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acquisitions present significant differences between
both groups of patients, as already proved by previ-
ous publications (Fisher et al., 2012). Results from
the group of patients present no significant differ-
ences from the results obtained for contra lateral ac-
quisitions while the group of subjects, presents higher
values of PLF and coherence for all frequencies, es-
pecially for beta-band. So, it is possible to assume
that while control subjects present no neuronal or
muscular anomalies and therefore higher synchrony
for beta-band, patients with ALS do not present syn-
chrony in any frequency, specially for beta-band. All
results allow to conclude that ipsilateral analysis is
a good measure of corticospinal pathways integrity.
Frequency spectrums were performed for contra lat-
eral acquisitions and it was demonstrated that beta-
band frequencies are present in instants of steady con-
traction. But, as proved by coherence and PLF analy-
sis beta-band frequencies in contralateral acquisitions
was not present in neither for patients or control sub-
jects. Neither differences or significance values were
found for both control and patients. Therefore, it is to
conclude that contra lateral frequency analysis is not a
good marker for beta-band frequencies studies. Com-
paring both methods used to study frequency domain,
PLF analysis may be seen as a more practical method
since it requires smaller sections of data, compared
to coherence. On the other hand, PLF can only be
analysed for a specific value of frequency, while co-
herence is analyzed for the range of frequencies pre-
sented on data. To conclude, as further work is sug-
gested to rely on the possibility of using PLF analysis
to observe beta-band and assess about neuronal path-
ways integrity in ipsilateral acquisitions. Therefore, it
seems possible that studying PLF serves as a method
of diagnosing ALS.
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