Conventional magnetic resonance imaging key features for distinguishing pathologically confirmed corticobasal degeneration from its mimics: a retrospective analysis of the J-VAC study.

PURPOSE: Due to the indistinguishable clinical features of corticobasal syndrome (CBS), the antemortem differentiation between corticobasal degeneration (CBD) and its mimics remains challenging. However, the utility of conventional magnetic resonance imaging (MRI) for the diagnosis of CBD has not been sufficiently evaluated. This study aimed to investigate the diagnostic performance of conventional MRI findings in differentiating pathologically confirmed CBD from its mimics. METHODS: Semiquantitative visual rating scales were employed to assess the degree and distribution of atrophy and asymmetry on conventional T1-weighted and T2-weighted images. Additionally, subcortical white matter hyperintensity (SWMH) on fluid-attenuated inversion recovery images were visually evaluated. RESULTS: In addition to 19 patients with CBD, 16 with CBD mimics (progressive supranuclear palsy (PSP): 9, Alzheimer's disease (AD): 4, dementia with Lewy bodies (DLB): 1, frontotemporal lobar degeneration with TAR DNA-binding protein of 43 kDa(FTLD-TDP): 1, and globular glial tauopathy (GGT): 1) were investigated. Compared with the CBD group, the PSP-CBS subgroup showed severe midbrain atrophy without SWMH. The non-PSP-CBS subgroup, comprising patients with AD, DLB, FTLD-TDP, and GGT, showed severe temporal atrophy with widespread asymmetry, especially in the temporal lobes. In addition to over half of the patients with CBD, two with FTLD-TDP and GGT showed SWMH, respectively. CONCLUSION: This study elucidates the distinct structural changes between the CBD and its mimics based on visual rating scales. The evaluation of atrophic distribution and SWMH may serve as imaging biomarkers of conventional MRI for detecting background pathologies.

Neuronal internalization of immunoglobulin G injected into the mouse brain by a novel absorption strategy to avoid unwanted interaction with immune complex using centrifugal filtration.

Monoclonal immunoglobulin-G (IgG) antibodies are now emerging as therapeutic tools to tackle various disorders, including those affecting the brain. However, little is known about how these IgG molecules behave in the brain. To better understand the potential behavior of IgG molecules in the brain, here we established a specific protocol to immunolocalize rat IgG injected into mouse striatum with an anti-rat IgG antibody. Using double immunolabeling, IgG-like immunoreactivity (IR) was mainly found in neurons but scarcely observed in glia 1 h after intrastriatal injection of IgG, whereas some surrounding glia contained IgG-like IR 24 h after injection. However, preabsorption with a large excess of rat IgG to confirm the authenticity of this labeling failed to eliminate this neuronal IgG-like IR but rather exhibited nuclear staining in glial cells. Because this unexpected nuclear staining escalated with increasing amount of absorbing IgG, we postulated that this nuclear staining is due to formation of immune complex IgG-anti-IgG, which can be removed by centrifugal filtration. As expected, this nuclear staining in glial cells was eliminated after centrifugal filtration of the IgG/anti-IgG mixture, and authentic IgG-like IR was chiefly detected in the cytoplasm of neurons around the injection channel. This study is the first demonstration of neuronal redistribution of injected IgG in the mouse brain. Neuronal internalization of exogenous IgG may be advantageous especially when the therapeutic targets of monoclonal IgG are intraneuronal such as neurofibrillary tangles or Lewy bodies.

An autopsy case of corticobasal syndrome with pure diffuse Lewy Body Disease.

Corticobasal syndrome (CBS) is associated with diverse pathological substrates such as tau, prion protein, transactive response and, rarely, alpha synuclein. We report the case of a54-year-old man, who presented with asymmetric levodopa-poor-responsive parkinsonism, frontal lobe signs and behavioral changes. He was diagnosed with CBS, and postmortem analyses revealed Lewy body disease Braak stage VI without comorbid pathologies. Retrospectively, the clinical course of our patient and previous reports indicate that CBS plus mood changes and autonomic dysfunction, including reduced uptake of metaiodobenzylguanidine, are predictive factors of Lewy body pathology, even if the clinical picture is atypical.

Comorbid argyrophilic grain disease in an 87-year-old male with spinocerebellar ataxia type 31 with dementia: a case report.

BACKGROUND: Spinocerebellar ataxia type 31 (SCA31) is not usually associated with dementia, and autopsy in a patient with both conditions is very rare. CASE PRESENTATION: An 87-year-old male patient presented with ataxia and progressive dementia. Genetic testing led to a diagnosis of SCA31. Fifteen years after his initial symptoms of hearing loss and difficulty walking, he died of aspiration pneumonia. A pathological analysis showed cerebellar degeneration consistent with SCA31 and abundant argyrophilic grains in the hippocampal formation and amygdala that could explain his dementia. CONCLUSIONS: This is the first autopsy report on comorbid argyrophilic grain disease with SCA31.

Secondary cardiac involvement in anti-SRP-antibody-positive myopathy: an 87-year-old woman with heart failure symptoms as the first clinical presentation.

BACKGROUND: Necrotizing myopathy (NM) is defined by the dominant pathological feature of necrosis of muscle fibers without substantial lymphocytic inflammatory infiltration. Anti-signal recognition particle (SRP)-antibody-positive myopathy is related to NM. Anti-SRP-antibody-positive myopathy can comorbid with other disorders in some patients, however, comorbidity with malignant tumor and myopericarditis has still not been reported. CASE PRESENTATION: An 87-year-old woman with dyspnea on exertion and leg edema was referred to our hospital because of suspected heart failure and elevated serum creatine kinase level. Upon hospitalization, she developed muscle weakness predominantly in the proximal muscles. Muscle biopsy and immunological blood test led to the diagnosis of anti-SRP-antibody-positive myopathy. A colon carcinoma was also found and surgically removed. The muscle weakness remained despite the tumor resection and treatment with methylprednisolone. Cardiac screening revealed arrhythmia and diastolic dysfunction with pericardial effusion, which recovered with intravenous immunoglobulin (IVIg) treatment. CONCLUSIONS: We reported the first case of anti-SRP-positive myopathy comorbid with colon carcinoma and myopericarditis. This case is rare in the point that heart failure symptoms were the first clinical presentation. The underlying mechanism is still not clear, however, physicians should be carefully aware of the neoplasm and cardiac involvement in anti-SRP-antibody positive-myopathy patients and should consider farther evaluation and management.

Neurofibrillary changes undergoing morphological and biochemical changes - How does tau with the profile shift of from four repeat to three repeat spread in Alzheimer brain?

The concept of the hierarchal spread of neurofibrillary tangles (NFTs) from the hippocampus to the cortex in Alzheimer's disease (AD)/aging brains, initially proposed by Braak and Braak, revolutionized our understanding by putatively explaining that tau lesions are being unidirectionally extended along neural connections. Because pathological misfolding of tau can serve as a seed to induce identical misfolding on normal tau, this prion-like property is considered to represent a molecular mechanism that may explain such lesion spread. However, double labeling studies for three repeat (3R) and four repeat (4R) tau demonstrated a profile shift in these tau isoforms along chronological change: initially positive only for 4R in early pretangles, gradual involvement of 3R in mature NFTs, and finally replaced by 3R in advanced ghost tangles. This profile shift is hardly explained by aggregation of a single tau molecule. Surprisingly, this profile shift from 4R to 3R tau is shared with the hierarchal spread of NFT around the hippocampus, which is hardly explained by a simple mechanism such as propagation of a single tau molecule. Some molecules other than tau or non-materialist influences such as neuronal activity may be candidate mechanisms to explain this regional profile shift if it is mediated by neural connections. Because this profile shift is shared with brainstem NFTs, it may instead represent a cell autonomous phenomenon, tightly linked with progression of AD but not necessarily linked with prion-like propagation along neural connections. In addition, we recently clarified that posttranslational deamidation of 4R tau at asparagine 279 to aspartate is a marker for AD, distinct from progressive supranuclear palsy (PSP)/corticobasal degeneration (CBD). This may provide another axis to see how AD-NFTs develop and how their 4R tau is distinct from 4R tau of PSP/CBD. Because tau species and their distributions are disease-specific, molecular homogenization, such as "tauopathy" to encompass AD, PSP/CBD and Pick body disease, is just an oversimplification that may obscure fundamental distinctions between human diseases. Careful reference to the realities of human brain disease may provide a solid and fruitful basis to improve diagnostic and therapeutic strategies to tackle these intractable diseases.

Parallel enlargement of Marinesco bodies and nuclei and progressive deposition of p62 in pigmented neurons of the substantia nigra.

Marinesco bodies (MBs) are spherical nuclear inclusions found in pigmented neurons of the substantia nigra. Although MBs are abundant in senescent brains, how they are related to aging processes remains unclear. Here, we performed a morphometric analysis of midbrain pigmented neurons to identify the possible influence of MBs on nuclear size. The transected area of the nucleus (nuclear area) was larger in the presence of MBs and was correlated with the area of MB (MB area) in all tested brains. The MB-associated nuclear enlargement was significant even after MB areas were subtracted from nuclear areas. Moreover, higher MB immunoreactivity of p62 was detected in the nucleoplasm of the enlarged MB-associated nuclei. This study on human brains is the first quantitative approach demonstrating MB-associated nuclear enlargement and progressive accumulation of small nucleoplasmic materials. Although cellular hypertrophy is usually considered to be an indication of the upregulation of cellular function, this might not always be the case. These findings suggest that an age-related decline of ubiquitin-proteasome and autophagy system activity and stagnation of undegradable materials are one of the candidate mechanisms to explain the age-related decline of neural activity in the substantia nigra.

Acute Spinal Cord Infarction with Preferential Involvement of Ventral Gray Matter: An Autopsy Report.

Herein, we report abdominal aortic thrombosis as a rare cause of acute spinal cord infarction. A 78-year-old man with multiple vascular risk factors developed acute paraplegia with sensory and urinary disturbances and signs of ischemia in both lower limbs. The post-mortem study done 3 days after the onset of symptoms revealed a large coagulum in the abdominal aorta, distal to the renal arteries and extending to bilateral common iliac arteries; in addition, marked atherosclerosis was present in most large blood vessels. Premature incomplete necrotic foci were seen in the ventral gray matter of the spinal cord from T6 through S5; the surrounding white matter and dorsal gray matter were spared. Considering our autopsy case, spinal cord gray matter may be more vulnerable to ischemia than the white matter.

Development of demyelinating lesions in progressive multifocal leukoencephalopathy (PML): Comparison of magnetic resonance images and neuropathology of post-mortem brain.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disorder caused by opportunistic infection of JC polyomavirus (JCV). Today, increased attention has been focused on PML development in multiple sclerosis (MS) patients under disease-modifying therapies (DMT). Although in the acquired immunodeficiency syndrome (AIDS) era, PML was thought to be a rapidly progressive disease with poor prognosis, drug-associated PML is relatively slow in progress, and a favorable outcome may be expected with early diagnosis. However, early PML diagnosis on magnetic resonance imaging (MRI) is frequently difficult, and JCV DNA copy number in cerebrospinal fluid (CSF) is usually low. To facilitate early PML diagnosis on MRI, the pre-mortem images were compared with neuropathology of the post-mortem brain, and underlying pathology corresponding to the MRI findings was evaluated. As a result, PML lesions of the autopsied brain were divided into three parts, based on the disease extension patterns: (A) Progressive white matter lesion in the right frontoparietal lobe including the precentral gyrus. Huge demyelinated lesions were formed with fusions of numerous small lesions. (B) Central lesion including deep gray matters, such as the putamen and thalamus. The left thalamic lesion was contiguous with the pontine tegmentum. (C) Infratentorial lesion of brainstem and cerebellum. Demyelination in the pontine basilar region and in cerebellar white matter was contiguous via middle cerebellar peduncles (MCPs). In addition, (D) satellite lesions were scattered all over the brain. These observations indicate that PML lesions likely evolve with three steps in a tract-dependent manner: (1) initiation; (2) extension/expansion of demyelinating lesions; and (3) fusion. Understanding of the PML disease evolution patterns would enable confident early diagnosis on MRI, which is essential for favorable prognosis with good functional outcome.

Does This Adult Patient With Jolt Accentuation of Headache Have Acute Meningitis?

OBJECTIVE: In order to identify appropriate candidates with suspected meningitis for lumbar puncture (LP), study designs and diagnostic values of jolt accentuation of headache (JA) were reviewed. BACKGROUND: Acute meningitis is a life-threatening disease that requires LP for accurate diagnosis. JA was reported the most sensitive indicator of cerebrospinal fluid pleocytosis; however, subsequent studies have failed to confirm this claim. METHODS: We reviewed articles concerning JA, published prior to December 2017, using MEDLINE and Japanese medical databases. Seven original articles based on independent cohorts were eligible for inclusion and articles citing these 7 were thoroughly searched (11 in total). Additionally, all medical records of our previously reported cohort were reviewed again to explore how the patients' background influenced diagnostic values of JA. RESULTS: We hypothesized that an oversimplified dichotomy of JA findings, pleocytosis, and meningitis created a misconception that JA is a universal indicator of meningitis. We clarify the difference between them and present altered mental status (AMS) as a key to decrease the sensitivity of JA. Notably, the sensitivity and specificity of JA were relatively low in unselected groups, while they tended to be high in the selected sub-groups with acute onset of headache and fever, without AMS or neurological deficits. Unselected populations included etiologies of pleocytosis other than acute meningitis, which might weaken the association between JA and pleocytosis. CONCLUSION: JA is not a universal, stand-alone, indicator of meningitis in febrile patients with headache. Therefore, we propose a stepwise approach for patients with suspected acute meningitis. AMS or neurological deficits suggest an intracranial pathology, which may necessitate a lumbar puncture. JA seems a useful tool for distinguishing acute aseptic meningitis from upper respiratory infection when used in the selected cohort of febrile patients (≥37°C) with recent-onset headache (within 2 weeks before presentation) and normal mental status. This approach and diagnostic values of JA should be further investigated by prospective studies using operationally sorted candidates.

Macroscopic Localized Subicular Thinning as a Potential Indicator of Amyotrophic Lateral Sclerosis.

Subicular degeneration occurs in amyotrophic lateral sclerosis (ALS) patients. However, it was unknown whether microscopic subicular degeneration could be observed as macroscopic changes and whether these changes were associated with the transactive-response DNA binding protein 43 kDa (TDP-43) pathology. Topographic differences between subicular degeneration caused by ALS and Alzheimer disease (AD) had also not been characterized. Here we investigated the subiculum and related areas in autopsied brains from 3 ALS and 3 AD patients. Macroscopic subicular thinning and corresponding astrocytosis were pronounced in ALS compared to AD. This thinning was frequently accompanied by TDP-43 pathology in the transentorhinal cortex and nucleus accumbens. The preferential susceptibility of the perforant pathway to TDP-43 deposition may be an underlying cause of subicular thinning in ALS.

An order in Lewy body disorders: Retrograde degeneration in hyperbranching axons as a fundamental structural template accounting for focal/multifocal Lewy body disease.

Initial clinical recognition of "paralysis agitans" by James Parkinson was expanded by Jean-Martin Charcot, who recognized additional clinical findings of his own, such as slowness (distinct from paralysis), rigidity (distinct from spasticity) and characteristic countenance. Charcot assembled these findings under the umbrella of "Parkinson disease (PD)". This purely clinical concept was so prescient and penetrating that subsequent neuropathological and biochemical evidences were ordered along this axis to establish the nigra-central trinity of PD (dopamine depletion, nigral lesion with Lewy bodies: LBs). Although dramatic efficacy of levodopa boosted an enthusiasm for this nigra-centralism, extranigral lesions were identified, especially after identification of alpha-synuclein (αS) as a major constituent of LBs. Frequent αS lesions in the lower brainstem with their presumed upward spread were coupled with the self-propagating property of αS molecule, as a molecular template, to constitute the prion-Braak hypothesis. This hybrid concept might expectedly explain clinical, structural and biochemical features of PD/dementia with Lewy bodies (DLB) as if they were stereotypic. In spite of this ordered explanation, recent studies have demonstrated unexpectedly that αS lesions in the human brain, as well as their corresponding clinical manifestations, are much more disordered. Even with such a chaos of LB disorders, affected neuronal groups are uniformly characterized by hyperbranching axons, which may facilitate distal-dominant degeneration and retrograde progression of LB-related degeneration along axons as a fundamental structural order to template LB disorders. This "structural template" hypothesis may explain why: (i) some selective groups are prone to develop Lewy pathology; (ii) their clinical manifestations (especially non-motor components) are vague and generalized without somatotopic accentuation; (iii) distal axons and terminals are preferentially affected early, which is clinically detectable as reduced myocardial uptake of meta-iodobenzylguanidine in PD/DLB. Because each Lewy-prone system develops LBs independently, their isolated presentation as "focal LB disease" or their whatever combinations as "multifocal LB disease" are a more plausible framework to explain clinicopathological diversities of LB disorders. Clinical criteria are now being revised to integrate these clinicopathological disorders of PD/DLB. To gain closer access to the reality of the human brain, it is necessary to facilitate more interactions between clinicopathological and experimental fields so that both are mutually critical and complementary for improved diagnosis and treatment.

Perirhinal accumulation of neuronal alpha-synuclein in a multiple system atrophy patient with dementia.

We report the case of a 79-year-old Japanese woman who developed cerebellar ataxia followed by rigidity, dysautonomia and cognitive disorders, and was thus clinically diagnosed as having possible MSA with dementia. Neuropathological findings demonstrated not only olivopontocerebellar and striatonigral degeneration with frequent glial cytoplasmic inclusions (GCIs), but also degenerative changes in the parahippocampal region, accentuated in the anterior portion of perirhinal cortex, where neuronal cytoplasmic inclusions (NCIs) and NFTs were numerous while GCIs were limited. NCIs were frequent in the deep layer, whereas NFTs were more frequent in superficial cortical layers. Other hippocampal subregions including subiculum, dentate fascia and cornu ammonis were minimally involved. NCIs in the perirhinal cortex showed intense argyrophilia with the Campbell-Switzer silver impregnation method, but not argyrophilic with the Gallyas method. Most neuronal alpha-synuclein aggregates in dendrosomatic fraction formed globular/tadpole-like, and ultrastructurally comprised granular-coated fine fibrils 12-24 nm in diameter. To the best of our knowledge, alpha-synuclein-related neuronal pathology localized in the perirhinal region without hippocampal involvement has not been previously reported in MSA, and may provide clues to elucidate how neuronal pathology evolves in the hippocampal/parahippocampal regions in MSA, particularly in cases with dementia.

Propagation of alpha-synuclein pathology: hypotheses, discoveries, and yet unresolved questions from experimental and human brain studies.

Progressive aggregation of alpha-synuclein (αS) through formation of amorphous pale bodies to mature Lewy bodies or in neuronal processes as Lewy neurites may be the consequence of conformational protein changes and accumulations, which structurally represents "molecular template". Focal initiation and subsequent spread along anatomically connected structures embody "structural template". To investigate the hypothesis that both processes might be closely associated and involved in the progression of αS pathology, which can be observed in human brains, αS amyloidogenic precursors termed "seeds" were experimentally injected into the brain or peripheral nervous system of animals. Although these studies showed that αS amyloidogenic seeds can induce αS pathology, which can spread in the nervous system, the findings are still not unequivocal in demonstrating predominant transsynaptic or intraneuronal spreads either in anterograde or retrograde directions. Interpretation of some of these studies is further complicated by other concurrent aberrant processes including neuroimmune activation, injury responses and/or general perturbation of proteostasis. In human brain, αS deposition and neuronal degeneration are accentuated in distal axon/synapse. Hyperbranching of axons is an anatomical commonality of Lewy-prone systems, providing a structural basis for abundance in distal axons and synaptic terminals. This neuroanatomical feature also can contribute to such distal accentuation of vulnerability in neuronal demise and the formation of αS inclusion pathology. Although retrograde progression of αS aggregation in hyperbranching axons may be a consistent feature of Lewy pathology, the regional distribution and gradient of Lewy pathology are not necessarily compatible with a predictable pattern such as upward progression from lower brainstem to cerebral cortex. Furthermore, "focal Lewy body disease" with the specific isolated involvement of autonomic, olfactory or cardiac systems suggests that spread of αS pathology is not always consistent. In many instances, the regional variability of Lewy pathology in human brain cannot be explained by a unified hypothesis such as transsynaptic spread. Thus, the distribution of Lewy pathology in human brain may be better explained by variable combinations of independent focal Lewy pathology to generate "multifocal Lewy body disease" that could be coupled with selective but variable neuroanatomical spread of αS pathology. More flexible models are warranted to take into account the relative propensity to develop Lewy pathology in different Lewy-prone systems, even without interconnections, compatible with the expanding clinicopathological spectra of Lewy-related disorders. These revised models are useful to better understand the mechanisms underlying the variable progression of Lewy body diseases so that diagnostic and therapeutic strategies are improved.

PART is part of Alzheimer disease.

It has been proposed that tau aggregation confined to entorhinal cortex and hippocampus, with no or only minimal Aß deposition, should be considered as a 'primary age-related tauopathy' (PART) that is not integral to the continuum of sporadic Alzheimer disease (AD). Here, we examine the evidence that PART has a pathogenic mechanism and a prognosis which differ from those of AD. We contend that no specific property of the entorhinal-hippocampal tau pathology makes it possible to predict either a limited progression or the development of AD, and that biochemical differences await an evidence base. On the other hand, entorhinal-hippocampal tau pathology is an invariant feature of AD and is always associated with its development. Rather than creating a separate disease entity, we recommend the continued use of an analytical approach based on NFT stages and Aß phases with no inference about hypothetical disease processes.

Quantitative correlation between cardiac MIBG uptake and remaining axons in the cardiac sympathetic nerve in Lewy body disease.

OBJECTIVES: Reduced cardiac meta-iodobenzylguanidine (MIBG) uptake and loss of cardiac sympathetic axons, as its possible anatomical substrate, were both recognised in Lewy body disease (LBD), while their direct correlation has so far remained speculative. Increasing availability of autopsy-confirmed cases of LBD prompted us to quantify residual cardiac sympathetic axons to establish their relationship to cardiac MIBG uptake. METHODS: We collected cardiac tissue samples from 23 patients with autopsy-confirmed LBD and two non-LBD control patients who underwent (123)I-MIBG cardiac scintigraphy in life. Samples of the left ventricular anterior wall were stained with anti-tyrosine hydroxylase (TH) and anti-neurofilament (NF) antibodies as markers of cardiac nerve axons. We quantified the immunolabelled areas and assessed their correlation to standardised heart to mediastinum (H/M) ratios of (123)I-MIBG cardiac scintigraphy. RESULTS: Cardiac MIBG uptake in the early and delayed phases was reduced in 90.9% and 95.7% of patients with LBD, respectively. The area of TH-immunoreactive axons correlated significantly with the H/M ratio in the early (p=0.036) as well as in the delayed (p=0.018) phases. The area of NF-immunoreactive axons also correlated with the H/M ratio in the early (p=0.003) as well as in the delayed (p=0.001) phases. CONCLUSIONS: Tight quantitative correlation between cardiac (123)I-MIBG uptake and corresponding loss of sympathetic axons in LBD, as established for the first time by this study, provides a scientific basis to confirm the reliability of MIBG cardiac scintigraphy as a powerful clinical tool to detect loss of these axons as a biomarker for the presence of Lewy body disease.