title: Functional evaluation of paraplegic monkeys (Macaca mulatta) over fourteen months post-lesion.
abstract: We report on the neurological and neurophysiological findings obtained from two adult Macaca mulatta sustaining complete spinal cord transections at T8-T9. We performed periodic neurological exams, recorded motor evoked potentials (MEPs) following transcranial magnetic stimulation (TMS), and recorded electromyograms (EMGs) during the execution of a lower limb motor test. The main observations were: (1) the spinal shock period lasted less than a week; tendon, cutaneous and withdrawal reflexes were uneven in range and occurrence, and Babinski's sign was not observed; (2) a protracted functional lesion in the tibial and common peroneal nerves appeared bilaterally early in the post-lesional period; (3) MEPs were elicited by TMS in the quadriceps muscle of both monkeys; they were recorded as early as the 5th week after lesion in one of the monkeys, and they persisted throughout the post-lesional period in both monkeys; and (4) motor unit action potentials in the quadriceps muscle recorded by EMG were simultaneous with attempts to perform intentional lower limb movements from post-lesion month 11 to 13.5 in both monkeys. The last two sets of observations argue in favor of a partial cortico-spinal functional gain and suggest that spinal cord regeneration can occur after complete spinal cord injury in primates.
authors.affiliation: Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Spain.
authors.forename: Aurelio
authors.initials: A
authors.lastname: Hernández-Laín
authors.forename: María José G M
authors.initials: MJ
authors.lastname: Piedras
authors.forename: Carmen
authors.initials: C
authors.lastname: Cavada
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D004195:Disease Models, Animal; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009416:Nerve Regeneration / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D013995:Time; D050781:Transcranial Magnetic Stimulation