To examine the efficacy, dosing, and safety profiles of intrathecal and oral baclofen
in treating spasticity after spinal cord injury (SCI).
PubMed and Cochrane Databases were searched between 1970-2018 with keywords baclofen, spinal cord injury and efficacy.
The database search yielded 588 sources and 10 additional relevant publications. After
removal of duplicates, 398 publications were screened.
Data was extracted using the following PICOS criteria: studies including adult SCI
patients with spasticity; the intervention could be oral or intrathecal administration
of baclofen; selection was inclusive for control groups, surgical management, rehabilitation
and alternative pharmaceutical agents; outcomes were efficacy, dosing and adverse
events. Randomized controlled trials, observational studies and case reports were
included. Meta-analyses and systematic reviews were excluded.
A total of 98 studies were included with 1,943 patients. Only four randomized, double-blinded
and placebo-controlled trials are reported. Thirty-nine studies examined changes in
modified Ashworth (MAS; 34 studies) and Penn spasm scores (PSF; 19 studies), with
average reductions of 1.7 ± 1.3 and 1.6 ± 1.4 in individuals with SCI, respectively.
Of these data, a total of six of the 34 studies (MAS) and two of the 19 studies (PSF)
analyzed oral baclofen. Forty-three studies addressed adverse events with muscle weakness
and fatigue frequently reported.
Baclofen is the most commonly-prescribed antispasmodic following SCI. Surprisingly,
there remains a significant lack of large, placebo-controlled, double-blinded clinical
trials, with most efficacy data arising from small studies examining treatment across
different etiologies. In the studies reviewed, baclofen effectively improved spasticity
outcome measures, with increased efficacy through intrathecal administration. Few
studies assessed how reduced neural excitability affected residual motor function
and activities of daily living (ADL). A host of adverse events were reported which
may negatively affect quality of life. Comparative randomized controlled trials of
baclofen and alternative treatments are warranted as these have demonstrated promise
in relieving spasticity with reduced adverse events and without negatively impacting
residual motor function.