Involuntary painful muscle contractions in Satoyoshi syndrome: A surface electromyographic study

Test-retest reliability of high-resolution surface electromyographic activities of facial muscles during facial expressions in healthy adults: A prospective observational study

Objectives

Surface electromyography (sEMG) is a standard method for psycho-physiological research to evaluate emotional expressions or in a clinical setting to analyze facial muscle function. High-resolution sEMG shows the best results to discriminate between different facial expressions. Nevertheless, the test-retest reliability of high-resolution facial sEMG is not analyzed in detail yet, as good reliability is a necessary prerequisite for its repeated clinical application.

Methods

Thirty-six healthy adult participants (53% female, 18–67 years) were included. Electromyograms were recorded from both sides of the face using an arrangement of electrodes oriented by the underlying topography of the facial muscles (Fridlund scheme) and simultaneously by a geometric and symmetrical arrangement on the face (Kuramoto scheme). In one session, participants performed three trials of a standard set of different facial expression tasks. On one day, two sessions were performed. The two sessions were repeated two weeks later. Intraclass correlation coefficient (ICC) and coefficient of variation statistics were used to analyze the intra-session, intra-day, and between-day reliability.

Results

Fridlund scheme, mean ICCs per electrode position: Intra-session: excellent (0.935–0.994), intra-day: moderate to good (0.674–0.881), between-day: poor to moderate (0.095–0.730). Mean ICC’s per facial expression: Intra-session: excellent (0.933–0.991), intra-day: good to moderate (0.674–0.903), between-day: poor to moderate (0.385–0.679). Kuramoto scheme, mean ICC’s per electrode position: Intra-session: excellent (0.957–0.970), intra-day: good (0.751–0.908), between-day: moderate (0.643–0.742). Mean ICC’s per facial expression: Intra-session: excellent (0.927–0.991), intra-day: good to excellent (0.762–0.973), between-day: poor to good (0.235–0.868). The intra-session reliability of both schemes were equal. Compared to the Fridlund scheme, the ICCs for intra-day and between-day reliability were always better for the Kuramoto scheme.

Conclusion

For repeated facial sEMG measurements of facial expressions, we recommend the Kuramoto scheme.

Fundamental Concepts of Bipolar and High-Density Surface EMG Understanding and Teaching for Clinical, Occupational, and Sport Applications: Origin, Detection, and Main Errors

Surface electromyography (sEMG) has been the subject of thousands of scientific articles, but many barriers limit its clinical applications. Previous work has indicated that the lack of time, competence, training, and teaching is the main barrier to the clinical application of sEMG. This work follows up and presents a number of analogies, metaphors, and simulations using physical and mathematical models that provide tools for teaching sEMG detection by means of electrode pairs (1D signals) and electrode grids (2D and 3D signals). The basic mechanisms of sEMG generation are summarized and the features of the sensing system (electrode location, size, interelectrode distance, crosstalk, etc.) are illustrated (mostly by animations) with examples that teachers can use. The most common, as well as some potential, applications are illustrated in the areas of signal presentation, gait analysis, the optimal injection of botulinum toxin, neurorehabilitation, ergonomics, obstetrics, occupational medicine, and sport sciences. The work is primarily focused on correct sEMG detection and on crosstalk. Issues related to the clinical transfer of innovations are also discussed, as well as the need for training new clinical and/or technical operators in the field of sEMG.

Muscle Activation in Middle-Distance Athletes with Compression Stockings

The aim of this study was to evaluate changes in electromyographic activity with the use of gradual compression stockings (GCSs) on middle-distance endurance athletes’ performance, based on surface electromyography measurement techniques. Sixteen well-trained athletes were recruited (mean ± SD: age 33.4 ± 6.3 years, VO_2max 63.7 ± 6.3 mL·kg⁻¹·min⁻¹, maximal aerobic speed 19.7 ± 1.5 km·h). The athletes were divided into two groups and were assigned in a randomized order to their respective groups according to their experience with the use of GCSs. Initially, a maximum oxygen consumption (VO_2max) test was performed to standardize the athletes’ running speeds for subsequent tests. Afterward, electromyographic activity, metabolic, and performance variables for each group were measured with surface electromyography. In addition, blood lactate concentration was measured, both with and without GCSs, during 10 min at 3% above VT2 (second ventilatory threshold), all of which were performed on the track. Next, surface electromyography activity was measured during a 1 km run at maximum speed. No significant changes were found in electromyography activity, metabolic and performance variables with GCSs use (p > 0.164) in any of the variables measured. Overall, there were no performance benefits when using compression garments against a control condition.

Treatment of Satoyoshi syndrome: a systematic review

BACKGROUND

Satoyoshi syndrome is a multisystemic rare disease of unknown etiology, although an autoimmune basis is presumed. Its main symptoms are: painful muscle spasms, diarrhea, alopecia and skeletal abnormalities. Clinical course without treatment may result in serious disability or death. A review of treatment and its response is still pending.

RESULTS

Sixty-four cases of Satoyoshi syndrome were published between 1967 and 2018. 47 cases described the treatment administered. Drugs used can be divided into two main groups of treatment: muscle relaxants/anticonvulsants, and corticosteroids/immunosuppressants. Dantrolene improved muscle symptoms in 13 out of 15 cases, but not any other symptoms of the disease. Other muscle relaxants or anticonvulsant drugs showed little or no effect. 28 out of 30 cases responded to a regimen that included costicosteroids. Other immunosuppressive drugs including cyclosporine, mycophenolate mofetil, azathioprine, methotrexate, tacrolimus and cyclophosphamide were used to decrease corticosteroid dose or improve efficacy. Immunoglobulin therapy was used in nine patients and four of them obtained a favorable response.

CONCLUSION

Corticosteroids was the most widely treatment employed with the best results in Satoyoshi syndrome. Further studies are needed to determine optimal dose and duration of corticosteroids as well as the role of other immunosuppressants and immunoglobulin therapy. Genetic or autoimmune markers will be useful to guide future therapies.

Adult-onset Satoyoshi syndrome in a young male

Satoyoshi syndrome is a rare condition of presumed autoimmune etiology that is characterized by intermittent painful spasms, diarrhea, hair loss, and bone abnormalities. We report the first case of adult onset Satoyoshi syndrome in South America. A 32-year-old Caucasian male presented with sudden involuntary muscle contractions and painful cramps that had started at the age of 21. He also presented with trismus and complete loss of body hair. Electroneuromyography showed abnormal spontaneous activity. Diagnosis of Satoyoshi syndrome was made after extensive investigation; improvement was achieved with corticosteroids and azathioprine. It is a rare disease; few cases have been described worldwide, most of them in Asian children and almost all sporadic. There are several atypical presentations described in the literature. Immunosuppression is the basis of treatment. Professionals dealing with neuromuscular diseases should be aware of this condition and its atypical presentations, given the possible response to immunosuppressive treatment.

Adult-onset Satoyoshi syndrome with prominent laterality of clinical features

We herein report the case of a patient with adult-onset Satoyoshi syndrome. Alopecia was detected on the patient's head, left leg and abdomen, with pigmentation on the left thigh and abdomen. Painful muscle spasms were also noted in the abdomen and left upper and lower extremities, and a sensory disturbance was present in the left thigh. A skin biopsy of this field showed lymphocyte infiltration, and the patient was found to be positive for antinuclear antibodies and rheumatoid factor. These clinical findings were atypical, as they were lateralized. This case is the first report of Satoyoshi syndrome associated with a sensory disturbance. The patient's histological findings and positivity for autoantibodies indicated the presence of immunological abnormalities in this case of Satoyoshi syndrome.

Satoyoshi syndrome with unusual skeletal abnormalities and parental consanguinity

Satoyoshi syndrome (SS) (OMIM 600705) is a rare multisystemic disorder of unknown etiology characterized by progressive painful intermittent muscle spasm, alopecia universalis, diarrhea, short stature, amenorrhea, and secondary skeletal abnormalities mimicking a metaphyseal chondrodysplasia. To date all reported cases have been sporadic. We describe a 26-year-old Mexican woman, a product of consanguineous parents with clinical characteristics of SS. Our patient, also showed skeletal anomalies not previously reported that seems to be a coincidental finding.

A case of adult-onset Satoyoshi syndrome with gastric ulceration and eosinophilic enteritis

BACKGROUND

The patient was misdiagnosed as having Sjögren's syndrome (on the basis of a lower-limb rash and dry eyes and mouth) in 1999, and then as having systemic lupus erythematosus (on the basis of hair loss and a high antinuclear antibody titer) in 2005. Total alopecia, muscular spasms and diarrhea developed over the following 2 years, and the patient experienced gastric ulceration in 2006. A rheumatologic opinion was sought in 2007.

INVESTIGATIONS

Physical examination, CBC, glucose tolerance test, iron studies, HLA typing, immunological investigations and complete gastrointestinal investigations, including gastroscopy, colonoscopy and small bowel biopsy.

DIAGNOSIS

Satoyoshi syndrome with autoimmune features (high levels of antinuclear antibody and antibodies to thyroid tissue) and malabsorption due to eosinophilic enteritis. This patient is only the fifth adult in the world reported to have Satoyoshi syndrome, and the first-reported adult case from South Africa.

MANAGEMENT

The patient had only a transitory response to glucocorticoid treatment. Complete amelioration of symptoms resulted on two occasions when treated with intravenous immunoglobulin; however, the remissions only lasted for 6-8 weeks. More-intensive immunosuppression with azathioprine is currently being attempted.

Clinical applications of high-density surface EMG: A systematic review

High density-surface EMG (HD-sEMG) is a non-invasive technique to measure electrical muscle activity with multiple (more than two) closely spaced electrodes overlying a restricted area of the skin. Besides temporal activity HD-sEMG also allows spatial EMG activity to be recorded, thus expanding the possibilities to detect new muscle characteristics. Especially muscle fiber conduction velocity (MFCV) measurements and the evaluation of single motor unit (MU) characteristics come into view. This systematic review of the literature evaluates the clinical applications of HD-sEMG. Although beyond the scope of the present review, the search yielded a large number of "non-clinical" papers demonstrating that a considerable amount of work has been done and that significant technical progress has been made concerning the feasibility and optimization of HD-sEMG techniques. Twenty-nine clinical studies and four reviews of clinical applications of HD-sEMG were considered. The clinical studies concerned muscle fatigue, motor neuron diseases (MND), neuropathies, myopathies (mainly in patients with channelopathies), spontaneous muscle activity and MU firing rates. In principle, HD-sEMG allows pathological changes at the MU level to be detected, especially changes in neurogenic disorders and channelopathies. We additionally discuss several bioengineering aspects and future clinical applications of the technique and provide recommendations for further development and implementation of HD-sEMG as a clinical diagnostic tool.