Making Sense of Right Hemisphere Discourse Using RHDBank

Kim²,

Stockbridge³

et al. 2022

Front. Neurol.

NIHSS score is higher for left vs. right hemisphere strokes of equal volumes. However, differences in each vascular territory have not been evaluated yet. We hypothesized that left vs. right differences are driven by the middle cerebral artery (MCA) territory, and there is no difference between hemispheres for other vascular territories. This study is based on data from 802 patients with evidence of acute ischemic stroke in one major arterial territory (MCA, n = 437; PCA, n = 209; ACA, n = 21; vertebrobasilar, n = 46). We examined differences in patients with left or right strokes regarding to lesion volume, NIHSS, and other covariates (age, sex, race). We used linear models to test the effects of these covariates on NIHSS. We looked at the whole sample as well as in the sample stratified by NIHSS (≤5 or >5) and by lesion location (MCA or PCA). Patients with left MCA strokes had significantly higher NIHSS than those with right strokes. Only patients with MCA strokes showed NIHSS score affected by the hemisphere when controlling for stroke volume and patient's age. This difference was driven by the more severe strokes (NIHSS>5). It is important to consider this systematic bias in the NIHSS when using the score for inclusion criteria for treatment or trials. Patients with right MCA stroke may be under-treated and left with disabling deficits that are not captured by the NIHSS.

Section: Discussionmentioning

confidence: 99%

Left Hemisphere Bias of NIH Stroke Scale Is Most Severe for Middle Cerebral Artery Strokes

Kim²,

Stockbridge³

et al. 2022

Front. Neurol.

“…Thus, patients with atrial fibrillation should be educated that they are at risk for strokes without motor symptoms. Even more of a concern is that right temporoparietal strokes may result in deficits that are difficult to detect without careful assessment, such as impaired empathy 8 , impaired recognition of emotional tone of voice or facial expressions, and altered discourse and appreciation of humor and metaphor [9][10][11][12][13] . Even hemispatial neglect is often not detected in patients with right hemisphere stroke 14 .…”

Section: Discussionmentioning

confidence: 99%

Association of inferior division MCA stroke location with populations with atrial fibrillation incidence

Kim

Stockbridge

et al. 2021

Preprint

Background and Aim: Anatomical features of Middle Cerebral Artery (MCA) bifurcation favors larger emboli entering the inferior rather than superior division. As cardiac source emboli are on average larger than arterial source emboli, we hypothesize that patients with atrial fibrillation have infarcts that involve more temporal and parietal lobes than frontal lobes. Methods: From 1,849 patients admitted with evidence of acute or early subacute ischemic stroke on diffusion-weighted MRI (DWI), 482 affected exclusively the lobar MCA (sparing the lenticulostriates). They were classified as frontal predominant (n=105) or temporoparietal predominant (n=197) if at least 75% of the infarct affected the frontal lobe or the temporal and parietal lobes, respectively. Differences between stroke location (frontal or temporoparietal), sex, and race were analyzed by Chi-square test. Results: Men were more likely than women, and white people were more likely than black people to have temporoparietal strokes versus frontal strokes. Patients with confirmed diagnosis of atrial fibrillation have more temporoparietal strokes, compared to frontal strokes. Conclusion: MCA ischemic strokes occur more often in temporoparietal areas in men and in white patients, populations with known elevated incidence of atrial fibrillation. Patients with confirmed diagnosis of atrial fibrillation have more temporoparietal strokes, compared to frontal strokes. Results align with the hypothesis that large emboli (mostly from cardiac source) are more likely to cause temporoparietal strokes in the MCA territory, compared to frontal strokes. This association can help guide search for the most likely etiology of infarcts.

“…It is important to recognize that the NIHSS does not capture right cortical dysfunction. Other right, mostly MCA, cortical functions include empathy 16,17 , recognition and expression of affective prosody (tone of voice to convey emotions 18,19 , recognition of facial expression 20 , awareness of deficits 21 , integration of information (getting the "big picture") 22,23 , understanding humor 5/14 and metaphor 24,25 , and so on. However, these cortical functions are more difficult to assess reliably at bedside.…”

Section: Discussionmentioning

confidence: 99%

Left Hemisphere Bias of NIH Stroke Scale is Most Severe for Middle Cerebral Artery Strokes

Kim

Stockbridge

et al. 2021

Preprint

Background and Aim: NIHSS score is higher for left versus right hemisphere strokes of equal volumes. However, differences in each vascular territory have not been evaluated yet. We hypothesized that left versus right differences are driven by the middle cerebral artery (MCA) territory, and there is no difference between hemispheres for other vascular territories. Methods: This study is based on data from 802 patients with evidence of acute or early subacute ischemic stroke. These patients had infarct restricted to one major arterial territory (MCA, n=437; PCA, n=209; ACA, n=21; vertebrobasilar, n=46) and received NIHSS and MRI at hospital admission. We examined differences in patients with left or right strokes regarding to lesion volume, NIHSS, and other covariates (age, sex, race). We used linear models to test the effects of these covariates on NIHSS. We looked at the whole sample as well as in the sample stratified by NIHSS (<=5 or >5) and by lesion location (MCA or PCA). Results: Patients with left MCA strokes had significantly higher NIHSS than those with right strokes. Only patients with MCA strokes showed NIHSS score affected by the hemisphere when controlling for stroke volume and patient's age. This difference was driven by the more severe strokes (NIHSS>5). In addition, stroke volume and patient's age significantly correlated with NIHSS. Conclusion: Right MCA infarcts are larger than left MCA infarcts associated with a given NIHSS score, after accounting for other significant associations, such as patient's age. It is important to consider this systematic bias in the NIHSS when using the score for inclusion criteria for treatment or trials. Patients with right MCA stroke may be under-treated and left with disabling deficits that are not captured by the NIHSS.