The Relationship Between Clinical Hand Dexterity and Diffusion Tensor Imaging Metrics in White Matter tracts of Patients with Multiple Sclerosis
Sulafa Saffarini1, Muhammad Raghib2, Fen Bao3, Evanthia Bernitsas4
1Neurology, Wayne State University/Detroit Medical Center, 2Wayne State University, 3Neurology, Wayne State University, 4Wayne State School of Medicine
Objective:
To identify areas of early white matter tract disruptions involved in hand dexterity in patients with relapsing remitting multiple sclerosis (RRMS).
Background:
Although loss of hand dexterity is a common finding in people with MS (pwMS), research is limited.
Design/Methods:
Thirty RRMS patients underwent 3T MRI scan of whole brain. Diffusion tensor imaging (DTI) parameters of 37 white matter tracts were obtained. Fractional Anisotropy (FA) and Mean Diffusivity (MD) metrics were recorded, and findings were correlated clinically with dominant (D) and non-dominant (ND) hand dexterity through utilizing the nine-hole peg test (9HPT). Correlation analysis to identify significant relationships was performed in SPSS v29.
Results:
Mean age and disease duration of patients were 43.9±10.3 years and 6.0±7.9 years respectively, with a median expanded disability status scale (EDSS) of 1.5(1.5-3.4). Mean 9HPT scores were 23.8±8.5 seconds in the D and 26.4±9.0 seconds in the ND hand. The 9HPT-D dexterity score was positively correlated with MD in the left arcuate fasciculus (p < 0.001, r = 0.691), and negatively correlated with FA in the left arcuate fasciculus (p = 0.001, r = -0.570) and right dorsal longitudinal fasciculus (p = 0.003, r = -0.534).
In addition, 9HPT-ND dexterity score was positively correlated with MD in the right arcuate fasciculus (p < 0.001, r = 0.619), left arcuate fasciculus (p = 0.001, r = 0.586) and right cingulum (p = 0.001, r = 0.569). Moreover, it was negatively correlated with FA in the right medial lemniscus (p < 0.001, r = -0.620) and superior cerebellar peduncle (p = 0.003, r = -0.536).
Conclusions:
Hand dexterity is a complex process and various white matter tracts are involved. More specifically, the left arcuate fasciculus appears to play an important role in dexterity in the D hand, while bilateral arcuate fasciculi contribute to dexterity of ND hand in pwMS.