Neural correlates of spelling difficulties in Alzheimer’s disease

Abstract

Abstract.Alzheimer's disease (AD) is associated with a general cognitive decline that affects the memory and language domains. Thus, an oral production deficit with a lexical-semantic origin has been widely observed in these patients. Their written production capacities, however, have been much less studied. We assessed the spelling abilities of 22 AD patients and a group of matched healthy controls with a test battery including written picture naming and word and pseudoword dictation tests, as well as text dictation and spontaneous writing tasks. The results of the AD patients in the discriminative tasks were then entered into voxel-based morphometry analyses along with their grey matter volumes. The patient group presented a selective impairment for word dictation, which contrasted with a spared capacity to spell pseudowords, and showed more difficulties for words with arbitrary and rule-based orthography. Moreover, they also produced less complete syntactic units in the spontaneous writing task. These results point out the lexical-semantic, as opposed to sublexical, nature of the spelling deficit associated to AD. In addition, we recognized a mainly left-lateralized cortical network, including areas in the posterior inferior temporal lobe and the superior region of the parietal cortex, which might be responsible for this impairment. Other regions, such as the putamen, were also associated to the deficit. The results of this study, hence, improve our understanding of the neuropsychological and neuroanatomical mechanisms that underlie the cognitive symptoms associated to AD.

Effect of age at onset on cortical thickness and cognition in posterior cortical atrophy

“…We also found a significant association between worse calculation skills and earlier AAO which is consistent with the greater parietal thinning in the earlier-onset subgroup because calculation performance is underpinned by the left dorsal angular gyrus and medial parietal cortex ( Gruber et al, 2001 ),. Regarding the deficits in spelling, these have been related to atrophy in the supramarginal and posterior-inferior temporal/fusiform gyrus ( Philipose et al, 2007 ) and specifically in AD spelling is associated with a left-lateralized cortical network involving the posteriorinferior temporal lobe and superior parietal cortex ( Rodriguez-Ferreiro et al, 2014 ). Finally, it might have been expected that in the subsample of 68 PCA (with neuropsychological assessment available) the earlier-onset patients showed lower MMSE because of their greater parietal impairment.…”

Written discourse in diagnosis for acquired neurogenic communication disorders: current evidence and future directions

“…Six of the papers reviewed addressed written discourse in PWA as compared to a control group ( Mortensen, 2005 ; Behrns et al, 2008 , 2009 , 2010 ; Vandenborre et al, 2018 ; Johansson-Malmeling et al, 2020 ). Seven articles sought to compare the written discourse of people with Alzheimer’s disease to that of a control group using a variety of discourse elicitation tasks and measures ( Forbes et al, 2004 ; Forbes-McKay and Venneri, 2005 ; Pekkala et al, 2013 ; Forbes-McKay et al, 2014 ; Rodríguez-Ferreiro et al, 2014 ; Davy et al, 2016 ). Two additional papers compared the written discourse of people with MCI to that produced by control groups ( Aramaki et al, 2016 ; Smolík et al, 2016 ), and one paper compared multiple levels of writing produced by people with MCI, AD, and a control group ( Hayashi et al, 2015 ).…”

Detection Test for Language Impairments in Adults and the Aged—A New Screening Test for Language Impairment Associated With Neurodegenerative Diseases: Validation and Normative Data

“…44,45 Spontaneous writing may also be affected in neurodegenerative diseases. 46,47 Impairment in this task usually mimics the manifestations observed in spoken production (ie, difficulties in lexical access, inflectional morphology, syntactic structure). A task involving spelling to dictation of words and nonwords and a spontaneous written sentence production task were selected to assess written production abilities.…”