Denny-Brown and Pennybacker: 80 years after their pioneering article on electromyography, fibrillation and fasciculation / Denny-Brown e Pennybacker: 80 anos da publicação de seu artigo pioneiro sobre eletromiografia, fibrilação e fasciculação

ABSTRACT We present a historical review, highlighting the role of Professor Derek Denny-Brown and doctor Joseph Buford Pennybacker in the development of current electromyography (EMG), of the 80 years since the publication of his original report in 1938 on fasciculation and fibrillation potentials and the subsequent studies describing most of the electrical changes necessary to perform and interpret the EMG.

RESUMO Os autores apresentam uma revisão histórica destacando o papel do Professor Derek Denny-Brown e do doutor Joseph Buford Pennybacker no desenvolvimento da eletromiografia atual, ao longo dos oitenta anos de seu artigo original em 1938, sobre potenciais de fasciculação e fibrilação, e os estudos subsequentes que descreveram a maioria das mudanças elétricas necessárias para realizar e interpretar EMG.

Usefulness of phrenic nerve conduction study in early diagnosis of isolated respiratory onset amyotrophic lateral sclerosis

Isolated respiratory onset amyotrophic lateral sclerosis (ALS) is a rare clinical manifestation and the diagnosis can be challenging. A 72-year-old man presented with dyspnea and hypercapnia that had started 11 months earlier. A phrenic nerve study was conducted and he was diagnosed promptly with ALS with no significant time delay. The phrenic nerve study is a noninvasive and useful tool in the diagnosis of respiratory onset ALS that can be applied easily in an emergency department.

Relationship between paravertebral muscle twitching and long-term effects of radiofrequency medial branch neurotomy

BACKGROUND: To achieve a prolonged therapeutic effect in patients with lumbar facet joint syndrome, radiofrequency medial branch neurotomy (RF-MB) is commonly performed. The purpose of this study was to evaluate the prognostic value of paravertebral muscle twitching when performing RF-MB in patients with lumbar facet joint syndrome. METHODS: We collected and analyzed data from 68 patients with confirmed facet joint syndrome. Sensory stimulation was performed at 50 Hz with a 0.5 V cut-off value. Patients were divided into 3 groups according to the twitching of the paravertebral muscle during 2 Hz motor stimulation: ‘Complete’, when twitching was observed at all needles; ‘Partial’, when twitching was present at 1 or 2 needles; and ‘None’, when no twitching was observed. The relationship between the long-term effects of RF-MB and paravertebral muscle twitching was analyzed. RESULTS: The mean effect duration of RF-MB was 4.6, 5.8, and 7.0 months in the None, Partial, and Complete groups, respectively (P = 0.47). Although the mean effect duration of RF-MB did not increase significantly in proportion to the paravertebral muscle twitching, the Complete group had prolonged effect duration (> 6 months) than the None group in subgroup analysis. (P = 0.03). CONCLUSIONS: Paravertebral muscle twitching while performing lumbar RF-MB may be a reliable predictor of long-term efficacy when sensory provocation under 0.5 V is achieved. However, further investigation may be necessary for clarifying its clinical significance.

Motor Neuron Disease Presenting With Acute Respiratory Failure: A Case Study

Motor neuron diseases (MNDs) refer to a heterogeneous group of progressive neurologic disorders caused by degeneration of motor neurons. The diseases affect either the upper motor neurons, lower motor neurons, or both, and are characterized by weakness, atrophy, fasciculation, spasticity, and respiratory failure. We report a case of a 61-year-old male patient with no past history of cardiovascular or pulmonary disease, who presented with only dyspnea, and no indication of any other symptom such as muscle weakness, atrophy, or bulbar dysfunction. Neuromuscular conduction study, including a study of the phrenic nerve, confirmed the diagnosis of MND. The patient greatly improved giving respiratory assistance at night, using a noninvasive ventilator. This case indicates that MNDs should be considered as differential diagnoses for patients showing acute respiratory failure of unknown causes. This report will aid in the prompt diagnosis and treatment of MNDs.

Prophylactic use of pregabalin for prevention of succinylcholine-induced fasciculation and myalgia: a randomized, double-blinded, placebo-controlled study / Uso profilático de pregabalina para prevenção de mialgia e fasciculação induzidas por succinilcolina: estudo randômico, duplo-cego e controlado por placebo

ABSTRACT BACKGROUND: Succinylcholine is commonly used to achieve profound neuromuscular blockade of rapid onset and short duration. OBJECTIVE: The present study compared the efficacy of pregabalin for prevention of succinylcholine-induced fasciculation and myalgia. DESIGN: Prospective, randomized, placebo controlled, double blinded study. MATERIALS AND METHODS: Patients of both genders undergoing elective spine surgery were randomly assigned to two groups. Patients in Group P (pregabalin group) received 150 mg of pregabalin orally 1 h prior to induction of anesthesia with sips of water and patients in Group C (control group) received placebo. Anesthesia was induced with fentanyl 1.5 mcg/kg, propofol 1.5-2.0 mg/kg followed by succinylcholine 1.5 mg/kg. The intensity of fasciculations was assessed by an observer blinded to the group allotment of the patient on a 4-point scale. A blinded observer recorded postoperative myalgia grade after 24 h of surgery. Patients were provided patient-controlled analgesia with fentanyl for postoperative pain relief. RESULTS: Demographic data of both groups were comparable (p > 0.05). The incidence of muscle fasciculation's was not significant between two groups (p = 0.707), while more patients in group C had moderate to severe fasciculation's compared to group P (p = 0.028). The incidence and severity of myalgia were significantly lower in group P (p < 0.05). CONCLUSION: Pregabalin 150 mg prevents succinylcholine-induced fasciculations and myalgia and also decreases the fentanyl consumption in elective sine surgery.

RESUMO JUSTIFICATIVA: A succinilcolina é comumente usada para atingir um bloqueio neuromuscular profundo, de início rápido e de curta duração. OBJETIVO: Comparar a eficácia de pregabalina na prevenção de mialgia e fasciculação induzidas por succinilcolina. DESENHO: Estudo prospectivo, randômico, duplo-cego e controlado por placebo. MATERIAIS E MÉTODOS: Pacientes de ambos os sexos submetidos a cirurgia eletiva de coluna foram aleatoriamente divididos em dois grupos. Os pacientes do Grupo P (pregabalina) receberam 150 mg de pregabalina oral uma hora antes da indução da anestesia e os pacientes do Grupo C (controle) receberam placebo. A anestesia foi induzida com fentanil (1,5 mcg/kg) e propofol (1,5-2,0 mg/kg), seguidos de succinilcolina 1,5 mg/kg. A intensidade da fasciculação foi avaliada por um observador, cego para a alocação dos grupos, com uma escala de 4 pontos. Um observador cego registrou o grau pós-operatório de mialgia após 24 horas de cirurgia. Para o alívio da dor no pós-operatório, fentanil foi usado em sistema de analgesia controlada pelo paciente. RESULTADOS: Os dados demográficos de ambos os grupos eram comparáveis (p > 0,05). A incidência de fasciculação muscular não foi significativa entre os dois grupos (p = 0,707), enquanto mais pacientes do Grupo C apresentaram fasciculação de moderada a grave em relação ao Grupo P (p = 0,028). A incidência e a gravidade da mialgia foram significativamente menores no grupo P (p < 0,05). CONCLUSÃO: Pregabalina (150 mg) previne mialgia e fasciculação induzidas por succinilcolina, além de diminur o consumo de fentanil em cirurgia eletiva de coluna.

Rapid Progression of Sporadic ALS in a Patient Carrying SOD1 p.Gly13Arg Mutation

Amyotrophic lateral sclerosis (ALS), the most common adult onset motor neuron disease, is pathologically characterized by progressive loss of the upper and lower motor neurons. Mutations in the Cu/Zn superoxide dismutase gene (SOD1) account for about 20% of familial ALS cases and a small percentage of sporadic ALS (SALS) cases, and have revealed a validated genotype-phenotype correlation. Herein, we report a p.Gly13Arg mutation in SOD1 exon 1 in a patient with SALS who presented with a rapidly progressive course, predominantly affecting the lower motor neurons. A 48-year-old man presented with progressive weakness and muscle atrophy of the left upper and lower limbs, followed by muscle fasciculation and cramping. The clinical features of the patient were clearly suggestive of ALS, and implied a sporadic form with rapid progression, predominantly affecting the lower motor neurons. Sequencing of the SOD1 gene by PCR revealed a missense mutation of G to C (c.37G>C) in exon 1, and amino acid substitution of glycine by arginine (p.Gly13Arg). This is the first case identifying the p.Gly13Arg mutation of SOD1 in the Korean population, and clinical assessments of this patient revealed a different phenotype compared with other cases.

Optimal precurarizing dose of rocuronium to decrease fasciculation and myalgia following succinylcholine administration / 대한마취과학회지

BACKGROUND: Succinylcholine commonly produces frequent adverse effects, including muscle fasciculation and myalgia. The current study identified the optimal dose of rocuronium to prevent succinylcholine-induced fasciculation and myalgia and evaluated the influence of rocuronium on the speed of onset produced by succinylcholine. METHODS: This randomized, double-blinded study was conducted in 100 patients randomly allocated into five groups of 20 patients each. Patients were randomized to receive 0.02, 0.03, 0.04, 0.05 and 0.06 mg/kg rocuronium as a precurarizing dose. Neuromuscular monitoring after each precurarizing dose was recorded from the adductor pollicis muscle using acceleromyography with train-of-four stimulation of the ulnar nerve. All patients received succinylcholine 1.5 mg/kg at 2 minutes after the precurarization, and were assessed the incidence and severity of fasciculations, while myalgia was assessed at 24 hours after surgery. RESULTS: The incidence and severity of visible muscle fasciculation was significantly less with increasing the amount of precurarizing dose of rocuronium (P < 0.001). Those of myalgia tend to decrease according to increasing the amount of precurarizing dose of rocuronium, but there was no significance (P = 0.072). The onset time of succinylcholine was significantly longer with increasing the amount of precurarizing dose of rocuronium (P < 0.001). CONCLUSIONS: Precurarization with 0.04 mg/kg rocuronium was the optimal dose considering the reduction in the incidence and severity of fasciculation and myalgia with acceptable onset time, and the safe and effective precurarization.

Comparison between Flail Arm Syndrome and Upper Limb Onset Amyotrophic Lateral Sclerosis: Clinical Features and Electromyographic Findings

Flail arm syndrome (FAS), an atypical presentation of amyotrophic lateral sclerosis (ALS), is characterized by progressive, predominantly proximal, weakness of upper limbs, without involvement of the lower limb, bulbar, or respiratory muscles. When encountering a patient who presents with this symptomatic profile, possible diagnoses include upper limb onset ALS (UL-ALS), and FAS. The lack of information regarding FAS may make differential diagnosis between FAS and UL-ALS difficult in clinical settings. The aim of this study was to compare clinical and electromyographic findings from patients diagnosed with FAS with those from patients diagnosed with UL-ALS. To accomplish this, 18 patients with FAS and 56 patients with UL-ALS were examined. Significant differences were observed between the 2 groups pertaining to the rate of fasciculation, patterns of predominantly affected muscles, and the Medical Research Council scale of the weakest muscle. The presence of upper motor neuron signs and lower motor neuron involvement evidenced through electromyography showed no significant between-group differences.

Decremental Responses to Repetitive Nerve Stimulation in X-Linked Bulbospinal Muscular Atrophy

BACKGROUND AND PURPOSE: X-linked bulbospinal muscular atrophy (X-BSMA) is characterized by bulbar and spinal muscular weakness and fasciculations. Although X-BSMA is a motor neuronopathy, there are several reports of myasthenic symptoms or decremental responses to repetitive nerve stimulation (RNS). We report the results of applying the RNS test to 15 patients among 41 with genetically confirmed X-BSMA; these 15 patients complained of fatigue, ease of becoming tired, or early muscular exhaustion. METHODS: The 3-Hz RNS test was performed on the trapezius, nasalis, orbicularis oculi, flexor carpi ulnaris, and abductor digiti quinti muscles. A decrement greater than 10% was considered abnormal. Additionally, a pharmacologic response to neostigmine was identified in three patients. RESULTS: A significant decrement was observed in 67% of patients, and was most common in the trapezius muscle (nine cases). The decrement of the trapezius muscle response ranged from 15.9% to 36.9%. The decrement was inversely correlated with the amplitude of compound muscle action potentials at rest. Neostigmine injection markedly improved the decrement in three patients, who showed noticeable decremental responses to 3-Hz RNS. CONCLUSIONS: This study shows that myasthenic symptoms and abnormal decremental responses to low-rate RNS are common in X-BSMA.

Inside-out vein graft vs autogenous nerve graft in promoting axonal regeneration: An experimental study in a rat model

BACKGROUND: An experimental study was done to compare the efficacy of inside-out vein graft versus autogenous nerve graft as nerve conduit in promoting axonal regeneration in a rat model.METHODS: The study used 16 Spraque-Dawley rats randomly divided into two groups: the inside-out vein graft group and control group (autognous nerve graft). The outcomes measured were histomorphology (axon number and diameter), muscle twitch response (amplitude) and the walking track analysis at 2, 4 6 and 8 weeks.RESULTS: The inverted vein graft and control groups showed similar axon diameter (P=0.76), and axon number (P=0.85), weeks and similar muscle twitch responses (P=0.87) after eight weeks. The walking track analysis showed no significant difference between the two groups at eight weeks.CONCLUSION: The study showed that the inside-out vein graft group had similar motor recovery as compared to control group based on the muscle twitch analysis and walking track analysis in a rat model.In terms of histomorphometric analysis, the two groups were similar in terms of axon diameter and axon count.

Clinical Characteristics and Analysis of CLCN1 in Patients with "EMG Disease"

BACKGROUND AND PURPOSE: While the etiology and clinical features of "EMG disease" - which is characterized by diffusely increased insertional activity on needle electromyography (EMG) in the absence of neuromuscular disease - are not well known, some authorities believe it may be a form of myotonia congenita (MC). The aims of this study were to determine the clinical features of EMG disease and its relationship with CLCN1 mutations in patients. METHODS: The detailed clinical and electrophysiological features of EMG disease were evaluated in six patients. All 23 coding exons and exon-intron boundaries in CLCN1 gene were analyzed by direct sequencing to detect nucleotide changes. RESULTS: The common clinical symptoms of EMG disease were chronic muscle stiffness or generalized myalgia, which were aggravated in a cold environment. Four patients complained of action myotonia several times a year. Short trains of provoked positive sharp waves were documented on needle EMG, but myotonic discharges, fibrillation potentials, and fasciculations were not. Increased insertional activity was identified at the asymptomatic muscles studied. One novel heterozygous mutation was identified in one patient following genetic testing for CLCN1 mutations (c.1679T>C, p.Met560Thr). CONCLUSIONS: The clinical features of EMG disease might be quite similar to those of MC, but CLCN1 mutation was found in only one subject. It is thus difficult to accept that EMG disease lies within the phenotypic spectrum of MC. Additional testing is needed to verify the pathogenetic cause of the diffusely increased insertional activity associated with this condition.

A Case of Motor Neuron Disease Presenting as Dyspnea in the Emergency Department / 가정의학회지

Motor neuron disease encompasses a group of progressive neurologic disorders that destroy cells responsible for the control of essential muscles. The disorders are characterized by progressive weakness, muscle atrophy and fasciculation, spasticity, dysarthria, dysphagia, and respiratory compromise. A 66-year-old male presented to the emergency department with progressive dyspnea and, ultimately, respiratory failure. In spite of extensive cardiopulmonary evaluation, a cause could not be identified except aging. After complete history taking, physical and neurologic examination, motor neuron disease was suspected at last. Thus, elderly patients with dyspnea in the emergency department could have hidden diseases beyond the normal aging process.

Hyoid Bone Fracture Associated with Hypoglossal Nerve Palsy: A Case Report

PURPOSE: Hyoid bone is a U-shaped bone in the anterior of the neck. Hyoid bone fractures are exceedingly rare and represent only 0.002% of all fractures because of its protective position relative to the mandible and its suspension by elastic musculature. We report a patient who presented hyoid bone fracture associated with hypoglossal nerve palsy. We also discuss the possible complication and treatment. METHODS: A 69-year-old man was transferred from another institution because of persistent purulent discharge from the left chin. He had a history of trauma in which a knuckle crane grabbed his face and neck in the construction site. A CT scan at the time of the accident demonstrated a comminuted fracture of the right side of the mandible and hyoid bone fracture at the junction between body and right greater cornua. The displaced fracture of hyoid bone and fullness in the pre-epiglottic space were noted, probably indicating some edema. The patient was transferred into ICU after treatment of emergency tracheostomy because the patient showed respiratory distress rapidly. When the patient was hospitalized in our emergency room, he complained of dysphagia and pain when swallowing. On examination of oral cavity, the presence of muscle wasting with fasciculation of the tongue was noted and the tongue deviates to the left side on protruding from the mouth. Pharyngolarygoscopy was performed to make sure that there was no evidence of progressive swelling and pharyngeal laceration. RESULTS: The patient underwent surgical removal of dead and infected tissue from the wound and reconstruction of mandibular bony defect by iliac bone grafting. Hyoid bone fracture was managed conservatively with oral analgesics, soft diet and restricted movement. Hypoglossal nerve palsy was resolved within 7 weeks after trauma without complications. CONCLUSION: Closed hyoid bone fracture is usually uncomplicated and thus it can be treated conservatively. Surgical intervention for hyoid bone fracture is recommended for patient with airway compromise, pharyngeal perforation and painful symptoms which show no response to conservative care. Furthermore, since respiratory distress syndrome may develop quickly, close observation is required. Besides, hypoglossal nerve palsy is a rarely recognized complication of hyoid bone fracture.

A case of idiopathic isolated hypoglossal nerve palsy in a Korean child / 소아과

Hypoglossal nerve palsy (HNP) is an uncommon neurological abnormality that can provoke characteristic clinical signs, including unilateral atrophy of the tongue musculature. We present the case of a healthy 11-year-old Korean male who was admitted to the outpatient department of our institution with acute onset dysarthria, tongue fasciculations, and right-sided tongue weakness upon awakening. His evaluation included a virology work-up, neck magnetic resonance imaging (MRI), brain MRI, and otorhinolaryngological physical examination; all tests were normal and showed no evidence of inflammation. Fifteen days after the onset of symptoms, the patient recovered completely. Herein, we report a case of idiopathic isolated HNP in a Korean male.

Ultrasonography in Neuromuscular Disorder

High-resolution (HR) ultrasound, which has been progressing continuously in technology, has improved in aspect of spatial and contrast resolution. The HR ultrasonography is a noninvasive, readily applicable imaging technique, which could get static and dynamic image in real-time for various neuromuscular disorders, especially in entrapment neuropathy. It is also a reliable tool to detect dynamic muscle movements such as fasciculation as well as muscle atrophy in chronic myopathies or neuropathies. Although reliability of the HR ultrasonography has not been investigated in large series of patients, different neuromuscular disorders tend to show specific changes on the ultrasound, which can be helpful in differential diagnosis. The HR ultrasonography is an ideal tool for the clinical and research investigation of neuromuscular system complementary to electrodiagnostic studies. This review briefly describes applicability for various neuromuscular disorders with previous study results and the technical aspects of ultrasound and its physical principles.

Comparative study of succinylcholine and precurarization with rocuronium on muscular effects in patients undergoing surgery under general anaesthesia

Succinylcholine remains the drug of choice in conditions where rapid paralysis and airway control are priorities. However it is associated with muscular side effects that have an overall incidence ranging from five to 83 percent. The administration of small doses of nondepolarizing muscle relaxants before the administration of succinylcholine has been shown to decrease the incidence and severity of muscular side effects experienced by the patients. This study was aimed at evaluating the efficacy of technique in reducing the muscular side effects of succinylcholine. Sixty healthy adults were enrolled in the study who were scheduled for minor muscle cutting surgeries under genera lanaesthesia. They were assigned at random to two groups of thirty patients each. They randomly received succinylcholine for intubation and a precurarization dose of rocuronium followed by succinylcholine for intubation. Intraoperative fasciculations and postoperative myalgia were graded and scored. There was a significantly increased incidence of fasciculations and myalgia in the succinlcholine group. In the precurarization group the incidence and severity of fasciculations and myalgia was significantly less as compared to the group which received succinylcholine alone. We found significant correlation between fasciculations and myalgia in the succinylchloine group. Present study concluded that precurarization with rocuronium was effective in reducing the succinylcholine-induced fasciculations and myalgia

Paraneoplastic motor neuron disease resembling amyotrophic lateral sclerosis in a patient with renal cell carcinoma

To report an unusual paraneoplastic syndrome, amyotrophic lateral sclerosis, associated with renal cell carcinoma. Case Presentation and Intervention: A 59-year-old man presented with muscle weakness and fasciculations in the upper extremities. Neurological examination showed that the fasciculations arose spontaneously in the upper limbs. Electrodiagnostic studies revealed an active neurogenic disorder. The patient was diagnosed with a motor neuron disease mimicking amyotrophic lateral sclerosis. Urine analysis revealed microscopic hematuria. Abdominal computerized tomography scans showed a 9.5 x 8 cm renal mass in the lower pole of the right kidney. Curative right radical nephrectomy was performed. Pathologic examination showed a clear cell adenocarcinoma. After nephrectomy, the muscle weakness and fasciculations disappeared spontaneously within 2 months. The patient was disease-free for 58 months after right radical nephrectomy. He complained of muscle weakness and fasciculation at the last follow-up again. Physical examination revealed fasciculation in the upper limbs. Abdominal tomography showed a 22 x 20 mm solid mass in the lower pole of the left kidney. Kidney-saving surgery was performed and the diagnosis of renal cell carcinoma was confirmed pathologically. Following surgery, fasciculations completely disappeared and muscle weakness diminished within 3 months. This case highlights motor neuron disease as a rare paraneoplastic syndrome in association with renal cell carcinoma and resolution after removal of the tumor

[ comparison of atracurium and lidocaine for decreasing succinylcholine induced fasciculation, myalgia and serum potassium change in patients during induction of anesthesia]

In the patients at risk of aspiration, it is necessary to induce general anesthesia and intubate their trachea as rapid sequence. Succinylcholine is the only neuromascular blocker with short onset and ultrashort acting effect, therefore choice of drug is in rapid sequence induction of anesthesia. This drug has many advantages, including low cost, short onset, short duration of action, and profound muscle relaxation with no need to reversal of muscle relaxation. The most important side effects of this drug are fasciculation, postoperative myalgia and rise in serum potassium. We compared lidocaine with atracurium in preventing these side effects. The patients aged 20-50 years, in class one or two physical status [ASA], were randomly assigned either to group A or group B. Those in group A were given atracurium [0.05 mg/kg], 3 minutes before succinylcholine. Those in group B received lidocaine [1.5 mg/kg], 30 seconds before succinylcholine at induction of anesthesia. All patients in both groups received sodium thiopental [4 mg/kg] and succinylcholine 1.5 mg/kg at induction of anesthesia. We evaluated and recorded fasciculation and myalgia in two days after operation. We also measured serum potassium before induction and 5 minutes after succinylcholine injection. In order to control of post-operative pain, we used intravenous morphine or acetaminophen as either oral or suppository. 160 patients were studied. The occurrence and severity of fasciculation were the same in two groups [p>0.05]. There were less myalgia in group B in comparison with group A, one and two days after operation [p<0.05]. There were no significant changes in serum potassium in two groups. Lidocaine is as effective as atracurium in decreasing the occurrence and severity of fasciculation, following succinylcholine injection at induction of anesthesia. Lidocaine is more effective than atracurium in decreasing the occurrence and severity of myalgia

Precurarización con rocuronio y d-tubocurarina: otra perspectiva / Precurarization with rocuronium and d-tubocurarine

Objetivo: Estudiar la precurarización de la succinilcolina utilizando d-tubocurarina y rocuronio introduciendo los métodos restrictivo, conceptos de velocidad de acción y recuperación y una nueva semiología para evaluar las fasciculaciones. Material y método: Se administraron succinilcolina (1 mg x Kg-1) (n =21) sola o precedida por rocuronio o d-tubocurarina (60 ó 50 ug x Kg-1) (n =21 c/u), determinándose: la fase inicial de comienzo hasta 80 por ciento de bloqueo, tiempo de comienzo, máximo efecto, duración clínica, tiempo de reversión espontánea entre 10 por ciento y 25 por ciento y 25 por ciento a 50 por ciento. Se calculó la velocidad de acción (inicial, final y global) como la relación tiempo/bloqueo fraccionado y la velocidad de recuperación. El método restrictivo fue empleado para el estudio del tiempo de comienzo, utilizando un rango restringido de bloqueo. Las fasciculaciones fueron evaluadas por su intensidad en seis regiones anatómicas por cuatro observadores imparciales e independientes y las medias de sus valoraciones utilizadas para analizarlas. Resultados: Aparentemente ambos desfasciculantes prolongan la fase inicial, tiempo de comienzo y velocidad de la succinilcolina, pero el método restrictivo únicamente lo confirmó para el tiempo de comienzo y la velocidad global. La velocidad inicial fue más rápida que la final. El rocuronio redujo el efecto y la duración clínica e incrementó la velocidad de recuperación de la succinilcolina. Las fasciculaciones fueron más frecuentes e intensas en el tronco y miembro superior izquierdo, pero los precurarizantes las redujeron tanto en intensidad como localización Discusión: La precurarización no modifica la fase inicial de comienzo, surgiendo la posibilidad de practicar una intubación temprana. Debido al acortamiento que provoca la precurarización con rocuronio se hace evidente la necesidad precoz de nuevas dosis de relajantes.

Objective: To study the precurarization of succinylcholine with d-tubocurarine and rocuronium, using the restrictive method, speed of action and recovery principles and a particular evaluation for fasciculations Material & Methods: Patients received succinylcholine (1 mg x Kg-1) (n =21) either alone or preceded by d-tubocurarine or rocuronium (60 ó 50 micron g x Kg-1) (n =21 e/a), and the following clinical measurements were made: earlyphase of onset time (up to 80 percent blockade), onset time, maximal block, clinical duration and recovery time between 10 percent and 25 percent and 25 percent to 50 percent. Speed of action (initial, final and global)as the ratio between time and fractional blockade and speed of recovery, were calculated. Restrictive method was used for the study of the entire onset time on patients included in a limited range of final block. Intensity of fasciculations was evaluated by four independent observers blind to the drugs used in six anatomical regions and their mean values used for analysis. Results: Apparently, precurarizing drugs prolonged initial phase, onset time and reduced speed for succinylcholine, but only onset time and global speed were confirmed by restrictive method. After rocuronium, maximal effect as well as clinical duration of succinylcholine werereduced and speed of recovery increased. Fasciculations were more frequent and intense at the trunk and left upper arm, but precurarization reduced both intensity and localization prevalence. Discussion: As lack of changes on the initial phase of onset time for succinylcholine inducedby precurarization was noticed, an early tracheal intubation could be contemplated. Due to reduction on clinical duration after rocuronium,new doses of muscle relaxants are sooner necessary. The present method for evaluation of fasciculations shows how far they are spread and how effective precurarization was, given rise to doubts on previous results.

Benign fasciculations responsive to gabapentin

Fasciculations are symptoms present in a broad spectrum of conditions, ranging from normal manifestations to motor neuron diseases. They also represent the main picture of benign fasciculation syndrome. We report a case of such syndrome: a 48-years-old woman complaining about fasciculations for three decades who remained with the symptoms even after the compensation of a disclosed hyperthyroidism. The introduction of gabapentin rendered control of her fasciculations. The available data in the literature about the therapeutic approaches for fasciculations are revised, as long as the rare reports of evolution from patients with "benign" fasciculations to cases of amyotrophic lateral sclerosis, underlining the importance of following the patients with fasciculations.

Fasciculações são sintomas presentes em um amplo espectro de condições, desde manifestações normais até doenças do neurônio motor. Elas representam também o principal aspecto da síndrome de fasciculações benignas. Relatamos um caso desta síndrome: uma paciente de 48 anos com queixas de fasciculações por três décadas que, mesmo após a compensação de um quadro de hipertireoidismo, permaneceu com os sintomas. A introdução de gabapentina levou a controle das fasciculações. Os dados disponíveis na literatura sobre as abordagens terapêuticas para fasciculações são revisados, assim como os raros relatos de evolução de pacientes com fasciculações "benignas" para casos de esclerose lateral amiotrófica, salientando a importância do seguimento dos pacientes com fasciculações.