Recruitment curve of the soleus H-reflex in chronic back pain and lumbosacral radiculopathy

Abstract

BackgroundNeedle EMG may be negative in mild or predominantly sensory lumbosacral radiculopathies. In such cases, an increase in the latency of the soleus H-reflex is a useful diagnostic criterion for establishing sensory fiber compromise at the S1 root level. However, if clinical signs of radicular involvement are lacking, the latency of the H-reflex is normal. We therefore studied the recruitment curve of the soleus H-reflex to investigate whether a change in the electrical threshold for eliciting the H-reflex might be a more sensitive criterion for detecting subclinical S1 root dysfunction.MethodsClinical and electrophysiological findings from 26 patients with chronic back pain and radiculopathy were compared with data obtained from 40 healthy subjects.ResultsAn increase in the mean H-reflex threshold was the only abnormal electrophysiological finding in patients with no clinical sign of root injury (58%). A decrease in the mean H-reflex amplitude and a prolongation of H-reflex latency was observed in patients with radicular signs (42%). In both patients groups, F-wave and needle EMG studies were normal. No radiological evidence of S1 root compression was found.ConclusionsThe study of the recruitment curve of the soleus H-reflex may be usefully associated to F-wave and needle EMG studies to detect possible S1 root dysfunction in mild lumbosacral radiculopathies. An increase in H-threshold may be the earliest abnormality in the absence of focal neurological signs.

Changes in coordination of postural control during dynamic stance in chronic low back pain patients

“…In this strategy, the muscles groups acting at the ankle joint are considered as the main musculature for the control of stability during quiet standing [24]. Patients with CLBP due to spondylolisthesis have been found to have abnormalities of the soleus H-reflex [25,26] which depends on the activation of large-diameter mechano-receptive afferents (group Ia fibres) in the muscle [27]. It is known that changes in Ia input may result in altered proprioception [28] and distortion of sensory maps [29].…”

Changes in Spinal Reflex Excitability Associated With Motor Sequence Learning

“…The H-reflex was analyzed separately for the low-and high-intensity electrical stimulations. Data obtained with low-intensity electrical stimuli constitute the main focus of the study, given that at this level of stimulation the H-reflex response is not likely to be contaminated by antidromic collisions (Hugon 1974;Lagerquist and Collins 2008;Mazzocchio et al 2001;Meinck 1980;Pierrot-Deseilligny et al 1976). Data from high-intensity stimulation are reported only for the M-response to determine whether this is affected by the task conditions.…”

Center of pressure excursion as a measure of balance performance in patients with non-specific low back pain compared to healthy controls: a systematic review of the literature

“…Ideally, the body should be able to generate quick COP transitions that just exceed the current position of the center of mass (COM) [3] and accelerate it into the opposite direction in order to maintain balance. On a basic level (chronic) damage of sensory tissues in the lumbar spine, trunk [9] or lower extremities [10] may affect postural stability. Deterioration of this proprioceptive information from these areas may be the determining factor in reducing the accuracy in the sensory integration process.…”