Clinical and Neurophysiological Characteristics of Patients with Compressive Radiculopathies

INTRODUCTION: Clinical manifestations of compressive vertebrogenic radiculopathies include pain disorders. This necessitates complex parameterization of individual components of pain syndrome and identification of the respective clinical and functional correlations. AIM: Comprehensive clinical and neurophysiological characteristics of patients with different effectiveness of conservative treatment of L5 and S1vertebrogenic radiculopathy. MATERIALS AND METHODS: The open prospective study included 61 patients. Based on the dynamics of pain syndrome on the visual-analog pain scale (VAS) at 3 weeks and 3 months, using cluster analysis, the patients were divided into groups with insignificant pain dynamics with conservative treatment (group 1 — 32 patients) and with significant pain regression (group 2 — 29 patients). In the patients, endogenous evoked potential of the contingent negative variation (CNV), somatosensory evoked potentials, late electroneuromyographic responses were recorded, and heart rate variability (HRV) was studied. RESULTS: In group 1, a higher CNV amplitude, higher HRV oscillation amplitude in the HF spectrum, and a lower amplitude of F-response on the affected side were revealed. There were found direct correlations between the CNV amplitudes and VLF HRV and VAS on day 1 of the visit, and negative correlations between the amplitude of somatosensory evoked potentials (SSEP) and VAS at 3 months. In group 2, direct correlations were found between the SSEP amplitude, stress index, and F-response from the VAS level on day 1 of the visit, as well as a correlation between heart rate variability and VAS on month 3 after treatment. A logit regression analysis model was created that permitted a highly sensitive distribution of patients into a group with high treatment effectiveness; the independent factors in this model were the CNV amplitude and the normalized HF HRV index. CONCLUSIONS: Correlates of the intensity of pain syndrome in the acute period are the severity of suprasegmental and sympathetic autonomic influences, the power of specific somatosensory afferentation, a high level of readiness for a motor response; upon that, predictor of alleviation of pain syndrome is an initially high level of specific somatosensory afferentation.