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%.