RESUMO
Organophosphorus (OP) compound poisoning with suicidal intent is common. It is one of the frequent cause for admission to hospital Emergencies and intensive care units in our region. We describe here a case of 19-year old girl who presented to the Emergency Department with atypical features of OP poisoning. She had perioral, tongue and lower limb fasciculations along with generalized muscle weakness with no or minimal muscarinic effects. OP poisoning with isolated nicotinic receptor mediated effect is often reported in children but in adult it is extremely rare. Based on history and clinical suspicion of nicotinic receptor mediated effect of OP, she was given intravenous atropine along with other supportive treatment. Patient got completely recovered from fasciculations and her motor weakness improved after 6â¯h of atropine therapy. Emergency physician should keep a high index of suspicion of isolated nicotinic and ganglionic mediated effect of OP and a trial of atropine should be given to the patient.
Assuntos
Atropina/uso terapêutico , Fasciculação/etiologia , Antagonistas Muscarínicos/uso terapêutico , Debilidade Muscular/etiologia , Intoxicação por Organofosfatos/diagnóstico , Administração Intravenosa , Atropina/administração & dosagem , Fasciculação/tratamento farmacológico , Feminino , Humanos , Inseticidas/intoxicação , Antagonistas Muscarínicos/administração & dosagem , Debilidade Muscular/tratamento farmacológico , Intoxicação por Organofosfatos/tratamento farmacológico , Intoxicação por Organofosfatos/urina , Tentativa de Suicídio , Adulto JovemRESUMO
Continuous fasciculation that occurs without weakness is referred to as benign fasciculation. Although generally considered non-threatening, cases that persist can significantly impact an individual's quality of life. This study presents a case of a male patient in his 30s experiencing unyielding twitching localized to the sole of his left foot for 2 years. His medical history was devoid of any notable neuromuscular diseases. Results from electromyography testing were also normal for all parameters. Attempts with pharmacological intervention did not yield any improvement of his condition. Although a nerve block targeting the left tibial nerve managed to reduce the severity of the twitching, it failed to decrease its frequency or provide a lasting solution. In search of a more effective treatment, botulinum toxin was administered via ultrasound guidance into the flexor hallucis and digitorum longus muscles. This approach resulted in a marked reduction in both the frequency and severity of the twitching, enabling the patient to resume his daily activities and achieve restful sleep without experiencing any adverse effects. Through this case, the efficacy of botulinum toxin injections as a treatment for intractable twitching is underscored, offering valuable insights into potential therapeutic strategies for similar clinical presentations.
Assuntos
Toxinas Botulínicas Tipo A , Humanos , Masculino , Adulto , Toxinas Botulínicas Tipo A/uso terapêutico , Toxinas Botulínicas Tipo A/administração & dosagem , Eletromiografia , Fasciculação/tratamento farmacológico , Resultado do Tratamento , Toxinas Botulínicas/uso terapêutico , Toxinas Botulínicas/administração & dosagem , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiopatologiaRESUMO
ABSTRACT: This case study presents a 31-yr-old male weightlifter without known neuromuscular disease who presented with 5 wks of atraumatic, constant fasciculations of his right teres major muscle without recent injury. Electromyography identified fasciculation potentials within the teres major and pronator teres, suggesting an acute C6 radiculopathy, although a cervical magnetic resonance imaging demonstrated no significant neuroforaminal stenosis. Trigger point injections and multiple medications failed to stop the fasciculations. Under electromyography and ultrasound guidance, he was focally injected with botulinum toxin to the teres major 10 wks from initial onset with subsequent complete resolution of the symptoms and no side effects.
Assuntos
Toxinas Botulínicas Tipo A , Fasciculação , Fármacos Neuromusculares , Adulto , Atletas , Toxinas Botulínicas Tipo A/uso terapêutico , Eletromiografia , Fasciculação/diagnóstico por imagem , Fasciculação/tratamento farmacológico , Humanos , Masculino , Músculo Esquelético , Fármacos Neuromusculares/uso terapêutico , Ultrassonografia de IntervençãoRESUMO
INTRODUCTION: Neurotoxicity following rattlesnake envenomation is reported with certain crotaline species. In some instances, crotaline Fab antivenom therapy that effectively halts progression of local tissue edema and hemotoxicity fails to reverse neurologic venom effects. CASE SERIES: A 50-year-old man presented following a rattlesnake envenomation to the left ring finger. He had swelling and pain in the affected hand and complained of dyspnea and dysphonia. Significant fasciculations were seen in the face, tongue, neck, trunk, and arms. The patient received crotaline Fab antivenom but continued to develop worsening respiratory distress. His respiratory insufficiency requiring ventilatory support appeared related to respiratory muscle incoordination as extremity motor function remained intact. Initial control of local edema progression and hematologic parameters was achieved with antivenom, but diffuse fasciculations involving the entire body worsened despite aggressive antivenom treatment. In another case, a 9-year-old boy was envenomated by a rattlesnake on the left thenar eminence. He presented with pain and swelling up to the forearm and fasciculations of the tongue, face, and upper extremities. The progression of edema was halted at the mid-bicep level and hematologic parameters normalized with crotaline Fab antivenom. However, fasciculations continued for two days despite antivenom treatment. CONCLUSION: We describe two cases of neurotoxicity following rattlesnake envenomation in which treatment with crotaline Fab antivenom adequately obtained initial control of local swelling and hematologic effects, but neurotoxic venom effects remained refractory to antivenom therapy. This phenomenon is anecdotally recognized following certain crotaline species envenomations.
Assuntos
Antivenenos/uso terapêutico , Venenos de Crotalídeos/imunologia , Mordeduras de Serpentes/tratamento farmacológico , Animais , Criança , Crotalus , Fasciculação/tratamento farmacológico , Humanos , Fragmentos Fab das Imunoglobulinas/imunologia , Masculino , Pessoa de Meia-Idade , Síndromes Neurotóxicas/tratamento farmacológicoRESUMO
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.
Assuntos
Aminas/uso terapêutico , Anticonvulsivantes/uso terapêutico , Ácidos Cicloexanocarboxílicos/uso terapêutico , Fasciculação/tratamento farmacológico , Ácido gama-Aminobutírico/uso terapêutico , Fasciculação/diagnóstico , Feminino , Gabapentina , Humanos , Pessoa de Meia-IdadeRESUMO
A 16-year-old boy was seen for severe episodic muscle cramps and generalized myokymia, consistent with Isaacs's syndrome. Bilateral calf hypertrophy (46-cm calf circumference) and ankle areflexia were noted. He was treated with phenytoin sodium, 300 mg/day. Within three months there was marked decrease in myokymia, total relief of cramps, return of ankle reflexes, and 6-cm reduction in calf circumference. We suggest that the excess muscle activity in Isaacs's syndrome may be responsible for the associated phenomena of muscle hypertrophy and areflexia.
Assuntos
Doenças Musculares/tratamento farmacológico , Fenitoína/uso terapêutico , Adolescente , Fasciculação/complicações , Fasciculação/tratamento farmacológico , Humanos , Hipertrofia , Masculino , Cãibra Muscular/complicações , Cãibra Muscular/tratamento farmacológico , Rigidez Muscular/complicações , Rigidez Muscular/tratamento farmacológico , Músculos/patologia , SíndromeRESUMO
We report nine patients with muscle aching, cramps, stiffness, exercise intolerance, and peripheral nerve hyperexcitability. Neurologic examination showed calf fasciculations in seven, quadriceps myokymia in two, and deltoid myokymia in one patient. Two patients had mild increase in serum creatine kinase. Muscle biopsy showed either no abnormality (three patients) or mild neurogenic changes (four patients). Fasciculations were the only abnormality on routine electrodiagnostic studies. Supramaximal stimulation of the median, ulnar, peroneal, and posterior tibial nerves at frequencies of 0.5, 1, 2, and 5 Hz produced showers of electrical potentials following the M response in at least one nerve. In three patients, the fasciculations and evoked electrical potentials were abolished by regional application of curare but not nerve block. Carbamazepine therapy caused moderate-to-marked reduction of symptoms and nerve hyperexcitability. We designate this hyperexcitable peripheral nerve disorder as the "cramp-fasciculation syndrome."
Assuntos
Fasciculação , Cãibra Muscular , Doenças do Sistema Nervoso Periférico , Carbamazepina/uso terapêutico , Eletrodiagnóstico , Fasciculação/diagnóstico , Fasciculação/tratamento farmacológico , Fasciculação/patologia , Seguimentos , Humanos , Cãibra Muscular/diagnóstico , Cãibra Muscular/tratamento farmacológico , Cãibra Muscular/patologia , Doenças do Sistema Nervoso Periférico/diagnóstico , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Doenças do Sistema Nervoso Periférico/patologia , SíndromeRESUMO
In five patients with Guillain-Barré syndrome, clinical myokymia increased and myokymic burst amplification occurred when ionized Ca++ was lowered by hyperventilation. Myokymia decreased when ionized Ca++ was increased after IV infusion of CaCl2. These responses were absent or diminished in the four patients with myokymia due to brainstem lesions, suggesting that the blood-brain barrier impedes the effects of altered serum ionized Ca++ on axonal excitability. Altering serum Ca++ can distinguish peripheral and central myokymia.
Assuntos
Tronco Encefálico/fisiologia , Cálcio/fisiologia , Fasciculação/etiologia , Doenças do Sistema Nervoso/etiologia , Potenciais de Ação/efeitos dos fármacos , Adolescente , Cloreto de Cálcio/uso terapêutico , Doenças do Sistema Nervoso Central/complicações , Fasciculação/tratamento farmacológico , Fasciculação/fisiopatologia , Feminino , Humanos , Hiperventilação/complicações , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/complicações , Polirradiculoneuropatia/complicaçõesRESUMO
A 56-year-old woman presented with a 10-year history of torsional diplopia and right monocular oscillopsia. These symptoms, which had been intermittent at first, continued practically uninterrupted during the last 2 years. She was diagnosed as having superior oblique myokymia of the right eye. Adequate trials of oral carbamazepine, baclofen and phenytoin were unsuccessful in suppressing her symptoms. One year after her initial presentation, she underwent a right superior oblique tenectomy and a right inferior oblique recession. She eventually required a second operation on her other eye to cure her of an annoying diplopia on down-gaze.
Assuntos
Fasciculação/cirurgia , Músculos Oculomotores , Carbamazepina/uso terapêutico , Fasciculação/tratamento farmacológico , Fasciculação/fisiopatologia , Feminino , Seguimentos , Humanos , Pessoa de Meia-IdadeRESUMO
The efficacy of diazepam in attenuation of succinylcholine-induced muscle fasciculations was studied in the dog. Dosage levels of 0.11, 0.22, 0.55, or 1.1 mg of diazepam/kg of body weight were studied in 4 groups of 5 dogs each; another group of 5 dogs served as a control. There was no difference in the occurrence or severity of succinylcholine-induced muscle fasciculations between dogs given diazepam and nontreated controls. Using serum potassium as a quantitative index of physiologic effects of muscle depolarization, differences could not be detected between treated and nontreated dogs.
Assuntos
Diazepam/uso terapêutico , Doenças do Cão/tratamento farmacológico , Fasciculação/veterinária , Manifestações Neurológicas/veterinária , Animais , Diazepam/administração & dosagem , Diazepam/farmacologia , Doenças do Cão/induzido quimicamente , Cães , Fasciculação/induzido quimicamente , Fasciculação/tratamento farmacológico , Feminino , Masculino , Potássio/sangue , Pré-Medicação , Succinilcolina/efeitos adversosRESUMO
Patients with hemifacial spasm (N = 25), blepharospasm (n = 8), and benign eyelid fasciculation (n = 2) were treated with botulinum toxin injections (PHLS, Porton Down, England). All patients reported substantial symptomatic relief. Marked improvement was seen in fifteen patients with hemifacial spasm and six patients with blepharospasm. Benign eyelid fasciculation was completely abolished. Beneficial effects was evident two to three days after injections, became maximum at one week, and remained effective for up to six months. Side effects were transitory and mild. They included periorbital edema, mild diplopia, ptosis and facial weakness. Only in two patients was ptosis unacceptable. Severity of side effects was dose-related. Reinjections had similar efficacy. Botulinum toxin therapy is a safe and effective treatment for these facial dyskinesias and should be considered a viable alternative to surgical procedures.
Assuntos
Blefarospasmo/tratamento farmacológico , Toxinas Botulínicas/uso terapêutico , Doenças Palpebrais/tratamento farmacológico , Músculos Faciais , Fasciculação/tratamento farmacológico , Espasmo/tratamento farmacológico , Adulto , Idoso , Blefarospasmo/fisiopatologia , Toxinas Botulínicas/administração & dosagem , Toxinas Botulínicas/efeitos adversos , Doenças Palpebrais/fisiopatologia , Fasciculação/fisiopatologia , Feminino , Humanos , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Espasmo/fisiopatologia , Gravação de VideoteipeRESUMO
A 35 year-old man developed a syndrome with muscle cramp, myokimia, generalized, fasciculations, excessive sweating, sleep disorders and severe impairment. It was a syndrome of continuous muscle fiber activity--or Isaacs syndrome--with central disorders (this may be called "Maladie de Morvan"). Previous reports have suggested that Isaac's syndrome might be an autoimmune disorder. Moreover, high doses intravenous immunoglobulins were given resulting in a substantial improvement six months after the onset of this treatment.
Assuntos
Fasciculação/tratamento farmacológico , Imunoglobulinas Intravenosas/uso terapêutico , Adulto , Fasciculação/diagnóstico , Fasciculação/imunologia , Humanos , Masculino , Fatores de TempoRESUMO
There is increasing evidence that autoimmunity is implicated in the pathogenesis of peripheral nerve hyperexcitability (neuromyotonia, NMT and Cramp-fasciculation syndrome C-FS ) and in Maladie de Morvan in which CNS features are also present. All three conditions can associate with thymoma, myasthenia gravis and other autoimmune disorders, and can often respond to plasma exchange. In NMT, patient's plasma or IgG can transfer the electrophysiological features to mice, and can reduce voltage-gated potassium channel currents in vitro. Antibodies to voltage-gated potassium channels can be detected in the serum of many patients who have peripheral nerve hyperexcitability, and also in those with Maladie de Morvan. These latter patients have clinical features similar to limbic encephalitis in which VGKC antibodies can also occur. Thus neuromyotonia, cramp-fasciculation syndrome and Maladie de Morvan can occur as antibody-mediated autoimmune ion channelopathies like myasthenia gravis and the Lambert-Eaton myasthenic syndrome. These discoveries should aid diagnosis and offer new approaches to treatment.
Assuntos
Miotonia/fisiopatologia , Animais , Autoanticorpos/análise , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/fisiopatologia , Eletrofisiologia , Fasciculação/tratamento farmacológico , Fasciculação/fisiopatologia , Humanos , Canais Iônicos/efeitos dos fármacos , Canais Iônicos/fisiologia , Cãibra Muscular/tratamento farmacológico , Cãibra Muscular/fisiopatologia , Relaxantes Musculares Centrais/uso terapêutico , Miotonia/tratamento farmacológico , Canais de Potássio/imunologia , Canais de Potássio/fisiologia , Siringomielia/tratamento farmacológico , Siringomielia/fisiopatologiaRESUMO
Pretreatment with 3 different doses of atracurium (0.035 mg/kg, 0.05 mg/kg, 0.07 mg/kg) was investigated in order to determine the optimal dose that would prevent suxamethonium-induced fasciculations with minimal side effects to the patient and without significant antagonism of suxamethonium block. A total of 80 patients was studied. There were 20 patients in each of three atracurium groups while a fourth group of 20 patients served as control. Atracurium reduced the incidence of fasciculations from 100% observed in the control to between 0 and 40% in the atracurium groups. The optimal dose of atracurium appears to be 0.05 mg/kg, using a pretreatment interval of 3 minutes. Routine pretreatment of all patients is not mandatory, but it is recommended whenever the side-effects of suxamethonium are particularly undesirable, as in ocular laceration, raised intracranial pressure, full stomach and in very muscular patients.
Assuntos
Atracúrio/administração & dosagem , Fasciculação/tratamento farmacológico , Pré-Medicação/normas , Succinilcolina/efeitos adversos , Adulto , Atracúrio/uso terapêutico , Fasciculação/induzido quimicamente , Fasciculação/epidemiologia , Feminino , Humanos , Incidência , MasculinoRESUMO
In three patients, men of 43, 44 and 55 years old with muscle cramps, fasciculations and easy fatiguability of muscles, cramp-fasciculation syndrome was diagnosed. This is a benign disorder which has to be differentiated from amyotrophic lateral sclerosis. Response to treatment (benzodiazepines or carbamazepine) is good.
Assuntos
Fasciculação/diagnóstico , Cãibra Muscular/diagnóstico , Adulto , Esclerose Lateral Amiotrófica/diagnóstico , Analgésicos não Narcóticos/uso terapêutico , Benzodiazepinas/uso terapêutico , Carbamazepina/uso terapêutico , Diagnóstico Diferencial , Fasciculação/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Cãibra Muscular/tratamento farmacológico , Fadiga MuscularRESUMO
Fasciculations are a common side effect of the use of succinylcholine for tracheal intubation. Many anesthesia care providers prefer to prevent them due to a possible association between fasciculations and increased intracranial and intraocular pressures. The purpose of this study was to compare the effectiveness of tubocurarine, rocuronium, and cisatracurium in the prevention and reduction of succinylcholine-induced muscle fasciculations. The study was a prospective, randomized, double-blind, clinical drug comparison. We randomly assigned 40 subjects to 1 of 4 pretreatment groups. Fasciculations were graded on a 4-point scale. A Kruskal-Wallis analysis of variance, used to analyze data collected from the fasciculation scale, demonstrated there was no statistically significant difference in efficacy between tubocurarine and rocuronium for defasciculation or between cisatracurium and saline for defasciculation. Significant differences were shown between the tubocurarine and cisatracurium groups and between the rocuronium and cisatracurium groups. Rocuronium is equally as efficacious as tubocurarine for defasciculation. Therefore, rocuronium is a valid alternative to tubocurarine for defasciculation. Cisatracurium is inferior to rocuronium and tubocurarine for defasciculation. Therefore, the use of cisatracurium is not recommended for defasciculation.
Assuntos
Androstanóis/administração & dosagem , Atracúrio/análogos & derivados , Atracúrio/administração & dosagem , Fasciculação/tratamento farmacológico , Fármacos Neuromusculares não Despolarizantes/administração & dosagem , Tubocurarina/administração & dosagem , Adulto , Fasciculação/induzido quimicamente , Feminino , Humanos , Masculino , Fármacos Neuromusculares não Despolarizantes/efeitos adversos , Enfermeiros Anestesistas , Estudos Prospectivos , Rocurônio , Succinilcolina/efeitos adversosRESUMO
INTRODUCTION: Acetazolamide responsive hereditary paroxysmal cerebellar ataxia with myokymia is a type of autosomal dominant cerebellar ataxia which locus was found to be linked to the short arm of chromosome 12 and the etiology is unknown. CLINICAL CASE: A 12 years-old man who suffered from childhood daily episodes of sudden attacks sport induced with giddiness, ataxia and dysarthria for minutes. The familial history shows the same clinical findings in three generations. Intercritical general neurologic evaluation is otherwise normal. The following tests were performed with normal results: Biochemistry, electroencephalogram, cerebral magnetic resonance imaging. The electromyography showed myokymic discharges. The patient's symptoms improve on treatment with acetazolamide immediately. CONCLUSIONS: Acetazolamide responsive hereditary paroxysmal cerebellar ataxia with myokymia needs to think on it to be diagnosed. No typical complementary test (electromyography exception) induces to base diagnosis in the clinical findings, the familial history and the fast clinical improvement after starting treatment with acetazolamide.
Assuntos
Acetazolamida/uso terapêutico , Anticonvulsivantes/uso terapêutico , Ataxia Cerebelar/complicações , Ataxia Cerebelar/genética , Fasciculação/complicações , Fasciculação/tratamento farmacológico , Periodicidade , Ataxia Cerebelar/classificação , Criança , Aberrações Cromossômicas/genética , Transtornos Cromossômicos , Cromossomos Humanos Par 12/genética , Humanos , Masculino , LinhagemRESUMO
A 34-year-old woman noted difficulty of gait initiation, then dilated finger opening and hyperhidrosis appeared. Her stature was a muscular habitus, and muscle stiffness and myokymia were found in all muscles of the extremities. Her stiffness persisted during sleep. Her calf muscles were large and a contracture was noticed in ankle joints. There was no evidence of wasting and weakness. A remarkable delay in voluntary relaxation of the contracted muscles without percussion myotonia was recognized. Tendon reflexes of lower extremities were absent. Laboratory examination revealed elevation of CPK, LDH, myoglobulin, aldolase and basal metabolic rate (BMR). An extraband of CPK isoenzyme between MB and MM fraction was observed. The thin layer gel filtration technique and immunofixation technique showed that this extraband was complexes of CPK and IgA, and light chain of the CPK linked IgA was lambda type. All other laboratory tests were normal for the following: urinalysis, ESR, a blood count, liver function, kidney function, glucose, rheumatoid factor, CRP, thyroid function, parathyroid function, serum electrolytes, ECG, EEG, cranial CT, without slight elevation of IgA, and CSF protein. In needle EMG and surface EMG spontaneous discharges were recorded at rest. These discharges consist of normal motor unit potentials, doublets, and triplets in needle EMG. The discharges were markedly reduced after the median nerve block with xylocaine. In needle EMG, myotonic discharge was not observed. Nerve conduction velocities were within normal ranges. According to these data, she was diagnosed as having Issacs' syndrome (continuous muscle fiber activity syndrome). Carbamazepine, 200 mg daily was administrated and showed a dramatic reversal of the symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Fasciculação/fisiopatologia , Músculos/fisiopatologia , Doenças do Sistema Nervoso/fisiopatologia , Adulto , Carbamazepina/uso terapêutico , Eletroencefalografia , Eletromiografia , Fasciculação/complicações , Fasciculação/tratamento farmacológico , Feminino , Humanos , Hiperidrose/complicações , Imunoglobulina A/análise , Imunoglobulina M/análise , Relaxamento Muscular , Doenças do Sistema Nervoso/etiologia , Reflexo de Estiramento , Sono REM/fisiologia , SíndromeRESUMO
A 21-year-old man complained of severe pain and muscle twitching localized in his right arm. Neurological examination showed muscle fasciculations in his right forearm but no myokymia or myotonia. Needle electromyography revealed fibrillation potentials in his biceps brachii muscle and extensor carpi radialis muscle at rest but no myokymic discharges. His serum anti-voltage-gated potassium channel (VGKC)-complex antibody level was significantly high (194.2pM; controls <100pM). Although anticonvulsant therapy relieved his pain, he was readmitted to our hospital because of severe pain in his left arm and both thighs three months later. A high-dose intravenous immunoglobulin (IVIG) therapy followed by steroid pulse therapy relieved his pain. This case with neither muscle cramp nor myokymia expands the phenotype of anti VGKC-complex antibody associated disorder.
Assuntos
Autoanticorpos/sangue , Fasciculação/tratamento farmacológico , Fasciculação/imunologia , Dor/tratamento farmacológico , Dor/imunologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/imunologia , Extremidade Superior , Adulto , Biomarcadores/sangue , Eletromiografia/métodos , Fasciculação/diagnóstico , Humanos , Imunoglobulinas Intravenosas/administração & dosagem , Masculino , Metilprednisolona/administração & dosagem , Pulsoterapia , Índice de Gravidade de Doença , Resultado do Tratamento , Adulto JovemRESUMO
PURPOSE: The present visual and electromyographic study was designed to evaluate muscle fasciculations caused by succinylcholine in adults pretreated with either remifentanil 1.5 microg/kg or saline. MATERIALS AND METHODS: The effect of remifentanil on succinylcholine-induced muscle fasciculations was studied using a double-blind method in 40 adults. After i.v. pretreatment with either remifentanil 1.5 microg/kg (remifentanil group, n = 20) or an equivalent volume of i.v. saline (saline group, n = 20), patients were anaesthetized with a 2.0 mg/kg of i.v. propofol followed by i.v. succinylcholine 1.0 mg/kg. Intensity and duration of muscle fasciculation following i.v. succinylcholine administration were recorded. Electromyography (EMG) was used to quantify the extent of muscle fasciculation following i.v. succinylcholine injection. Myalgia was evaluated 24 hours after induction time. Serum potassium levels were measured five minutes after i.v. succinylcholine administration and creatine kinase (CK) levels 24 hours after induction time. RESULTS: Compared to saline treated controls, remifentanil decreased the intensity of muscle fasciculations caused by i.v. succinylcholine [fasciculation severity scores (grade 0 to 3) were 2/1/12/5 and 3/13/4/0 (patients numbers) in the saline group and the remifentanil group, respectively, p < 0.001]. The mean (SD) maximum amplitude of muscle action potential (MAP) by EMG was smaller in the remifentanil group [283.0 (74.4) microV] than in the saline group [1480.4 (161.3) microV] (p = 0.003). Postoperative serum CK levels were lower in the remifentanil group (p < 0.001). Postoperative myalgia was not different between the two groups. CONCLUSION: Remifentanil 1.5 microg/kg attenuated intensity of muscle fasciculations by succinylcholine.