The effect of gabapentin, an anticonvulsant developed for treating epilepsy but used mostly in the management of neuropathic pain, has been investigated as an antispastic in SCI (Clark 2002).
Gruenthal et al. (1997) conducted a randomized, placebo-controlled trial and were able to reveal modest improvements as measured by Ashworth and Likert Scale scores (p=0.044 and 0.013, respectively). Despite the robust study design, no confidence intervals were reported and the sample size was relatively small.
There is level 1b evidence (from one RCT: Gruenthal et al. 1997) that supports the use of gabapentin for SCI-related spasticity. Despite the robust study design and validated outcome measures, no confidence intervals were reported and the sample size was relatively small.