Article

Recent work has shown that resting-state functional connectivity
(rsFC) between homotopic, motor-related brain regions is associated with
upper-extremity control early after stroke. This study examined
various patterns of rsFC in chronic stroke, a time at which extensive neural
reorganization has occurred. Associations between homotopic somatomotor
connectivity and clinical measures, representing separate domains of
upper-extremity function, were determined. METHODS: A total of 19 persons >/=6
months poststroke participated. Four connectivity patterns within a somatomotor
network were quantified using functional magnetic resonance imaging.
Upper-extremity gross muscle activation, control, and real-world use were
evaluated with the Motricity Index, Action Research Arm Test, and accelerometry,
respectively. RESULTS: Connectivity between homotopic regions was stronger than
that in the contralesional and ipsilesional hemispheres. No differences in
connectivity strength were noted between homotopic pairs, indicating that a
specific brain structure was not driving somatomotor network connectivity.
Homotopic connectivity was significantly associated with both upper-extremity
control (r = 0.53; P= .02) and real-world use (r = 0.54; P= .02); however, there
was no association with gross muscle activation (r = 0.23; P=.34). The
combination of clinical measures accounted for 40% of the variance in rsFC (=
.05). CONCLUSIONS: The results reported here expand on previous findings,
indicating that homotopic rsFC persists in chronic stroke and discriminates
between varying levels of upper-extremity control and real-world use. Further
work is needed to evaluate its adequacy as a biomarker of motor recovery
following stroke.
CI - (c) The Author(s) 2014.

Langue : ANGLAIS