Argyrophilic grain disease: An update on a frequent cause of dementia

Abstract

Argyrophilic grain disease (AGD) is a sporadic, very late-onset tauopathy, accounting for approximately 4–13% of neurodegenerative dementias. AGD may manifest with a range of symptoms such as cognitive decline and behavioral abnormalities. To date, no study has been able to demonstrate a distinct clinical syndrome associated with AGD. The diagnosis is exclusively based on postmortem findings, the significance of which remains controversial because up to 30% of AGD cases are diagnosed in subjects without any cognitive impairment, while AGD findings often overlap with those of other neurodegenerative processes. Nevertheless, the presence of AGD is likely to have a significant effect on cognitive decline. The neuropathological hallmarks of AGD are argyrophilic grains, pre-neurofibrillary tangles in neurons and coiled bodies in oligodendrocytes found mainly in the entorhinal cortex and hippocampus. This review aims to provide an up-to-date overview of AGD, emphasizing pathological aspects. Additionally, the findings of a Brazilian case series are described.

The Neuropathology of Huntington’s Disease: Classical Findings, Recent Developments and Correlation to Functional Neuroanatomy

“…Along with shrunken nerve cells, ballooned nerve cells represent the vast majority of remaining cerebellar nerve cells of HD patients and have also been abundantly observed in the degenerated thalamus and brainstem of clinically diagnosed and genetically confi rmed HD patients (Figs. They may also occur in large quantities at multiple brain sites in human tauopathies (i.e., Alzheimer's disease, AD; argyrophilic grains disease, AGD; corticobasal degeneration, CBD; progressive supranuclear palsy, PSP), but their brain distribution pattern in these human tauopathies is different from that observable in HD (Dickson 1999 ;Fujino et al 2004 ;Grinberg and Heinsen 2009 ;Kato et al 1992 ;Rüb et al 2013a ;Stover and Watts 2001 ). 5.2 ).…”

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

“…In our study, there were no AGD‐like clinical symptoms, such as behavioral abnormalities, personality changes and emotional/mood imbalances, in any of the cases of PD with ArG, but the presence of ArG was associated with dementia, as observed in previous studies . With regard to correlation between ArG and non‐motor symptoms, particularly psychosis, in PD, Grau‐Rivera et al .…”

“…For distribution of ArG, we also used the staging system of ArG proposed by Saito et al 17 On the basis of the clinical and pathological findings, we classified the 20 PD cases into those with dementia and those without dementia, and the latter group was divided into three subtypes. The following four groups resulted: PD without dementia (PDND, n = 8; cases 1-8), PDD with ArG (PDD-ArG, n = 5; cases 9-13), PDD with TER SpC (PDD-TER SpC, n = 5; cases [14][15][16][17][18], and PDD with neither ArG nor TER SpC (PDD not otherwise specified (PDD-NOS), n = 2; cases 19 and 20) (Tables 1, 3,4). Two of the 20 PD cases analyzed revealed AGD pathology and both were in the PDD-ArG group (cases 9 and 11).…”

“…AGD is well known as an adult‐onset progressive neurodegenerative disorder with dementia; it is clinically characterized by cognitive decline, dementia, behavioral abnormalities, personality changes and emotional/mood imbalances, and pathologically characterized by the presence of ArG in the entorhinal cortex (ER), transentorhinal cortex (TER), hippocampus (particularly CA1), amygdala and neighboring temporal cortex …”

“…2 Furthermore, ArG has also been shown to be mainly associated with dendrites rather than axons. 2 AGD is well known as an adult-onset progressive neurodegenerative disorder with dementia; it is clinically characterized by cognitive decline, dementia, behavioral abnormalities, personality changes and emotional/mood imbalances, 3,4 and pathologically characterized by the presence of ArG in the entorhinal cortex (ER), transentorhinal cortex (TER), hippocampus (particularly CA1), amygdala and neighboring temporal cortex. 1,3,5,6 Further, it is also well known that ArG is sometimes present in various other conditions, including: Alzheimer's disease; Lewy body disease (LBD), including Parkinson's disease (PD) and dementia with Lewy bodies (DLB); corticobasal degeneration; progressive supranuclear palsy; Pick's disease; amyotrophic lateral sclerosis; frontotemporal dementia; hippocampal sclerosis; vascular lesions; and non-demented aging.…”