ID 200 – The reappearance of F-waves in patients with cervical spinal injury as the criteria of spinal shock ending

Abstract

The aim of our research was to develop the neurophysiological criteria for testing the end of spinal shock. Patients (18 male and 12 women, age 18-33 y.o) with spinal cord injury at the C4-C7 level were investigated 5-7 days (First point) and 2 months (Second point) after trauma. The F-waves were tested bilaterally in nn. medianus, ulnaris, peroneus, tibialis in every patient; the central motor conduction was tested with the transcranial magnetic stimulation (TMS) for mm. Abd.Poll.Brevis and Add.Hallucis. At the First point F-waves were absent in all patients and TMS revealed conduction block (CB) at the cervical level. At the second point in 28 patients the F-waves reappeared only for n.tibialis, with CB in 26 cases and restored conduction in 2 patients from Add.Hallucis on one side; in 2 patients at the Second point here were persistent absence of F-waves and full CB. The reappearance of F-waves in n.Tibialis can be used as a criteria for testing the end of spinal shock and restoration of segmental motor neurons excitability.