Discrepancies in hand motor performance and executive function in older adults

There is increasing interest in using motor function tests to identify risk of cognitive impairment in older adults (OA). This study examined associations among grip strength, with and without adjustment for muscle mass, manual dexterity and Trail Making Test (TMT) A and B in 77 OA (73.4 ± 5.2 years) with globally intact cognition. A subset of OA who exhibited mismatched motor function (e.g., in the highest strength and lowest dexterity tertiles, or vice versa) was identified and analyzed. Dexterity showed stronger associations with TMT-A and -B than grip strength (absolute or adjusted). OA with mismatched motor function scored worse on tests of TMT-B, but not -A than those with matched motor function. Dexterity may have more promise than grip strength for identifying increased risk of cognitive impairment. Intriguing, though limited, data suggest that mismatched motor function (strength vs. dexterity) in OAs might be an even more robust marker of such risk.