Article

Weakness is often profound in the contralesional hand after stroke.
Relative contributions of various neural and mechanical mechanisms to this
impairment, however, have not been quantified. In this study, the extent of one
potential contributor, muscle atrophy, was noninvasively assessed in index finger
musculature using ultrasonographic techniques. METHODS: Twenty-five stroke
survivors (45-65 years old) with severe hand impairment resulting from a stroke
occurring 2-4 years prior participated, along with 10 age-matched control
subjects. Muscle cross sectional area and thickness were geometrically measured
from ultrasound images on both limbs of participants. FINDINGS: Muscle size on
the paretic limb of stroke survivors was smaller for all 7 hand muscles
investigated. An average difference of 15% (SD 4) was seen for muscle cross
sectional area and 11% (SD 2) for muscle thickness, while the difference between
the dominant and non-dominant limbs for control subjects (6% (SD 2) and 1% (SD 4)
for the muscle cross sectional area and muscle thickness, respectively) was not
significant. INTERPRETATION: Although muscle atrophy was detected in the paretic
limb following stroke, it is not explanatory of the marked impairment in strength
seen in this stroke population. However, other alterations in muscle morphology,
such as fatty infiltrations and changes in fiber structure, may contribute to the
emergent muscle weakness post-stroke.
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Langue : ANGLAIS