Page 159 - Read Online

Page 12 of 14 Zoghi et al. Neuroimmunol Neuroinflammation 2019;6:14 I http://dx.doi.org/10.20517/2347-8659.2019.03

Another marker for the existence of supraspinal influences is the tendon tap response [25,30] . In this study,
Participants 4, 8, 10, 11, 12, 13, 16, 17 and 18 showed tendon tap responses in at least one of the assessed
muscles without extending to other spinal segments. This response has been reported in previous studies as
well [14,31] . There is significant supraspinal influence on inhibitory interneurons at different spinal segments
and propriospinal neurons that can extend to other segmental levels, as well as a direct influence on alpha
and gamma motoneurons. It has been shown that a reduction of supraspinal influences over propriospinal
interneuron networks increases their excitability, which in turn increases the possibility of motor unit
[32]
activation in other spinal levels including on the contralateral side .

In the present study, participants in the whole-body training group completed 12 weeks of training
including trunk, upper and lower limb exercises and LT, FES-assisted cycling. These participants received
FES, which increased the sensory inputs to the propriospinal network and intraspinal circuits through
dromic and anti-dromic currents in the stimulated nerves and sensory feedback from the contracted
[33]
muscles and joint receptors post-muscle contractions . Plasticity of these networks plays a significant role
in functional recovery in patients with incomplete SCI by forming new connections and re-establishing
[34]
corticospinal connections to the affected muscles . The increased sensory inputs to the spinal cord could
increase the excitability of the propriospinal network and promote multi-level muscle co-activations
or reflex responses, which can adversely decrease the SIs for different tasks. However, it is unlikely that
this was the case in the present study, as these responses were seen in participants in both groups. As we
assessed a small number of patients, this speculation needs to be confirmed in larger studies.

Limitations of the study
BMCA requires specialised equipment and expertise in collecting and analysing the data, which may not be
readily available at all sites. The sample size in this study was low as the BMCA assessments were limited to
participants at only one site of a multi-centre trial. The number of tasks was limited to just four unilateral
tasks. In future studies, other lower limb movements should also be assessed, e.g., hip abduction/adduction.
In addition, all the tasks were completed in the supine position in order to standardise the testing position.
This could affect the control of anti-gravity movements, e.g., hip and knee flexion, and increase the inter-
subject variability significantly. Other factors were the variability in time post-injury within this group of
participants (1.5-50 years), and their unique patterns of injury, which may also affect the interpretation of
the data.

In conclusion, knowledge about how to improve function in people with SCI is growing, with new
therapeutic approaches, modification of previous approaches and new technologies to facilitate
compensatory function. In line with this, the need for objective evaluation of the effectiveness of these
therapeutic approaches will also grow. Neurophysiological assessment will assist clinicians to monitor
their patients’ progress during rehabilitation programs with more resolution and potentially lead to
individualised adjustment to optimise rehabilitation outcomes. BMCA is a valuable objective assessment
tool that can refine the clinical evaluation of patients with SCI and assist in maximising their functional
capabilities. Reporting the BMCA findings after different therapeutic techniques and rehabilitation
programs, even in a small number of patients, will help to increase our knowledge of the effects of those
interventions on movement patterns and residual supraspinal effects.

DECLARATIONS
Authors’ contributions
Designed the study, obtained funding, collected and interpreted the data, and revised the manuscript: Galea
M
Collected, analysed and interpreted data, prepared the manuscript and all tables and figures, and revised
the manuscript: Zoghi M