Clinical manifestations of Multiple Sclerosis (MS) indicate the involvement of motor,
sensory, visual systems, cognition and emotion, as well as peripheral autonomic system
(PAS). Disease modifying therapies (DMTs) are immunomodulatory drugs designed to dampen
the immune reaction occurring in MS. Indeed, MS pathogenesis is supposed to rely on the
break of immunological tolerance against myelin epitopes, which trigger an inflammatory
cascade that leads to chronic inflammation, axonal loss and neurodegeneration. T cell
population in MS presents several metabolic dysfunctions, such as glycolysis alterations
that can be attenuated by DMTs. Studies of synaptic transmission conducted on both MS
patients, via transcranial magnetic stimulation (TMS), and EAE mice, via
electrophysiological recordings of single neurons, showed an early synaptopathy
characterized by an impairment of glutamatergic and GABAergic transmissions. Such
synaptopathy is independent of demyelination and caused by inflammation. Importantly, TMS
cortical excitability measures positively correlate with disability in MS patients.
Moreover, chimeric experiments obtained incubating MS T cells and murine brain slices,
clearly indicate that T cells drive synaptic damage during MS, suggesting that
interfering with T cell-neuron crosstalk could be a possible therapeutic target.
Due to the complexity and the heterogeneity of the disease course and the clinical
symptoms, the search for the appropriate personalized treatment and the disease
management remains a challenging issue. It is increasingly recognized that a
multi-disciplinary approach in MS treatment, including non-pharmacological interventions
is required to treat MS. Active-rehabilitation or exercise has been proven effective in
the improvement of cardiovascular functions, aerobic capacity, muscular strength and
ambulatory performance, while some data indicate that other outcomes, like balance and
depression can be positively influenced by exercise. Symptoms of sympathovagal imbalance,
like altered heart rate variability (HRV), previously shown to depend on inflammatory
bulk in MS, may be positively modulated by exercise, which is known to regulate both the
peripheral nervous system and the immune system. However, the mechanisms involved in
exercise-beneficial effects as well as the impact of exercise on MS pathophysiological
hallmarks, especially those regarding the immune-synaptic axis, are still poorly
elucidated.
This longitudinal, interventional, non-pharmacological study is designed to enrol 44 MS
patients and 30 healthy controls matched by gender and age to the MS group. The MS
patient group will undergo a conventional 6-week rehabilitation program. Physical therapy
will be performed for 6 days/week for 6 weeks and will consist of 3 hours of treatment
per day. The rehabilitation program will be planned by a physician specialized in
physical and rehabilitation medicine and will consist of both passive and active
therapeutic exercises specifically aimed at restoring or maintaining muscular
flexibility, range of motion, balance, coordination of movements, postural passages and
transfers, and ambulation. According to the patient's disability status, different
therapeutic exercises will be performed by qualified physiotherapists. Intensity of
exercise will be tailored to the level of patient's disability. Furthermore, advanced
robotic therapy such as Lokomat® exoskeleton (Hocoma AG, Volketswil, Switzerland),
Biodex® Stability System (BSS, Biodex, Inc, Shirley, NY), G-EO System™ (Reha Technology
AG, Olten, Svizzera) and Indego® Therapy (Parker USA), will be used to standardize
rehabilitation treatment and obtain more objective indices of motor function and will be
applied according to clinical indications. Three time-points (t) of evaluations are
included in the study: t0 (before starting the rehabilitation period), t1 (soon after
rehabilitation) and t2 (follow-up, after 8 weeks by the end of rehabilitation).
Therapeutic efficacy will be evaluated at the end of the exercise program (t1) by
repeating evaluations performed at t0, which include neurological and psychological
assessments, together with measures of brain synaptic activity and vagal function and
immune function. At t2, analysis will be limited to neurological and psychological
assessments and immune function. Thus, blood samples will be collected at t0, t1 and t2
to study changes in immune function that might correlate with clinical parameters
described as primary and secondary outcomes at the different time-points.
Statistical analysis will be performed by IBM SPSS Statistics 15.0. Data will be tested
for normality distribution through the Kolmogorov-Smirnov test. Differences between pre-
and post-values will be analyzed using parametric Student's t-test for matched pairs, or
if necessary, nonparametric Wilcoxon signed-rank test for matched pairs. Changes in
categorical variables will be assessed by McNemar test. Correlation analysis will be
performed by calculating Pearson or Spearman coefficients as appropriate. Changes in
categorical variables will be evaluated by the test McNemar. Data will be presented as
the mean (standard deviation, sd) or median (25th- 75th percentile). The significance
level is established at p<0.05.
Sample size calculation was performed according to the following criteria. Assuming that
in MS patients the cytokine values in particular the TNF level after exercise therapy
decrease in a manner similar to that showed in the study by Hedegaard et al (2008). Based
on these results, calculating an average difference between pre and post exercise values
of TNF equal to 1365.1 pg / ml (sd = 2570), d = 0.53, in order to appreciate a moderate
effect with a statistical capacity of 95% and assuming a two-tailed a = 0.05 and applying
a Wilcoxon rank test for paired values, the investigators estimate a total number of
patients equal to 40. Analysis was performed with the G * POWER v3.1.9.2 program.
Considering possible drop-outs, the investigators estimate to increase the number of
patients recruited by one percentage equal to 10%, meaning 4 subjects. Moreover, using
Power Analysis d=0.61, it has been calculated that the number of healthy volunteer
subjects needed to be recruited for the study of the immunophenotype and secretoma will
be 30 subjects per experimental group, in order to be able to refuse the null hypothesis
that the two groups are equal with a test power of 95% and appreciate a difference of
1600.9 pg / ml between the means of the experimental groups (healthy control vs MS)
(standard deviation equal to 2599), d = 0.61. The probability of Type I error associated
with this test for this hypothesis is 5%.