Review of physiological motor outcome measures in spinal cord injury using transcranial magnetic stimulation and spinal reflexes

Abstract

Abstract-This article reviews methods that have been developed as part of a clinical initiative on improving outcome measures for motor function assessment in subjects with spinal cord injury (SCI). Physiological motor outcome measures originally developed for limbs-transcranial magnetic stimulation (TMS) of the motor cortex to elicit motor-evoked potentials (MEPs) and mechanical stimulation to elicit spinal reflexes-have been extended to muscles of the trunk. The impetus for this development is the lack of a motor component in the American Spinal Injury Association clinical assessment for the thoracic myotomes. The application of TMS to the assessment of limb muscles is reviewed, followed by consideration of its application to the assessment of paravertebral and intercostal muscles. Spinal reflex testing of paravertebral muscles is also described. The principal markers for the thoracic SCI motor level that have emerged from this clinical initiative are (1) the threshold of MEPs in paravertebral muscles in response to TMS of the motor cortex, (2) the facilitation pattern and latency of MEPs in intercostal muscles during voluntary expiratory effort, and (3) the absence of long-latency reflex responses and the exaggeration of short-latency reflex responses in paravertebral muscles.

Does locomotor training improve pulmonary function in patients with spinal cord injury?

“…In addition, a functional connection of the corticospinal tract fibers, from motor cortex to the spinal motor circuitry of the respiratory and accessory respiratory muscles, has also been shown. [13][14][15][16][17][18] Furthermore, LT has been shown to enhance corticospinal connectivity to spinal motor circuitry in the leg muscles of chronic incomplete SCI patients. 19 In a study by Harkema et al, 20 specific motor tasks generated electromyographic activity in the trunk muscles and extremities, showing that LT provides intensive proprioceptive feedback to the spinal cord.…”

Diagnostic transcranial magnetic stimulation as a prognostic tool in children with acute transverse myelitis

“…Among other TMS values, which may be of use as prognostic tools in further studies of children with myelitis, are the threshold of MEPs in paravertebral muscles in response to TMS of the motor cortex and the facilitation pattern and latency of MEPs in intercostal muscles during voluntary expiratory effort. 10 These parameters were not included in our protocol, but this design may significantly improve it in the future works.…”

The Sir Ludwig Guttmann Lecture 2012: the contribution of Stoke Mandeville Hospital to spinal cord injuries

“…Since then we have contributed to the validation of the International Standards for Neurological Classification of Spinal Cord injury 52 and development of some new, more precise methods of quantifying the level and density of spinal cord lesions, 53 as part of the International Spinal Research Trust (ISRT) funded studies of physiological [54][55][56] and clinical outcome measures. [57][58][59][60] AGEING AND SURVIVAL Together with the Northwest Regional Spinal Injuries Centre, Southport, UK, and in collaboration with Craig Hospital, Englewood, CO, USA, we have undertaken a longitudinal study on Ageing with SCI in order to provide information on health, functional ability and psychosocial wellbeing in persons with long-term spinal cord injury.…”