Neurophysiological Profile, Walking Performance Tests and Self-Reported Questionnaires in Spastic Patients with MS: A Pilot Study

Nabiximols is currently being used as an add-on therapeutic option to treat severe forms of multiple sclerosis (MS) spasticity, especially in the progressive phase of the disease. The aim of this exploratory study is to evaluate the response to Nabiximols therapy and modifications in neurophysiological profile, improvement in walking performance tests and self-reported questionnaires, as possible further outcome measures of spasticity. 8 MS patients were recruited to start Nabiximols therapy, all responders in terms of significant reduction of numerical rating scale (NRS). The patients underwent measurements of lower limbs H-reflex and F wave before treatment (baseline) and after 4 and 8 weeks (T1 and T2) of treatment with Nabiximols titrated to optimal dosage, along with timed 25-foot walk test (T25FW), six-minute walk test (6MWT) and questionnaires evaluating subjectively reported spasticity, fatigue and walking abilities (MSSS-88, MFIS, MSWS-12). A reduction of the latencies of the H-reflex and F wave was found between baseline and at T1, which was more strongly confirmed at T2 (P=0.04 relative to H-reflex; P=0.05 and P=0.007 relative to minimal and medium F wave latencies). A significant reduction in time to perform T25FW test was observed between baseline and after treatment (P<0.05), together with a trend towards an improvement in the 6MWT. After the treatment period significant variations in part of the self-reported questionnaires administered were found, as a reduction of the MSSS-88 and MFIS total scores (P<0.05). Nabiximols treatment might have an impact in different objective measurements, including neurophysiological and walking performance tests and self-reported questionnaires. Latencies reduction in H-reflex and F-wave may reflect modifications in the generation of spasticity mechanisms. Moreover, spasticity control is related with an improvement in quality of life of MS patients as it may have a positive impact on walking abilities and reduction of global perception of fatigue.