A review of the effects of baclofen and of THC:CBD oromucosal spray on spasticity-related walking impairment in multiple sclerosis.

Multiple sclerosis (MS) is a complex disease with a heterogeneous and unpredictable clinical course. Mobility impairment after progressive paralyses and muscle tone spasticity is common. Areas covered: The prevalence, assessment, and pharmacological management of gait impairment and spasticity in MS and their effects on health-related quality of life (HRQoL) are discussed. The roles of oral and intrathecal baclofen and of delta-9-tetrahydrocannabinol/cannabidiol (THC:CBD) oromucosal spray in treating MS spasticity-related gait impairment are reviewed. Expert commentary: Mobility impairment and spasticity are experienced by approximately 90% and 80% of MS patients, respectively, during the disease course. Prevalence and severity of gait impairment and spasticity increase as disease progresses. The symptoms are related and both impact negatively on HRQoL. Oral baclofen and tizanidine are generally used for first-line treatment of MS spasticity but are ineffective in approximately 40% of cases. Second-line therapy includes add-on THC:CBD spray for patients with resistant MS spasticity. Results of studies evaluating baclofen for treating MS spasticity gait impairment are equivocal. In studies of patients with resistant MS spasticity, THC:CBD spray consistently improved the timed 10-meter walk test and significantly improved multiple spatial-temporal and kinematic gait parameters. THC:CBD oromucosal spray warrants further investigation as a treatment for MS spasticity-related gait impairment.