Using the Flexor Reflex in a Chronic Stroke Patient for Gait Improvement: A Case Report

The flexor reflex or withdrawal reflex can be elicited by electrical stimulation of the sole of the foot, which serves as a reflex to protect the stimulated limb against tissue damage and consists of flexion movements in the hip, knee, and ankle joint. Triggering this reflex might improve walking abilities in hemiparetic patients. We report the first case of a chronic stroke patient with the most severe impairment of walking. She was examined with and without flexor reflex activation by the Incedo® system. Tests included a 10-m walk and a 2-min walk at baseline, after 3 weeks of training with the Incedo® system and after a follow-up 3 weeks later. Moreover, a kinematic gait analysis was done before and after the training period. At baseline, activation of the flexor reflex induced an improved gait velocity. After the training period, the patient walked twice as fast compared with baseline. Her gait velocity without Incedo® was faster than the gait velocity with Incedo® at baseline. Examination at follow-up indicated that the improvements remained almost unchanged. The kinematic analysis showed an improved stride length and gait velocity during flexor reflex activation. Initially, the foot was elevated higher above the ground during flexor reflex activation. In conclusion, this first case report of a chronic stroke patient demonstrates that flexor reflex activation is feasible and improves gait parameters despite severe impairment of walking abilities.

Nociceptive disorders in patients with microvascular angina pectoris and patients with silent myocardial ischemia

Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): North-western State Medical University named after I.I.Mechnikov The purpose of this study was to study the diagnostic value of the nociceptive flexor reflex (NFR) method in patients with MVA and patients with silent myocardial ischemia. Materials and methods. A total of 158 people were examined, including 131 patients with ischemic heart disease and 31 healthy volunteers (control group). Patients with coronary artery disease were represented by three groups: patients with MVA - 49 people (main group), patients with angina pectoris due to atherosclerotic lesions of the coronary arteries - 40 people (comparison group 1), patients with a diagnosis of painless myocardial ischemia (SMI) - 42 people (comparison group 2). To determine pain indicators, the method of nociceptive flexor reflex (NFR) was used during electrical stimulation of the sural nerve (Nicolet Viking (USA)). Results. The coefficient (k) of pain threshold / reflex threshold (Pb / Pr) in the control group of healthy volunteers was 0.94 ± 0.01, which corresponds to the accepted norms (1-0.9) according to literature data. In the study of NFR in patients with MVA, a decrease in the pain threshold, reflex threshold and ratio (Pb / Pr) was revealed. In the MVS group, PB= 9.5 ± 0.58 mA; Pr = 12.1 ± 0.58 mA; Pb / Pr = 0.78 ± 0.02. The pain threshold in patients with MBS turned out to be statistically significantly lower in comparison with comparison group 1 and comparison group 2 and control group (p <0.01; p <0.001; p <0.001, respectively). The reflex threshold in patients with MVA is statistically significantly lower than in comparison group 1, comparison group 2 (SIM) and control group (p <0.02; p <0.001; p <0.01, respectively). In patients with angina pectoris, PB = 13.8 ± 0.31 mA; Pr = 14.8 ± 0.33 mA; Pb / Pr = 0.94 ± 0.01. In patients with SIM, PB = 24.9 ± 0.99 mA; Pr = 22.9 ± 0.79 mA; Pb / Pr = 1.2 ± 0.02. There was a significant increase in the pain threshold, reflex threshold and the pain threshold / reflex threshold ratio in the group of patients with silent myocardial ischemia compared with similar indicators in the control group, the main group and comparison group 1 (p <0.001; p <0.001; p <0.001 respectively). Conclusions. In patients with MVA compared with healthy individuals in the control group and comparison groups, there is a decrease in NFR indices, which indicates the presence of nociceptive disorders. In patients with SIM, the reflex threshold values are lower in value than the pain threshold. Thus, in patients with SIM the muscle response occurs before the onset of the subjective sensation of pain.

Endothelial dysfunction and features of nociceptive sensitivity in patients with microvascular angina

Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): фГБ ОУ ВО СЗГМУ им. И.И. Мечникова Introduction. The pathogenesis of microvascular angina pectoris (MVA) is not completely clear to the end, some authors consider the violation of pain (nociceptive) sensitivity to be an important cause of this disease. The purpose of this study was to study the perception of pain and serum endothelin-1 in patients with MVA. Materials and methods. The criteria for inclusion in the group with MVA (49 patients): chest pain, positive stress test, unchanged coronary artery according to coronary angiography, the presence of a violation of myocardial perfusion and a decrease in the coronary reserve according to the positron emission tomography (PET) of the myocardium in rest, with a sample with adenosine and a cold test. Pain in the chest was noted in all 49 patients. Assessment of the nature of the pain syndrome was carried out using a 10-point visual-analogue scale (VAS), verbal rank scale (VRS). All subjects underwent a study of the functional activity of nociceptive and antinociceptive systems using the nociceptive flexor reflex method on the Nicolet VikingSelect expert class equipment, the pain threshold (Pb), the threshold of the reflex (Pr), and ratio coefficient (Pb / Pr), which in healthy people is approximately 0.9-1.0. The content of endothelin-1 in the serum of peripheral blood was determined by the method of enzyme immunoassay using test systems "Endotelin 1-21" (the normal values are up to 0.26 fmol / l) Fresh samples immediately after collection of blood were placed on ice and centrifuged during the day. Results. The intensity of pain in the usual attacks in patients with MVA according to the VAS data (5.51 ± 0.2) in most cases was moderate and none of the subjects reached the maximum possible values. According to VRS, moderate pain was described by 60% of patients with MVA, strong - 34.3%.In the study of NFR in patients with MVA, the group as a whole showed a decrease in the pain threshold, the threshold of the reflex, and the ratio coefficient (Pb / Pr) as compared with normal values. In the MVA group, Pb was equal to 9.5 ± 0.58 mA; Pr = 12.1 ± 0.58 mA; Pb / Pr = 0.78 ± 0.02. When studying the level of endothelin-1 in patients with MVA the level of this peptide was raised to 2.9 ± 0.82 fmol / l. According to the correlation analysis between endothelin-1 and the parameters of NFR, an inverse correlation was observed: between endothelin-1 and pain threshold (r = -0.4; p <0.01); between the level of endothelin-1 and the ratio coefficient of PB / PR (r = -0.9; p <0.01). Based on the results of the correlation analysis of the pain intensity index on the VAS scale and endothelin-1 level in patients with MVA, a significant relationship was found (r = 0.6, p <0.01) Conclusions. In patients with MVA, a decrease in the pain threshold and an elevated level of endothelin-1 were found. Thus, the severity of endothelial dysfunction in patients with MVA was interrelated with the process of perception of pain.

Clinical and MRI findings in two unrelated cats with globoid cell leucodystrophy

Two unrelated male cats, both five months old, were referred for progressive neurological signs characterised by intentional tremors, paraplegia with absence of nociception in the pelvic limbs, weakness, dysmetria with reduced flexor reflex in the thoracic limbs, and bilaterally reduced menace response. MRI, performed by a 0.25 T Esaote Vet Grande, showed diffuse and irregular intramedullary T2 weighted hyperintensity between T3 and L3; these lesions were isointense on T1 weighted images without contrast uptake. In one patient MRI of the brain was obtained and mild cerebellar volume reduction was found. Histological examination of the brain and spinal cord demonstrated myelin loss and perivascular accumulation of periodic acid-Schiff-positive big macrophages. These findings were consistent with globoid cell leucodystrophy, as previously described in cats. Although not specific, in young cats with progressive spinal neurological signs, especially when associated with cerebellar signs, and irregular but diffuse T2 intramedullary hyperintensity and T1 isointensity without contrast uptake, globoid cell leucodystrophy should be suspected.

P6434Evaluation of the nociceptive flexor reflex, as a new method for the diagnosis of microvascular angina

The purpose of this study was to study the diagnostic value of the nociceptive flexor reflex (NFR) method in patients with microvascular angina. Materials and methods The study included 49 patients with MVA (main group), 40 patients with classical angina II-III f.c. (comparison group 1), 42 patients with silent myocardial ischemia (comparison group 2) and 32 healthy volunteers (control group). Criteria for inclusion in the group with MVA: chest pain, positive stress test, unchanged coronary arteries according to coronary angiography, the presence of myocardial perfusion disturbance and reduction of the coronary reserve according to positiron-emission tomography of the myocardium at rest, with adenosine and cold one test. Chest pain syndrome was observed in all 49 patients. All subjects studied the functional activity of nociceptive and antinociceptive systems using the nociceptive flexor reflex method on the equipment of expert class electromyography system, the pain threshold (Pb) values, the reflex threshold (Pr) were calculated and the ratio of pain and reflex threshold was calculated to calculate the pain threshold / threshold reflex (Pb/Pr), which in healthy people is about 0.9–1.0. Results and discussion In te study of NFR in patients with MVA in the group as a whole, a decrease in the pain threshold, reflex threshold and Pb/Pr ratio compared with normal values were found. The pain threshold in patients in the group was lower (statistically significantly) when compared with the group 1, the group 2 and the control group (p<0.0001; p<0.0001; p<0.0001, respectively). The reflex threshold in patients of the MCC group was also significantly lower when compared with the group 1, the group 2 and the control group (p<0.001; p<0.0001; p<0.001, respectively). Due to the fact that the low pain threshold was found in 84.4% of the examined patients with MVA who had microvascular dysfunction according to positron-emission tomography, we evaluated the prognostic value of the NFR method for diagnosing the disease. To do this, an assessment was made of the odds ratio (OR) of identifying MVA in groups of patients with different levels of index K (the ratio of the pain threshold value to the reflex threshold value). We have chosen the value of index K with the highest specificity and high sensitivity equal to 0.8892. Based on the data obtained, the diagnostic value of the NFR method was calculated during the verification of the MVA. When conducting a mathematical analysis, it was found that this technique has high sensitivity (84.4%), specificity (95.12%), positive (90.48%) and negative predictive value (91.76%). We have not found information in the literature on the use of the NFR assessment method and its diagnostic value in MVA. Findings Due to the high diagnostic value of determining the NFR, we propose to include this method in the MVA diagnostic algorithm as an additional one.