Background: Hand motor function is central to human existence, including ADLs, social interactions, and communication. Persistent hand motor deficits are common after stroke, however their relationship with functional outcomes has received limited study. In healthy elderly subjects, stronger hand grip strength (HGS) is firmly linked with less disability, depression, and cognitive impairment. We tested the hypothesis that HGS 3-mo post-stroke predicts global disability, depression, and cognitive impairment 12-mo post-stroke. Methods: Patients with stroke were studied longitudinally across 28 US sites. Live exam at 3-mo included HGS via Jamar dynamometer. The 12-mo exam (by phone) included modified Rankin Scale (mRS), PHQ8 depression, medication review, and telephone-Montreal Cognitive Assessment (tMoCA). Models used HGS ratio (paretic/nonparetic) at 3-mo as the independent variable; and age, gender, stroke subtype (ischemic vs. hemorrhagic), and side of paresis as covariates. Results: There were 376 subjects: age 61.7+/-15.2 yr (mean+/-SD), 41.2% female, 82.2% ischemic, 39.9% R-side paretic. At 3-mo, HGS ratio = 0.77+/-0.35, with 58.4% having significant hand weakness. At 12-mo, PHQ8=5.9+/-5.6, tMoCA=16.9+/-4.0, median mRS=2, and 30.0% were taking an antidepressant. Stronger HGS at 3 mo post-stroke predicted the following at 12 mo: 1 better global function, i.e., lower mRS score (OR 14.3, 95% CI 7.8 to 26.8; p<0.0001); a 1 unit increase in HGS ratio (i.e., from 0=plegia to 1=normal) meant 14.3 X more likely to shift to lower mRS score. 2 better cognitive status, with tMoCA score increasing 1.2 points (95% CI 0 to 2.5) for a 1 unit increase in HGS ratio (p=0.05). 3 no effect on depression (p=0.39 for PHQ8) but stronger 3-mo HGS predicted less likely to be on an antidepressant at 12-mo (OR 0.38 for a 1 unit increase in HGS ratio, 95% CI 0.19 to 0.74, p=0.004). Conclusions: Stronger grip strength 3-mo post-stroke—when functional recovery is at a plateau--predicts better global function and cognitive status, and a lower likelihood of taking an antidepressant, at 12-mo post-stroke. These findings echo relationships well established in studies of normal aging. Use of HGS to assess motor status has advantages: it is simple to acquire, inexpensive, safe, valid, reliable, provides a continuous outcome measure, and makes minimal cognitive demands on subjects. These findings argue for inclusion of HGS measurements in guidelines and care pathways after stroke.
Cramer et al. (Thu,) studied this question.