Cortical and vestibular stimulation reveal preserved descending motor pathways in individuals with motor-complete spinal cord injury

Abstract

These results highlight the importance of using multiple electrophysiological techniques to assist in determining the potential preservation of muscle activity below the clinically-defined level of injury in individuals with a motor-complete spinal cord injury. These techniques may provide clinicians with more accurate information about the state of various motor pathways, and could offer a method to more accurately target rehabilitation.

Does galvanic vestibular stimulation decrease spasticity in clinically complete spinal cord injury?

“…Our results support and extend the previous observations suggesting some degree of vestibulospinal preservation in cases of clinically complete (AIS-A) SCI. However, the reported changes in spasticity after GVS in two out of seven SCI patients reported here are in contrast to the lower prevalence of medium latency responses in the erector spinae muscles below the level detected by Iles et al (2004) in only two of nine patients or the presence of vestibular-evoked myogenic potentials reported by Squair et al (2016) in two of 16 AIS-A patients. Thus, the accumulated evidence is consistent with broader neuro-physiological observations suggesting traces of somato-sensory (Finnerup et al, 2004;Awad et al, 2015;Wrigley et al 2018) and motor preservation (Sherwood et al, 1992;McKay et al, 2004;Dimitrijević et al, 2015;Mayr et al, 2016) is patients classified as having the AIS-A injury, which is also supported by the autopsy studies (Kakulas and Kaelan, 2015).…”

“…We applied real versus sham GVS in a full cross-over design and assessed the effects by the Modified Ashworth score (MAS, Bohannon and Smith, 1987), and the Pendulum test goniogram, tachogram, and pendulum test (PT) score (Bajd and Vodovnik, 1984;Popović-Maneski et al, 2018). The inclusion of clinically complete SCI patients was prompted by the presence of the erector spinae responses recorded below the level of lesion in two out of nine AIS-A patients following binaural GVS (Iles et al, 2004) and also by the presence of vestibular-evoked myogenic potentials in the soleus muscle in two out of 16 patients with motor-complete SCI following a series of high-intensity, short-tone burst acoustic stimuli (Squair et al, 2016). In contrast to the acoustic stimulation, which activates only a small part of the vestibular apparatus (saccule), the galvanic stimulation excites the entire vestibular nerve, that is, the afferents originating from the semicircular canals and the otoliths.…”

Aplicações dos potenciais evocados miogênicos vestibulares: revisão sistemática de literatura

“…The VEMP has been utilized to study a variety of vestibular diseases. Among peripheral diseases, Meniere's disease (5,6) , vestibular neuritis (7) , superior semicircular canal dehiscence (8)(9)(10) , large vestibular aqueduct syndrome (11) , and vestibular schwannoma (12,13) are highlighted, whereas among central vestibular diseases, vestibular migraine (14) , Parkinson's disease (15) , central ischemic lesions (16)(17)(18) , and motor myelopathies (19)(20)(21)(22)(23)(24)(25) stand out.…”

Paired associative stimulation after spinal cord injury: Who should undergo?

“…2 However, it is also assumed that even when clinically complete injury is observed and MEPs could not be recorded, there could be some preserved connections through the lesion but non-functional at the moment. 3 This is why techniques which could be able to enforce such kind of connections are widely studied last years. 4 As some animal research demonstrates, time dependent stimulation of neuros above and below the injury side may induce neuroplasticity and improve functional outcome.…”