Argyrophilic grain disease as a neurodegenerative substrate in late-onset schizophrenia and delusional disorders

Validation of the neuropathological criteria of the fourth Consortium on dementia with Lewy Bodies in autopsy cases from psychiatric hospitals

AIM

The pathological criteria from the fourth Consortium on Dementia With Lewy bodies (DLB) in psychiatric cohorts has not been validated. Also, the pathological differences in prodromal DLB subtypes remain unclear. This study aimed to elucidate the clinicopathological features of patients with DLB in psychiatric hospitals.

METHODS

Of 165 autopsied cases, patients who developed psychiatric symptoms at 50 years or older were investigated based on the current criteria of DLB. Clinicopathological findings were compared among prodromal DLB subtypes.

RESULTS

Sixteen of 30 cases with DLB pathology had no parkinsonism, which represented diverse nigral neurodegeneration. Regarding the scheme to estimate the likelihood of DLB syndrome, the prevalence of core clinical features excluding rapid eye movement sleep behavior disorder and probable DLB diagnosis were significantly higher in the high-likelihood group than in the low-likelihood group. Regarding the prodromal DLB subtypes, mild cognitive impairment (MCI) onset was identified in 60%, psychiatric onset in 20%, delirium onset in 10%, and motor onset in 10% of cases, and the proportion of psychiatric onset or delirium onset was significantly higher compared with those without DLB pathology. Coexistence of MCI and psychiatric symptoms was observed in 41.6% of the MCI-onset cases. Patients with psychiatric-onset cases were significantly younger at the onset, with a longer disease duration than those with MCI-onset cases. No differences were observed in other clinicopathological variables among the subtypes.

CONCLUSION

The fourth Consortium pathological criteria for DLB were applicable in a psychiatric cohort. MCI-onset cases in conjunction with core clinical features is the main prodromal DLB subtype, and four cases exhibited isolated psychiatric symptoms for long-term duration.

The Diagnostic Challenges of Late-onset Neuropsychiatric Symptoms and Early-onset Dementia: A Clinical and Neuropathological Case Study

The emergence of new-onset neuropsychiatric symptoms in middle age presents a diagnostic challenge, particularly when differentiating between a primary psychiatric disorder and an early neurodegenerative disease. The discrepancy between bedside clinical diagnosis and subsequent neuropathological findings in such cases further highlights the difficulty of accurately predicting pathology, especially when there are no evident focal lesions or changes in brain volume. Here we present the case of a 59-year-old woman with inconclusive neuroimaging who exhibited pronounced neuropsychiatric and behavioral symptoms initially suggestive of a mood disorder, then of behavioral variant frontotemporal dementia. However, upon autopsy, we identified coexisting Lewy body disease pathology and tau-related changes, including argyrophilic grain disease and primary age-related tauopathy. This case illustrates the challenges encountered when diagnosing late-onset neuropsychiatric symptoms, emphasizes the link between such symptoms and early-onset dementia and argyrophilic grain disease, and contributes to our understanding of the impact of mixed neuropathology in this population. Accurate diagnosis is essential for the development of molecular-specific therapies and, as well as for accurate prognosis and enrollment in clinical trials.

Clinicopathological study of dementia with grains presenting with parkinsonism compared with a typical case

Argyrophilic grain disease (AGD) is one of the major pathological backgrounds of senile dementia. Dementia with grains refers to cases of dementia for which AGD is the sole background pathology responsible for dementia. Recent studies have suggested an association between dementia with grains and parkinsonism. In this study, we aimed to present two autopsy cases of dementia with grains. Case 1 was an 85-year-old man who exhibited amnestic dementia and parkinsonism, including postural instability, upward gaze palsy, and neck and trunk rigidity. The patient was clinically diagnosed with progressive supranuclear palsy and Alzheimer's disease. Case 2 was a 90-year-old man with pure amnestic dementia, clinically diagnosed as Alzheimer's disease. Recently, we used cryo-electron microscopy to confirm that the tau accumulated in both cases had the same three-dimensional structure. In this study, we compared the detailed clinical picture and neuropathological findings using classical staining and immunostaining methods. Both cases exhibited argyrophilic grains and tau-immunoreactive structures in the brainstem and basal ganglia, especially in the nigrostriatal and limbic systems. However, Case 1 had more tau immunoreactive structures. Considering the absence of other disease-specific structures such as tufted astrocytes, astrocytic plaques and globular glial inclusions, lack of conspicuous cerebrovascular disease, and no history of medications that could cause parkinsonism, our findings suggest an association between AGD in the nigrostriatal system and parkinsonism.

Characteristics associated with progression to probable dementia with Lewy bodies in a cohort with very late-onset psychosis

BACKGROUND

Very late-onset psychosis (VLOP) is associated with higher rates of dementia but the proportion who develop dementia with Lewy bodies (DLB) is unknown. We aimed to identify individuals with VLOP who develop dementia and DLB and characterize the risk factors for progression.

METHODS

Anonymized data were retrieved from electronic records for individuals with VLOP. Patients developing dementia after psychosis were identified, in addition to those with >2 core features of DLB at the time of dementia or DLB identified by a natural language processing application (NLP-DLB). Demographic factors, Health of the National Outcome Scale (HoNOS) and symptoms at index psychosis were explored as predictors of progression to dementia.

RESULTS

In 1425 patients with VLOP over 4.29 years (mean) follow up, 197 (13.8%) received a subsequent diagnosis of dementia. Of these, 24.4% (n = 48) had >2 core features of DLB and 6% (n = 12) had NLP-DLB. In cox proportional hazard models, older age and cognitive impairment at the time of psychosis were associated with increased risk of incident dementia. Visual hallucinations and 2+ core features of DLB at index psychosis were associated with increased risk of dementia with 2+ symptoms of DLB but not all-cause dementia. Two or more core features of DLB at index psychosis were associated with 81% specificity and 67% sensitivity for incident NLP-DLB.

CONCLUSIONS

In patients with VLOP who develop dementia, core features of DLB are common. Visual hallucinations or two core features of DLB in VLOP should prompt clinicians to consider DLB and support further investigation.

Pure argyrophilic grain disease revisited: independent effects on limbic, neocortical, and striato-pallido-nigral degeneration and the development of dementia in a series with a low to moderate Braak stage

Agyrophilic grains (AGs) are age-related limbic-predominant lesions in which four-repeat tau is selectively accumulated. Because previous methodologically heterogeneous studies have demonstrated inconsistent findings on the relationship between AGs and dementia, whether AGs affect cognitive function remains unclear. To address this question, we first comprehensively evaluated the distribution and quantity of Gallyas-positive AGs and the severity of neuronal loss in the limbic, neocortical, and subcortical regions in 30 cases of pure argyrophilic grain disease (pAGD) in Braak stages I-IV and without other degenerative diseases, and 34 control cases that had only neurofibrillary tangles with Braak stages I-IV and no or minimal Aβ deposits. Then, we examined whether AGs have independent effects on neuronal loss and dementia by employing multivariate ordered logistic regression and binomial logistic regression. Of 30 pAGD cases, three were classified in diffuse form pAGD, which had evident neuronal loss not only in the limbic region but also in the neocortex and subcortical nuclei. In all 30 pAGD cases, neuronal loss developed first in the amygdala, followed by temporo-frontal cortex, hippocampal CA1, substantia nigra, and finally, the striatum and globus pallidus with the progression of Saito AG stage. In multivariate analyses of 30 pAGD and 34 control cases, the Saito AG stage affected neuronal loss in the amygdala, hippocampal CA1, temporo-frontal cortex, striatum, globus pallidus, and substantia nigra independent of the age, Braak stage, and limbic-predominant age-related TDP-43 encephalopathy (LATE-NC) stage. In multivariate analyses of 23 pAGD and 28 control cases that lacked two or more lacunae and/or one or more large infarctions, 100 or more AGs per × 400 visual field in the amygdala (OR 10.02, 95% CI 1.12-89.43) and hippocampal CA1 (OR 12.22, 95% CI 1.70-87.81), and the presence of AGs in the inferior temporal cortex (OR 8.18, 95% CI 1.03-65.13) affected dementia independent of age, moderate Braak stages (III-IV), and LATE-NC. Given these findings, the high density of limbic AGs and the increase of AGs in the inferior temporal gyrus may contribute to the occurrence of dementia through neuronal loss, at least in cases in a low to moderate Braak stage.

Clinical presentations and diagnostic application of proposed biomarkers in psychiatric-onset prodromal dementia with Lewy bodies

Research criteria for the diagnosis of prodromal dementia with Lewy bodies (DLB) include three clinical subtypes: mild cognitive impairment with Lewy bodies (MCI-LB), delirium-onset prodromal DLB, and psychiatric-onset prodromal DLB. Late-onset psychiatric manifestations are at a higher risk of developing dementia, but its relation to prodromal DLB remains unclear. In addition to the risk of severe antipsychotic hypersensitivity reactions, accurate discrimination from non-DLB cases is important due to the potential differences in management and prognosis. This article aims to review a rapidly evolving psychiatric topic and outline clinical pictures of psychiatric-onset prodromal DLB, including the proposed biomarker findings of MCI-LB: polysomnography-confirmed rapid eye movement sleep behaviour disorder, cardiac [123I]metaiodobenzylguanidine scintigraphy, and striatal dopamine transporter imaging. We first reviewed clinical pictures of patients with autopsy-confirmed DLB. Regarding clinical reports, we focused on the patients who predominantly presented with psychiatric manifestations and subsequently developed DLB. Thereafter, we reviewed clinical studies regarding the diagnostic applications of the proposed biomarkers to patients with late-onset psychiatric disorders. Clinical presentations were mainly late-onset depression and psychosis; however, other clinical manifestations were also reported. Psychotropic medications before a DLB diagnosis may cause extrapyramidal signs, and potentially influences the proposed biomarker findings. These risks complicate clinical manifestation interpretation during the management of psychiatric symptoms. Longitudinal follow-up studies with standardised evaluations until conversion to DLB are needed to investigate the temporal trajectories of core features and proposed biomarker findings. In patients with late-onset psychiatric disorders, identification of patients with psychiatric-onset prodromal DLB provides the opportunity to better understanding the distinct prognostic subgroup that is at great risk of incident dementia. Advances in the establishment of direct biomarkers for the detection of pathological α-synuclein may encourage reorganising the phenotypic variability of prodromal DLB.

Characteristics of very late-onset schizophrenia-like psychosis classified with the biomarkers for Alzheimer's disease: a retrospective cross-sectional study

OBJECTIVES

We aimed to investigate the association between very late-onset schizophrenia-like psychosis (VLOSLP), a schizophrenia spectrum disorder with an onset of ≥60 years, and Alzheimer's disease (AD) using biomarkers.

DESIGN

Retrospective cross-sectional study.

SETTING

Neuropsychology clinic of Osaka University Hospital in Japan.

PARTICIPANTS

Thirty-three participants were classified into three groups: eight AD biomarker-negative VLOSLP (VLOSLP-AD), nine AD biomarker-positive VLOSLP (VLOSLP+AD), and sixteen amnestic mild cognitive impairment due to AD without psychosis (aMCI-P+AD) participants.

MEASUREMENTS

Phosphorylated tau levels in the cerebrospinal fluid and 18F-Florbetapir positron emission tomography results were used as AD biomarkers. Several scales (e.g. the Mini-Mental State Examination (MMSE), Wechsler Memory Scale-Revised (WMS-R) Logical Memory (LM) I and II, and Neuropsychiatric Inventory (NPI)-plus) were conducted to assess clinical characteristics.

RESULTS

Those in both VLOSLP-AD and +AD groups scored higher than those in aMCI-P+AD in WMS-R LM I. On the other hand, VLOSLP+AD participants scored in between the other two groups in the WMS-R LM II, with only VLOSLP-AD participants scoring significantly higher than aMCI-P+AD participants. There were no significant differences in sex distribution and MMSE scores among the three groups or in the subtype of psychotic symptoms between VLOSLP-AD and +AD participants. Four VLOSLP-AD and five VLOSLP+AD participants harbored partition delusions. Delusion of theft was shown in two VLOSLP-AD patients and five VLOSLP+AD patients.

CONCLUSION

Some VLOSLP patients had AD pathology. Clinical characteristics were different between AD biomarker-positive and AD biomarker-negative VLOSLP, which may be helpful for detecting AD pathology in VLOSLP patients.

Neuropathological substrate of incident dementia in older patients with schizophrenia: A clinicopathological study

AIM

Clinical studies reported that patients with schizophrenia are at a higher risk of developing dementia than people without schizophrenia. However, early neuropathological studies have shown that the incidence of Alzheimer's disease (AD) in schizophrenia patients does not differ from that in controls. These inconsistent results may be attributable to the inclusion of non-AD dementia, but there have been few clinicopathological studies in older patients with schizophrenia based on the current neuropathological classification. This study aimed to investigate the neuropathological basis of incident dementia in older patients with schizophrenia.

METHODS

We systematically examined 32 brains of old patients with schizophrenia using standardized pathological methods. The severity of dementia-related neuropathologies was analyzed using standardized semiquantitative assessments. After excluding patients who fulfilled the neuropathological criteria, clinicopathological variables were compared between patients with and without incident dementia to identify potential differences.

RESULTS

Seven patients fulfilled the pathological criteria for AD (n = 3), argyrophilic grain disease (AGD) (n = 2), dementia with Lewy bodies (n = 1), and AGD/progressive supranuclear palsy (n = 1). Among 25 patients for whom a neuropathological diagnosis was not obtained, 10 had dementia, but the clinicopathological findings did not differ from the remaining 15 patients without dementia.

CONCLUSION

Two types of older schizophrenia patient present dementia: patients with co-existing neurodegenerative disease and patients who do not meet pathological criteria based on the current classification. To understand the neurobiological aspects of incident dementia in older patients with schizophrenia, further clinicopathological studies are needed that do not simply analyze incident dementia as a comorbidity of conventional dementia-related neuropathologies.

Neuropsychiatric Manifestations in Alzheimer's Disease Patients: Genetics and Treatment Options

BACKGROUND

Alzheimer's disease (AD) is characterized by neuropsychiatric symptoms (NPS), which cause great misery to those with dementia and those who care for them and may lead to early institutionalization.

OBJECTIVE

The present systematic review aims to discuss the various aspects of Alzheimer's, including treatment options.

METHODS

The databases Embase, PubMed, and Web of Science were searched to collect data.

RESULTS

Incipient cognitive deterioration is commonly accompanied by these early warning signals of neurocognitive diseases. The neurobiology of NPSs in Alzheimer's disease, as well as particular symptoms, including psychosis, agitation, apathy, sadness, and sleep disorders, will be examined in this review. For NPSs in Alzheimer's disease, clinical trial designs, as well as regulatory issues, were also addressed. A fresh wave of research, however, is helping to push the discipline ahead. For medication development and repurposing, we highlight the most recent results in genetics, neuroimaging, and neurobiology. Even though identifying and treating psychosis in adults with dementia is still a challenging endeavor, new options are coming up that give the field fresh focus and hope. Conclsuion: It can be concluded from the complete literature survey that Alzheimer's-related psychosis as well as other symptoms that are not psychotic, have made significant progress in the last decade. These milestones in the development of safer, more effective treatments have been achieved as a consequence of great focus on non-pharmacological interventions like DICE or WHELD; the investigation into ways to improve existing drugs like aripiprazole, risperidone, amisulpride, and Escitalopram for safer precision-based treatment; and the development of a clinical trial program for pimavanserin.

Cognitive impairment and development of dementia in very late-onset schizophrenia-like psychosis: a systematic review

OBJECTIVES

This study aimed to review the evidence base regarding cognitive impairment and the development of dementia in patients with very late-onset schizophrenia-like psychosis (VLOSLP).

METHODS

We conducted a systematic literature search of PubMed, PsycINFO and Web of Science according to Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. Two reviewers independently screened records first by title and abstract and then by full text, resolving differences after each stage. Selected studies were assessed for quality using the GRADE system, and data on study design, participants, cognitive ability and rates of developing dementia were extracted and synthesised.

RESULTS

Seventeen publications were identified for review. They were generally poor in quality and heterogenous in design. VLOSLP patients were found to have impaired global cognition compared to non-psychotic controls, but no difference was found between VLOSLP patients and aged early-onset schizophrenia (EOS) patients. No single cognitive domain was consistently affected. Patients with VLOSLP demonstrated significantly higher rates of dementia diagnosis (ranging from 4.4% over 3 years to 44.4% over 15 years) than controls, but no difference was found between VLOSLP patients and aged EOS patients.

CONCLUSIONS

VLOSLP may not necessarily predict cognitive decline, but few studies have adequately investigated cohorts on a longitudinal basis. Heterogeneity between and within cohorts and varying selection criteria compromise the clinical generalisability of studies investigating the association between VLOSLP and neurodegenerative disease. Further studies on the clinical presentation, cognitive profile and neuropathology of VLOSLP with comparison to EOS/late-onset schizophrenia (LOS) and neurodegenerative disease are needed to better inform the diagnosis and management of VLOSLP.

Argyrophilic grain disease is common in older adults and may be a risk factor for suicide: a study of Japanese forensic autopsy cases

BACKGROUND

Neuropathological diagnosis of argyrophilic grain disease (AGD) is currently based primarily on the combination of argyrophilic grain (AG) visualized using Gallyas-Braak silver staining, phosphorylated tau-positive pretangles, coiled bodies, and ballooned neuron detection. Although AGD is common in patients with dementia and/or prominent psychiatric symptoms, whether it is a distinct neurological disease entity or a by-product of the aging process remains unclear.

METHODS

In 1449 serial forensic autopsy cases > 40 years old (823 males and 525 females, aged 40-101 years, mean age 70.0 ± 14.1 years), we examined the frequency and comorbid pathology of AGD cases and investigated the clinical appearance by comparing those with non-AGD cases using the propensity score.

RESULTS

Of the 1449 cases, we detected 342 AGD cases (23.6%; mean age 79.7 years; 177 males and 165 females). The AGD frequency and stage increased with age (P < 0.001). Among AGD cases, 80 (23.4%) patients had dementia, and 51 (15.2%) had a history of psychiatric hospital visits. The frequency of suicide and history of psychiatric disorders were significantly higher in AGD cases than in AGD-negative cases, matched for age, sex, and comorbidity pathology, with a relative risk of suicide of 1.72 (1.30-2.26). The frequency of suicide was significantly higher in AGD cases than in non-AGD cases in female but not male cases. The relative risk of suicide increased to 2.27 (1.20-4.30) and 6.50 (1.58-26.76) in AGD patients with Lewy and progressive supranuclear palsy pathology, respectively, and decreased to 0.88 (0.38-2.10) in those with advanced AD pathology. In AGD cases, 23.4% had dementia; however, the difference was not significant after controlling for age, sex, and comorbid pathology.

CONCLUSION

Our study demonstrated that AGD is a significant and isolated risk factor for psychiatric hospital visits and suicide completion. In older adults, AGs may contribute to the progression of functional impairment of the limbic system, which leads to psychiatric disorders and suicide attempts.

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 Aβ 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.

Four-repeat tauopathies and late-onset psychiatric disorders: Etiological relevance or incidental findings?

Argyrophilic grain disease (AGD), progressive supranuclear palsy (PSP) and corticobasal degeneration are four-repeat (4R) tauopathies that develop in the presenium or later. Whether these diseases are associated with the occurrence of late-onset psychiatric disorders remains unclear. To facilitate the accumulation of clinicopathological findings regarding this issue, we here present a selected series of 11 cases that clinically developed psychotic disorder (n = 7; age at onset: 41-75 years), depressive disorder (n = 1; 49 years), bipolar disorder (n = 2; 32 and 37 years) and somatoform disorder (n = 1; 88 years), and had at least one pathological hallmark of these tauopathies. The mean age at death was 74.3 years. No case showed dementia, at least in the early stage of the course. Nine cases had AGD. Granular fuzzy astrocytes in the amygdala were noted in all AGD cases and one non-AGD case. Two AGD cases had tufted astrocytes (TAs) in the amygdala but not in the frontal cortex and striatum. Three AGD and two non-AGD cases had TAs in the frontal cortex and/or striatum but not in the amygdala. One AGD case had a small number of astrocytic plaques in the frontal cortex, striatum and globus pallidus. Only one case was diagnosed as atypical PSP according to the NINDS-PSP neuropathological criteria. No case had high-level Alzheimer's disease pathology, Lewy body disease or limbic-predominant age-related TDP-43 encephalopathy. Two cases had mild neuronal loss in the hippocampus and substantia nigra, respectively. Clinicopathological studies focusing especially on early changes of 4R tauopathies, as well as the development of surrogate markers of these diseases, may be necessary for better understanding of the pathogenic backgrounds of late-onset psychiatric disorders.

Towards an understanding of the pathological basis of senile depression and incident dementia: Implications for treatment

Senile depression (SD) is a heterogeneous syndrome. Several clinical profiles are more likely to appear in SD than in early-life depression, but it remains unclear whether the pathophysiology is different. The prevalence of dementia increases with aging, and the underlying pathophysiological processes in the preclinical phase begin even before cognitive deficits or neurological signs appear. SD may be either a risk factor for developing dementia or a prodromal stage of dementia. The inconsistent findings regarding the association between SD and incident dementia may be attributable to the neuropathological heterogeneity underlying SD. Most studies have focused on patients with the clinical diagnosis of Alzheimer disease (AD) as an outcome, but several clinicopathological studies suggest that primary age-related tauopathy and argyrophilic grain disease may account for a proportion of cases clinically misdiagnosed as AD in the elderly population. Furthermore, most AD cases have additional neuropathologic changes such as cerebrovascular disease and Lewy body disease. Here, we review the neuropathological findings linking SD to incident dementia, focusing on common age-related neuropathologies. In particular, the roles of disturbance of neural circuity, imbalance of monoaminergic systems, dysregulation of the hypothalamic-pituitary-adrenal axis, and elevated neuroinflammatory status are discussed. Finally, we review the current treatment of SD in the context of age-related neuropathological changes.

Pineal volume reduction as the neural correlate of very late-onset schizophrenia-like psychosis

This study aimed to examine the relationship between pineal parenchymal volume (PPV) and schizophrenia-like psychosis (SLP) at the onset of ≥ 60 years. Exactly 21 patients with SLP, 50 with Alzheimer's disease (AD) with delusions of theft, and 35 with normal cognition were selected. The PPVs in patients with SLP and patients with AD with delusional theft were significantly lower than those in patients with normal cognition. Moreover, PPVs in nine patients with Very late-onset schizophrenia-like psychosis (VLOSLP) tended to be lower than that in patients with normal cognition. Thus, pineal volume reduction could be a neural correlate of VLOSLP.

Characteristics of very late-onset schizophrenia-like psychosis as prodromal dementia with Lewy bodies: a cross-sectional study

Background

This study aimed to identify cases of potential prodromal DLB in very late-onset schizophrenia-like psychosis (VLOSLP), using indicative biomarkers of dementia with Lewy bodies (DLB), and to evaluate the characteristics of psychosis as prodromal DLB.

Methods

Data of patients with VLOSLP without dementia and Parkinsonism, who underwent testing for at least one indicative biomarker of DLB, were retrospectively collected from the database of the psychiatry clinic at the Osaka University Hospital. Patients were divided into two groups based on the positive (VLOSLP+LB) and negative (VLOSLP–LB) results of the indicative biomarkers of DLB. Age, gender, cognitive battery scores, prevalence of each type of delusions and hallucinations, cerebral volume, and cerebral perfusion were compared between the two groups.

Results

Eleven VLOSLP+LB and 23 VLOSLP–LB participants were enrolled. There were no significant differences in age, proportion of females, and MMSE scores between the two groups. The standardized score of the digit symbol substitution test was significantly lower in the VLOSLP+LB than in VLOSLP–LB group (6.9 [3.1] vs. 10.0 [2.7], p = 0.005). The prevalence of visual hallucinations was significantly higher in the VLOSLP+LB group than in the VLOSLP-LB group (81.8% vs. 26.1%, p = 0.003). Auditory hallucinations were prevalent in both groups (43.5% in VLOSLP–LB, and 45.5% in VLOSLP+LB). Among patients with auditory hallucinations, auditory hallucinations without coexistent visual hallucinations tended to be more prevalent in VLOSLP–LB (7 out of 10) than in VLOSLP+LB patients (1 out of 5). Although cerebral volume was not different in any region, cerebral perfusion in the posterior region, including the occipital lobe, was significantly lower in the VLOSLP+LB group.

Conclusions

Psychomotor slowing, visual hallucinations, and reduced perfusion in the occipital lobe may be suggestive of prodromal DLB in VLOSLP patients, even though the clinical manifestations were similar in many respects between VLOSLP+LB and VLOSLP–LB. Although auditory hallucinations were prevalent in both groups, most patients in VLOSLP+LB complained of auditory hallucinations along with visual hallucinations. Future studies with a larger number of patients without selection bias are desirable.

Clinical Spectrum of Tauopathies

Tauopathies are both clinical and pathological heterogeneous disorders characterized by neuronal and/or glial accumulation of misfolded tau protein. It is now well understood that every pathologic tauopathy may present with various clinical phenotypes based on the primary site of involvement and the spread and distribution of the pathology in the nervous system making clinicopathological correlation more and more challenging. The clinical spectrum of tauopathies includes syndromes with a strong association with an underlying primary tauopathy, including Richardson syndrome (RS), corticobasal syndrome (CBS), non-fluent agrammatic primary progressive aphasia (nfaPPA)/apraxia of speech, pure akinesia with gait freezing (PAGF), and behavioral variant frontotemporal dementia (bvFTD), or weak association with an underlying primary tauopathy, including Parkinsonian syndrome, late-onset cerebellar ataxia, primary lateral sclerosis, semantic variant PPA (svPPA), and amnestic syndrome. Here, we discuss clinical syndromes associated with various primary tauopathies and their distinguishing clinical features and new biomarkers becoming available to improve in vivo diagnosis. Although the typical phenotypic clinical presentations lead us to suspect specific underlying pathologies, it is still challenging to differentiate pathology accurately based on clinical findings due to large phenotypic overlaps. Larger pathology-confirmed studies to validate the use of different biomarkers and prospective longitudinal cohorts evaluating detailed clinical, biofluid, and imaging protocols in subjects presenting with heterogenous phenotypes reflecting a variety of suspected underlying pathologies are fundamental for a better understanding of the clinicopathological correlations.

Psychosis in Alzheimer disease - mechanisms, genetics and therapeutic opportunities

Psychosis is a common and distressing symptom in people with Alzheimer disease, and few safe and effective treatments are available. However, new approaches to symptom assessment and treatment are beginning to drive the field forward. New nosological perspectives have been provided by incorporating the emergence of psychotic symptoms in older adults - even in advance of dementia - into epidemiological and neurobiological frameworks as well as into diagnostic and research criteria such as the International Psychogeriatric Association criteria for psychosis in neurocognitive disorders, the Alzheimer's Association International Society to Advance Alzheimer's Research and Treatment (ISTAART) research criteria for psychosis in neurodegenerative disease, and the ISTAART criteria for mild behavioural impairment. Here, we highlight the latest findings in genomics, neuroimaging and neurobiology that are informing approaches to drug discovery and repurposing. Current pharmacological and non-pharmacological treatment options are discussed, with a focus on safety and precision medicine. We also explore trial data for pimavanserin, a novel agent that shows promise for the treatment of psychosis in people with dementia, and discuss existing agents that might be useful but need further exploration such as escitalopram, lithium, cholinesterase inhibitors and vitamin D. Although the assessment and management of psychosis in people with dementia remain challenging, new opportunities are providing direction and hope to the field.

A case report of late-onset schizophrenia differentiated from a dementing disorder

We report a case of late-onset schizophrenia that required differentiation from a dementing disorder. The patient was an 83-year-old woman who had experienced auditory hallucinations since she was 67 years old. The patient had slightly elevated total tau and slightly decreased amyloid β1-42, cerebrospinal fluid biomarkers. This case was identified as late-onset schizophrenia. However, the results of cerebrospinal fluid biomarkers indicated that neurofibrillary tangles and neuronal death, which are characteristic of Alzheimer 's disease, may also have been present. Late-onset schizophrenia should be treated based on an appropriate differential diagnosis, including neuropathological consideration of dementing disorders.

Excess tau PET ligand retention in elderly patients with major depressive disorder

Depression is one of the common psychiatric disorders in old age. Major depressive disorder (MDD) has been identified as a risk factor or prodrome for neurodegenerative dementias, suggesting neuropathological overlaps and a continuum between MDD and neurodegenerative disorders. In this study, we examined tau and amyloid-β (Aβ) accumulations in the brains of MDD and healthy controls using positron emission tomography (PET) to explore pathological substrates of this illness. Twenty MDD and twenty age-matched, healthy controls were examined by PET with a tau radioligand, [¹¹C]PBB3, and an Aβ radioligand, [¹¹C]PiB. Radioligand retentions were quantified as a standardized uptake value ratio (SUVR). We also assessed clinical manifestations of the patients using the 17-item Hamilton Depression Scale, the Geriatric Depression Scale, and psychotic symptoms. Mean cortical [¹¹C]PBB3 SUVRs in MDD patients were significantly higher than those of healthy controls. These values were higher in MDD patients with psychotic symptoms than in those without any. The present findings indicate that tau depositions may underlie MDD, and especially in patients with psychotic symptoms. PET detection of tau accumulations may provide mechanistic insights into neuronal dysfunctions in these cases and could serve as predictions of their clinical consequences.

Psychotic Features Among Patients in the Prodromal Stage of Dementia with Lewy Bodies During Longitudinal Observation

BACKGROUND

Many cases of dementia with Lewy bodies (DLB) present with various psychotic features, including hallucinations, depression, catatonia, and delusions before the onset of cognitive impairment. However, the characteristic features of these psychotic symptoms in prodromal DLB have not been sufficiently described.

OBJECTIVE

To clarify and describe the psychotic features of prodromal DLB before overt cognitive impairment.

METHODS

The authors analyzed the characteristic psychotic features of prodromal DLB in 21 subjects who developed severe psychotic symptoms without dementia and were diagnosed as DLB after the longitudinal observation period. They were then confirmed to have DLB through indicative and supportive biomarkers of scintigraphy.

RESULTS

The psychotic features included a wide variety of symptoms, but convergent to three principal categories: catatonia, delusions-hallucinations, and depression and/or mania. Catatonia was observed in nine cases, five were delusional-hallucinatory, and seven were manic and/or depressive. Seven of the 21 cases exhibited delirium during longitudinal observation. A psychotic state repeatedly appeared without any trigger in 20 of the 21 patients. All subjects developed cognitive impairment at 9.1±4.6 (mean±SD) years after the initial appearance of psychotic symptoms, and subsequently diagnosed with DLB at 71.3±6.1 (mean±SD) years.

CONCLUSION

Elderly patients with psychotic symptoms, such as catatonia, delusion-hallucination, manic and/or depressive features, and delirium without dementia, could indicate symptomatic psychosis or a prodromal stage of any neurocognitive disorder such as DLB. Therefore, further extensive workout (e.g., radioisotope neuroimaging) is required to avoid misdiagnosis.

Recent Advances and Future Directions in Brain MR Imaging Studies in Schizophrenia: Toward Elucidating Brain Pathology and Developing Clinical Tools

Schizophrenia is a common severe psychiatric disorder that affects approximately 1% of general population through the life course. Historically, in Kraepelin's time, schizophrenia was a disease unit conceptualized as dementia praecox; however, since then, the disease concept has changed. Recent MRI studies had shown that the neuropathology of the brain in this disorder was characterized by mild progression before and after the onset of the disease, and that the brain alterations were relatively smaller than assumed. Although genetic factors contribute to the brain alterations in schizophrenia, which are thought to be trait differences, other changes include factors that are common in psychiatric diseases. Furthermore, it has been shown that the brain differences specific to schizophrenia were relatively small compared to other changes, such as those caused by brain development, aging, and gender. In addition, compared to the disease and participant factors, machine and imaging protocol differences could affect MRI signals, which should be addressed in multi-site studies. Recent advances in MRI modalities, such as multi-shell diffusion-weighted imaging, magnetic resonance spectroscopy, and multimodal brain imaging analysis, may be candidates to sharpen the characterization of schizophrenia-specific factors and provide new insights. The Brain/MINDS Beyond Human Brain MRI (BMB-HBM) project has been launched considering the differences and noises irrespective of the disease pathologies and includes the future perspectives of MRI studies for various psychiatric and neurological disorders. The sites use restricted MRI machines and harmonized multi-modal protocols, standardized image preprocessing, and traveling subject harmonization. Data sharing to the public will be planned in FY 2024. In the future, we believe that combining a high-quality human MRI dataset with genetic data, randomized controlled trials, and MRI for non-human primates and animal models will enable us to understand schizophrenia, elucidate its neural bases and therapeutic targets, and provide tools for clinical application at bedside.

Case Report: Usefulness of Biomarkers for Alzheimer's Disease in Two Cases With Very-Late-Onset Schizophrenia-Like Psychosis

The association between primary psychotic disorders emerging in later life and neurodegenerative diseases, including Alzheimer's disease (AD), is controversial. We present two female non-demented cases of psychosis with onset above the age of 60 years. Cases 1 and 2 were aged was 68 and 81 years, respectively. They suffered from persecutory delusions and scored 28 on the Mini-Mental State Examination (MMSE) at the first examination. Although detailed neuropsychological tests detected amnesia, they had preserved daily life function. Brain magnetic resonance imaging, N-isopropyl-p-[123I] iodoamphetamine (123I-IMP) single-photon emission computed tomography, and cardiac [123I]-metaiodobenzylguanidine (123I-MIBG) scintigraphy showed no specific abnormalities in either case. We diagnosed them with very-late-onset schizophrenia-like psychosis (VLOSLP) because there was no evidence that their psychoses were derived from organic diseases or affective disorders. Upon close inspection, the AD biomarkers, cerebrospinal fluid (CSF) testing and Florbetapir F 18 positron emission tomography (PET), were positive in Case 1 and negative in Case 2. Case 1 scored 25 1 year later and 23 2 years later on the MMSE and was finally diagnosed as AD dementia. These two cases suggest that some clinically diagnosed VLOSLPs may be a prodromal AD. Although VLOSLP is a disease entity supposed to be a primary psychotic disorder, some are probably secondary psychosis with insidious neurodegeneration. Advanced biomarkers such as amyloid PET and CSF may contribute to the detection of secondary psychosis from clinically diagnosed VLOSLP.

Strategic Timing of Glial HMOX1 Expression Results in Either Schizophrenia-Like or Parkinsonian Behavior in Mice

Aims: In this original research communication, we assess the impact of shifting the window of glial HMOX1 overexpression in mice from early-to-midlife to mid-to-late life, resulting in two disparate conditions modeling schizophrenia (SCZ) and Parkinson's disease (PD). Mesolimbic hyperdopaminergia is a widely accepted feature of SCZ, while nigrostriatal hypodopaminergia is the sine qua non of idiopathic PD. Although the advent of parkinsonian features in SCZ patients after treatment with antidopaminergic agents is intuitive, subtle features of parkinsonism commonly observed in young, drug-naïve schizophrenics are not. Similarly, emergent psychosis in PD subjects receiving levodopa replacement is not unusual, whereas spontaneous hallucinosis in nonmedicated persons with idiopathic PD is enigmatic. Investigations using GFAP.HMOX1 mice may shed light on these clinical paradoxes. Results: Astroglial heme oxygenase-1 (HO-1) overexpression in mice throughout embryogenesis until 6 or 12 months of age resulted in hyperdopaminergia, hyperkinesia/stereotypy ameliorated with clozapine, deficient prepulse inhibition of the acoustic startle response, reduced preference for social novelty, impaired nest building, and cognitive dysfunction reminiscent of SCZ. On the contrary, astroglial HO-1 overexpression between 8.5 and 19 months of age yielded a PD-like behavioral phenotype with hypodopaminergia, altered gait, locomotor incoordination, and reduced olfaction. Innovation: We conjecture that region-specific disparities in the susceptibility of dopaminergic and other circuitry to the trophic and degenerative influences of glial HMOX1 induction may permit the concomitant expression of mixed SCZ and PD traits within affected individuals. Conclusion: Elucidation of these converging mechanisms may (i) help better understand disease pathogenesis and (ii) identify HO-1 as a potential therapeutic target in neurodevelopmental and neurodegenerative disorders.

Hippocampal Sclerosis, Argyrophilic Grain Disease, and Primary Age-Related Tauopathy

PURPOSE OF REVIEW

Hippocampal sclerosis, argyrophilic grain disease, and primary age-related tauopathy are common Alzheimer disease mimics that currently lack clinical diagnostic criteria. Increased understanding of these pathologic entities is important for the neurologist who may encounter patients with an unusually slowly progressive degenerative dementia that may appear to meet criteria for Alzheimer disease but who progress to develop symptoms that are unusual for classic Alzheimer disease RECENT FINDINGS: Hippocampal sclerosis has traditionally been associated with hypoxic/ischemic injury and poorly controlled epilepsy, but it is now recognized that hippocampal sclerosis may also be associated with a unique degenerative disease of aging or may be an associated pathologic finding in many cases of frontotemporal lobar degeneration. Argyrophilic grain disease has been recognized as an enigma in the field of pathology for over 30 years, but recent discoveries suggest that it may overlap with other tau-related disorders within the spectrum of frontotemporal lobar degeneration. Primary age-related tauopathy has long been recognized as a distinct clinical entity that lies on the Alzheimer pathologic spectrum, with the presence of neurofibrillary tangles that lack the coexistent Alzheimer plaque development; thus, it is thought to represent a distinct pathologic entity.

SUMMARY

Despite advances in dementia diagnosis that suggest that we have identified and unlocked the mysteries of the major degenerative disease states responsible for cognitive decline and dementia in the elderly, diseases such as hippocampal sclerosis, argyrophilic grain disease, and primary age-related tauopathy demonstrate that we remain on the frontier of discovery and that our diagnostic repertoire of diseases responsible for such clinical symptoms remains in its infancy. Understanding such diagnostic confounds is important for the neurologist in assigning appropriate diagnoses and selecting appropriate therapeutic management strategies for patients with mild cognitive impairment and dementia.

Amisulpride for very late-onset schizophrenia-like psychosis: the ATLAS three-arm RCT

BACKGROUND

Very late-onset (aged ≥ 60 years) schizophrenia-like psychosis (VLOSLP) occurs frequently but no placebo-controlled, randomised trials have assessed the efficacy or risks of antipsychotic treatment. Most patients are not prescribed treatment.

OBJECTIVES

The study investigated whether or not low-dose amisulpride is superior to placebo in reducing psychosis symptoms over 12 weeks and if any benefit is maintained by continuing treatment thereafter. Treatment safety and cost-effectiveness were also investigated.

DESIGN

Three-arm, parallel-group, placebo-controlled, double-blind, randomised controlled trial. Participants who received at least one dose of study treatment were included in the intention-to-treat analyses.

SETTING

Secondary care specialist old age psychiatry services in 25 NHS mental health trusts in England and Scotland.

PARTICIPANTS

Patients meeting diagnostic criteria for VLOSLP and scoring > 30 points on the Brief Psychiatric Rating Scale (BPRS).

INTERVENTION

Participants were randomly assigned to three arms in a two-stage trial: (1) 100 mg of amisulpride in both stages, (2) amisulpride then placebo and (3) placebo then amisulpride. Treatment duration was 12 weeks in stage 1 and 24 weeks (later reduced to 12) in stage 2. Participants, investigators and outcome assessors were blind to treatment allocation.

MAIN OUTCOME MEASURES

Primary outcomes were psychosis symptoms assessed by the BPRS and trial treatment discontinuation for non-efficacy. Secondary outcomes were extrapyramidal symptoms measured with the Simpson-Angus Scale, quality of life measured with the World Health Organization's quality-of-life scale, and cost-effectiveness measured with NHS, social care and carer work loss costs and EuroQol-5 Dimensions.

RESULTS

A total of 101 participants were randomised. Ninety-two (91%) participants took the trial medication, 59 (64%) completed stage 1 and 33 (56%) completed stage 2 treatment. Despite suboptimal compliance, improvements in BPRS scores at 12 weeks were 7.7 points (95% CI 3.8 to 11.5 points) greater with amisulpride than with placebo (11.9 vs. 4.2 points; p = 0.0002). In stage 2, BPRS scores improved by 1.1 point in those who continued with amisulpride but deteriorated by 5.2 points in those who switched from amisulpride to placebo, a difference of 6.3 points (95% CI 0.9 to 11.7 points; p = 0.024). Fewer participants allocated to the amisulpride group stopped treatment because of non-efficacy in stages 1 (p = 0.01) and 2 (p = 0.031). The number of patients stopping because of extrapyramidal symptoms and other side effects did not differ significantly between groups. Amisulpride treatment in the base-case analyses was associated with non-significant reductions in combined NHS, social care and unpaid carer costs and non-significant reductions in quality-adjusted life-years (QALYs) in both stages. Including patients who were intensive users of inpatient services in sensitivity analyses did not change the QALY result but resulted in placebo dominance in stage 1 and significant reductions in NHS/social care (95% CI -£8923 to -£122) and societal costs (95% CI -£8985 to -£153) for those continuing with amisulpride.

LIMITATIONS

The original recruitment target of 300 participants was not achieved and compliance with trial medication was highly variable.

CONCLUSIONS

Low-dose amisulpride is effective and well tolerated as a treatment for VLOSLP, with benefits maintained by prolonging treatment. Potential adverse events include clinically significant extrapyramidal symptoms and falls.

FUTURE WORK

Trials should examine the longer-term effectiveness and safety of antipsychotic treatment in this patient group, and assess interventions to improve their appreciation of potential benefits of antipsychotic treatment and compliance with prescribed medication.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN45593573 and EudraCT2010-022184-35.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 67. See the NIHR Journals Library website for further project information.

Neuropathological comorbidity associated with argyrophilic grain disease

Argyrophilic grain disease (AGD) is a common four-repeat tauopathy in elderly people. While dementia is a major clinical picture of AGD, recent studies support the possibility that AGD may be a pathological base in some patients with mild cognitive impairment, late-onset psychosis, bipolar disorder and depression. AGD often coexists with various other degenerative changes. The frequency of AGD in progressive supranuclear palsy (PSP) cases was reported to range from 18.8% to 80%. The frequency of AGD in corticobasal degeneration (CBD) cases tends to be higher than that in PSP cases, ranging from 41.2% to 100%. Conversely, in our previous study of the frequencies of mild PSP and CBD pathologies in AGD cases, five of 20 AGD cases (25%) had a few Gallyas-positive tufted astrocytes, six cases (30%) had a few granular/fuzzy astrocytes, and one case (5.0%) had a few Gallyas-positive astrocytic plaques in the putamen, caudate nucleus and/or superior frontal gyrus. Both Gallyas-positive tufted astrocytes and Gallyas-negative tau-positive granular/fuzzy astrocytes preferentially developed in the putamen, caudate nucleus and superior frontal cortex in AGD cases, being consistent with the predilection sites of Gallyas-positive tufted astrocytes in PSP cases. Further, in AGD cases, the quantities of Gallyas-positive tufted astrocytes, overall tau-positive astrocytes, and tau-positive neurons in the subcortical nuclei and superior frontal cortex were significantly correlated with Saito AGD stage, respectively. The frequency of AGD in AD cases was reported to reach up to 25% when using four-repeat tau immunohistochemistry. Pretangles are essential pathologies in AGD; however, the Braak stage of three-repeat tau-positive NFTs, which may indicate mild AD pathology or primary age-related tauopathy, was not correlated with Saito AGD stage. Clinicians should be aware of the possibility that coexisting AGD may impact clinical and radiological features in cases of other degenerative diseases.

Argyrophilic Grain Disease: Demographics, Clinical, and Neuropathological Features From a Large Autopsy Study

Argyrophilic grain disease (AGD) is a frequent late-onset, 4-repeat tauopathy reported in Caucasians with high educational attainment. Little is known about AGD in non-Caucasians or in those with low educational attainment. We describe AGD demographics, clinical, and neuropathological features in a multiethnic cohort of 983 subjects ≥50 years of age from São Paulo, Brazil. Clinical data were collected through semistructured interviews with an informant and included in the Informant Questionnaire on Cognitive Decline in the Elderly, the Clinical Dementia Rating, and the Neuropsychiatric Inventory. Neuropathologic assessment relied on internationally accepted criteria. AGD was frequent (15.2%) and was the only neuropathological diagnosis in 8.9% of all cases (mean, 78.9 ± 9.4 years); it rarely occurred as an isolated neuropathological finding. AGD was associated with older age, lower socioeconomic status (SES), and appetite disorders. This is the first study of demographic, clinical, and neuropathological aspects of AGD in different ethnicities and subjects from all socioeconomic strata. The results suggest that prospective studies of AGD patients include levels of hormones related to appetite control as possible antemortem markers. Moreover, understanding the mechanisms behind higher susceptibility to AGD of low SES subjects may disclose novel environmental risk factors for AGD and other neurodegenerative diseases.

Neuropathologic features of suicide victims who presented with acute poststroke depression: significance of association with neurodegenerative disorders

To investigate the neuropathologic characteristics of poststroke depression (PSD) leading to suicide, we retrospectively selected deceased subjects who had been diagnosed as having early PSD. Cases were divided into subjects who had committed suicide and those who had not. Neuropathologic examinations, including immunohistochemistry, were conducted. Twenty-four subjects fulfilled criteria for early PSD; 11 of these had committed suicide, and the other 13 had not. Lesion type, size of stroke, and location of stroke were variable but did not differ significantly between the groups. Alzheimer disease-related pathology stages also did not differ between the groups. Argyrophilic grain disease was found in both the suicide group (6 of 11) and the nonsuicide group (2 of 13); there were 2 highly possible cases of early progressive supranuclear palsy in the suicide group. Together, argyrophilic grain disease and progressive supranuclear palsy were found significantly more frequently in suicide cases than in nonsuicide cases (p = 0.01). These data suggest that overlapping 4-repeat tauopathies, which include argyrophilic grain disease and progressive supranuclear palsy, might be an important aggravating factor of PSD that could lead to suicide. The presence of other neurodegenerative diseases does not preclude PSD because the prevalence of these diseases in older persons suggests that they might often occur concomitantly.

New perspectives on schizophrenia in later life: implications for treatment, policy, and research

Worldwide, in the past few decades, the demographics of older people (ie, people 55 years and over) with schizophrenia have changed completely with respect to absolute numbers of people affected, the proportion of all people with the disorder, life expectancy, and residential status. The ageing schizophrenia population has created vast health-care needs and their medical comorbidity contributes to higher mortality than in the general population. Proposals to classify schizophrenia into early-onset, late-onset, and very-late-onset subtypes now should be tempered by the recognition that comorbid medical and neurological disorders can contribute to psychotic symptoms in later life. The concept of outcome has become more nuanced with an appreciation that various outcomes can occur, largely independent of each other, that need different treatment approaches. Data show that schizophrenia in later life is not a stable end-state but one of fluctuation in symptoms and level of functioning, and show that pathways to improvement and recovery exist. Several novel non-pharmacological treatment strategies have been devised that can augment the clinical options used to address the specific needs of older adults with schizophrenia.

Corticobasal degeneration initially developing motor versus non-motor symptoms: a comparative clinicopathological study

BACKGROUND

Clinical presentations of pathologically confirmed corticobasal degeneration (CBD) vary, and the heterogeneity makes its clinical diagnosis difficult, especially when a patient lacks any motor disturbance in the early stage.

METHODS

We compared clinical and pathological features of four pathologically confirmed CBD cases that initially developed non-motor symptoms, including behavioural and psychiatric symptoms but without motor disturbance (CBD-NM), and five CBD cases that initially developed parkinsonism and/or falls (CBD-M). The age range at death for the CBD-NM and CBD-M subjects (58-85 years vs 45-67 years) and the range of disease duration (2-18 years vs 2-6 years) did not significantly differ between the groups.

RESULTS

Prominent symptoms in the early stage of CBD-NM cases included self-centred behaviours such as frontotemporal dementia (n = 1), apathy with and without auditory hallucination (n = 2), and aggressive behaviours with delusion and visual hallucination (n = 1). Among the four CBD-NM cases, only one developed asymmetric motor disturbance, and two could walk without support throughout the course. Final clinical diagnoses of the CBD-NM cases were frontotemporal dementia (n = 2), senile psychosis with delirium (n = 1), and schizophrenia (n = 1). Neuronal loss was significantly less severe in the subthalamic nucleus and substantia nigra in the CBD-NM cases than in the CBD-M cases. The severity of tau pathology in all regions examined was comparable in the two groups.

CONCLUSION

CBD cases that initially develop psychiatric and behavioural changes without motor symptoms may have less severe degenerative changes in the subthalamic nucleus and substantia nigra, and some CBD cases can lack motor disturbance not only in the early stage but also in the last stage of the course.