Neurophysiological Evaluation of Neural Transmission in Brachial Plexus Motor Fibers with the Use of Magnetic versus Electrical Stimuli.

The anatomical complexity of brachial plexus injury requires specialized in-depth diagnostics. The clinical examination should include clinical neurophysiology tests, especially with reference to the proximal part, with innovative devices used as sources of precise functional diagnostics. However, the principles and clinical usefulness of this technique are not fully described. The aim of this study was to reinvestigate the clinical usefulness of motor evoked potential (MEP) induced by a magnetic field applied over the vertebrae and at Erb's point to assess the neural transmission of brachial plexus motor fibers. Seventy-five volunteer subjects were randomly chosen to participate in the research. The clinical studies included an evaluation of the upper extremity sensory perception in dermatomes C5-C8 based on von Frey's tactile monofilament method, and proximal and distal muscle strength by Lovett's scale. Finally, 42 healthy people met the inclusion criteria. Magnetic and electrical stimuli were applied to assess the motor function of the peripheral nerves of the upper extremity and magnetic stimulus was applied to study the neural transmission from the C5-C8 spinal roots. The parameters of compound muscle action potential (CMAP) recorded during electroneurography and MEP induced by magnetic stimulation were analyzed. Because the conduction parameters for the groups of women and men were comparable, the final statistical analysis covered 84 tests. The parameters of the potentials generated by electrical stimulus were comparable to those of the potentials induced by magnetic impulse at Erb's point. The amplitude of the CMAP was significantly higher following electrical stimulation than that of the MEP following magnetic stimulation for all the examined nerves, in the range of 3-7%. The differences in the potential latency values evaluated in CMAP and MEP did not exceed 5%. The results show a significantly higher amplitude of potentials after stimulation of the cervical roots compared to potentials evoked at Erb's point (C5, C6 level). At the C8 level, the amplitude was lower than the potentials evoked at Erb's point, varying in the range of 9-16%. We conclude that magnetic field stimulation enables the recording of the supramaximal potential, similar to that evoked by an electric impulse, which is a novel result. Both types of excitation can be used interchangeably during an examination, which is essential for clinical application. Magnetic stimulation was painless in comparison with electrical stimulation according to the results of a pain visual analog scale (3 vs. 5.5 on average). MEP studies with advanced sensor technology allow evaluation of the proximal part of the peripheral motor pathway (between the cervical root level and Erb's point, and via trunks of the brachial plexus to the target muscles) following the application of stimulus over the vertebrae.

End-to-Side vs. Free Graft Nerve Reconstruction-Experimental Study on Rats.

The long history of regeneration nerve research indicates many clinical problems with surgical reconstruction to be resolved. One of the promising surgical techniques in specific clinical conditions is end-to-side neurorrhaphy (ETS), described and then repeated with different efficiency in the 1990s of the twentieth century. There are no reliable data on the quality of recipient nerve regeneration, possible donor nerve damage, and epineural window technique necessary to be performed. This research attempts to evaluate the possible regeneration after end-to-side neurorrhaphy, its quality, potential donor nerve damage, and the influence of epineural windows on regeneration efficiency. Forty-five female Wistar rats were divided into three equal groups, and various surgical technics were applied: A-ETS without epineural window, B-ETS with epineural window, and C-free graft reconstruction. The right peroneal nerve was operated on, and the tibial nerve was selected as a donor. After 24 weeks, the regeneration was evaluated by (1) footprint analysis every two weeks with PFI (peroneal nerve function index), TFI (tibial nerve function index), and SFI (sciatic nerve function index) calculations; (2) the amplitude and latency measurements of motor evoked potentials parameters recorded on both sides of the peroneal and tibial nerves when electroneurography with direct sciatic nerve electrical stimulation and indirect magnetic stimulation were applied; (3) histomorphometry with digital conversion of a transverse semithin nerve section, with axon count, fibers diameter, and calculation of axon area with a semiautomated method were performed. There was no statistically significant difference between the groups investigated in all the parameters. The functional indexes stabilized after eight weeks (PFI) and six weeks (TFI and SFI) and were positively time related. The lower amplitude of tibial nerve potential in groups A and B was proven compared to the non-operated side. Neurophysiological parameters of the peroneal nerve did not differ significantly. Histomorphometry revealed significantly lower diameter and area of axons in operated peroneal nerves compared to non-operated nerves. The axon count was at a normal level in every group. Tibial nerve parameters did not differ from non-operated values. Regeneration of the peroneal nerve after ETS was ascertained to be at the same level as in the case of free graft reconstruction. Peroneal nerves after ETS and free graft reconstruction were ascertained to have a lower diameter and area than non-operated ones. The technique of an epineural window does not influence the regeneration result of the peroneal nerve. The tibial nerve motor evoked potentials were characterized by lower amplitudes in ETS groups, which could indicate axonal impairment.

Delayed Surgical Treatment in Patients with Chronic Carpal Tunnel Syndrome Is Still Effective in the Improvement of Hand Function.

Background and Objectives: Severe carpal tunnel syndrome (CTS) is the most common compression neuropathy in the upper extremities treated conservatively; later, when advanced, CTS is treated mostly surgically. The most prevalent symptoms comprise numbness, as well as sensation loss in the thumb, index, and middle finger, and thenar muscle strength loss, resulting in impaired daily functioning for patients. Data on the results of CTS treatment in patients with delayed surgical intervention are scarce. The aim of this study was to determine the postoperative results of chronic carpal tunnel syndrome treatment in patients with symptoms lasting for at least 5 years. Materials and Methods: A total of 86 patients (69 females, 17 males) with a mean age of 58 years reporting symptoms of CTS for at least 5 years (mean: 8.5 years) were prospectively studied. The average follow-up time was 33 months. All patients underwent the surgical open decompression of the median nerve at the wrist. A preoperative observation was composed of an interview and a clinical examination. The subjects completed the DASH (the Disabilities of the Arm, Shoulder, and Hand), PRWE (Patient-Rated Wrist Evaluation), and self-report questionnaires. Global grip strength, sensory discrimination, characteristic symptoms of CTS, and thenar muscle atrophy were examined. Postoperatively, clinical and functional examinations were repeated, and patients expressed their opinions by completing a BCTQ (Boston Carpal Tunnel Syndrome Questionnaire). Results: We found improvements in daily activities and hand function postoperatively. Overall, 88% of patients were satisfied with the outcome of surgery. DASH scores decreased after surgery from 44.82 to 14.12 at p < 0.001. PRWE questionnaire scores decreased from 53.34 to 15.19 at p < 0.001. The mean score of the BCTQ on the scale regarding the severity of symptoms was 1.48 and 1.62 on the scale regarding function after surgery. No significant differences were found in the scores between the male and female groups or between age groups (p > 0.05). A significant increase in global grip strength from 16.61 kg to 21.91 kg was observed postoperatively at p < 0.001. No significant difference was detected in the measurement of sensory discrimination (6.02 vs. 5.44). In most of the examined patients, night numbness and wrist pain subsided after surgery at p < 0.001. Thenar muscle atrophy diminished after surgery at p < 0.001. Conclusions: Most patients were satisfied with the results of CTS surgery regarding the open decompression of the median nerve even after 5 years of ineffective conservative treatment. Significant improvement of the hand function was confirmed in the functional studies.

Monitoring of the pharmacological treatment availability in patients with multiple sclerosis in the Greater Poland population.

Introduction: There is no clear explanation for the availability of multiple sclerosis (MS) pharmacological treatment for patients in Greater Poland and it can be assumed that the same reason is common in most of the developed countries in the United Europe. As an autoimmune disease MS can overlap with other diseases especially rheumatic disease (RD) as well as some feature of RD may mimic MS, such as MS-like syndrome in the course of primary Sjögren's syndrome. Therefore proper diagnosis and sufficient treatment of MS is important not only for neurologists but also for other clinicians including rheumatologists.The study aims to provide insights that could help healthcare managers create more effective logistical guidelines to improve the timely initiation of pharmacological treatment for MS. Materials and methods: The analysis of the treatment of MS patients has been conducted on a group of 500 patients who were under the management of one healthcare center in Greater Poland. Results: The results point to the different factors influencing the delay in the undertaking the pharmacological treatment, among others the age of the patient, waiting time for clinical evaluation and the final diagnosis from first symptoms to diagnosis, and the patient's waiting time from diagnosis to referral for qualification for treatment. Conclusions: The outcomes of this study have the potential to serve as a valuable resource for healthcare managers. The study's findings could be used as a foundation for developing logistical guidelines aimed at enhancing the pharmacological treatment of MS patients.Furthermore, the study suggests that the reasons behind treatment delays in MS patients might be prevalent in many countries across the United Europe region. However, it's important to note that confirming this conclusion requires additional comparative studies.

Update on neuromonitoring procedures applied during surgery of the spine - observational study.

Introduction: Motor evoked potentials (MEPs) are currently considered as a more useful method for neurophysiological intraoperative monitoring than somatosensory evoked potentials in cases of surgery applied to patients with adolescent idiopathic scoliosis. The non-invasive approach is preferred to modify MEP recordings, criticizing, in many cases, the fundamentalism for neurophysiological monitoring based only on needle recordings. The aim of the review is to provide our own experience and practical guidelines with reference to neuromonitoring innovations. Material and methods: Recordings of MEPs with surface electrodes instead of needle electrodes including nerve instead of muscle combinations during neurophysiological monitoring associated with surgical interventions to the spine have become more relevant for pediatric purposes, avoiding the anesthesiology-related influences. Observations on 280 patients with Lenke A-C types of spine curvature are presented before and after the surgical correction. Results: The MEPs recorded from nerves do not undergo fluctuations at different stages of scoliosis corrections and the anesthesia effect more than MEPs recorded from muscles. The use of non-invasive surface electrodes during neuromonitoring for MEP recordings shortens the total time of the surgical procedure without diminishing the precision of the neural transmission evaluation. The quality of MEP recordings during intraoperative neuromonitoring from muscles can be significantly influenced by the depth of anesthesia or administration of muscle relaxants but not those recorded from nerves. Conclusions: The proposed definition of "real-time" neuromonitoring comprises the immediate warning from a neurophysiologist about the changes in a patient's neurological status during scoliosis surgery (especially during pedicle screws' implantation, corrective rods' implantation, correction, distraction and derotation of the spine curvature) exactly during the successive steps of corrective procedures. This is possible due to the simultaneous observation of MEP recordings and a camera image of the surgical field. This procedure clearly increases safety and limits financial claims resulting from possible complications.

Standard neurophysiological studies and motor evoked potentials in evaluation of traumatic brachial plexus injuries - A brief review of the literature.

PURPOSE: Traumatic damage to the brachial plexus is associated with temporary or permanent motor and sensory dysfunction of the upper extremity. It may lead to the severe disability of the patient, often excluded from the daily life activity. The pathomechanism of brachial plexus injury usually results from damage detected in structures taking origin in the rupture, stretching or cervical roots avulsion from the spinal cord. Often the complexity of traumatic brachial plexus injury requires a multidisciplinary diagnostic process including clinical evaluation supplemented with clinical neurophysiology methods assessing the functional state of its structures. Their presentation is the primary goal of this paper. METHODS: The basis for the diagnosis of brachial plexus function is a clinical examination and neurophysiology studies: electroneurography (ENG), needle electromyography (EMG), somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) assessing the function of individual brachial plexus elements. CONCLUSIONS: The ENG and EMG studies clarify the level of brachial plexus damage, its type and severity, mainly using the Seddon clinical classification. In contrast to F-wave studies, the use of the MEPs in the evaluation of traumatic brachial plexus injury provides valuable information about the function of its proximal part. MEPs study may be an additional diagnostic in confirming the location and extent of the lesion, considering the pathomechanism of the damage. Clinical neurophysiology studies are the basis for determining the appropriate therapeutic program, including choice of conservative or reconstructive surgery which results are verified in prospective studies.

Evaluation of Mandibular Movement Functions Using Instrumental Ultrasound System.

PURPOSE: The article deals with routinely performed instrumental temporomandibular joint (TMJ) examinations and interpretation of findings obtained from the Arcus Digma ultrasound device in individuals with or without clinical symptoms of temporomandibular disorders (TMD). The aim of this study was to analyze mandibular movement functions and the relationship between incisors and condylar movement parameters during jaw opening, which may be helpful for clinical evaluation in these patients. MATERIALS AND METHODS: The study group consisted of 84 young students with no dental problems and other serious acute or chronic diseases in the medical history; the students were examined both clinically and with the Arcus Digma ultrasound device. RESULTS: Helkimo Di = I was the most common score in 49 participants, and Helkimo Di = II in a significantly (p < 0.01, Di = I vs. Di = II) smaller number of participants. Medical history revealed symptoms of unilateral mastication in 15 participants and a statistically significant increased (p < 0.02, participants with symptoms of unilateral mastication vs. asymptomatic) condylar range of motion parameter during retrusion. Also a significant decrease (p < 0.03, participants with symptoms of unilateral mastication vs. asymptomatic) of the incisal and condylar ranges of motion during mouth opening was found. Limitation of mouth opening, defined as a decrease of inter-incisal distance, appeared in 19 participants (22.6%) and in 25 participants (29.8%) measured instrumentally with the Arcus Digma device. A comparison of instrumental result examinations of the right and left TMJs showed positive correlations of the range of mandible opening movement with the Posselt opening movement (r = 0.75) and opening/closing movements with the Posselt closing movements (r = 0.70). A correlation was demonstrated (r = 0.81) between the condylar range of motion studied on the left and on the right TMJ during mandible opening movement. Correlations were also found between opening-closing movements and the condylar range of motion of the left TMJ, and between the opening-closing movement and the condylar range of motion of the right TMJ during the opening movement. CONCLUSIONS: According to the results of this study with instrumental Arcus Digma ultrasound device measurements of mandibular movements, data were provided on irregularities in TMJ function not detected in participants with or without clinical symptoms of TMD.

Surface electromyography studies in standing position confirm that ankle strategy remains disturbed even following successful treatment of patients with a history of sciatica.

[Purpose] It is hypothesized that ankle strategy can be changed in patients with a history of sciatica. The aim of this study was to detect residual disturbances following successful treatment. [Subjects and Methods] In patients with a history of sciatica (N=11) and pseudo-sciatica (N=9), differences in muscle activity were recorded with bilateral surface polyelectromyography and stability measurements (center of foot pressure sway and center of spectrum) in normal standing and tandem positions. Results were compared with recordings in healthy people (N=9) to identify abnormalities in electromyographic and postural studies. [Results] Increased amplitude of electromyographic recordings from the gastrocnemius and extensor digiti muscles on the affected side was detected more in patients with a history of sciatica than pseudo-sciatica syndromes in tandem position. Fewer amplitude fluctuations were observed in both positions preferably in patients following sciatica. Changes in center of foot pressure sway and center of spectrum during balance platform studies were detected in normal standing position in this group of patients. No similar abnormalities in electromyographic and postural studies were detected in healthy people. [Conclusion] Sciatica and pseudo-sciatica evoke persistent disturbances in activity of muscles responsible for ankle strategy. Electromyography differentiates the two groups of patients better than postural studies.

Correlations between the clinical, histological and neurophysiological examinations in patients before and after parotid gland tumor surgery: verification of facial nerve transmission.

Parotid gland tumor surgery sometimes leads to facial nerve paralysis. Malignant more than benign tumors determine nerve function preoperatively, while postoperative observations based on clinical, histological and neurophysiological studies have not been reported in detail. The aims of this pilot study were evaluation and correlations of histological properties of tumor (its size and location) and clinical and neurophysiological assessment of facial nerve function pre- and post-operatively (1 and 6 months). Comparative studies included 17 patients with benign (n = 13) and malignant (n = 4) tumors. Clinical assessment was based on House-Brackmann scale (H-B), neurophysiological diagnostics included facial electroneurography [ENG, compound muscle action potential (CMAP)], mimetic muscle electromyography (EMG) and blink-reflex examinations (BR). Mainly grade I of H-B was recorded both pre- (n = 13) and post-operatively (n = 12) in patients with small (1.5-2.4 cm) benign tumors located in superficial lobes. Patients with medium size (2.5-3.4 cm) malignant tumors in both lobes were scored at grade I (n = 2) and III (n = 2) pre- and mainly VI (n = 4) post-operatively. CMAP amplitudes after stimulation of mandibular marginal branch were reduced at about 25 % in patients with benign tumors after surgery. In the cases of malignant tumors CMAPs were not recorded following stimulation of any branch. A similar trend was found for BR results. H-B and ENG results revealed positive correlations between the type of tumor and surgery with facial nerve function. Neurophysiological studies detected clinically silent facial nerve neuropathy of mandibular marginal branch in postoperative period. Needle EMG, ENG and BR examinations allow for the evaluation of face muscles reinnervation and facial nerve regeneration.

Evaluation of palpation, pressure algometry, and electromyography for monitoring trigger points in young participants.

OBJECTIVE: The aims of this study were to assess trigger points (TrPs), their pain threshold, and the activity of motor units in the neck and shoulder girdle muscles of young volunteers and to assess palpation, algometry, and surface electromyography (EMG) for their detection. METHODS: Seventy participants aged from 19 to 26 years (20.6 ± 1.4 years [mean ± SD]) were examined to identify TrPs through palpation, an algometer test for pressure pain threshold (PPT), a test for the activity of muscle motor units at rest (rEMG) and at maximal contraction (mcEMG) with surface EMG recordings. RESULTS: Palpation studies revealed numerous symmetrical nonreferring latent TrPs (379/560 performed tests), referring latent TrPs (91/560), and few active TrPs (4/560). Algometry confirmed the lowest PPT in active TrPs and the highest PPT in participants with no TrPs (86/560). Pressure pain thresholds were lower in nonpregnant women than in men, especially in the trapezius and sternocleidomastoid muscles with nonreferring and referring latent TrPs. Trigger points evoked a moderate increase of rEMG amplitude but with no evident changes in mcEMG. CONCLUSIONS: This study showed that the preliminary algometry and rEMG recordings monitored a decrease in PPT and an increase in muscle tension in all cases of TrPs in each of the 3 types detected in people younger than 30 years.

Visual biofeedback exercises for improving body balance control after anterior cruciate ligament reconstruction.

[Purpose] To evaluate the effects of balance training after arthroscopic anterior cruciate ligament reconstruction. [Subjects and Methods] Sixteen patients (mean 33 ± 8 years old) who underwent anterior cruciate ligament reconstruction three months prior to participating in a one-month rehabilitation program. The control group included 15 people aged 34 ± 4 years. Patients' functional level was evaluated according to the Lysholm knee score, and balance quality was ascertained by static and dynamic tests. A balance platform was used to measure the center of foot pressure deflection. Two dynamic balance tests evaluated time of task execution. [Results] Lysholm knee score improved significantly after rehabilitation. Balance in the sagittal plane with eyes closed improved significantly after rehabilitation. The average velocity of center of foot pressure swing in both the frontal and sagittal planes with eyes closed differed significantly from those of controls. Execution time required for the two dynamic tests decreased significantly after rehabilitation and were significantly better than those in the controls. [Conclusion] Maintaining static balance with eyes closed is very challenging after anterior cruciate ligament reconstruction. Maintaining balance in the sagittal plane is particularly difficult. A one-month rehabilitation program partially improves static and dynamic balance.

Brachial Plexus Injury Influences Efferent Transmission on More than Just the Symptomatic Side, as Verified with Clinical Neurophysiology Methods Using Magnetic and Electrical Stimulation.

The variety of sources of brachial plexus injuries (BPIs) and the severity and similarity of their clinical symptoms with those of other injuries make their differential diagnosis difficult. Enriching their diagnosis with objective high-sensitivity diagnostics such as clinical neurophysiology may lead to satisfactory treatment results, and magnetic stimulation (MEP) might be an advantageous addition to the diagnostic standard of electrical stimulation used in electroneurography (ENG). The asymptomatic side in BPI cases sometimes shows only subclinical neurological deficits; this study aimed to clarify the validity and utility of using MEP vs. ENG to detect neural conduction abnormalities. Twenty patients with a BPI and twenty healthy volunteers with matching demographic and anthropometric characteristics were stimulated at their Erb's point in order to record the potentials evoked using magnetic and electrical stimuli to evaluate their peripheral motor neural transmission in their axillar, musculocutaneous, radial, and ulnar nerves. MEP was also used to verify the neural transmission in participants' cervical roots following transvertebral stimulations, checking the compatibility and repeatability of the evoked potential recordings. The clinical assessment resulted in an average muscle strength of 3-1 (with a mean of 2.2), analgesia that mainly manifested in the C5-C7 spinal dermatomes, and a pain evaluation of 6-4 (mean of 5.4) on the symptomatic side using the Visual Analog Scale, with no pathological symptoms on the contralateral side. A comparison of the recorded potentials evoked with magnetic versus electrical stimuli revealed that the MEP amplitudes were usually higher, at p = 0.04-0.03, in most of the healthy volunteers' recorded muscles than in those of the group of BPI patients, whose recordings showed that their CMAP and MEP amplitude values were lower on their more symptomatic than asymptomatic sides, at p = 0.04-0.009. In recordings following musculocutaneous and radial nerve electrical stimulation and ulnar nerve magnetic stimulation at Erb's point, the values of the latencies were also longer on the patient's asymptomatic side compared to those in the control group. The above outcomes prove the mixed axonal and demyelination natures of brachial plexus injuries. They indicate that different types of traumatic BPIs also involve the clinically asymptomatic side. Cases with predominantly median nerve lesions were detected in sensory nerve conduction studies (SNCSs). In 16 patients, electromyography revealed neurogenic damage to the deltoid and biceps muscles, with an active denervation process at work. The predominance of C5 and C6 brachial plexus injuries in the cervical root and upper/middle trunk of patients with BPI has been confirmed. A probable explanation for the bilateral symptoms of dysfunction detected via clinical neurophysiology methods in the examined BPI patients, who showed primarily unilateral damage, maybe the reaction of their internal neural spinal center's organization. Even when subclinical, this may explain the poor BPI treatment outcomes that sometimes occur following long-term physical therapy or surgical treatment.

"Real-Time Neuromonitoring" Increases the Safety and Non-Invasiveness and Shortens the Duration of Idiopathic Scoliosis Surgery.

Introduction: A practical solution to the incidental unreliability of intraoperative neuromonitoring (IONM) may be the simultaneous neurophysiological recording and control of the surgical field through a camera (the concept of "Real-time" IONM). During "Real-time" IONM, the surgeon is immediately warned about the possibility of damage to the neural structures during, but not after, standard idiopathic scoliosis (IS) corrective surgery procedures (the concept of "Surgeon-neurophysiologist" interactive, verbal IONM). This study aimed to compare the advantages, utilities, reliabilities, and time consumption of the two IONM scenarios. Methods: Studies were performed in two similar groups of patients undergoing surgery primarily due to Lenke 2 idiopathic scoliosis (N = 120), when both IONM approaches were applied. Neurophysiological evaluations of the spinal transmission were performed pre- (T0), intra- (before (T1) and after (T2) surgery), and postoperatively (T3), as well as once in healthy volunteers (control, N = 60). Non-invasive and innovative recordings of the motor evoked potentials (MEPs) bilaterally from the peroneal (PER) nerve and tibialis anterior (TA) muscle were performed with surface electrodes as a result of transcranial magnetic stimulation (TMS) or electrical stimulation (TES) at T0-T3. Results: In both groups, the MEP amplitudes and latencies recorded from the PER nerve were approximately 67% lower and 3.1 ms shorter than those recorded from the TA muscle. The MEP recording parameters differed similarly at T0-T3 compared to the control group. In all patients, the MEP parameters induced by TMS (T0) and TES (T1) did not differ. The MEP amplitude parameters recorded from the TA and PER at T1 and T2 indicated a bilateral improvement in the neural spinal conduction due to the surgical intervention. The TMS-induced MEP amplitude at T3 further increased bilaterally. In both IONM groups, an average 51.8 BIS level of anesthesia did not affect the variability in the MEP amplitude, especially in the PER recordings when the applied TES strength was 98.2 mA. The number of fluctuations in the MEP parameters was closely related to the number of warnings from the neurophysiologist during the transpedicular screw implantation, corrective rod implantation, and distraction, derotation, and compression procedures, and it was higher in the "Surgeon-neurophysiologist" IONM group. The average duration of surgery was shorter by approximately one hour in the "Real-time" IONM group. The number of two-way communications between the surgeon and the neurophysiologist and vice versa in the "Real-time" IONM group decreased by approximately half. Conclusions: This study proves the superiority of using "Real-time" IONM over the standard "Surgeon-neurophysiologist" IONM procedure in increasing the safety and non-invasiveness, shortening the time, and lowering the costs of the surgical treatment of IS patients. The modifications of the MEP nerve-conduction-recording technology with surface electrodes from nerves enable precise and reliable information on the pediatric patient's neurological condition at every stage of the applied surgical procedures, even under conditions of slight fluctuations in anesthesia.

Meniscus suture provides better clinical and biomechanical results at 1-year follow-up than meniscectomy.

BACKGROUND: Surgery of meniscus tear results in limitation of function. The aim of study was functional assessment of knee 1 year after surgery with two techniques in cases of the medial meniscus tear followed by the same supervised rehabilitation. MATERIALS AND METHODS: A total of 30 patients with good KOSS scores constituted two equal groups after partial meniscectomy or meniscus suture. Measurements of knee extensors and flexors muscles peak torques were performed with angular velocities 60, 180, 240 and 300 s(-1) using Biodex IV system. One-leg-hop and one-leg-rising tests ascertained the function of operated knee. Results of examinations were compared with reference to healthy volunteers. Results of biomechanical and clinical studies were correlated to create complex and objective method evaluating treatment. RESULTS: Extensors peak torque values at 60 s(-1) angular velocity and H/Q coefficient were decreased after meniscectomy more than meniscus suture in comparison to healthy volunteers (P ≤ 0.001; P ≤ 0.05). Analysis of functional tests revealed that patients after meniscectomy showed difference between operated and non-operated knee (P ≤ 0.01) while patients with meniscus suture differed the least to controls (P ≤ 0.05). Extensors peak torque values at 60 s(-1) angular velocity correlated with results of one-leg-rising test. CONCLUSION: Results suggest worse functional effects when meniscectomy is applied which implies modification of the rehabilitative methods in a postoperative period.

Comparing Parameters of Motor Potentials Recordings Evoked Transcranially with Neuroimaging Results in Patients with Incomplete Spinal Cord Injury: Assessment and Diagnostic Capabilities.

This study aimed to investigate the relationships between the different levels and degrees of incomplete spinal cord injury (iSCI) evaluated with magnetic resonance imaging (MRI) and the results of non-invasive electromyography (mcsEMG), motor-evoked potentials (MEP), and electroneurography (ENG). With a focus on patients with injuries at four different levels, C3-C5, C6-Th1, Th3-Th6, and Th7-L1, this research delved into the intricate interplay of spinal circuits and functional recovery. The study uses MEP, EMG, and ENG assessments to unveil the correlations between the MEP amplitudes and the MRI injury scores. We analysed data from 85 iSCI patients (American Spinal Injury Association-ASIA scale; ASIA C = 24, and D = 61). We compared the MRI and diagnostic neurophysiological test results performed within 1-2 months after the injury. A control group of 80 healthy volunteers was examined to establish reference values for the clinical and neurophysiological recordings. To assess the structural integrity of spinal white and grey matter on the transverse plane reconstructed from the sagittal readings, a scoring system ranging from 0 to 4 was established. The spinal cord was divided into two halves (left and right) according to the midline, and each half was further divided into two quadrants. Each quadrant was assessed separately. MEP and EMG were used to assess conduction in the corticospinal tract and the contraction properties of motor units in key muscles: abductor pollicis brevis (APB), rectus abdominis (RA), rectus femoris (RF), and extensor digitorum brevis muscles (EXT). We also used electroneurography (ENG) to assess peripheral nerve conduction and to find out whether the changes in this system significantly affect patients' scores and their neurophysiological status. The study revealed consistent positive correlations in iSCI patients between the bilateral decrease of the spinal half injury MRI scores and a decrease of the transcranially-evoked MEP amplitudes, highlighting the complex relationship between neural pathways and functional outcomes. Positive correlations are notably pronounced in the C3-C5, C6-Th1, and Th3-Th6 subgroups (mostly rs 0.5 and above with p < 0.05), while Th7-L1 presents distinct patterns (rs less than 0.5 and p being statistically insignificant) potentially influenced by unique structural compensation mechanisms. We also revealed statistically significant relationships between the decrease of the cumulative mcsEMG and MEP amplitudes and the cumulative ENG scores. These insights shed light on the multifaceted interactions between spinal cord injury levels, structural damage, neurophysiological measures, and motor function outcomes. Further research is warranted to unravel the intricate mechanisms driving these correlations and their implications for enhancing functional recovery and the rehabilitation algorithms in patients with iSCI.

The Role of Transcranial Magnetic Stimulation, Peripheral Electrotherapy, and Neurophysiology Tests for Managing Incomplete Spinal Cord Injury.

Efforts to find therapeutic methods that support spinal cord functional regeneration continue to be desirable. Natural recovery is limited, so high hopes are being placed on neuromodulation methods which promote neuroplasticity, such as repetitive transcranial magnetic stimulation (rTMS) and electrical stimulation used as treatment options for managing incomplete spinal cord injury (iSCI) apart from kinesiotherapy. However, there is still no agreement on the methodology and algorithms for treatment with these methods. The search for effective therapy is also hampered by the use of different, often subjective in nature, evaluation methods and difficulties in assessing the actual results of the therapy versus the phenomenon of spontaneous spinal cord regeneration. In this study, an analysis was performed on the database of five trials, and the cumulative data are presented. Participants (iSCI patients) were divided into five groups on the basis of the treatment they had received: rTMS and kinesiotherapy (N = 36), peripheral electrotherapy and kinesiotherapy (N = 65), kinesiotherapy alone (N = 55), rTMS only (N = 34), and peripheral electrotherapy mainly (N = 53). We present changes in amplitudes and frequencies of the motor units' action potentials recorded by surface electromyography (sEMG) from the tibialis anterior-the index muscle for the lower extremity and the percentage of improvement in sEMG results before and after the applied therapies. The increase in values in sEMG parameters represents the better ability of motor units to recruit and, thus, improvement of neural efferent transmission. Our results indicate that peripheral electrotherapy provides a higher percentage of neurophysiological improvement than rTMS; however, the use of any of these additional stimulation methods (rTMS or peripheral electrotherapy) provided better results than the use of kinesiotherapy alone. The best improvement of tibialis anterior motor units' activity in iSCI patients provided the application of electrotherapy conjoined with kinesiotherapy and rTMS conjoined with kinesiotherapy. We also undertook a review of the current literature to identify and summarise available works which address the use of rTMS or peripheral electrotherapy as neuromodulation treatment options in patients after iSCI. Our goal is to encourage other clinicians to implement both types of stimulation into the neurorehabilitation program for subjects after iSCI and evaluate their effectiveness with neurophysiological tests such as sEMG so further results and algorithms can be compared across studies. Facilitating the motor rehabilitation process by combining two rehabilitation procedures together was confirmed.

Motor evoked potentials recorded from muscles versus nerves after lumbar stimulation in healthy subjects and patients with disc-root conflicts.

OBJECTIVE: The study aimed to describe properties and to prove diagnostic usefulness of motor evoked potentials (MEPs) recordings from muscles versus nerves of lower extremities when induced at lumbar levels with magnetic field. METHODS: Methodologically similar MEPs recordings from muscles and nerves of lower extremities were performed once in healthy volunteers (N = 43) and patients with disc-root conflicts at lumbar spine levels (N = 43, proven in MRI studies). Simultaneous electroneurographic (ENG) recordings following stimulation of peroneal nerves verified neural impulses transmission in motor fibers peripherally and at L5 ventral roots. RESULTS: ENG studies in patients proven only moderate axonal type of peroneal nerves injury. The mean values of MEPs amplitudes recorded from nerves were significantly different from those recorded in anatomically related muscles, both in controls (1179.6 ± 451.2 vs 1718.3 ± 481.3) and patients (495.6 ± 275.9 vs 1218.2 ± 465.5) (p = 0.0009-0.0000012); they are about 30% and 51% smaller, respectively. In both groups of subjects, latencies of MEPs recorded from nerves were shorter at about 3.0 ms and characterized by a slightly longer duration (3.0-5.0 ms) than those recorded from muscles. Results revealed positive correlations between decrease of amplitudes in sEMG and MEPs recordings from lower extremities muscles indicating consequences of pathology in neural transmission from spinal centers. CONCLUSIONS: Results of this study point to clear-cut characteristics of MEPs induced oververtebrally with the magnetic field in parameters recorded in healthy subjects and patients with consequences of chronic L4-L5 low back pain, which can be easily implemented in clinical practice. Non-invasive method of MEPs recorded from nerves can be helpful for diagnosing of patients with visible atrophic changes in muscles and simultaneous symptoms of only slight pathology in transmission of nerve impulses peripherally.

Temporary Occlusion of Common Carotid Arteries Does Not Evoke Total Inhibition in the Activity of Corticospinal Tract Neurons in Experimental Conditions.

Temporary occlusion of the common cervical artery is the reason for ischemic stroke in 25% of patients. Little data is provided on its effects, especially regarding neurophysiological studies verifying the neural efferent transmission within fibers of the corticospinal tract in experimental conditions. Studies were performed on 42 male Wistar rats. In 10 rats, ischemic stroke was evoked by permanent occlusion of the right carotid artery (group A); in 11 rats, by its permanent bilateral occlusion (B); in 10 rats, by unilateral occlusion and releasing after 5 min (C); and in 11 rats, by bilateral occlusion and releasing after 5 min (D). Efferent transmission of the corticospinal tract was verified by motor evoked potential (MEP) recordings from the sciatic nerve after transcranial magnetic stimulation. MEPs amplitude and latency parameters, oral measurements of temperature, and verification of ischemic effects in brain slides stained with hematoxylin and eosin staining (H + E) were analyzed. In all groups of animals, the results showed that five minutes of uni- or bilateral occlusion of the common carotid artery led to alterations in brain blood circulation and evoked changes in MEP amplitude (by 23.2% on average) and latency parameters (by 0.7 ms on average), reflecting the partial inability of tract fibers to transmit neural impulses. These abnormalities were associated with a significant drop in the body temperature by 1.5 °C on average. Ten minutes occlusion in animals from groups A and B resulted in an MEP amplitude decrease by 41.6%, latency increase by 0.9 ms, and temperature decrease by 2.9 °C of the initial value. In animals from groups C and D, five minutes of recovery of arterial blood flow evoked stabilization of the MEP amplitude by 23.4%, latency by 0.5 ms, and temperature by 0.8 °C of the initial value. In histological studies, the results showed that ischemia was most prominent bilaterally in sensory and motor areas, mainly for the forelimb, rather than the hindlimb, innervation of the cortex, putamen and caudate nuclei, globulus pallidus, and areas adjacent to the fornix of the third ventricle. We found that the MEP amplitude parameter is more sensitive than the latency and temperature variability in monitoring the ischemia effects course following common carotid artery infarction, although all parameters are correlated with each other. Temporary five-minute lasting occlusion of common carotid arteries does not evoke total and permanent inhibition in the activity of corticospinal tract neurons in experimental conditions. The symptoms of rat brain infarction are much more optimistic than those described in patients after stroke, and require further comparison with the clinical observations.

The Usefulness of Motor Potentials Evoked Transvertebrally at Lumbar Levels for the Evaluation of Peroneal Nerve Regeneration after Experimental Repair in Rats.

Motor evoked potentials (MEPs) are used in neurology as part of a precise diagnostic method to study the transmission of efferent neural impulses at the central and peripheral levels of the nervous system. Previous attempts have been made to apply MEPs in animal studies for evaluating neural transmission at the motor cortex center level to the muscles of the forelimbs and hindlimbs. In clinical and experimental studies, little attention is focused on the significance of the magnetic stimulation of spinal cord structures with the direct recording of the evoked potentials from peripheral nerve motor fibers. The aim of this paper was to evaluate the usefulness of the motor potentials evoked transvertebrally at lumbar levels in the evaluation of experimental peroneal nerve regeneration in rats. The bilateral transmission of efferent impulses in the distal parts of the peroneal and tibial nerves was verified by recordings of evoked potentials following transvertebral magnetic stimulation at lumbar levels (MEPs) and the electrical stimulation of the sciatic nerve in classical electroneurographic (ENG) tests for comparison. Recordings were performed 24 weeks after grafts on surgically treated hindlimbs as well as on non-operated hindlimbs as controls. Both the MEP and ENG stimulations resulted in evoked potentials with larger amplitude values following the application of the magnetic pulses, with more being recorded on the non-operated hindlimbs than on the operated ones when recordings were taken from peroneal nerve branches. We observed statistically significant correlations between the MEP and ENG results for peroneal and tibial nerve amplitude on the non-operated side and peroneal nerve amplitude on the operated side. The recorded latencies of the evoked potentials were shorter in the ENG studies than in the MEPs for the non-operated side. The results demonstrated the phenomenon of regeneration in the motor fibers of the peroneal nerves 24 weeks after grafting in the experimental conditions. In this study, the MEPs were as useful as the ENG studies for evaluating regeneration in the motor fibers of hindlimb nerves in rats, although they were not significantly different. This paper discusses the clinical importance of transvertebral MEPs induced at the lumbosacral and cervical levels with a magnetic field for the diagnostic evaluation of efferent impulse transmission at different levels of the motor pathway.

Comparison of Motor Evoked Potentials Neuromonitoring Following Pre- and Postoperative Transcranial Magnetic Stimulation and Intraoperative Electrical Stimulation in Patients Undergoing Surgical Correction of Idiopathic Scoliosis.

The relationships between the results of pre- and intraoperative motor evoked potential recordings during neuromonitoring and whether idiopathic scoliosis (IS) surgical correction improves the spinal efferent transmission have not been specified in detail. This study aims to compare the results of surface-recorded electromyography (EMG), electroneurography (ENG, M, and F-waves), and especially motor evoked potential (MEP) recordings from tibialis anterior muscle (TA) bilaterally in 353 girls with right idiopathic scoliosis (types 1-3 according to Lenke classification). It has not yet been documented whether the results of MEP recordings induced by transcranial single magnetic stimulus (TMS, pre- and postoperatively) and trains of electrical stimuli (TES; intraoperatively in T0-before surgery, T1-after pedicle screws implantation, and T2-after scoliosis curvature distraction and derotation following two-rod implantation) can be compared for diagnostic verification of the improvement of spinal cord neural transmission. We attempted to determine whether the constant level of optimal anesthesia during certain surgical steps of scoliosis treatment affects the parameters of MEPs recorded during neuromonitoring procedures. No neurological deficits have been observed postoperatively. The values of amplitudes but not latencies in MEP recordings evoked with TMS in IS patients compared before and after surgery indicated a slight improvement in efferent neural transmission. The results of all neurophysiological studies in IS patients were significantly asymmetrical and recorded worse on the concave side, suggesting greater neurological motor deficits at p = 0.04. The surgeries brought significant improvement (p = 0.04) in the parameters of amplitudes of sEMG recordings; however, the consequences of abnormalities in the activity of TA motor units were still reflected. ENG study results showed the symptoms of the axonal-type injury in peroneal motor fibers improving only on the concave side at p = 0.04, in parallel with F-wave parameters, which suggests that derotation and distraction might result in restoring the proper relations of the lumbar ventral roots in the spinal central canal, resembling their decompression. There were no significant differences detected in the amplitudes or latencies of MEPs induced with TMS or TES when comparing the parameters recorded preoperatively and intraoperatively in T0. The amplitudes of TES-evoked MEPs increased gradually at p = 0.04 in the subsequent periods (T1 and T2) of observation. A reduction in MEP latency at p = 0.05 was observed only at the end of the IS surgery. Studies on the possible connections between the level of anesthesia fluctuations and the required TMS stimulus strength, as well as the MEP amplitude changes measured in T0-T2, revealed a lack of relationships. These might not be the factors influencing the efferent transmission in spinal pathways beside the surgical procedures. Pre- (TMS-evoked) and intraoperative (TES-evoked) recordings are reliable for evaluating the patient's neurological status before and during surgical scoliosis correction procedures. An increase in MEP amplitude parameters recorded on both sides after scoliosis surgery proves the immediate improvement of the total efferent spinal cord transmission. Considering comparative pre- and postoperative sEMG and ENG recordings, it can be concluded that surgeries might directly result in additional lumbar ventral root decompression. We can conclude that MEP parameter changes are determined by the surgery procedures during neuromonitoring, not the anesthesia conditions if they are kept stable, which influences a decrease in the number of false-positive neuromonitoring warnings.