RESUMO
BACKGROUND AND PURPOSE: Decreased plasma progranulin levels are a very specific marker for the diagnosis of frontotemporal lobar degeneration (FTLD) caused by mutations in the progranulin gene (GRN). A frequent neuroimaging pattern in this type of dementia is asymmetric cortical atrophy. The aim of this study was to screen for GRN-linked FTLD in cases with different cortical dementia phenotypes and asymmetric perisylvian atrophy. METHODS: Progranulin plasma levels were analyzed in a variety of FTLD phenotypes (n = 71), dementia of the Alzheimer type (DAT) (n = 22) and probable Lewy body dementia (n = 8), both latter groups presented with asymmetric perisylvian atrophy. A group of elderly controls (n = 29) and DAT cases with symmetric atrophy (n = 33) were also analyzed. The GRN gene was sequenced in cases with lower plasma levels. RESULTS: Four cases with clinical FTLD phenotypes and plasma levels below 70 ng/ml were found to carry different GRN mutations: M1?, C139R, a point mutation in the splice donor site of intron 3 (A89VfsX41), and a deletion in exon 9 (A303AfsX57), this latter one being a new mutation. Thirteen cases with levels between 72 and 85 ng/ml did not show pathogenic changes in the GRN gene. None of the cases with asymmetric atrophy and clinical phenotypes other than FTLD had GRN mutations. CONCLUSIONS: Asymmetric perisylvian atrophy is not likely to predict progranulin-linked FTLD unless it is associated with a consistent FTLD clinical phenotype.
Assuntos
Demência/sangue , Demência/patologia , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Idoso , Idoso de 80 Anos ou mais , Atrofia , Demência/genética , Ensaio de Imunoadsorção Enzimática , Feminino , Degeneração Lobar Frontotemporal/sangue , Degeneração Lobar Frontotemporal/genética , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Mutação , Fenótipo , ProgranulinasRESUMO
OBJECTIVE: Age at onset of diagnostic motor manifestations in Huntington disease (HD) is strongly correlated with an expanded CAG trinucleotide repeat. The length of the normal CAG repeat allele has been reported also to influence age at onset, in interaction with the expanded allele. Due to profound implications for disease mechanism and modification, we tested whether the normal allele, interaction between the expanded and normal alleles, or presence of a second expanded allele affects age at onset of HD motor signs. METHODS: We modeled natural log-transformed age at onset as a function of CAG repeat lengths of expanded and normal alleles and their interaction by linear regression. RESULTS: An apparently significant effect of interaction on age at motor onset among 4,068 subjects was dependent on a single outlier data point. A rigorous statistical analysis with a well-behaved dataset that conformed to the fundamental assumptions of linear regression (e.g., constant variance and normally distributed error) revealed significance only for the expanded CAG repeat, with no effect of the normal CAG repeat. Ten subjects with 2 expanded alleles showed an age at motor onset consistent with the length of the larger expanded allele. CONCLUSIONS: Normal allele CAG length, interaction between expanded and normal alleles, and presence of a second expanded allele do not influence age at onset of motor manifestations, indicating that the rate of HD pathogenesis leading to motor diagnosis is determined by a completely dominant action of the longest expanded allele and as yet unidentified genetic or environmental factors.
Assuntos
Doença de Huntington/genética , Expansão das Repetições de Trinucleotídeos , Adulto , Idade de Início , Alelos , Feminino , Genótipo , Humanos , Doença de Huntington/diagnóstico , MasculinoRESUMO
The dementia with Lewy bodies (DLB) Consortium has revised criteria for the clinical and pathologic diagnosis of DLB incorporating new information about the core clinical features and suggesting improved methods to assess them. REM sleep behavior disorder, severe neuroleptic sensitivity, and reduced striatal dopamine transporter activity on functional neuroimaging are given greater diagnostic weighting as features suggestive of a DLB diagnosis. The 1-year rule distinguishing between DLB and Parkinson disease with dementia may be difficult to apply in clinical settings and in such cases the term most appropriate to each individual patient should be used. Generic terms such as Lewy body (LB) disease are often helpful. The authors propose a new scheme for the pathologic assessment of LBs and Lewy neurites (LN) using alpha-synuclein immunohistochemistry and semiquantitative grading of lesion density, with the pattern of regional involvement being more important than total LB count. The new criteria take into account both Lewy-related and Alzheimer disease (AD)-type pathology to allocate a probability that these are associated with the clinical DLB syndrome. Finally, the authors suggest patient management guidelines including the need for accurate diagnosis, a target symptom approach, and use of appropriate outcome measures. There is limited evidence about specific interventions but available data suggest only a partial response of motor symptoms to levodopa: severe sensitivity to typical and atypical antipsychotics in approximately 50%, and improvements in attention, visual hallucinations, and sleep disorders with cholinesterase inhibitors.
Assuntos
Encéfalo/patologia , Encéfalo/fisiopatologia , Doença por Corpos de Lewy/diagnóstico , Doença por Corpos de Lewy/fisiopatologia , Encéfalo/metabolismo , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Corpo Estriado/fisiopatologia , Diagnóstico Diferencial , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Tolerância a Medicamentos/fisiologia , Humanos , Corpos de Lewy/metabolismo , Corpos de Lewy/patologia , Doença por Corpos de Lewy/tratamento farmacológico , Transtorno do Comportamento do Sono REM/diagnóstico , Transtorno do Comportamento do Sono REM/etiologia , Transtorno do Comportamento do Sono REM/fisiopatologia , alfa-Sinucleína/metabolismoRESUMO
Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) are neurodegenerative disorders that share progressive dementia as the common major clinical symptom. Damages to memory-related brain structures are the likely pathological correlate, and in both illnesses deposition of amyloidogenic proteins are present mainly within these limbic structures. Amyloid-beta-positive plaques and phospho-tau-positive neurofibrillary tangles are the main feature of AD and alpha-synuclein-positive Lewy bodies and Lewy neurites are found in DLB. Interestingly the associated proteins also interfere with synaptic function and synaptic plasticity. Here, we propose that the same neuronal circuits are disturbed within the hippocampal formation in AD and DLB and that in both diseases the associated proteins might lead to changes in synaptic plasticity and function. Thus both classic neuropathological changes and cellular dysfunctions might contribute to the cognitive impairments in AD and DLB.
Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença por Corpos de Lewy/metabolismo , Doença por Corpos de Lewy/patologia , Neuritos/patologia , Plasticidade Neuronal , Transmissão Sináptica , Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Animais , Humanos , Doença por Corpos de Lewy/fisiopatologia , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Transtornos da Memória/fisiopatologia , Degeneração Neural/metabolismo , Degeneração Neural/patologia , Degeneração Neural/fisiopatologia , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/metabolismo , Vias Neurais/metabolismo , Vias Neurais/patologia , Vias Neurais/fisiopatologia , Sinucleínas , alfa-SinucleínaRESUMO
Huntington disease (HD) is a neurodegenerative disorder caused by the abnormal expansion of CAG repeats in the HD gene on chromosome 4p16.3. Past studies have shown that the size of expanded CAG repeat is inversely associated with age at onset (AO) of HD. It is not known whether the normal Huntington allele size influences the relation between the expanded repeat and AO of HD. Data collected from two independent cohorts were used to test the hypothesis that the unexpanded CAG repeat interacts with the expanded CAG repeat to influence AO of HD. In the New England Huntington Disease Center Without Walls (NEHD) cohort of 221 HD affected persons and in the HD-MAPS cohort of 533 HD affected persons, we found evidence supporting an interaction between the expanded and unexpanded CAG repeat sizes which influences AO of HD (P = 0.08 and 0.07, respectively). The association was statistically significant when both cohorts were combined (P = 0.012). The estimated heritability of the AO residual was 0.56 after adjustment for normal and expanded repeats and their interaction. An analysis of tertiles of repeats sizes revealed that the effect of the normal allele is seen among persons with large HD repeat sizes (47-83). These findings suggest that an increase in the size of the normal repeat may mitigate the expression of the disease among HD affected persons with large expanded CAG repeats.
Assuntos
Doença de Huntington/genética , Repetições de Trinucleotídeos , Adolescente , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos de Coortes , Humanos , Pessoa de Meia-Idade , New England , Probabilidade , Taxa de SobrevidaRESUMO
INTRODUCTION: Huntington s disease has been clearly recognized since 1872. It is characterized by the appearance of a motor disorder (chorea) accompanied by selective cognitive deterioration which is not interfered with by aging. DEVELOPMENT: Since the genetic defect causing it has been identified (expansion of CAG triplets on the IT 15 gene of chromosome 4) it has been possible to study families from the preclinical stage (asymptomatic persons who carried the mutation) to the stage of full development of the clinical syndrome. The behaviour disorders most often seen in these patients are depression, mania, schizophrenia, paranoia, anxiety, obsessive and obsessive compulsive disorders although other disorders may also occur. Different clinical forms of motor disorders and dementia have been reported in relation to the age of onset of the symptoms. The commonest cognitive symptoms are defects of attention, memory, planning, sequencing and visuo spatial deficits, as occurs in subcortical dementia. Our objective is to present the different clinical forms of the disorder according to the age of presentation, implication of the symptoms, severity of the genetic defect (number of CAG triplets) and to describe the study made of asymptomatic carriers so as to be able to detect incipient cognitive deterioration in these persons.
Assuntos
Doença de Huntington/diagnóstico , Adolescente , Adulto , Idade de Início , Criança , Transtornos Cognitivos/etiologia , Humanos , Doença de Huntington/genética , Doença de Huntington/fisiopatologia , Pessoa de Meia-IdadeRESUMO
Oculomotor abnormalities have long been recognized in Huntington's disease (HD). The precise correlation between them and other clinical findings has not yet been determined. Using videonystagmography, we studied reflexive, visually guided horizontal saccades in 32 patients with genetically confirmed HD: nine female and 23 male patients, including six with young onset HD (YOHD), 19 with adult onset HD (AOD), and seven with late onset HD (LOHD). Huntington's patients exhibited increased saccade latency (P < 0.05), decreased saccade velocity (P < 0.0005), and impaired saccade accuracy (P < 0.01). A significant difference between the different groups of patients could be determined, and YOHD was characterized by normal latency and decreased saccade velocity while LOHD showed increased saccade latency but normal velocity. Furthermore, we found a significant difference between the genetic data (length of CAG-repeats) and saccadic abnormalities, with higher repeat numbers corresponding to shorter latency and decreased velocity, as in YOHD. The study of saccade parameters might be useful as an objective method for testing the effectiveness of future therapies.
Assuntos
Doença de Huntington/diagnóstico , Movimentos Sacádicos , Adolescente , Adulto , Fatores Etários , Idoso , Eletronistagmografia , Feminino , Seguimentos , Humanos , Doença de Huntington/genética , Masculino , Pessoa de Meia-Idade , Fenótipo , Tempo de Reação/genética , Movimentos Sacádicos/genética , Gravação em VídeoRESUMO
BACKGROUND: Studies of patients meeting clinical and pathologic criteria for Alzheimer disease (AD) have not consistently found associations between the presence of Lewy bodies (LBs) at postmortem examination and a higher frequency during life of the clinical features of dementia with LBs. OBJECTIVE: To evaluate the clinical correlates of LBs in patients with AD. DESIGN AND METHODS: Fifty-one patients were diagnosed as having probable AD during life and met pathologic criteria for AD. Semiquantitative ratings for LBs were obtained in 4 brain regions: substantia nigra, cingulate, insular cortex, and hippocampus. The patients had been followed up semiannually for up to 9.9 years before death, and clinical features associated with dementia with LBs, including extrapyramidal signs and visual hallucinations, were assessed at each study visit. Logistic regression analyses determined whether patients who had LBs were more likely than those without LBs to express specific clinical signs during follow-up. Cox analyses determined whether patients with LBs developed clinical signs or died earlier. Generalized estimating equations were used to compare rates of cognitive or functional change. RESULTS: Nineteen of the 51 patients had at least 1 LB in one of the studied regions. In no case was a significant relation noted between LBs and the presence of a measured clinical sign. No LB measure was associated with an increased risk of developing any of the evaluated clinical signs earlier in the disease. There was no association between the presence of LBs and more rapid mortality or more rapid disease progression. CONCLUSIONS: In patients diagnosed as having AD during life, we did not observe a relation of LBs noted during postmortem examination with the presence of any clinical feature that we assessed or with the rapidity of disease progression. The relation between LBs and specific clinical manifestations may be tenuous in these patients.
Assuntos
Doença de Alzheimer/patologia , Encéfalo/patologia , Corpos de Lewy/patologia , Idoso , Doença de Alzheimer/mortalidade , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Valor Preditivo dos Testes , Índice de Gravidade de DoençaRESUMO
Morphometric studies of the tail of the caudate nucleus, the site where the pathology is first seen, were performed on 16 brain specimens collected from individuals at risk for inheriting Huntington's disease (HD). Medical records and information obtained from immediate family members indicated that all had died without symptoms of HD. Six individuals had 37 or more CAG repeats and were designated HD gene carriers, whereas 10 were determined to be non-carriers. Cell counts of the tail of the caudate nucleus revealed an increased density of oligodendrocytes among the presymptomatic HD gene carriers (mean cells/field: carriers = 40.0, noncarrier = 21.3; age, sex, repeated measure adjusted F[126] = 11.7, p = 0.0008). No statistically significant differences were found between HD carriers and noncarriers in the density of neurons (carriers = 16.9, noncarriers = 15.5), astrocytes (carriers = 27.8, noncarriers = 21.3) or microglial cells (carriers = 7.9, noncarriers = 5.6). Ubiquitin immunostaining performed in 3 gene carriers revealed intranuclear inclusions in all 3 cases, including 1, with 37 repeats, who died 3 decades before the expected age for onset of the clinical syndrome. Normal densities of other cell types and careful macroscopic examination suggest that the increase in oligodendroglial density is not a consequence of atrophy and may instead reflect a developmental effect of the HD gene.
Assuntos
Núcleo Caudado/patologia , Doença de Huntington/patologia , Adulto , Idoso , Feminino , Humanos , Imuno-Histoquímica , Lactente , Masculino , Pessoa de Meia-IdadeRESUMO
The consistent regional and laminar distribution of cortical Lewy bodies (LB) in brains of patients with dementia with Lewy bodies (DLB) suggests that only a certain subpopulation of neurons develops these alpha-synuclein-immunoreactive cytoplasmic inclusions. This study examined whether four non-overlapping neuronal subpopulations, defined by the expression of non-phosphorylated neurofilaments (SMI-32) and several calcium binding proteins (parvalbumin, calretinin and calbindin D28k), are vulnerable to LB formation. We performed peroxidase immunostaining to examine the distribution and to quantitate each neuronal subpopulation within the superior temporal sulcus (STS) area, and double-label immunohistochemistry to test for colocalization of alpha-synuclein and each neuronal marker in the STS and the entorhinal cortex. There were no significant differences between DLB brains and controls in the proportional quantity or laminar distribution of each neuronal subpopulation. Parvalbumin-immunoreactive neurons represented around 7%, calbindin D28k 8%, calretinin 10%, and SMI-32 about 20% of the total neuronal population in the STS cortex. Neurons expressing parvalbumin and SMI-32 showed a widespread distribution across layers II to VI. Neurons expressing calretinin were present in superficial layers (II to IV), and calbindin D28k-immunoreactive neurons were mostly distributed within granular layers II and IV. None of the LB observed in the STS or the entorhinal cortex were located in neurons expressing calcium binding proteins; 25% of the LB were contained in SMI-32 immunoreactive neurons. In conclusion, cortical neurons expressing calcium binding proteins are spared in DLB, while SMI-32-positive neurons are affected in proportion to their density in the cortex. However, the majority of cortical LB develop in neurons not identified by any of these markers.
Assuntos
Proteínas de Ligação ao Cálcio/análise , Doença por Corpos de Lewy/patologia , Neurônios/patologia , Lobo Temporal/patologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Feminino , Humanos , Doença por Corpos de Lewy/fisiopatologia , MasculinoRESUMO
Amyloid beta protein deposition in cortical and leptomeningeal vessels, causing the most common type of cerebral amyloid angiopathy, is found in sporadic and familial Alzheimer's disease (AD) and is the principal feature in the hereditary cerebral hemorrhage with amyloidosis, Dutch type. The presence of the Apolipopriotein E (APOE)-epsilon4 allele has been implicated as a risk factor for AD and the development of cerebral amyloid angiopathy in AD. We report clinical, pathological and biochemical studies on two APOE-epsilon4 homozygous subjects, who had senile dementia and whose main neuropathological feature was a severe and diffuse amyloid angiopathy associated with perivascular tau neurofibrillary pathology. Amyloid beta protein and ApoE immunoreactivity were observed in leptomeningeal vessels as well as in medium-sized and small vessels and capillaries in the parenchyma of the neocortex, hippocampus, thalamus, cerebellum, midbrain, pons, and medulla. The predominant peptide form of amyloid beta protein was that terminating at residue Val40, as determined by immunohistochemistry, amino acid sequence and mass spectrometry analysis. A crown of tau-immunopositive cell processes was consistently present around blood vessels. DNA sequence analysis of the Amyloid Precursor Protein gene and Presenilin-1 (PS-1) gene revealed no mutations. In these APOE-epsilon4 homozygous patients, the pathological process differed from that typically seen in AD in that they showed a heavy burden of perivascular tau-immunopositive cell processes associated with severe amyloid beta protein angiopathy, neurofibrillary tangles, some cortical Lewy bodies and an absence of neuritic plaques. These cases emphasize the concept that tau deposits may be pathogenetically related to amyloid beta protein deposition.
Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Apolipoproteínas E/genética , Angiopatia Amiloide Cerebral/metabolismo , Angiopatia Amiloide Cerebral/patologia , Proteínas tau/metabolismo , Idoso , Alelos , Doença de Alzheimer/genética , Apolipoproteína E4 , Apolipoproteínas E/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Angiopatia Amiloide Cerebral/genética , Progressão da Doença , Genótipo , Homozigoto , Humanos , Masculino , Neurônios/metabolismo , Neurônios/patologia , Testes Neuropsicológicos , Placa Amiloide/metabolismo , Placa Amiloide/patologia , Desempenho PsicomotorRESUMO
The cortex of the brain is organized into clear horizontal layers, laminae, which subserve much of the connectional anatomy of the brain. We hypothesize that there is also a vertical anatomical organization that might subserve local interactions of neuronal functional units, in accord with longstanding electrophysiological observations. We develop and apply a general quantitative method, inspired by analogous methods in condensed matter physics, to examine the anatomical organization of the cortex in human brain. We find, in addition to obvious laminae, anatomical evidence for tightly packed microcolumnar ensembles containing approximately 11 neurons, with a periodicity of about 80 microm. We examine the structural integrity of this new architectural feature in two common dementing illnesses, Alzheimer disease and dementia with Lewy bodies. In Alzheimer disease, there is a dramatic, nearly complete loss of microcolumnar ensemble organization. The relative degree of loss of microcolumnar ensembles is directly proportional to the number of neurofibrillary tangles, but not related to the amount of amyloid-beta deposition. In dementia with Lewy bodies, a similar disruption of microcolumnar ensemble architecture occurs despite minimal neuronal loss. These observations show that quantitative analysis of complex cortical architecture can be applied to analyze the anatomical basis of brain disorders.
Assuntos
Doença de Alzheimer/patologia , Córtex Cerebral/patologia , Doença por Corpos de Lewy/patologia , Neurônios/patologia , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/citologia , Humanos , Processamento de Imagem Assistida por Computador , Neurônios/citologiaRESUMO
alpha-Synuclein is a presynaptic protein recently identified as a specific component of Lewy bodies (LB) and Lewy neurites. The aim of this study was to assess the morphology and distribution of alpha-synuclein immunoreactivity in cases of dementia with LB (DLB), and to compare alpha-synuclein with ubiquitin immunostaining. We examined substantia nigra, paralimbic regions (entorhinal cortex, cingulate gyrus, insula and hippocampus), and neocortex (frontal and occipital association cortices) with double alpha-synuclein and ubiquitin immunostaining in 25 cases meeting neuropathological criteria for DLB. alpha-Synuclein immunostaining was more specific than ubiquitin immunostaining in that it differentiated LB from globose tangles. It was also slightly more sensitive, staining 4-5% more intracytoplasmic structures, especially diffuse alpha-synuclein deposits that were ubiquitin negative. In addition to LB, alpha-synuclein staining showed filiform and globose neurites in the substantia nigra, CA2-3 regions of the hippocampus, and entorhinal cortex. A spectrum of alpha-synuclein staining was seen in substantia nigra: from diffuse "cloud-like" inclusions to aggregated intracytoplasmic inclusions with variable ubiquitin staining to classic LB. We hypothesize that these represent different stages in LB formation.
Assuntos
Encéfalo/patologia , Doença por Corpos de Lewy/patologia , Proteínas do Tecido Nervoso/análise , Neurônios/patologia , Ubiquitinas/análise , Idoso , Idoso de 80 Anos ou mais , Feminino , Imunofluorescência , Humanos , Corpos de Lewy/patologia , Sistema Límbico/patologia , Masculino , Pessoa de Meia-Idade , Neocórtex/patologia , Neuritos/patologia , Substância Negra/patologia , Sinucleínas , alfa-SinucleínaRESUMO
Huntington's disease (HD) is characterized by the presence of hyperkinesias, but bradykinesia is also present in most patients. We studied the motor performance of 18 patients with genetically proven HD (age, 38.5 +/- 10 y; clinical stage, 1.7 +/- 1.7; (CAG) triplet length, 49.2 +/- 6.8 triplets; all but three patients were free from neuroleptics) and compared with a control group (n = 18) and with a typical Parkinson's disease (PD) group (n = 20). Motor study included the four timed tests commonly used for PD: Pronation-supination (PS), finger dexterity (FD), movement between two points (MTP) and walking test (WT). Tests were done at 9 AM. The PD group was studied in "off" condition, with no medication given for 12 hours. The HD group was slower than the controls on all tasks (all tests significant, p < 0.01, Mann-Whitney U test) and even slower than PD group (for FD, p < 0.05). A significant correlation was found between each test and clinical stage (for PS, r = 0.84; for FD, r = 0.75; for MTP, r = 087, and for WT, r = 0.77, Pearson). Severe bradykinesia was present in HD, and motor impairment is related to clinical stage.
Assuntos
Doença de Huntington/fisiopatologia , Hipocinesia/fisiopatologia , Adulto , Humanos , Atividade Motora , Doença de Parkinson/complicações , Doença de Parkinson/fisiopatologia , Desempenho PsicomotorRESUMO
Dementia with Lewy bodies (DLB) is characterized pathologically by widespread Lewy body (LB) neuronal inclusions in the brain, but the contribution of LBs to the clinical syndrome of dementia and parkinsonism is unclear. In a clinical-pathological study of 25 cases with DLB, we examined the regional neuroanatomical distribution of Lewy-related pathology using alpha-synuclein immunostaining to evaluate the relationship between LBs, neuronal loss, Alzheimer-type changes, and the clinical phenotype. Compared to traditional ubiquitin immunostaining, alpha-synuclein immunohistochemistry was more specific and slightly more sensitive, staining about 5% more intracytoplasmic structures. There was a consistent pattern of vulnerability to LB formation across subcortical, paralimbic, limbic, and neocortical structures, which was independent of concomitant Alzheimer-type changes. There were no significant differences in regional LB densities among patients with or without cognitive fluctuations, visual hallucinations, delusions, recurrent falls or parkinsonism. Duration of disease correlated weakly with LB density. There was no neuronal loss in superior temporal sulcus or entorhinal cortex in pure DLB cases compared to nondemented controls. Thus, DLB is characterized by a specific neuroanatomical vulnerability to LB pathology, distinct from AD pathology, with a complicated relationship to clinical symptoms.
Assuntos
Encéfalo/patologia , Corpos de Lewy/patologia , Doença por Corpos de Lewy/patologia , Doença por Corpos de Lewy/fisiopatologia , Proteínas do Tecido Nervoso/análise , Idoso , Feminino , Humanos , Doença por Corpos de Lewy/psicologia , Masculino , Neurônios/patologia , Sinucleínas , alfa-SinucleínaRESUMO
OBJECTIVE: To address the relationship between dementia and neuropathologic findings in dementia with Lewy bodies (DLB) in comparison with AD. METHODS: We evaluated the clinical presentation of autopsy-confirmed DLB in comparison with AD according to new Consortium on DLB criteria and compared the two conditions using quantitative neuropathologic techniques. This clinicopathologic series included 81 individuals with AD, 20 with DLB (7 "pure" DLB and 13 "DLB/AD"), and 33 controls. We counted number of LB, neurons, senile plaques (SP), and neurofibrillary tangles (NFT) in a high order association cortex, the superior temporal sulcus (STS), using stereologic counting techniques. RESULTS: The sensitivity and specificity of Consortium on DLB clinical criteria in this series for dementia, hallucinations, and parkinsonism are 53% and 83%, respectively, at the patient's initial visit and 90% and 68%, respectively, if data from all clinic visits are considered. In pathologically confirmed DLB brains, LB formation in an association cortical area does not significantly correlate with duration of illness, neuronal loss, or concomitant AD-type pathology. Unlike AD, there is no significant neuronal loss in the STS of DLB brains unless there is concomitant AD pathology (neuritic SP and NFT). CONCLUSIONS: The evaluation of new Consortium on DLB criteria in this series highlights their utility and applicability in clinicopathologic studies but suggests that sensitivity and specificity, especially at the time of the first clinical evaluation, are modest. The lack of a relationship of LB formation to the amount of Alzheimer-type changes in this series suggests that DLB is a distinct pathology rather than a variant of AD.
Assuntos
Doença de Alzheimer/patologia , Doença por Corpos de Lewy/patologia , Lobo Temporal/patologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Feminino , Humanos , Corpos de Lewy/patologia , Doença por Corpos de Lewy/diagnóstico , Masculino , Emaranhados Neurofibrilares/patologia , Testes Neuropsicológicos , Placa Amiloide/patologiaRESUMO
The primary neuroaxonal dystrophies (NAD), which include infantile NAD and Hallervorden-Spatz syndrome (HSS), are characterized by dystrophic terminal axons and axonal swellings. Lewy bodies have been found in some cases. In Parkinson disease (PD) and dementia with Lewy bodies (DLB), Lewy bodies and neurites display prominent alpha-synuclein immunoreactivity. We examined 2 cases of HSS and 4 cases of infantile NAD with alpha-synuclein immunohistochemistry to test the hypothesis that these disorders with similar morphological findings might share a biochemical phenotype. Furthermore, we compared them to 8 cases of secondary or physiologic NAD of various causes and 2 cases of recent traumatic head injury. Alpha-synuclein positive neuronal cytoplasmic inclusions, including Lewy bodies, and neurites were numerous in 1 HSS and 1 infantile NAD case. In addition, axonal spheroids were immunostained in all 6 cases of primary NAD, 5 cases of secondary NAD, and 2 cases of recent head injury. Axonal spheroids were faintly stained in the 3 physiologic NAD cases. Alpha-synuclein positive axonal swellings may suggest a mechanism, such as axonal injury, leading to the neuronal cytoplasmic accumulation of alpha-synuclein in NAD and other disorders.
Assuntos
Axônios/metabolismo , Axônios/patologia , Lesões Encefálicas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Distrofias Neuroaxonais/metabolismo , Neurodegeneração Associada a Pantotenato-Quinase/metabolismo , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Citoplasma/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Corpos de Inclusão/metabolismo , Masculino , Pessoa de Meia-Idade , Neuritos/metabolismo , Neurópilo/metabolismo , Sinucleínas , Ubiquitinas/metabolismo , alfa-SinucleínaRESUMO
OBJECTIVES: To examine the distribution of cortical Lewy bodies (LB) and their contribution to the clinical syndrome in dementia with LB (DLB) and to address their relationship to the pathologic markers of AD and PD. METHODS: We studied 25 cases meeting neuropathologic criteria for DLB: 13 cases without AD (Braak stage I or II) and 12 cases with concomitant AD changes (Braak stages III to V). Age at onset, disease duration, and clinical symptoms were reviewed for each case. We quantified the regional distribution of LB in substantia nigra, paralimbic areas (cingulate gyrus, insula, entorhinal cortex, and hippocampus), and neocortex (frontal and occipital association areas) using anti-alpha-synuclein immunostaining. We compared the LB pathology between groups of patients with different symptoms at onset or with specific clinical phenotypes. RESULTS: There were no significant differences in clinical symptoms or LB density between cases with or without concomitant AD. LB density showed a consistent gradient as follows: substantia nigra > entorhinal cortex > cingulate gyrus > insula > frontal cortex > hippocampus > occipital cortex. LB density in substantia nigra and neocortex was not significantly different in cases that started with parkinsonism compared with those that started with dementia. There were no significant differences in LB density in any region among patients with or without cognitive fluctuations, visual hallucinations, delusions, recurrent falls, or parkinsonism. Duration of the disease correlated with a global LB burden for each case (p = 0.02) but did not correlate with LB density in any individual area. Paralimbic and neocortical LB density were highly correlated with each other (p<0.0001), but neither of these correlated well with the number of LB in substantia nigra. LB density did not correlate with Braak stage or frequency of neuritic plaques. CONCLUSIONS: There is a consistent pattern of vulnerability to LB formation across subcortical, paralimbic, and neocortical structures that is similar for DLB cases with or without concomitant AD. Paralimbic and neocortical LB do not correlate with LB in substantia nigra, suggesting that DLB should not be considered just a severe form of PD. LB density correlates weakly with clinical symptoms and disease duration.
Assuntos
Demência/patologia , Corpos de Lewy/patologia , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Encéfalo/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
In the last decade, a new degenerative dementia, probably the second most common after Alzheimer's disease (AD), has been increasingly recognized under the consensus name of dementia with Lewy bodies (DLB). This article reviews current clinical, genetic, and pathological DLB data and indicates directions for future research. DLB overlaps in clinical, pathological, and genetic features with AD and Parkinson's disease (PD). Clinically, it is characterized by progressive cognitive impairment with significant fluctuations in alertness, parkinsonism, and psychosis with recurrent hallucinations. The neuropathological hallmarks are the intracytoplasmic inclusions in substantia nigra typical of PD, known as Lewy bodies (LB) but distributed widely throughout paralimbic and neocortical regions. Most of the cases also coexist with a plaque predominant AD. It is probably the unique and differential distribution of the lesions throughout cortical and subcortical structures in each of these disorders that supports a specific clinical syndrome and may ultimately prove most useful in understanding their different etiologies. Several genes have recently been implicated in LB formation. Special interest arises from mutations in the alpha-synuclein gene, which appears to be responsible for autosomal dominant PD in several kindreds. This gene encodes a presynaptic protein, a fragment of which is present in AD plaques. Recent studies show intense and quite specific alpha-synuclein immunoreactivity in LB and related neurites, suggesting a potential role of this protein in the aggregation or precipitation of LB inclusions.