Diabetic Neuropathy: a Critical, Narrative Review of Published Data from 2019.

PURPOSE OF REVIEW: This manuscript is a systematic, narrative review that compiles and describes all data available from 2019 related to epidemiologic, diagnostic, and therapeutic advances in diabetic neuropathy (DN). RECENT FINDINGS: Epidemiology of DN is discussed. Diagnostic modalities include predictive models, electrodiagnostics, imaging, and biomarkers. A majority of studies on the treatment of diabetic peripheral neuropathy (DPN) involve pharmacotherapy, but complementary and alternative medicine, exercise, modalities, psychological, interventional, and surgical options are also explored. DN is a highly prevalent and debilitating consequence of diabetes that can present challenges to the clinician as the assessment is largely subjective with different phenotypic presentations among patients. Treatment of DN is largely symptomatic as the pathogenesis of DN is not fully understood and is likely multifactorial. It is evident from the broad range of treatments that too often provide unsatisfactory relief that there is no consensus about a single most effective treatment for DN, and monotherapy rarely proves to be successful.

Myeloradiculoneuropathy due to vitamin B12 deficiency: an unusual clinical and radiological presentation.

A 42-year-old man from rural India presented with asymmetric progressive paraparesis mimicking compressive dorsal myelopathy, followed by distal upper limb, truncal and neck-flexor weakness, further complicated by acute urinary retention. His sensory deficits were marked by loss of joint position sense (JPS) and graded loss of vibration sense, along with a definite sensory level. Deep tendon jerks were hypo-to-areflexic, plantar was bilaterally extensor. He had become less attentive and occasionally failed to keep track with conversations. A syndromic diagnosis of myeloradiculoneuropathy with cognitive impairments was made. Further tailored investigations revealed vitamin B12 deficiency with positive anti-parietal cell antibody. Diagnosis of subacute combined cord degeneration (SACD) was confirmed. Neuro-imaging revealed intramedullary intensity changes only along lateral aspect of spinal cord instead of characteristic posterior involvement. Following parenteral vitamin B12 supplementation, patient started showing improvement in motor power and subjective sensory symptoms. His bladder symptoms persisted initially, however recovered finally after 6 months.

Eletrodiagnóstico e perfil energético com o Ryodoraku em medicina tradicional chinesa: revisão integrativa / Eletrodiagnostic and energy profile with Ryodoraku in chinese traditional medicine: integrative review / Eletrodiagnóstico y perfil energético con el Ryodoraku en medicina tradicional china: revisión integrativa

Objective: To synthesize the evidence in the literature on the applicability of the Ryodoraku system in the energy diagnosis based on the precepts of Traditional Chinese Medicine. Method: integrative review, carried out by independent reviewers in databases. Results: we found 324 studies. After exclusion, eight were analyzed, with a predominance of descriptive studies. There was agreement about the 24 points selected for the application of Ryodoraku; however, there is disagreement as to their location. Conclusions: Ryodoraku still does not present consistent evidence on its use, limiting the evaluation of its applicability

Objetivo: Sintetizar as evidências disponíveis na literatura sobre a aplicabilidade do sistema Ryodoraku no diagnóstico energético baseado nos preceitos da Medicina Tradicional Chinesa. Método: revisão integrativa, realizada por revisores independentes em bases de dados. Resultados: encontrou-se 324 estudos. Após exclusões, oito foram analisados, com predomínio de estudos descritivos. Houve concordância acerca dos 24 pontos selecionados para a aplicação do Ryodoraku; entretanto, há divergência quanto à localização dos mesmos. Conclusões: o Ryodoraku ainda não apresenta evidências consistentes sobre sua utilização, limitando a avaliação de sua aplicabilidade.

Objetivo: Sintetizar las evidencias de la literatura sobre la aplicabilidad del sistema Ryodoraku en el diagnóstico energético basado en los preceptos de la Medicina Tradicional China. Método: revisión integrativa, realizada por revisores independientes en bases de datos. Resultados: se han encontrado 324 estudios. Después de exclusiones, ocho fueron analizados, con predominio de estudios descriptivos. Hubo concordancia sobre los 24 puntos seleccionados para la aplicación del Ryodoraku; sin embargo, hay divergencia en cuanto a la localización de los mismos. Conclusión: el Ryodoraku todavía no presenta evidencias consistentes sobre su utilización, limitando la evaluación de su aplicabilidad

Head phantoms for bioelectromagnetic applications: a material study.

BACKGROUND: Assessments of source reconstruction procedures in electroencephalography and computations of transcranial electrical stimulation profiles require verification and validation with the help of ground truth configurations as implemented by physical head phantoms. For these phantoms, synthetic materials are needed, which are mechanically and electrochemically stable and possess conductivity values similar to the modeled human head tissues. Three-compartment head models comprise a scalp layer with a conductivity range of 0.137 S/m to 2.1 S/m, a skull layer with conductivity values between 0.066 S/m and 0.00275 S/m, and an intracranial volume with an often-used average conductivity value of 0.33 S/m. To establish a realistically shaped physical head phantom with a well-defined volume conduction configuration, we here characterize the electrical conductivity of synthetic materials for modeling head compartments. We analyzed agarose hydrogel, gypsum, and sodium chloride (NaCl) solution as surrogate materials for scalp, skull, and intracranial volume. We measured the impedance of all materials when immersed in NaCl solution using a four-electrode setup. The measured impedance values were used to calculate the electrical conductivity values of each material. Further, the conductivities in the longitudinal and transverse directions of reed sticks immersed in NaCl solution were measured to test their suitability for mimicking the anisotropic conductivity of white matter tracts. RESULTS: We obtained conductivities of 0.314 S/m, 0.30 S/m, 0.311 S/m (2%, 3%, 4% agarose), 0.0425 S/m and 0.0017 S/m (gypsum with and without NaCl in the compound), and 0.332 S/m (0.17% NaCl solution). These values are within the range of the conductivity values used for EEG and TES modeling. The reed sticks showed anisotropic conductivity with a ratio of 1:2.8. CONCLUSION: We conclude that agarose, gypsum, and NaCl solution can serve as stable representations of the three main conductivity compartments of the head, i.e., scalp, skull, and intracranial volume. An anisotropic conductivity structure such as a fiber track in white matter can be modeled using tailored reed sticks inside a volume conductor.

Chronic nerve health following implantation of femoral nerve cuff electrodes.

BACKGROUND: Peripheral nerve stimulation with implanted nerve cuff electrodes can restore standing, stepping and other functions to individuals with spinal cord injury (SCI). We performed the first study to evaluate the clinical electrodiagnostic changes due to electrode implantation acutely, chronic presence on the nerve peri- and post-operatively, and long-term delivery of electrical stimulation. METHODS: A man with bilateral lower extremity paralysis secondary to cervical SCI sustained 5 years prior to enrollment received an implanted standing neuroprosthesis including composite flat interface nerve electrodes (C-FINEs) electrodes implanted around the proximal femoral nerves near the inguinal ligaments. Electromyography quantified neurophysiology preoperatively, intraoperatively, and through 1 year postoperatively. Stimulation charge thresholds, evoked knee extension moments, and weight distribution during standing quantified neuroprosthesis function over the same interval. RESULTS: Femoral compound motor unit action potentials increased 31% in amplitude and 34% in area while evoked knee extension moments increased significantly (p < 0.01) by 79% over 1 year of rehabilitation with standing and quadriceps exercises. Charge thresholds were low and stable, averaging 19.7 nC ± 6.2 (SEM). Changes in saphenous nerve action potentials and needle electromyography suggested minor nerve irritation perioperatively. CONCLUSIONS: This is the first human trial reporting acute and chronic neurophysiologic changes due to application of and stimulation through nerve cuff electrodes. Electrodiagnostics indicated preserved nerve health with strengthened responses following stimulated exercise. Temporary electrodiagnostic changes suggest minor nerve irritation only intra- and peri-operatively, not continuing chronically nor impacting function. These outcomes follow implantation of a neuroprosthesis enabling standing and demonstrate the ability to safely implant electrodes on the proximal femoral nerve close to the inguinal ligament. We demonstrate the electrodiagnostic findings that can be expected from implanting nerve cuff electrodes and their time-course for resolution, potentially applicable to prostheses modulating other peripheral nerves and functions. TRIAL REGISTRATION: ClinicalTrials.gov NCT01923662 , retrospectively registered August 15, 2013.

The utility of electrodiagnostic inching study and conservative treatment in supracondylar process syndrome: A case report.

RATIONALE: Supracondylar process is a rare bony anomaly that can cause neurovascular symptoms. Previous reports on supracondylar process syndrome mostly suspect the condition by physical examination and simple radiograph with little assistance of electrodiagnostic methods and report efficiency of surgical treatment. PATIENTS CONCERNS: A 45-year-old woman working at an assembly line packing boxes presented with tingling pain at her middle and ring fingers that started 2 months ago. She had positive Tinel sign at the medial side of the distal arm. DIAGNOSIS: Electrodiagnostic inching study on median nerve was conducted and the conduction velocity at the segment between 3 cm to 5 cm proximal to the elbow crease was decreased to 27m/s. Following imaging studies revealed supracondylar process at 4.2 cm proximal to the medial epicondyle. She was successfully treated with conservative treatment. INTERVENTIONS: Oral medications including Non-steroidal anti-inflammatory drug and pregabalin were prescribed along with superficial and deep heat modalities. The extent of manual labor was modified. Additionally, self-massage and stretching/nerve-gliding exercises were delivered. OUTCOMES: The symptoms substantially improved and she could sleep without trouble, however, complete resolution was not achieved. After a year, she was nearly symptom-free after changing occupations with only occasional tingling after manual labor of unusual intensity. LESSONS: This case report enlightens the versatility of electrodiagnostic inching study in localizing median neuropathy at the distal arm and the effectiveness of conservative treatment in supracondylar process syndrome.

Electroneurography cannot predict when facial synkinesis develops in patients with facial palsy.

The objective of this study is to clarify when facial palsy patients with lower value of Electroneurography (ENoG) should begin the rehabilitation to prevent the development of facial synkinesis. For this purpose, we examined the relationship between the value of ENoG measured 10-14 days after facial palsy onset and the onset day of the development of oral-ocular synkinesis. Sixteen patients with facial palsy including 11 with Bell's palsy and 5 with Ramsay Hunt syndrome (7 men and 9 women ; 15-73 years old ; mean age, 41.6 years) were enrolled in this study. There was no correlation between ENoG value and the onset day of the development of oral-ocular synkinesis (ρ = .09, p = .73). Oral-ocular synkinesis began to develop in 4.0 ±â€…0.7 months (mean ±â€…SD ; range : 3.1-5.0 months) after facial palsy onset regardless of ENoG value. In conclusion, ENoG value cannot predict when facial synkinesis develops in patients with facial palsy. We recommend that facial palsy patients with a high risk for the development of synkinesis begin the biofeedback rehabilitation with mirror to prevent the development of facial synkinesis 3 months after facial palsy onset. J. Med. Invest. 67 : 87-89, February, 2020.

Comparisons of electrophysiological and clinical findings between young and elderly patients with Carpal Tunnel Syndrome.

BACKGROUND: Few studies have been published on differences between young and old patients with Carpal Tunnel Syndrome regarding clinical and electrophysiological findings. We compared the findings in participants of two age ranges. METHODS: For one year from August 2016, we performed a two-group cross-sectional study in an outpatient clinic of physical medicine and rehabilitation at a University Hospital. Two samples of young and old women with a diagnosis of the syndrome without known risk factors affecting electrophysiological findings were selected. We measured sensory and motor amplitudes and latencies, the conduction velocity of the median nerve, severity, and recurrence of the manifestations, weakness, atrophy, and severity of the syndrome. RESULTS: We had two groups of 24 young (<35 years) and 24 old (>65 years) patients with CTS. Severity of symptoms was higher in young participants [Mean (SD) 3.0(0.6) vs. 2.0(0.8), P<0.001]. Muscular weakness was not different [young 2.6(0.88) vs. old 1.9(1.6), P=0.541]. Five young and nine old participants showed thenar wasting (P=0.104). The severity of CTS was similar (P=0.129). For the group young patients, mean sensory amplitude was higher [14.07(10.98) vs. 7.58(5.08), P=0.012], while mean latency was lower [3.86(0.57) vs. 5.15(1.17), P<0.001]. In motor studies, mean latency was more prolonged in the group old patients [3.86(0.57) vs. 5.15(1.17), P<0.001]. CONCLUSION: Clinical symptoms are more severe among young people, while the pathophysiological process is more intense in the elderly. Patients should not be clinically judged merely by subjective manifestations. Both diagnostic workup and treatment should be designed holistically with all the evidence taken into consideration.

Acupuncture for Carpal Tunnel Syndrome: A Randomized Controlled Trial Studying Changes in Clinical Symptoms and Electrodiagnostic Tests.

BACKGROUND: Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy in humans. Nonsurgical management is still a matter of debate, and conservative treatments include splinting, local steroid injections, ultrasound, and oral steroids. Acupuncture and electroacupuncture therapy for symptomatic CTS may improve symptoms and aid nerve repair as well as improve sensory and motor functions. However, limited evidence based on comprehensive evaluation methods is available regarding the effects of those treatments. OBJECTIVE: The study intended to compare the short-term effects of acupuncture and conventional medical treatment on CTS patients' clinical symptoms and on the results of their electrodiagnostic tests. DESIGN: The research team designed a randomized controlled trial. SETTING: The study took place at the electrodiagnostic clinic of the School of Persian and Complementary Medicine at Mashhad University of Medical Sciences (Mashhad, Iran). PARTICIPANTS: Participants were 60 patients at the clinic with the clinical diagnosis of CTS. INTERVENTIONS: Participants were randomly assigned to 1 of 2 groups. Patients in the control group received 100 mg of Celebrex as tablets, 2 times daily. Patients in the intervention group received 12 sessions of acupuncture, each for 30 min, for 4 wk. The needle insertion points were fixed for all sessions. In addition, wrist braces were provided to wear at night for 1 mo in both groups. OUTCOME MEASURES: At baseline, postintervention at the end of week 4, and at a 3-mo follow-up at the end of week 16, participants' clinical symptoms-pain, numbness, tingling, weakness/clumsiness, and night awakenings-and the results of their electrodiagnostic studies were evaluated and compared. RESULTS: In total, 49 patients completed the study-24 in the control group and 25 in the intervention group. Compared with the control group, the intervention group's clinical symptoms-pain, numbness, tingling, and muscular weakness-based on the subscales of the global symptoms score questionnaire as well as the overall score on that questionnaire improved significantly (P < .05). Regarding the electrodiagnostic studies, only the distal motor latency showed a significantly greater decrease in the acupuncture group in comparison to controls (P = .001). CONCLUSION: All clinical symptoms and the results of the electrodiagnostic tests improved significantly in the intervention group, and the improvements continued during the 3 mo postintervention. The therapeutic results of acupuncture were mostly similar to and in certain cases better than those of the conventional medical treatment. Therefore, acupuncture can be suggested as a safe and suitable therapeutic method in CTS.

Compressive peroneal neuropathy by an intraneural ganglion cyst combined with L5 radiculopathy: A case report.

RATIONALE: Most cases of foot drop are known to result from lower motor neuron pathologies, particularly lumbar radiculopathy and peripheral neuropathy, including common peroneal neuropathy. To improve the prognosis of foot drop, it is important to quickly and accurately diagnose the etiology and provide appropriate treatment. PATIENT CONCERNS: A 65-year-old female patient with a history of L4-5 intervertebral disc herniation presented with right foot drop that had developed 1 month previously. DIAGNOSIS: Electrodiagnostic examination revealed common peroneal neuropathy combined with L5 radiculopathy, with the former being the main cause of the foot drop. MRI of the right knee was performed to identify the cause of the peroneal nerve lesion, which revealed an intraneural ganglion cyst in the common peroneal nerve. INTERVENTIONS: The patient was treated by ultrasound-guided percutaneous cyst aspiration and corticosteroid injection into the decompressed ganglion, followed by strengthening exercise, electrical stimulation therapy, and prescription of an ankle foot orthosis. OUTCOMES: We confirmed regeneration of the injured peroneal nerve at the follow-up electrodiagnostic examination 12 weeks after the intervention. In addition, the manual motor power test demonstrated an increase in the ankle dorsiflexor function score by one grade. LESSONS: Diagnosing the cause of foot drop can be difficult with multiple co-existing pathologies, and consideration of various possible etiologies is the key for appropriate diagnosis and treatment. In addition to imaging modalities such as MRI, electrodiagnostic examination can help to improve diagnostic accuracy. Intraneural ganglion cyst of the common peroneal nerve is rare, but should be considered as a possible cause of foot drop.

Instrumentation for electrodiagnostic studies.

The instrument and accessories are an important part of the electrodiagnostic (EDX) testing. Their functional understanding is useful to recognize and reduce various artifacts and noise/interference in the signal. In this review, we will describe the technical specifications of various components of the instrument, and their effect on signals and noise. This will be illustrated using example of electromyography and nerve conduction studies. However the same principles also apply to other modalities of testing. We will also provide general strategies to reduce noise and artifacts, followed by some modality specific examples.

Variation in Nonsurgical Services for Carpal Tunnel Syndrome Across a Large Integrated Health Care System.

PURPOSE: To evaluate facility-level variation in the use of services for patients with carpal tunnel syndrome (CTS) receiving care in the Veterans Health Administration (VHA). METHODS: A national cohort of VHA patients diagnosed with CTS during fiscal year 2013 was divided into nonsurgical and operative treatment groups for comparison. We assessed the use of 5 types of CTS-related services (electrodiagnostic studies [EDS], imaging, steroid injection, oral steroids, and therapeutic modalities) in the prediagnosis and postdiagnosis periods before any operative intervention at the patient and facility levels. RESULTS: Among 72,599 patients newly diagnosed with CTS, 5,666 (7.8%) received carpal tunnel release within 12 months. The remaining 66,933 (92.2%) were in the nonsurgical group. Therapeutic modalities and EDS were the most commonly employed services after the index diagnosis and had large facility-level variation in use. At the facility level, the use of therapeutic modalities ranged from 0% to 93% in the operative group (mean, 32%) compared with 1% to 67% (mean, 30%) in the nonsurgical group. The use of EDS in the postdiagnosis period ranged from 0% to 100% (mean, 59%) in the operative treatment group and 0% to 55% (mean, 26%) in the nonsurgical group at the facility level. CONCLUSIONS: There is wide facility variation in the use of services for CTS among patients receiving operative and nonsurgical treatment. Care delivered by facilities with the highest and lowest rates of service use may suggest overuse and underuse, respectively, of nonsurgical CTS services and a lack of consideration of individual patient factors in making health care decisions regarding use. CLINICAL RELEVANCE: Surgeons must understand the degree of treatment variability for CTS, comprehend the ramifications of large variation in reimbursement and waste in the health care system, and become involved in devising strategies to optimize hand care across all phases of care.

AANEM Choosing Wisely - second list.

Choosing Wisely is an initiative of the ABIM Foundation in partnership with Consumer Reports that seeks to advance a national dialogue on avoiding wasteful or unnecessary medical tests, treatments and procedures. The American Association for Neuromuscular & Electrodiagnostic Medicine's (AANEM) Professional Practice Committee (PPC) identified areas in neuromuscular and electrodiagnostic medicine that have the greatest potential for overuse/misuse and provided five recommendations for both patients and physicians to consider before proceeding with the specified test or treatment. This is the second list created by the PPC. The first was published in 2015. A combined list can be found online: http://www.choosingwisely.org/societies/american-association-of-neuromuscular-electrodiagnostic-medicine/. Muscle Nerve 57: 335-336, 2018.

Disruption of cortical network activity by the general anaesthetic isoflurane.

BACKGROUND: Actions of general anaesthetics on activity in the cortico-thalamic network likely contribute to loss of consciousness and disconnection from the environment. Previously, we showed that the general anaesthetic isoflurane preferentially suppresses cortically evoked synaptic responses compared with thalamically evoked synaptic responses, but how this differential sensitivity translates into changes in network activity is unclear. METHODS: We investigated isoflurane disruption of spontaneous and stimulus-induced cortical network activity using multichannel recordings in murine auditory thalamo-cortical brain slices. RESULTS: Under control conditions, afferent stimulation elicited short latency, presumably monosynaptically driven, spiking responses, as well as long latency network bursts that propagated horizontally through the cortex. Isoflurane (0.05-0.6 mM) suppressed spiking activity overall, but had a far greater effect on network bursts than on early spiking responses. At isoflurane concentrations >0.3 mM, network bursts were almost entirely blocked, even with increased stimulation intensity and in response to paired (thalamo-cortical + cortical layer 1) stimulation, while early spiking responses were <50% blocked. Isoflurane increased the threshold for eliciting bursts, decreased their propagation speed and prevented layer 1 afferents from facilitating burst induction by thalamo-cortical afferents. CONCLUSIONS: Disruption of horizontal activity spread and of layer 1 facilitation of thalamo-cortical responses likely contribute to the mechanism by which suppression of cortical feedback connections disrupts sensory awareness under anaesthesia.

[The meteopathic reactions as reflected in the indicators of electropuncture diagnostics. A pilot study]. / Otrazhenie meteopaticheskikh reaktsii v pokazateliakh élektropunkturnoi diagnostiki. Pilotnoe issledovanie.

The present article was designed to report the results of the electropuncture diagnostics (EPD) with the use of the 'Prognoz' electropunctural device obtained during the examination of 12 patients who experienced meteopathic reactions (MPR) during magnetic storms. The most frequently detected changes were deviations affecting the acupuncture channels (AC) of the heart, pericardium and triple energizer. The latter underwent the most pronounced deviation from the 'balanced condition'. In 2 cases out of the three (66,6%), its hypofunction was documented The pericardium channel was characterized by extreme asymmetry of its left and right branches. To a lesser extent, a similar asymmetry was apparent in the acupuncture channels of the heart. The present pilot study revealed the noticeable changed in the functional state of two AC (pericardium and triple energizer) in people suffering from meteopathic reactions. It is concluded that the further studies involving a larger population of the weather-dependent subjects is likely to identify other sensitive acupuncture channels; the analysis of their functional condition may be instrumental in determining the typical MPR profiles based on the results of the evaluation of the effectiveness of electropunctural diagnostics. The newly detected patterns may be useful for the development of the personalized approach to the prediction, prevention, and relief of the meteopathic reactions.

An approach to an acute emotional stress reference scale. / Aproximacion a una escala de referencia de estres emocional agudo.

INTRODUCTION: The clinical diagnosis aims to identify the degree of affectation of the psycho-physical state of the patient as a guide to therapeutic intervention. In stress, the lack of a measurement tool based on a reference makes it difficult to quantitatively assess this degree of affectation. AIM: To define and perform a primary assessment of a standard reference in order to measure acute emotional stress from the markers identified as indicators of the degree. SUBJECTS AND METHODS: Psychometric tests and biochemical variables are, in general, the most accepted stress measurements by the scientific community. Each one of them probably responds to different and complementary processes related to the reaction to a stress stimulus. The reference that is proposed is a weighted mean of these indicators by assigning them relative weights in accordance with a principal components analysis. RESULTS: An experimental study was conducted on 40 healthy young people subjected to the psychosocial stress stimulus of the Trier Social Stress Test in order to perform a primary assessment and consistency check of the proposed reference. The proposed scale clearly differentiates between the induced relax and stress states. CONCLUSIONS: Accepting the subjectivity of the definition and the lack of a subsequent validation with new experimental data, the proposed standard differentiates between a relax state and an emotional stress state triggered by a moderate stress stimulus, as it is the Trier Social Stress Test. The scale is robust. Although the variations in the percentage composition slightly affect the score, but they do not affect the valid differentiation between states.

TITLE: Aproximacion a una escala de referencia de estres emocional agudo.Introduccion. El diagnostico clinico persigue identificar el grado de afectacion del estado psicofisico del paciente como orientacion hacia la intervencion terapeutica. En el estres, la falta de un instrumento de medicion por comparacion con una referencia dificulta la valoracion cuantitativa del nivel de afectacion. Objetivo. Definir y hacer una primera validacion de un patron de referencia para la medida del estres emocional agudo a partir de marcadores identificados como indicadores del nivel. Sujetos y metodos. En general, las medidas mas solidas y aceptadas de estres por la comunidad cientifica son los test psicometricos y las variables bioquimicas. Cada uno de ellos responde probablemente a procesos distintos y complementarios de la reaccion frente a un estimulo estresante. La referencia que se propone es una media ponderada de estos indicadores, asignandoles pesos relativos de acuerdo con un analisis de componentes principales. Resultados. Para una primera aproximacion y verificacion de coherencia de la referencia propuesta, se ha utilizado un estudio experimental con una muestra de 40 jovenes sanos sometidos al estimulo estresante psicosocial del Trier Social Stress Test. La escala propuesta diferencia netamente entre los dos estados con distintos niveles de estres inducido. Conclusiones. Aceptando la subjetividad de la definicion, y a falta de una validacion posterior con nuevos datos experimentales, el patron propuesto diferencia entre un estado de relax y uno de estres emocional generados con un estimulo estresante moderado, como es el Trier Social Stress Test. La escala es robusta, ya que variaciones en la composicion porcentual repercuten ligeramente en la puntuacion, pero no en la diferenciacion valida entre estados.

An unusual case of sodium channel myotonia with transient weakness upon initiating movements which is characteristic in Becker disease.

We reported a 32-year-old man who was a sporadic case of myotonic syndrome with muscle stiffness or transient weakness of limbs upon initiating movements after rest. On examination, he showed painless myotonia with warm-up phenomenon, Hercules-like hypertrophic musculature and myotonic discharges in EMG. The clinical findings resembled to those of Becker disease rather than Thomsen disease. But electrodiagnosis suggested sodium channel myotonia instead of chloride channelopathy. Genetic testing detected a novel missense mutation (p.V1166A) in the SCN4A gene but not in the CLCN1 gene. Transient weakness upon initiating movements is usually observed in Becker disease but rare in Thomsen disease, which is not reported in sodium channel myotonia so far. He was probably the first case of sodium channel myotonia with transient weakness upon initiating movements, which was confirmed by 10 Hz repetitive nerve stimulation test as depolarization block.