Cognitive dysfunction in corticobasal degeneration

Abstract

Corticobasal degeneration (CBD) is a rare and progressive neurodegenerative disease. It was originally described as a distinct clinicopathological entity in 1967 1 and later recognized as a polymorphous disease due to its complexity. In fact, the classical set of symptoms -namely asymmetric motor features associated with higher cortical function -were found to be associated with multiple histological presentations. Furthermore, the distinctive histopathological findings of cortical and striatal neuronal deposition of tau, and glial inclusions, were also linked to a wide variety of clinical phenotypes 2 . Hence, recent literature refers to corticobasal syndrome (CBS) as the constellation of symptoms described originally, limiting CBD to the distinctive histopathological findings .The different terminology with a seemingly paradoxical intrinsic overlap between these conditions makes diagnosis challenging. For instance, only 25% to 56.25% of patients with pathologically-confirmed CBD had previously presented with symptoms of CBS 4,5,6 . On the other hand, the proportion of patients diagnosed with CBS presenting with the histologic hallmarks of CBD is highly variable, ranging from 23.8% to 100% 4,5,6,7 . Considering the enormous difficulty in accurately diagnosing CBD during life, it is clear that current ABSTRACTCorticobasal degeneration (CBD) was originally described as a distinct clinicopathological entity in 1967. Since then, different phenotypic presentations have emerged as possible manifestations of CBD histopathological findings. In addition, pathophysiological findings and the molecular basis have been delineated and several aspects of its cognitive manifestations have been clarified. Thus, not only the spectrum of what is currently designated as CBD has expanded, but overlap with other degenerative and even secondary disorders has made clinical diagnostic certainty even more challenging in the absence of specific and readily-available markers. Cognitive deficits in CBD are now recognized as a frequent initial presentation and may appear up to eight years before the motor symptoms, depending on the phenotypic variant. Characteristic cognitive features of CBD involve language deficits, visuospatial and executive dysfunctions, apraxia, and behavioral disorders. Semantic and episodic memories are usually preserved, while language is often impaired in the early stages.Keywords: dementia; cognition; corticobasal degeneration. RESUMOA degeneração corticobasal (DCB) foi originalmente descrita como uma entidade clínico-patológica distinta em 1967. Desde então, nossa compreensão sobre DCB evoluiu substancialmente. Diferentes apresentações fenotípicas emergiram refletindo possíveis manifestações das anormalidades histopatológicos da DCB. Adicionalmente, dados fisiopatológicos e moleculares foram delineados e aspectos das manifestações cognitivas foram explorados. Assim, não só o espectro do que é atualmente designado DCB foi expandido, mas a sobreposição com outras doenças degenerativas e até mesmo secundárias to...

Caracterização de fala e linguagem na síndrome corticobasal

“…Estudos mostram que 25% a 56% dos casos de DCB são diagnosticados corretamente em vida (Armstrong et al, 2013). É provável que a escassez de dados sobre a incidência e a prevalência da DCB deva-se a essa dificuldade (Mahapatra et al, 2004;Boeve, 2005;Hodges, 2008;Grijalvo-Perez;Litvan, 2014;Oliveira et al, 2017). Estima-se, no entanto, que a incidência seja de 0,6-0,9/100.000 habitantes ao ano, com prevalência de 4,9-7,3/100.000 habitantes e que a DCB corresponda a 4%-6% dos casos de parkinsonismo (Mahapatra et al, 2004;Hodges, 2008;Constantinides et al, 2019).…”

“…Não há evidências de que a SCB afete de forma diferente um dos sexos (Wenning et al, 1998;Wadia;Lang, 2007;Kouri et al, 2011;Oliveira et al, 2017).…”

“…Acredita-se que os déficits de memória episódica sejam leves e alguns autores sugerem que esses podem estar relacionados a uma dificuldade no uso de estratégias de codificação e acesso à informação Hodges, 2003;Oliveira et al, 2017).…”

“…Em um estudo retrospectivo com 147 pacientes com SCB, 29% da amostra apresentava disartria (Kompoliti et al, 1998 (Carvalho, 2006). Déficits de função executiva são descritos em, ao menos, 50% dos pacientes com SCB (Kertesz;McMonagle, 2010;Oliveira et al, 2017). Desse modo, acreditamos que o impacto nesse domínio pode estar relacionado tanto aos déficits linguísticos quanto à função executiva.…”

“…Por outro lado, a DCB é frequentemente encontrada em pacientes com diagnóstico clínico de outras síndromes (Grijalvo-Perez; Litvan, 2014; Hodges; Rowe, 2014; Parmera et al, 2016;Oliveira et al, 2017). Tendo em vista essa heterogeneidade clínico-patológica, há um crescente interesse na busca por biomarcadores que auxiliem no diagnóstico antemortem da patologia de base da SCB (Zalewski et al, 2014;Parmera et al, 2016;Beyer et al, 2018).…”