbalance between the neurons and the vessels. We suggest that the observed structural correlation between neurons and blood vessels is related to neurovascular abnormalities in schizophrenia.

Advanced glycation end products and cognitive impairment in schizophrenia.

Advanced glycation end products play a key role in the pathophysiology of schizophrenia. Cognitive impairment is one of the central features of schizophrenia; however, the association between advanced glycation end products and cognitive impairment remains unknown. This study investigated whether advanced glycation end products affect the cognitive domain in patients with schizophrenia. A total of 58 patients with chronic schizophrenia were included in this cross-sectional study. Plasma advanced glycation end products were measured using high-performance liquid chromatography (HPLC). Neuropsychological and cognitive functions were assessed using the Wechsler Adult Intelligence Scale, Third Version, and the Wisconsin Card Sorting Test Keio-FS version. Multiple regression analysis adjusted for age, sex, body mass index, educational years, daily dose of antipsychotics, and psychotic symptoms revealed that processing speed was significantly associated with plasma pentosidine, a representative advanced glycation end product (standardized ß = -0.425; p = 0.009). Processing speed is the cognitive domain affected by advanced glycation end products. Considering preceding evidence that impaired processing speed is related to poor functional outcome, interventions targeted at reducing advanced glycation end products may contribute to promoting recovery of patients with schizophrenia as well as cognitive function improvement.

Structural diverseness of neurons between brain areas and between cases.

The cerebral cortex is composed of multiple cortical areas that exert a wide variety of brain functions. Although human brain neurons are genetically and areally mosaic, the three-dimensional structural differences between neurons in different brain areas or between the neurons of different individuals have not been delineated. Here we report a nanometer-scale geometric analysis of brain tissues of the superior temporal gyrus of schizophrenia and control cases. The results of the analysis and a comparison with results for the anterior cingulate cortex indicated that (1) neuron structures are significantly dissimilar between brain areas and that (2) the dissimilarity varies from case to case. The structural diverseness was mainly observed in terms of the neurite curvature that inversely correlates with the diameters of the neurites and spines. The analysis also revealed the geometric differences between the neurons of the schizophrenia and control cases. The schizophrenia cases showed a thin and tortuous neuronal network compared with the controls, suggesting that the neuron structure is associated with the disorder. The area dependency of the neuron structure and its diverseness between individuals should represent the individuality of brain functions.

Case report of anorexia nervosa showing periventricular gliosis at autopsy.

Anorexia nervosa (AN) is a serious eating disorder characterized by self-starvation and extreme weight loss. It has the highest mortality rate among all psychiatric disorders. Recent research indicates that malnutrition in AN patients induces various kinds of functional brain damage, but the pathophysiology of AN remains unclear. We report here the neuropathological findings of a 31-year-old Japanese woman. At age 24, she had a fear of gaining weight and reduced her dietary intake; she had extremely low body weight associated with overeating then self-induced vomiting. She was clinically diagnosed as having AN and was admitted to a psychiatric hospital with severe depression and suicidal thoughts. At age 31, she died despite intensive physical care and psychotherapy. Neuropathological examination revealed increased capillary blood vessels and slight fibrillary gliosis in the mammillary bodies, with similarities to Wernicke encephalopathy. The brainstem exhibited the characteristic features of central pontine myelinolysis, characterized by a sharply demarcated region of myelin pallor and relative sparing of axons. Senile changes, including neurofibrillary tangles/senile plaques, were not significant. Severe fibrillary gliosis was prominent around periventricular regions, including the caudate nucleus and nucleus accumbens, which are associated with cognition, emotion, and emotional behaviors via the dopaminergic pathways. These findings indicate that prolonged malnutrition in AN patients may induce brain damage, leading to dysfunction of the reward-related dopaminergic pathways. Furthermore, they represent the first pathological evidence that dysfunction of the cortico-limbic-striatal circuitry is involved in the pathophysiology of psychiatric symptoms in AN patients.

Distinct early symptoms in neuropathologically proven frontotemporal lobar degeneration.

OBJECTIVES: Frontotemporal lobar degeneration (FTLD) is associated with accumulation of neurodegeneration-related protein, such as tau, TAR DNA-binding protein 43 (TDP-43), or fused in sarcoma protein (FUS). There have been very few systematic studies of the early symptoms of clinical phenotypes: behavioral variant frontotemporal dementia (bvFTD), semantic variant primary progressive aphasia (svPPA). Clinical subtypes and the patterns of atrophy reflect protein-accumulation patterns, but the relationship between early symptoms and pathological findings remains unclear. METHODS: We retrospectively investigated the clinical records and examined the neuropathology of 39 bvFTD and 6 svPPA patients to identify symptoms appearing within 2 years of the first clinically apparent changes. RESULTS: The bvFTD group consisted of 13 FTLD-tau, 18 FTLD-TDP, and 8 FTLD-FUS, and the svPPA group consisted of 6 FTLD-TDP. Age at death is significantly younger in FTLD-FUS (52.8 ± 12.6; P = 0.0104 < 0.05). Over 50% of bvFTD patients show apathy or inertia, and distinct language features appear early in svPPA. Interestingly, bvFTD and svPPA frequently present additional symptoms, not included in the diagnostic criteria, such as physical signs, reticence, dazed condition, and delusions. Stereotyped behaviors, hyperorality and dietary changes are prominent in FTLD-FUS, while linguistic deficits are greater in FTLD-TDP. CONCLUSIONS: Specific symptoms tend to appear in the early stage of FTLD in each pathological background. They might reflect the morphological features and pathological progression, and should be helpful in the stratification of patients for future therapeutic trials based on the proteinopathies.

Intracellular dynamics of Ataxin-2 in the human brains with normal and frontotemporal lobar degeneration with TDP-43 inclusions.

TAR DNA-binding protein of 43 kDa (TDP-43) is a major component of intracellular aggregates formed in brains of the patients with frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS), which are correctively referred to as TDP-43 proteinopathies. A link between Ataxin-2 (ATXN2) and TDP-43 proteinopathies was established when intermediate CAG repeat expansions of ATXN2 gene were found to be associated with ALS and it was shown that ATXN2 modifies TDP-43 toxicity. Although ATXN2's contribution to TDP-43 proteinopathies has been mostly studied in ALS, recent studies have shown that intermediate repeat expansions of ATXN2 also influence the phenotype of FTLD by an unknown mechanism. To address this issue, we immunohistochemically and biochemically analyzed the intracellular dynamics of ATXN2 in brains of normal controls and FTLD-TDP cases. The immunohistochemical studies revealed that ATXN2 localized in the neuronal cytoplasm and proximal dendrites, and expressed widely and uniformly in normal human brains. A semi-quantitative immunofluorescent analysis of normal brains revealed that the cytoplasmic ATXN2 strongly associates with ribosomal protein S6 and poly-A binding protein 1 and partially overlaps with the endoplasmic reticulum marker Calnexin, suggesting a major role of ATXN2 in protein synthesis. The results of immunohistochemical and biochemical analyses of brains from FTLD-TDP cases showed the colocalization of ATXN2 and phosphorylated TDP-43 in the dystrophic neurites and the neuronal cytoplasmic inclusions in the hippocampal region, and a significant reduction of ATXN2 protein compared to controls. These results suggest that ATXN2 is involved in the pathological process of FTLD-TDP. It remains to be clarified whether reduced ATXN2 expression induces neurodegeneration by impairing protein synthesis or plays a neuroprotective role by attenuating the toxicity of TDP-43 aggregates in FTLD-TDP and other TDP-43 proteinopathies.

Epigenome-wide association study of narcolepsy-affected lateral hypothalamic brains, and overlapping DNA methylation profiles between narcolepsy and multiple sclerosis.

Narcolepsy with cataplexy is a sleep disorder caused by a deficiency in hypocretin neurons in the lateral hypothalamus (LH). Here we performed an epigenome-wide association study (EWAS) of DNA methylation for narcolepsy and replication analyses using DNA samples extracted from two brain regions: LH (Cases: N = 4; Controls: N = 4) and temporal cortex (Cases: N = 7; Controls: N = 7). Seventy-seven differentially methylated regions (DMRs) were identified in the LH analysis, with the top association of a DMR in the myelin basic protein (MBP) region. Only five DMRs were detected in the temporal cortex analysis. Genes annotated to LH DMRs were significantly associated with pathways related to fatty acid response or metabolism. Two additional analyses applying the EWAS data were performed: (1) investigation of methylation profiles shared between narcolepsy and other disorders and (2) an integrative analysis of DNA methylation data and a genome-wide association study for narcolepsy. The results of the two approaches, which included significant overlap of methylated positions associated with narcolepsy and multiple sclerosis, indicated that the two diseases may partly share their pathogenesis. In conclusion, DNA methylation in LH where loss of orexin-producing neurons occurs may play a role in the pathophysiology of the disease.

Cutting-edge morphological studies of post-mortem brains of patients with schizophrenia and potential applications of X-ray nanotomography (nano-CT).

Kraepelin expected that the neuropathological hallmark of schizophrenia would be identified when he proposed the concept of dementia praecox 120 years ago. Although a variety of neuropathological findings have been reported since then, a consensus regarding the pathology of schizophrenia has not been established. The discrepancies have mainly been ascribed to limitations in the disease definition of schizophrenia that accompanies etiological heterogeneity and to the incompleteness of the visualization methodology and technology for biochemical analyses. However, macroscopic structural changes in the schizophrenia brain, such as volumetric changes of brain regions, must entail structural changes to cells composing the brain. This paper overviews neuropathology of schizophrenia and also summarizes recent application of synchrotron radiation nanotomography (nano-CT) to schizophrenia brain tissues. Geometric parameters of neurites determined from the 3-D nano-CT images of brain tissues indicated that the curvature of neurites in schizophrenia cases is significantly higher than that of controls. The schizophrenia case with the highest curvature carried a frameshift mutation in the glyoxalase 1 gene and exhibited treatment resistance. Controversies in the neuropathology of schizophrenia are mainly due to the difficulty in reproducing histological findings reported for schizophrenia. Nano-CT visualization using synchrotron radiation and subsequent geometric analysis should shed light on this long-standing question about the neuropathology of schizophrenia.

Tau progression in single severe frontal traumatic brain injury in human brains.

The neuropathological features of chronic traumatic encephalopathy (CTE), caused by repeated traumatic brain injury (TBI), include abnormal accumulations of hyper-phosphorylated tau (p-tau) protein in neurons, neurites and astrocytes, considered to progress via neuronal circuits in brains. Some previous reports suggest that a single severe TBI (sTBI) can also induce CTE and p-tau accumulation, but it is not clear whether the pathology is the same as that of repetitive TBI (rTBI). Since prefrontal leucotomy could be regarded as a model of sTBI, in this study we evaluated two autopsied schizophrenia with this procedure. Histopathologically, gliosis and neuronal loss were found not only in the primary ablated prefrontal region, but also in secondary affected areas, i.e., cingulate gyrus, medial nucleus of the thalamus, and nucleus accumbens, which are connected to prefrontal areas. Accumulation of p-tau was mostly seen in neurons, neurites and glias around small blood vessels in the leucotomized prefrontal region. In addition, secondary regions showed some p-tau-positive neurons/glias, as well as many axonal spheroids. Regions of neuronal/glial p-tau pathology showed immunoreactivity to both 3R/4R tau antibodies. Immunoblot analyses of sarkosyl-insoluble tau from frozen brains showed an AD-type tau banding pattern with strong immunoreactivities. sTBI patients showed limited comorbidities, such as TDP-43, alpha-synuclein or AD pathology, whereas rTBI patients have high frequencies of them. The findings suggest that p-tau in the primary affected lesion might progress to connected regions via neuronal circuits over time, and a single severe axonal injury might lead to CTE pathology different from that caused by rTBI.

Three-dimensional alteration of neurites in schizophrenia.

Psychiatric symptoms of schizophrenia suggest alteration of cerebral neurons. However, the physical basis of the schizophrenia symptoms has not been delineated at the cellular level. Here, we report nanometer-scale three-dimensional analysis of brain tissues of schizophrenia and control cases. Structures of cerebral tissues of the anterior cingulate cortex were visualized with synchrotron radiation nanotomography. Tissue constituents visualized in the three-dimensional images were traced to build Cartesian coordinate models of tissue constituents, such as neurons and blood vessels. The obtained Cartesian coordinates were used for calculating curvature and torsion of neurites in order to analyze their geometry. Results of the geometric analyses indicated that the curvature of neurites is significantly different between schizophrenia and control cases. The mean curvature of distal neurites of the schizophrenia cases was ~1.5 times higher than that of the controls. The schizophrenia case with the highest neurite curvature carried a frame shift mutation in the GLO1 gene, suggesting that oxidative stress due to the GLO1 mutation caused the structural alteration of the neurites. The differences in the neurite curvature result in differences in the spatial trajectory and hence alter neuronal circuits. It has been shown that the anterior cingulate cortex analyzed in this study has emotional and cognitive functions. We suggest that the structural alteration of neurons in the schizophrenia cases should reflect psychiatric symptoms of schizophrenia.

Pathological alterations of chondroitin sulfate moiety in postmortem hippocampus of patients with schizophrenia.

Perineuronal nets comprise chondroitin sulfate moieties and their core proteins, and their neuropathological alterations have been implicated in schizophrenia. To explore the molecular mechanism of the perineuronal net impairments in schizophrenia, we measured the immunoreactivity of chondroitin sulfate moieties, major components of perineuronal nets, in three brain regions (postmortem dorsolateral prefrontal cortex, caudate nucleus, and hippocampus) of schizophrenia patients and control subjects. Immunoblotting for chondroitin 4-sulfate and chondroitin 6-sulfate moieties revealed a significant increase in intensity of a 180 kD band of chondroitin 4-sulfate immunoreactivity in the hippocampus of patients, although we detected no significant alteration in their immunoreactivities with any other molecular sizes or in other brain regions. The levels of immunoreactivity were not correlated with postmortem interval, age, or storage time. We failed to find such an increase in a similar molecular range of the chondroitin 4-sulfate immunoreactivity in the hippocampus of the rats chronically treated with haloperidol. These results suggest that the level alteration of the chondroitin 4-sulfate moiety might contribute to the perineuronal net abnormality found in patients with schizophrenia.

Clinical features of the behavioural variant of frontotemporal dementia that are useful for predicting underlying pathological subtypes of frontotemporal lobar degeneration.

BACKGROUND: The behavioural variant of frontotemporal dementia (bvFTD) is the most common phenotype of frontotemporal lobar degeneration (FTLD). FTLD is divided into three main pathological subtypes: tau-positive FTLD (FTLD-tau), FTLD-TAR DNA-binding protein (TDP), and FTLD-Fused in sarcoma (FUS). At present, it is difficult to predict the underlying pathological subtypes of sporadic bvFTD before a patient's death. METHODS: We retrospectively investigated the clinical features of 34 Japanese patients with sporadic bvFTD, with or without motor neuron disease (MND), who had been pathologically diagnosed with FTLD. We examined whether, and how, the clinical features differed among Pick's disease, FTLD-TDP, and FTLD-FUS patients. RESULTS: Six of the 34 patients developed MND during the course of bvFTD. These six bvFTD-MND patients were all pathologically diagnosed with FTLD-TDP. The other 28 patients were composed of 12 FTLD-tau patients including 11 Pick's disease patients, 8 FTLD-TDP patients, and 8 FTLD-FUS patients. A comparison of the clinical features of the three pathological subtypes of the 33 patients demonstrated that the age at onset was significantly younger in FTLD-FUS patients than in Pick's disease or FTLD-TDP patients. Furthermore, while hyperorality and dietary changes in the early stage of the disease were present in approximately 40% of Pick's disease and FTLD-FUS patients, they were absent in FTLD-TDP patients. CONCLUSION: The comorbidity of MND, a younger age at onset, and hyperorality and dietary changes in the early stage may be useful clinical features for predicting underlying pathological subtypes of sporadic bvFTD. The results of our study should be confirmed by prospective studies employing a larger number of cases.

The neuropathological study of myelin oligodendrocyte glycoprotein in the temporal lobe of schizophrenia patients.

OBJECTIVE: Recent studies based on the neuroimaging analysis, genomic analysis and transcriptome analysis of the postmortem brain suggest that the pathogenesis of schizophrenia is related to myelin-oligodendrocyte abnormalities. However, no serious neuropathological investigation of this protein in the schizophrenic brain has yet been performed. In this study, to confirm the change in neuropathological findings due to the pathogenesis of this disease, we observed the expression of myelin-oligodendrocyte directly in the brain tissue of schizophrenia patients. METHODS: Myelin oligodendrocyte glycoprotein (MOG) was evaluated in the cortex of the superior temporal gyrus (STG) and the hippocampus in 10 schizophrenic and nine age- and sex-matched normal control postmortem brains. RESULTS: The expression of MOG was significantly lower in the middle layer of the neocortex of the STG and stratum lucidum of CA3 in the hippocampus in the long-term schizophrenic brains (patients with ≥30 years of illness duration) than in the age-matched controls. Furthermore, the thickness of MOG-positive fibre-like structures was significantly lower in both regions of the long-term schizophrenic brains than in the age-matched controls. CONCLUSION: These findings suggest that a long duration of illness has a marked effect on the expression of MOG in these regions, and that myelin-oligodendrocyte abnormalities in these regions may be related to the progressive pathophysiology of schizophrenia.

Delirium prior to dementia as a clinical phenotype of Lewy body disease: an autopsied case report.

Although delirium shares clinical characteristics with dementia with Lewy bodies (DLB), there is limited information regarding the relationship between delirium and Lewy body pathology. Here, we report an 89-year-old Japanese woman with an episode of delirium who was pathologically confirmed to have limbic-type Lewy body disease (LBD). Although she exhibited transient visual hallucinations during the delirium, she had no overt dementia. She developed no core clinical features of DLB and died of pneumonia at the age of 90 years. This autopsied case suggests that delirium may be one of the clinical phenotypes of LBD prior to the onset of dementia.

Chorea as a clinical feature of the basophilic inclusion body disease subtype of fused-in-sarcoma-associated frontotemporal lobar degeneration.

Choreoathetoid involuntary movements are rarely reported in patients with frontotemporal lobar degeneration (FTLD), suggesting their exclusion as a supportive feature in clinical diagnostic criteria for FTLD. Here, we identified three cases of the behavioral variant of frontotemporal dementia (bvFTD) that display chorea with fused in sarcoma (FUS)-positive inclusions (FTLD-FUS) and the basophilic inclusion body disease (BIBD) subtype. We determined the behavioral and cognitive features in this group that were distinct from other FTLD-FUS cases. We also reviewed the clinical records of 72 FTLD cases, and clarified additional clinical features that are predictive of the BIBD pathology. Symptom onset in the three patients with chorea was at 44.0 years of age (±12.0 years), and occurred in the absence of a family history of dementia. The cases were consistent with a clinical form of FTD known as bvFTD, as well as reduced neurological muscle tone in addition to chorea. The three patients showed no or mild parkinsonism, which by contrast, increased substantially in the other FTLD cases until a later stage of disease. The three patients exhibited severe caudate atrophy, which has previously been reported as a histological feature distinguishing FTLD-FUS from FTLD-tau or FTLD-TAR DNA-binding protein 43. Thus, our findings suggest that the clinical feature of choreoathetosis in bvFTD might be associated with FTLD-FUS, and in particular, with the BIBD subtype.