Improving language mapping in clinical fMRI through assessment of grammar

Abstract

IntroductionBrain surgery in the language dominant hemisphere remains challenging due to unintended post-surgical language deficits, despite using pre-surgical functional magnetic resonance (fMRI) and intraoperative cortical stimulation. Moreover, patients are often recommended not to undergo surgery if the accompanying risk to language appears to be too high. While standard fMRI language mapping protocols may have relatively good predictive value at the group level, they remain sub-optimal on an individual level. The standard tests used typically assess lexico-semantic aspects of language, and they do not accurately reflect the complexity of language either in comprehension or production at the sentence level. Among patients who had left hemisphere language dominance we assessed which tests are best at activating language areas in the brain.MethodWe compared grammar tests (items testing word order in actives and passives, wh-subject and object questions, relativized subject and object clauses and past tense marking) with standard tests (object naming, auditory and visual responsive naming), using pre-operative fMRI. Twenty-five surgical candidates (13 females) participated in this study. Sixteen patients presented with a brain tumor, and nine with epilepsy. All participants underwent two pre-operative fMRI protocols: one including CYCLE-N grammar tests (items testing word order in actives and passives, wh-subject and object questions, relativized subject and object clauses and past tense marking); and a second one with standard fMRI tests (object naming, auditory and visual responsive naming). fMRI activations during performance in both protocols were compared at the group level, as well as in individual candidates.ResultsThe grammar tests generated more volume of activation in the left hemisphere (left/right angular gyrus, right anterior/posterior superior temporal gyrus) and identified additional language regions not shown by the standard tests (e.g., left anterior/posterior supramarginal gyrus). The standard tests produced more activation in left BA 47. Ten participants had more robust activations in the left hemisphere in the grammar tests and two in the standard tests. The grammar tests also elicited substantial activations in the right hemisphere and thus turned out to be superior at identifying both right and left hemisphere contribution to language processing.ConclusionThe grammar tests may be an important addition to the standard pre-operative fMRI testing.

Presurgical language fMRI: Clinical practices and patient outcomes in epilepsy surgical planning

“…Tremblay & Dick, 2016]. Of particular relevance to clinicians is a compelling recent reanalysis and reinterpretation of the nature of Wernicke's area [Binder, 2015], which suggests discrete bilateral and unilateral components in typically organized individuals [see also Price, 2012], as and the suggestion that more sophisticated tasks (e.g., evaluating grammar) may better map language regions such as the angular gyrus [Polczynska et al, 2017]. …”

“…Researchers presenting findings to clinical teams may improve patient care by helping their colleagues understand that the apparent boundaries of language areas will vary with a patient's language skill (Figure a); analysis parameters (Figure b); signal loss not evident in the final map (Figure c); the task and control conditions used (Figure d); and the areas the analyst is asked (or not asked) to identify (Figure e). Just as importantly, the fact that language fMRI represents task‐correlated changes in blood oxygenation (rather than neural activation) and may show non‐critical regions may be emphasized Połczynska et al, ).…”

How Does Rasch Model Reveal Dishonesty between Coastal Students and Easy Grammar Test?

“…They were supposed to be able to analyze each part of a given item. A report stated that testing grammar is not only used to measure comprehension of its knowledge as a whole, but also to know its parts (Połczyńskaa, et al, 2017). The other purpose was to know the higher percentage of those who are assumed to do cheating based upon their origins and sex.…”

“…After that, someone is able to create, comprehend, and judge the combinations through his or her grammaticality. Testing grammar is not only used to measure comprehension of its knowledge as a whole, but also to know its parts (Połczyńskaa, et al, 2017). A test like multiple choice question (MCQ) is a favorite test form in educational assessment (Brady, 2005).…”

Translating state-of-the-art brain magnetic resonance imaging (MRI) techniques into clinical practice: multimodal MRI differentiates dementia subtypes in a traditional clinical setting

“…To w a r d t h i s e n d , s e v e r a l i m p o r t a n t s t u d i e s have investigated such tools for differentiation of neurodegenerative disease (NDD) within large, publicly available datasets (6)(7)(8)(9)(10)(11). In smaller participant pools, support vector regressions have been trained to differentiate neurodegenerative conditions from healthy aging using standard clinical structural MRI (12)(13)(14); however, this work must be expanded to evaluate for the clinical utility of other nontraditional MRI modalities which currently exist solely in the research space.…”