DMDDuchenne muscular dystrophy AIM To investigate tactile perception and manual dexterity, with or without visual feedback, in males with Duchenne muscular dystrophy (DMD).METHOD Forty males with DMD (mean age 9y 8mo, SD 2y 3mo; range 5-14y), recruited from the teaching hospital of the School of Medicine of the University of São Paulo, with disease severity graded as '1' to '6' on the Vignos Scale and '1' on Brooke's Scale, and 49 healthy males (mean age 8y 2mo; range 5-11y; SD 1y 11mo), recruited from a local education center, participated in the study. We assessed tactile perception using two-point discrimination and stereognosis tests, and manual dexterity using the Pick-Up test with the eyes either open or closed. Analysis of variance was used to compare groups; a p value of less than 0.05 was considered statistically significant.
RESULTSMales with DMD exhibited no impairment in tactile perception, as measured by the two-point discrimination test and the number of objects correctly named in the stereognosis test. Manipulation during stereognosis was statistically slower with both hands (p<0.001), and manual dexterity was much worse in males with DMD when there was no visual feedback (p<0.001).INTERPRETATION Males with DMD exhibited disturbances in manipulation during stereognosis and dexterity tests. Hand control was highly dependent on visual information rather than on tactile perception. Motor dysfunction in males with DMD, therefore, might be related to altered neural control.Duchenne muscular dystrophy (DMD) is the most common and severe neuromuscular disease and the second most prevalent genetic disorder in children. Dystrophin synthesis impairment causes progressive and irreversible muscular weakness, leading to loss of ambulation by adolescence. New treatment approaches have enhanced the survival of individuals with DMD to the third decade of life. 1 This has increased the need to identify functional outcomes in DMD in order to evaluate the efficacy of existing therapeutic interventions.As a result of the proximal-to-distal progression of muscular weakness, upper limb assessment is possible in almost all patients and may represent an important functional outcome at different stages of the disease.2 However, as has been described in the past few years, reach and grasp control can also be affected by altered brain function. 3,4 Morphological and functional changes in sensorimotor areas of the cerebral cortex 3,5 seem to be related to diminished manual dexterity in children with DMD. In addition, reductions in glucose metabolism in the post-central gyrus and cerebellum 3 have also been reported in these patients. The hypometabolism in these brain regions may interfere with the integration of somatosensory inputs, particularly the tactile afferent inputs of the hands, which are required for adjusting prehension force, 6,7 velocity, and dexterity. 8 Color vision impairment 9 or other visual problems, caused by lack of dystrophin in the retina 10 and decreased visual-spatial attention, 11 could also have an...
