[Abstract Title]. - Society for Neuroscience

possible active support levels. At the 5 most difficult active support levels for each participant,
the isometric forces generated by the fingers/wrist were measured. Subsequently, the effect of
electrical stimulation of the extensor digitorum communis (EDC) on abnormal FF activity during
hand opening as a function of active limb support was investigated in the second part of this
study. At each of the 5 active support levels used in part 1, participants lifted the paretic arm,
maximally extended the elbow, and tried to open the hand. Each participant completed trials both
with stimulation of the EDC (STIM) to aid hand opening and without stimulation (NO-STIM).
Statistical analysis revealed that FF force was significantly higher for the paretic limb compared
to non-paretic controls at support levels 2-5 (P < 0.001). Furthermore, a significant interaction
between support level and limb (P < 0.0001) indicated that for the paretic limb, FF forces
increased incrementally over the support levels, whereas forces for the non-paretic limb
remained constant. The total change in FF forces from support level 1to 5 over all trials, was
calculated and the Spearman correlation test indicated a significant linear relationship (rho =
0.96, P = 0.003) between total change in FF force and impairment level, as measured by Fugl-
Meyer Assessment Score. For the EDC stimulation protocol, the percent of isometric FF force
that remained during hand opening as compared to rest was significantly lower for the STIM
condition compared to the NO-STIM condition, for all support levels (P < 0.0001).
In conclusion, results show that progressive limb loading of the paretic upper limb incrementally
increases the FF that occurs in chronic hemiparetic stroke thus extending our previous work
showing this phenomenon at the elbow. Finally, electrical stimulation of the EDC can overcome
the FF bias at all support levels.
Disclosures: L.C. Miller, None; M. Wieser, None; T. Keller, None; J.P.A. Dewald, None.
Poster
273. Basal Ganglia: Transmitters and Neuromodulation I
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 273.1/II16
Topic: D.15.a. Transmitters and neuromodulation
Support: CIHR MOP-5781
Title: Dopamine and serotonin innervation of the striatum in Parkinson's and Huntington's
diseases
Authors: *C. BEDARD 1 , M.-J. WALLMAN 1 , M. PARENT 2 , A. PARENT 1 ;
1 Anat. & Physiol., Laval Univ., Quebec, QC, Canada; 2 Montreal Univ., Montreal, QC, Canada