Prominent psychiatric symptoms in patients with Parkinson's disease and concomitant argyrophilic grain disease

Clinicoradiological features in progressive supranuclear palsy comorbid with argyrophilic grains

Background

Contrary to pure cases, the influence of comorbid argyrophilic grain disease (AGD) in progressive supranuclear palsy (PSP) has not been sufficiently evaluated.

Objectives

We compared the clinicoradiological features of 12 patients with PSP with (PSPw/AG) and 8 patients without AGD (PSPw/oAG).

Methods

Medical records and magnetic resonance imaging were checked retrospectively from a single brain bank database.

Results

Other than AGD, no differences were observed in any other neurodegenerative pathologies between the 2 groups. Ages at onset and deaths of patients with PSPw/AG were higher than those of patients with PSPw/oAG (77.9 ± 4.9 vs. 68.9 ± 5.9, and 87.0 ± 5.7 vs. 78.1 ± 5.0; P = 0.003 and P = 0.002, respectively). In addition to the later onset of motor symptoms, initial amnestic presentations were limited to 5 patients with PSPw/AG. Both characteristic midbrain atrophy and severe ambient gyrus atrophy were detected exclusively in 8 patients with PSPw/AG.

Conclusions

Initial amnestic presentations and ambient gyrus atrophy may be characteristic of PSPw/AG.

[Contemporary approaches to clinical diagnosis and treatment of tau-protein accumulation related multisystem degenerations]

Tau-protein pathology is the basis of a great variety of neurodegenerative diseases. Misfolding tau-protein conformation structure is the key pathogenetic mechanism of development of such multisystem degenerations as progressive supranuclear palsy, corticobasal syndrome, and fronto-temporal degeneration, as well as relatively recently added primary age-associated tauopathies and others. This review presents current views on the pathogenesis of various forms of neurodegenerative pathology linked to tau-protein accumulation. Potential of clinical diagnosis and modern diagnostic criteria, as well as existing therapy approaches, are discussed.

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.

Auditory and visual hallucination prevalence in Parkinson's disease and dementia with Lewy bodies: a systematic review and meta-analysis

BACKGROUND

Non-motor features of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), such as auditory hallucinations (AH), contribute to disease burden but are not well understood.

METHODS

Systematic review and random-effects meta-analyses of studies reporting AH associated with PD or DLB. Prevalence of visual hallucinations (VH) in identified studies meeting eligibility criteria were included in meta-analyses, facilitating comparison with AH. Synthesis of qualitative descriptions of AH was performed. PubMed, Web of Science and Scopus databases were searched for primary journal articles, written in English, published from 1970 to 2017. Studies reporting AH prevalence in PD or DLB were screened using PRISMA methods.

RESULTS

Searches identified 4542 unique studies for consideration, of which, 26 met inclusion criteria. AH pooled prevalence in PD was estimated to be 8.9% [95% confidence interval (CI) 5.3-14.5], while in DLB was estimated to be 30.8% (±23.4 to 39.3). Verbal hallucinations, perceived as originating outside the head, were the most common form of AH. Non-verbal AH were also common while musical AH were rare. VH were more prevalent, with an estimated pooled prevalence in PD of 28.2% (±19.1 to 39.5), while in DLB they were estimated to be 61.8% (±49.1 to 73.0). Meta-regression determined that the use of validated methodologies to identify hallucinations produced higher prevalence estimates.

CONCLUSIONS

AH and VH present in a substantial proportion of PD and DLB cases, with VH reported more frequently in both conditions. Both AH and VH are more prevalent in DLB than PD. There is a need for standardised use of validated methods to detect and monitor hallucinations.

Argyrophilic Grain Pathology in Frontotemporal Lobar Degeneration: Demographic, Clinical, Neuropathological, and Genetic Features

Frontotemporal lobar degeneration (FTLD) is a clinically, pathologically, and genetically heterogeneous group of disorders that affect the frontal and temporal lobes of the brain. FTLD classification distinguishes three main neuropathological groups: FTLD-tau, FTLD-TDP, and FTLD-FUS. As a four-repeat tauopathy, argyrophilic grain disease (AGD) is included in the FTLD-tau group. AGD may also appear in association with other neuropathological disorders. We describe the demographic, clinical, neuropathological, and genetic characteristics of a series of FTLD cases presenting with AGD. For this purpose, a clinico-pathological study of 71 autopsy-confirmed FTLD cases from different tissue banks was performed. AGD was found in 52.1% of FTLD cases. The presence of AGD increased with the increasing age (up to 88.9% in cases older than 80 years; p < 0.001) and was associated with higher ages at onset (p < 0.001) and death (p < 0.001). In AGD cases, progressive supranuclear palsy (PSP) was the most frequent clinical diagnosis (29.7%) and gait disturbance was the most common symptom (64.5%); behavioral and language symptoms were less frequent as compared with non-AGD cases (p = 0.055; p = 0.012). PSP was the most frequent neuropathological diagnosis among cases with AGD (32.4%). This group also showed less brain atrophy (p = 0.094) and higher prevalence of Alzheimer (p = 0.002) and vascular pathology (p = 0.047) as compared to the non-AGD group. We also observed that H1/H1 genotype was overrepresented in AGD cases (p = 0.018) and that there was no association with any specific APOE allele. A subanalysis of PSP cases according to the AGD status was carried out, yielding no significant differences.

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.

Regional Overlap of Pathologies in Lewy Body Disorders

Lewy body disorders (LBD) are common neurodegenerative diseases characterized by the presence of aggregated α-synuclein in Lewy bodies and Lewy neurites in the central and peripheral nervous systems. The brains of patients with LBD often display other comorbid pathologies, i.e. insoluble tau, β-amyloid aggregates, TAR DNA-binding protein 43 (TDP-43) deposits, and argyrophilic grain disease (AGD). The incidence and physiological relevance of these concurrent pathological findings remain controversial. We performed a semiquantitative detailed mapping of α-synuclein, tau, β-amyloid (Aβ), TDP-43, and AGD pathologies in 17 areas in 63 LBD cases (44 with Parkinson disease [PD], 28 with dementia, and 19 with dementia with Lewy bodies). APOE and MAPT genetic variants were also investigated. A majority of LBD cases had 2 or 3 concomitant findings, particularly Alzheimer disease-related pathology. Pathological stages of tau, β-amyloid and α-synuclein pathologies were increased in cases with dementia. Aβ score was the best correlate of the time to dementia in PD. In addition, β-amyloid deposition correlated with α-synuclein load in all groups. MAPT H1 haplotype did not influence any assessed pathology in PD. These results highlight the common concurrence of pathologies in patients with LBD that may have an impact on the clinical expression of the diseases.

Psychosis in Parkinson's Disease: Epidemiology, Pathophysiology, and Management

Psychotic symptoms are common in Parkinson's disease (PD) and are associated with poorer quality of life and increased caregiver burden. PD psychosis is correlated with several factors, such as more advanced disease, cognitive impairment, depression, and sleep disorders. The underlying causes of psychosis in PD thus involve a complex interplay between exogenous (e.g., drugs, intercurrent illnesses) and endogenous (e.g., PD disease pathology) factors. Current theories of the pathophysiology of PD psychosis have come from several neuropathological and neuroimaging studies that implicate pathways involving visual processing and executive function, including temporo-limbic structures and neocortical gray matter with altered neurotransmitter functioning (e.g., dopamine, serotonin, and acetylcholine). Treatment of PD psychosis requires a step-wise process, including initial careful investigation of treatable triggering conditions and a comprehensive evaluation with adjustment of PD medications and/or initiation of specific antipsychotic therapies. Clozapine remains the only recommended drug for the treatment of PD psychosis; however, because of regular blood monitoring, quetiapine is usually first-line therapy, although less efficacious. Emerging studies have focused on agents involving other neurotransmitters, including the serotonin 5-HT2A receptor inverse agonist pimavanserin, cholinesterase inhibitors, and antidepressants and anxiolytics.

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.

Medial temporal regional argyrophilic grain as a possible important factor affecting dementia in Parkinson's disease

Argyrophilic grain (ArG) is the main pathological feature of argyrophilic grain disease (AGD) and is clinically characterized by cognitive impairment, behavioral abnormalities, personality changes, and emotional imbalances. However, ArG can not only be found in AGD but also in various other neurological disorders, including Parkinson's disease (PD). The association of ArG with psychosis and/or dementia in various neurological disorders remains unknown; in this study, we have investigated this in PD. The distribution and degree of ArG deposition, spongiform change in the transentorhinal cortex (TER SpC), and phosphorylated alpha-synuclein-positive neurites in CA2/3 were assessed, and we used formalin-fixed, paraffin-embedded specimens obtained from the anterior/posterior medial temporal region of 20 autopsy cases diagnosed as PD. These cases were clinically divided into two groups: PD without dementia (PDND) and PD with dementia (PDD). Most PDD cases revealed scattered to numerous ArG or moderate to severe TER SpC, both of which were rarely observed in the PDND group. Furthermore, by the degree of ArG density and TER SpC, the PDD group was further divided into three subtypes: PDD with ArG, with TER SpC and without ArG/TER SpC. Scattered-to-numerous ArG and/or moderate-to-severe TER SpC were observed only in PDD, which suggested that both ArG and TER SpC could be important factors affecting dementia in PD and that their distribution and degree are equally important.

Olfactory function and neuropsychological profile to differentiate dementia with Lewy bodies from Alzheimer's disease in patients with mild cognitive impairment: A 5-year follow-up study

BACKGROUND

Mild cognitive impairment (MCI) is a well-known precursor of Alzheimer's disease (AD) but often also precedes dementia with Lewy bodies (DLB). The early differentiation of DLB from AD is important to delay disease progression. Olfactory dysfunction is a well-known early sign of both AD and Lewy body disorders, including Parkinson's disease (PD) and DLB. Thus, the aim of the present study was to determine whether olfactory and neuropsychological tests can aid in the differentiation of DLB from AD at the MCI stage.

METHODS

The present study included 122 MCI patients who were monitored until they developed dementia or until their condition stabilized; the follow-up period averaged 4.9 years (range: 3.9-6.2 years). Baseline olfactory function as measured with the Cross-Cultural Smell Identification (CCSI) test and neuropsychological data were compared.

RESULTS

During the follow-up period, 32 subjects developed probable AD (MCI-AD), 18 had probable DLB (MCI-DLB), 45 did not convert to dementia (MCI-stable), and eight developed a non-AD/DLB dementia. The mean CCSI score (95% confidence interval [CI]) in patients with MCI-DLB (4.6; 95% CI: 4.0-5.3) was significantly lower than that of MCI-AD patients (6.4; 95% CI: 6.0-6.7, p<0.001) and MCI-stable patients (7.3; 95% CI: 6.9-7.8, p<0.001). The area under the curve of the receiver operating characteristic to discriminate MCI-DLB from MCI-AD using CCSI scores was (0.84; 95% CI: 0.72-0.97). Frontal-executive function and visuospatial ability was worse in patients with MCI-DLB, while verbal recognition memory impairment was greater in those with MCI-AD.

CONCLUSION

Olfactory and neuropsychological tests can help predict conversion to DLB or AD in patients with MCI.

Argyrophilic grain disease: An underestimated tauopathy

Argyrophilic grain disease (AGD) is an under-recognized, distinct, highly frequent sporadic tauopathy, with a prevalence reaching 31.3% in centenarians. The most common AGD manifestation is slowly progressive amnestic mild cognitive impairment, accompanied by a high prevalence of neuropsychiatric symptoms. AGD diagnosis can only be achieved postmortem based on the finding of its three main pathologic features: argyrophilic grains, oligodendrocytic coiled bodies and neuronal pretangles. AGD is frequently seen together with Alzheimer's disease-type pathology or in association with other neurodegenerative diseases. Recent studies suggest that AGD may be a defense mechanism against the spread of other neuropathological entities, particularly Alzheimer's disease. This review aims to provide an in-depth overview of the current understanding on AGD.