Preoperative Electromyograms Research Articles

Is the pre-operative lateral spread response on facial electromyography a valid diagnostic tool for hemifacial spasm?

The lateral spread response (LSR) on preoperative facial electromyogram (EMG) is a useful tool in evaluating patients with hemifacial spasm (HFS). There may be some instances where the LSR does not appear on the preoperative EMG, thus disrupting the diagnosis and treatment of HFS. In this study, we evaluated the patients who did not exhibit LSR on preoperative EMG but underwent microvascular decompression (MVD) for hemifacial spasm. We searched for patients who underwent MVD for HFS but had an absence of LSR on preoperative EMG between January 2016 and June 2018. Surgical outcomes were evaluated at 1, 3, and 6months after surgery. Follow-up facial EMG was performed 3months after surgery. Results were divided into two categories: (1) spasm relief within 24h of surgery and (2) spasm was observed immediately post-operation. The following parameters were analyzed when comparing between the two groups: age, sex, affected side, duration of symptoms, and offending vessel(s). A total of 306 patients underwent MVD for HFS during the study period. Among them, 13 (4.2%) patients had no LSR on preoperative EMG. Eight patients (61.5%) were female and five patients were male. The 13 patients had a mean age of 51years. All patients exhibited probable offending vessels in the root exit zone (REZ) of the facial nerve on preoperative magnetic resonance (MR) imaging that was confirmed during surgery. Seven patients were free of HFS immediately after surgery, though six patients were not. Only one (7.7%) patient had persisted symptom 6months after surgery. No patients experienced recurrence of spasm, nor exhibited abnormal waves on follow-up facial EMG. LSR on facial EMG is a valuable tool for evaluating hemifacial spasm. However, although LSR did not appear on preoperative EMG, if the patient presents with typical symptoms and the offending vessels are identified on MRI, we expect good results after MVD for HFS.

ANTERIOR TRANSPOSITION VERSUS IN SITU NEUROLYSIS IN CUBITAL TUNNEL SYNDROME: A COMPARISON BASED ON FUNCTIONAL AND ELECTRO-DIAGNOSTIC EVALUATION

Objective: The aim of the present study is to compare that results of in situ neurolysis and anterior transposition procedures both clinically and electro-diagnostically in those patients diagnosed with cubital tunnel syndrome. Material and Methods: Twenty of 34 patients who had undergone both preoperative, postoperative electromyogram (EMG) nerve conduction tests and regular follow-up were included in our study. Then, the patients were divided into 2 groups - in situ neurolysis (group A) and anterior transposition (group B). Both groups were compared based on modified Bishop functional scores, preoperative and postoperative EMG parameters. Results: There was no statistically significant difference in relation to EMG parameters between the two groups. When comparing preoperative and postoperative EMG results, in the patients with anterior transposition surgery ‘elbow to below-elbow’ and ‘below-elbow to wrist’ motor conduction velocity was increased significantly (p=0.018 and 0.04). While the average Bishop score was 7.9 in group A and 9.3 in group B, there was no statistical difference between the two groups in terms of Bishop Scores. Conclusion: In the management of cubital tunnel syndrome, the choice of technique doesn’t affect the functional results; however, anterior transposition of the nerve provides better recovery in ‘elbow to below-elbow’ and ‘below-elbow to wrist’ motor conduction velocity. 

Current Status of Nerve Transfers: “Supercharge End-to-Side Transfer in Severe Cubital Syndrome”

Supercharge end-to-side (SETS) technique has been increasingly implemented in the treatment of nerve pathologies. It was known for its use in ulnar injury, and although it seemed that its usefulness was more directed to injuries due to ulnar nerve section, with this work and based on all the literature available to date, the aim is to assess the possibilities of implementation based on the results of the articles published in compression-type injuries, especially those classified as severe that have little treatment available to improve their evolutionary course, and where their use to date was doubtful. A compilation is made of all the evidence to date of cubital tunnel syndrome, focused on treatments, and on the emergence of the SETS technique as a therapeutic option. The purpose of the study was to collect and review the indications, results, and complications of end-to-side axonal super feeding transfer of the interosseous nerve anterior to the ulnar nerve. Twenty-one articles that met the inclusion and exclusion criteria were finally reviewed, most of them retrospective (level of evidence IV) and some review or case series (level of evidence II/ III). The data has been pooled and analyzed focusing on the primary outcomes: intrinsic muscle recovery and complications. SETS is a successful procedure with low morbidity, which can restore the function of the intrinsic musculature in patients with severe proximal ulnar nerve compression injuries thanks to the anterior interosseous nerve (median branch) that serves as a donor. Although the technique has already begun to be introduced in the sketch of the treatment of the lesion, to implement it with assured success, prospective studies should be carried out that corroborate it with greater certainty than the articles published on the subject to date. Even so, it has been possible to verify as previous indications for performing supercharge: a normal donor nerve electromyogram (it will be performed in a pronator square), a preoperative electromyogram of the injured nerve that must have a reduced amplitude of compound muscle action potential (demonstrating axonal loss) and an electromyogram to know if the denervated motor endplates remain receptive to reinnervation (check they have spontaneous activity and this is shown by fibrillation potentials and / or acute positive waves).

Étude électromyographique du muscle temporalis avant une myoplastie d’allongement dans le syndrome de Moebius

Temporalis muscle lengthening myoplasty improves tightening of the lips and rehabilitates smile for patients with congenital facial palsies. Because Moebius syndrome is heterogeneous, a careful evaluation is mandatory before deciding to perform myoplasty. This series shows the role of electromyography for investigating temporalis muscle and trigeminal nerve motor functions. We conducted a retrospective study of 18 patients with no upward movements of the labial commissure and absent or unsightly smile. Electromyography was used to study the temporalis muscle bilaterally. Analysis focused on the recruitment pattern of voluntary contraction and electrical silence or activity at rest. Traces were classified as normal, neurogenic, or low-amplitude. Functional outcomes of myoplasty were evaluated by measuring the upward movement of the commissure (mm), and qualified as high (≥10), medium (>5), or little (≤5). Surgery was cancelled for 5 patients with abnormal electromyographic signs, neurogenic (2) or low-amplitude (3). Myoplasty was performed in 7 patients (age: 8-17 years), unilaterally (3) or bilaterally (4). Preoperative electromyogram was normal (3), or showed moderate neurogenic (2) or low-amplitude (2) changes. Follow-up period after surgery was from 2 to 12 years; functional outcomes were high (5), medium (1), or little (1). Electromyographic study of the temporalis can detect muscle denervation or atrophy, or dyspraxia, and guide decision to encourage or discourage performing myoplasty, or enhance rehabilitation programme and make the patient aware of possibly modest outcome.

Median Nerve Compression by the Feeding Vessels of a Large Arteriovenous Malformation in the Axilla.

Median Nerve Compression by the Feeding Vessels of a Large Arteriovenous Malformation in the Axilla.

Neuropathy of the suprascapular nerve and massive rotator cuff tears: a prospective electromyographic study

An association between massive rotator cuff tear (RCT) and suprascapular nerve neuropathy has previously been suggested. The anatomic course of the suprascapular nerve is relatively fixed along its passage. Thus, injury to the nerve by trauma, compression, and iatrogenic reasons is well documented. However, the association between retraction of the RCT and development of neuropathy of the suprascapular nerve remains unclear. We aimed to prospectively evaluate the suprascapular nerve for preoperative neurodiagnostic abnormalities in shoulders with massive RCT. A prospective study was performed in 2 centers. Fifty patients with retracted tears of both supraspinatus and infraspinatus were evaluated. This was confirmed with preoperative computed tomography arthrography, and the fatty infiltration of the affected muscles was graded. Forty-nine preoperative electromyograms were performed in a standardized fashion and the results analyzed twice. Of 49 shoulders, 6 (12%) had neurologic lesions noted on electromyography: 1 suprascapular nerve neuropathy, 1 radicular lesion of the C5 root, 1 affected electromyogram in the context of a previous stroke, and 3 cases of partial axillary nerve palsy with a history of shoulder dislocation. No difference or diminution of the latency or amplitude of the electromyographic curve was found in the cases that presented significant fatty infiltration. This study did not detect a suprascapular lesion in the majority of cases of massive RCT. With a low association of neuropathy with massive RCT, we find no evidence to support the routine practice of suprascapular nerve release when RCT repair is performed.

Massive rotator cuff tears in patients younger than 65 years. Epidemiology and characteristics

Currently, there is little information on the clinical, radiographic and electric profile of patients younger than 65 years of age with large rotator cuff tear. According to our hypothesis, massive rotator cuff tear, when discovered after recent traumatism, do not provide typical radiographic findings and suprascapular nerve impairment in large rotator cuff tears is uncommon. This is a prospective, descriptive, multicenter study of a series of 112 patients younger than 65 years, including 66 males and 46 females with extensive or massive cuff tear. Duration of symptoms was less than 6 months in 28 cases and secondary to trauma in 57 cases. Patients had loss of elevation or external rotation or both in 57 cases. An electromyogram (EMG) of suprascapular nerve was performed in 50 cases. A higher incidence of advanced fatty infiltration of the infraspinatus muscle (>stage 2 according to Goutallier) was observed in case of long-term symptomatology or in the absence of known trauma. Traumatic status was commonly found in patients with functional deficit in shoulder elevation, thus reporting a significantly lower Constant score (p<0.0001). Patients with both loss of shoulder elevation and external rotation had a significantly narrower subacromial space (5 mm versus 7.2 mm). No significant relationship could be established between electric impairment and massive cuff tear. According to the present study, in case of traumatic context and recent symptomatology, subacromial height and fatty infiltration of the infraspinatus muscle are better prognostic factors despite a pseudoparalytic shoulder. Repair should thus be considered. Moreover, the interest of a preoperative suprascapular nerve EMG is questionable.

Facial Nerve Problems and Hearing Loss in Patients With Temporal Bone Fractures: Demographic Data

The incidence of temporal bone fractures have increased in recent decades together with the increasing traffic and population. The aim of this study is to evaluate the cause, treatment methods, radiologic, and intraoperative findings in patients with temporal bone fractures. Thirty-five patients with temporal bone fracture who have been followed between 1992 and 2006 were retrospectively reviewed. Computerized tomography and audiometric tests were obtained. Electrophysiological evaluation of the facial nerve in patients with traumatic facial paralysis was carried by serial electromyogram (EMG). House-Brackmann grading system was used to evaluate the function of the facial nerve. Twenty-three patients underwent operation for facial paralysis or hearing loss. Results of medical and surgical therapy were documented. Traffic crash was the most common cause (54%). Eighteen (51.4%) of patients had conductive hearing loss, 6 (17.14%) of the patients had sensorineural hearing loss, and 11 (31.42%) had normal hearing. Transient or persistent facial paralysis was detected in 24 of 35 patients (68.57%). Nineteen patients underwent partial or total facial decompression. Preoperative EMG of the majority of the operated patients revealed total axonal degeneration. The most common affected area of the facial nerve by trauma was the vertical segment (31.58%). House-Brackmann 1 and 2 grade was achieved in majority of the patients. Fourteen ossicular abnormalities were detected in 10 patients, and the abnormality was usually related to the incus. More than 10 dB air-bone gap closure was achieved in six of eight patients (75%). Traffic crashes continue to be the main cause of temporal bone fractures. Facial paralysis caused by temporal bone trauma can be satisfactorily treated by decompression. EMG, clinical grading, and onset of the paralysis are important guides for the surgery. Restoration of the hearing can be achieved in majority of patients.

Transaxillary approach in thoracic outlet syndrome: the importance of resection of the first-rib.

The aim of this study was to analyze the transaxillary surgical approach and results of thoracic outlet cases in our clinic in the light of the recent literature data. Between 1996 and 2002 a series of 35 cases diagnosed as thoracic outlet syndrome (TOS) hospitalized and surgically treated in our clinic have been studied retrospectively. Twenty-six of our cases were females (75%) and the mean age was 25+/-1 (17-40 years). The most important symptom was localized pain in the arm. In 90% of the cases the Adson, hyperabduction and abduction external rotation (AER) tests were positive. There was paresthesia in 30 cases (85%), atrophy in 3 cases (10%), and cyanosis in 6 cases (20%). Preoperative electromyogram (EMG) was demonstrated as 56.7 m/s (50-65) and postoperative EMG was demonstrated as 65.1 m/s (60-71). Postoperative EMG values were significantly higher than the preoperative EMG values (p<0.001). All patients were operated using the transaxillary approach. A total number of 40 operations were performed. Upon radiological investigation (n=17) 50% of the patients were found to have cervical ribs. In 30 cases (85%) the results were very good and in four cases (12%) good, and in one case (3%) the results were bad. There was no recurrence and reoperation in the long term follow-up. Careful patient history and physical examination should be done by a team, which consists of thoracic surgeon, physical therapy specialist, and a neurologist. Total resection of the first-rib with periosteally should be preferred in all of these cases with accompanying pathologies such as cervical rib, fibrous ligaments, and scalenius muscles. The transaxillary approach has provided a good exposure for the resection of cervical ribs, the first-rib and excision of fibrous ligaments and scalenius muscle by a perfect cosmetic result. All the patients should be encouraged for 2 months of physical exercises starting from early postoperative period.

A Comparison of the Vastus Splitting and Median Parapatellar Approaches in Total Knee Arthroplasty

This prospective randomized study was undertaken to evaluate the vastus splitting approach as an alternative to the median parapatellar approach in primary total knee arthroplasty. Fifty-one knees in 42 patients were randomized preoperatively. Clinical parameters were evaluated preoperatively and at regular postoperative intervals. Electromyography was performed preoperatively and postoperatively to evaluate each approach relative to its effect on the innervation of the quadriceps mechanism. There were no significant preoperative differences. Postoperatively, there were no significant differences regarding strength, range of motion, knee scores, tourniquet time, proprioception, or patellar replacement. There were significantly more lateral releases performed and greater blood loss in the patients in the parapatellar group. The results of all preoperative electromyograms were normal, as were all of the results of postoperative electromyograms in the patients in the parapatellar group. However, the results of nine of 21 (43%) of the electromyograms performed postoperatively on patients who had the vastus splitting approach were abnormal. Significantly fewer lateral releases were performed and there was less blood loss in the patients in the vastus group. However, the postoperative electromyographic results revealed neurologic injuries in the vastus medialis muscle that only were present after the vastus splitting approach. The clinical significance of denervation of the vastus medialis muscle by the vastus approach remains to be determined by longer term clinical and electromyographic studies.

Posttraumatic Piriformis Syndrome

Posttraumatic piriformis syndrome is a rare disorder that is not clearly defined in the orthopaedic literature. We report on the specific diagnosis, operative treatment, and outcome of treatment of fifteen cases of piriformis syndrome (in fourteen patients), treated by one surgeon, in which the common etiology was blunt trauma to the buttock. We are unaware of any previously published report of this kind. Fourteen patients (fifteen cases of piriformis syndrome), with an average age of thirty-eight years (range, twenty-four to fifty-six years), were managed with an operative release of the piriformis tendon and sciatic neurolysis. All fourteen patients had a history of a blow to the buttock, and all had pain in the buttock, intolerance to sitting, tenderness to palpation of the greater sciatic notch, and pain with flexion, adduction, and internal rotation of the hip. Eleven patients (twelve cases) had severe radicular pain in the affected lower limb. All fourteen patients failed to improve after a prolonged period of conservative treatment with nonsteroidal medication or physical therapy, or both. On the average, the patients had been evaluated by three physicians who were not orthopaedic surgeons and by two orthopaedic surgeons before they were referred to the senior one of us. They had had an average of 4.5 diagnostic tests and an average delay of thirty-two months (range, four to seventy-one months) between the time of the injury and the operation. Preoperative electromyograms revealed extrapelvic compression of the sciatic nerve in six of the eight patients who had this study. Intraoperative findings revealed adhesions between the piriformis muscle, the sciatic nerve, and the roof of the greater sciatic notch. Clinical examination at a minimum of twenty-four months (average, thirty-eight months) postoperatively revealed eleven excellent and four good results according our symptom-rating scale. All of the patients returned to work or to their usual daily activities at an average of 2.3 months postoperatively, and the time to maximum subjective improvement averaged 2.1 months. Complications included a seroma and an infected hematoma. Patients who have blunt trauma to the buttock and then have signs and symptoms that are suggestive of lumbar nerve-root compression may have posttraumatic piriformis syndrome. In our group of carefully selected patients, release of the piriformis tendon and sciatic neurolysis led to encouraging results with few complications.

Operative treatment of carpal tunnel syndrome in Denmark: Results of a questionnaire

The aim of our study was to determine the incidence of operative treatment for carpal tunnel syndrome in Denmark and to see whether there was a consensus about the place of preoperative electromyography and nerve conduction studies. A questionnaire was mailed to all surgical departments (n = 70) and all registered private surgical practices (n = 214) in Denmark. The incidence of operation was about 0.61 per 1,000 population. Most surgeons used preoperative electromyograms and nerve conduction studies in less than 50% of cases. The use of preoperative testing was related to the surgical speciality.

Functional Recovery of Noncemented Total Hip Arthroplasty

Eighteen patients with unilateral hip disease had noncemented total hip arthroplasty. Clinical follow-up data were complete to five years postsurgery. Gait analysis was done preoperatively, at three and six months, and at one and two years. Force plate data showed continued weakness of the operated hip in all patients at two years postsurgery. Preoperative dynamic electromyograms (EMGs) were abnormal in eight patients and showed two patterns. Stance loss seen in three patients was characterized by absence of activity of the gluteus medius and upper and lower gluteus maximus muscles. In five patients, continuous activity occurred in the tensor fascia lata, rectus femoris, and adductor longus muscles during the entire gait cycle. Postoperatively, all abnormal EMGs returned to normal. Four patients with a normal preoperative EMG developed abnormal EMG patterns postoperatively, demonstrating either a prolonged stance or stance loss pattern. All four of these hips have been revised. Although gait characteristics return to normal by two years postsurgery, weakness of the hip persists. This weakness jeopardizes the implant fixation interface. This study supports the prohibition of activities that cause high impact loading of total hip arthroplasties and suggests that a prolonged exercise program be employed postoperatively.

The effect on gait of lengthening of the medial hamstrings in cerebral palsy.

The purpose of this study was to analyze the effect of lengthening of the medial hamstrings on the gait of patients who had spastic cerebral palsy. Thirty-one patients had preoperative and postoperative gait analyses. Standard parameters, such as velocity, cadence, and stride length, were evaluated, as were motion graphs of the hip, knee, and ankle. There was little difference between the preoperative and postoperative mean values for velocity, cadence, and stride length, which were expressed as percentages of normal for the patient's age. The contours of the postoperative motion graphs of the knees changed very little compared with those of the preoperative graphs; when a graph showed restricted motion preoperatively, it did so postoperatively. Although extension of the knee in stance phase improved postoperatively, the improvement was accompanied by decreased flexion of the knee during swing phase. When spasticity of both the hamstrings and the quadriceps was noted on the preoperative electromyogram, motion of the knee in the sagittal plane was markedly restricted.