Introduction: Changes in spinal reflexes can result from alterations in the spinal cord and descending pathways. We studied whether H-reflex excitability and its recovery depend on the level and/or severity of spinal cord injury (SCI).
Methods: The soleus Hmax and Mmax responses and the H-reflex recovery curve (HRC) at interstimulus intervals (ISIs) ranging from 50 to 1,000 ms were recorded in 38 SCI individuals and 18 healthy subjects.
Results: Amplitude of Mmax correlated with level and severity of lesion (smaller amplitude correlated with more severe SCI or with more caudal lesion). Hmax/Mmax correlated only with age in the SCI group. HRC was increased significantly in complete SCI at ISIs < 500 ms and in incomplete SCI at ISIs > 200 ms with respect to healthy subjects.
Conclusions: The changes in spinal reflexes as measured by the H-reflex and its recovery curve after SCI depend on the severity, but not on the level of the lesion.
Keywords: H-reflex; severity of SCI; spinal cord injury; spinal level.
© 2015 Wiley Periodicals, Inc.