Administration Of Edrophonium Chloride Research Articles

Detecting myasthenia gravis as a cause of unclear dysphagia with an endoscopic tensilon test.

Aims:The flexible endoscopic evaluation of swallowing-tensilon test (FTT) was developed to diagnose myasthenia gravis (MG) in patients with unclear pharyngeal dysphagia. The purpose of this study was to determine sensitivity and specificity of the FTT and compare its diagnostic validity with that of other diagnostic markers.Methods:In this single-centre pragmatic clinical cohort study, a total of 100 patients with unclear pharyngeal dysphagia were eligible to undergo FTT. All patients were subjected to FTT and subsequently followed up clinically. FTT was considered positive if a significant improvement of pharyngeal swallowing function could be objectified endoscopically upon administration of edrophonium chloride. In addition, repetitive nerve stimulation test and serum MG antibody analysis were conducted.Results:All subjects (mean age 62.5 ± 14.1 years, female 33) underwent FTT without any complications. According to the results of the diagnostic procedures and based on long-term clinical follow-up for at least 3 years, 51 patients were finally diagnosed with MG. The sensitivity and specificity for the FTT was 88.2% and 95.9%, respectively. Application of the Cochran’s Q test showed statistically significant heterogeneity among the diagnostic tests, with results indicating FTT performance to be more accurate than the repetitive nerve stimulation results (p < 0.001) and comparable with serum antibody tests (p > 0.99).Conclusion:FTT has excellent clinical properties to be used routinely in the assessment of dysphagia with isolated or predominant pharyngeal muscle involvement allowing rapid and accurate diagnosis of MG.

Thymolipoma associated with myasthenia gravis

A 51-year-old woman with a 3-year history of diplopia was admitted to our hospital. Repetitive stimulation of the right median nerve revealed decreasing hand muscle responses. Edrophonium chloride administration alleviated the symptoms. The serum antiacetylcholine receptor antibody level was 3.3 nmol/l; thus, myasthenia gravis was diagnosed. A chest roentgenogram revealed a left inferior mediastinal mass, and a chest computed tomographic scan revealed a fat density mass partly containing soft tissue areas in the left side of the anterior mediastinum. Median sternotomy and extended thymectomy were performed. The pathology examination of the tumor revealed mature adipose tissue including islands of thymic tissue containing Hassall's corpuscles, without germinal centers. The tumor was a thymolipoma of the anterior mediastinum. Her postoperative course was good, and she is doing well at 1 year postoperatively.

This Month in ANESTHESIOLOGY

This Month in ANESTHESIOLOGY

Suspected congenital myasthenia gravis in Brahman calves

Four, three- to four-week-old Brahman calves, with a common sire and a common maternal grandsire, developed progressive muscular weakness which was exacerbated by exercise and improved with rest. Although the...

Clinical forms of acquired myasthenia gravis in dogs: 25 cases (1988-1995).

The purpose of this project was to investigate the clinical forms of acquired myasthenia gravis in dogs. The medical records from 25 dogs with seropositive acquired myasthenia gravis were reviewed, and the following data were recorded for each patient: signalment, history, clinical findings; results of IV edrophonium chloride administration, repetitive nerve stimulation, and presence or absence of muscle membrane staining by immunocytochemical methods; serum acetylcholine receptor antibody concentration; treatment; and outcome. Several clinical forms of acquired myasthenia gravis were identified. Nine of the 25 patients (36%) had no historical or clinical evidence of appendicular muscle weakness, and were designated as focal myasthenics. These dogs exhibited focal weakness in one or more of the following muscle groups: facial (3 of 9), pharyngeal (3 of 9), and laryngeal (3 of 9). The remaining 16 dogs (64%) exhibited appendicular muscle weakness. Four of these 16 dogs had acute onset and rapid development of clinical signs, and were designated as acute fulminating myasthenics. The remaining 12 dogs were classified as generalized myasthenics. All 4 dogs with acute fulminating myasthenia gravis had megaesophagus, 2 had facial muscle weakness, and 1 had pharyngeal muscle weakness. Ten of the 12 dogs with generalized myasthenia gravis had megaesophagus, 4 had facial muscle weakness, 4 had pharyngeal muscle weakness, and 3 had laryngeal muscle weakness. Historical or clinical evidence of exercise-associated appendicular weakness was found in only 6 of the 12 (50%) dogs with generalized myasthenia gravis, and in none of the dogs with acute fulminating myasthenia gravis. Seven of the 12 dogs with generalized myasthenia gravis had weakness primarily (n = 1) or exclusively (n = 6) of the pelvic limbs. Two of the 4 dogs with acute fulminating myasthenia gravis had primarily pelvic limb weakness. Twelve of the 25 dogs (48%) died or were euthanized shortly after admission to the hospital due to aspiration pneumonia. The dogs with acute fulminating myasthenia gravis had a markedly higher 1-year mortality rate in comparison with the other 2 groups. The use of immunosuppressive therapy had a significant positive effect on patient survival, regardless of the type of myasthenia gravis. This investigation demonstrates that acquired myasthenia gravis in dogs is a disorder with a wide spectrum of clinical forms, similar to the analogous disorder in people.

Anorectal function and morphology in patients with sporadic proctalgia fugax.

The pathophysiology of sporadic proctalgia fugax remains unknown. This study investigates whether patients with this syndrome exhibit alterations in anal function and morphology. Eighteen patients with sporadic proctalgia fugax and 18 sex-matched and age-matched healthy controls were studied. Manometric studies investigated anal resting and squeeze pressures, the rectoanal inhibitory reflex, rectal compliance, and smooth muscle response to edrophonium chloride administration. External and internal sphincter thickness was measured endosonographically. Patients had slightly higher (P = 0.0291) anal resting pressures (65.5 +/- 11.4 mmHg) than controls (56 +/- 9.9 mmHg). However, anal squeeze pressure, sphincter relaxation during rectal distention, and rectal compliance were similar in both groups, and no alterations were detected in external and internal anal sphincter thickness. Edrophonium chloride administration was followed by sharp postrelaxation contractions in two patients, whereas anal function remained unaltered in controls. Acute episodes of proctalgia, which occurred in two patients while under study, were associated with a rise in anal resting tone and an increase in slow wave amplitude. In the resting state, patients with proctalgia fugax have normal anorectal function and morphology. However, they may exhibit a motor abnormality of the anal smooth muscle during an acute attack.

Myasthenia Gravis in the Cat

Myasthenia gravis (MG) was diagnosed in four cats--one had an apparently congenital form and three had the acquired autoimmune form. All four cats were examined because of episodes of weakness including gait abnormalities, voice change, neck ventroflexion, and regurgitation. Palpebral reflexes were absent in all cats. Administration of edrophonium chloride resulted in transient resolution of clinical signs in all four cats. Three cats were tested for the presence of serum autoantibodies against acetylcholine receptor (AChR) by radioimmunoassay. Two cats with acquired MG had anti-AChR antibody titers of 10.5 and 96.8 nmol/l (normal, less than or equal to 0.03 nmol/l). Antibodies were not detected in the cat with presumptive congenital MG. All four cats were treated with pyridostigmine bromide. Two cats with acquired MG were euthanatized because of clinical deterioration. The third cat with acquired MG has been asymptomatic since 2 months after diagnosis. The cat with presumed congenital MG is alive 3 years after diagnosis.

Esophageal chest pain. Value of high-dose provocative testing with edrophonium chloride in patients with normal esophageal manometries.

The unequivocal diagnosis of esophageal chest pain requires the demonstration of simultaneous manometric changes and chest pain. Numerous provocative agents have been used to enhance the diagnostic value of esophageal manometry. Our aims were to: evaluate consecutively a large group of patients with proven noncardiac chest pain and normal baseline manometric studies, using edrophonium chloride, 10 mg, and determine the value of provocative testing in clinical practice. One hundred twenty patients with normal standard baseline esophageal manometries were studied using blinded testing with edrophonium chloride and followed clinically by questionnaire. A positive response of both chest pain and manometric changes was observed in 34%, a negative response in 49%, and an indeterminate response in 17% of patients. Baseline manometric features, including high-amplitude contractions, did not predict the response to edrophonium chloride. Following edrophonium chloride administration, the change in amplitude, duration, and number of repetitive contractions from baseline was significantly greater in positive responders. Edrophonium decreased the velocity of propagated contractions in positive responders (P less than 0.05), but not in nonresponders. Response to edrophonium chloride could not be predicted by patient age, sex, or clinical symptomatology. Seventy percent of patients in both groups had symptoms indistinguishable from ischemic heart disease. After making a specific diagnosis of esophageal chest pain, patients showed a marked clinical improvement, with a significant decrease in physical limitation, emergency room visits, hospital and CCU admissions, and in further cardiac testing. We conclude that provocative testing with edrophonium chloride will make it possible to definitively implicate the esophagus in over 30% of patients with normal baseline manometric findings and noncardiac chest pain.

Early closure of the tricuspid valve in a case of Ebstein's anomaly with type B Wolff-Parkinson-White Syndrome.

Echocardiographic studies of a 19-year-old female with Ebstein's anomaly and type B Wolff-Parkinson-White syndrome showed an earlier closure of the anterior tricuspid leaflet (ATL) than of the anterior mitral leaflet (AML), contrary to the previous reports. The interval between the closure of the ATL and the AML was 20 msec and 30 msec, respectively, before and after administration of edrophonium chloride. However, closure of the AML preceded that of the ATL after administration of atropine sulfate and during supraventricular tachycardia by 10 msec and 60 msec, respectively, concomitant with the shortening of the duration of the QRS complex. We conclude that early closure of the ATL may depend on preexcitation of the right ventricle.

Amyotrophic Lateral Sclerosis

Neuromuscular transmission was studied in the ulnar-hypothenar group in 55 patients with amyotrophic lateral sclerosis. A decremental response was found in 67.0%. The decrement was larger and present more often in muscles showing atrophy. In addition, muscles with frequent fasciculations showed a larger decrement than the ones with rare fasciculation. A temperature effect similar to that in myasthenia gravis was observed, with a reduction of the decrement following local cooling of the muscles. Administration of edrophonium chloride improved the synaptic defect. Posttetanic exhaustion was observed as well. It is thought that the defect of neuromuscular transmission is due to a decreased trophic function of the neuron followed by morphological changes at the endplate.

Horner's Syndrome with Ipsilateral Accommodative Paresis

In a 12-year-old girl with Horner's syndrome and an ipsilateral accommodative paresis, intravenous administration of edrophonium chloride improved the accommodative defect on several occasions, which suggested a possible relationship to myasthenia gravis. Additional testing of the accommodative paresis revealed some of the characteristics of Adie's syndrome and suggested a relationship to pupil-sparing Adie's syndrome.

Botulism. Ten-year experience.

A large number of botulism cases occur in Colorado because the boiling temperature at high altitudes is too low to destroy spores. Clinical features in 14 patients representing five outbreaks included normal pupils in most, improvement in muscle strength after administration of edrophonium chloride in two, and nearly total long-term recovery in survivors. Guanidine hydrochloride, which enhances the release of acetylcholine at the nerve terminal, sometimes is useful in treating botulism. However, respiratory muscles respond to a lesser degree than do limb and extraocular muscles. In severe cases, or overwhelming poisoning, the drug effect may be negligible. Electrical abnormality in botulism resembles that seen in Eaton-Lambert syndrome but may not be apparent early in the disease. Moderately paralyzed patients can show a greater potentiation with rapid repetitive nerve stimulation than those severely paralyzed.

Optic Neuropathy of Graves Disease, Hyperthyroidism, and Ocular Myasthenia Gravis

A patient with diagnoses of hyperthyroidism at 14 years old and myasthenia gravis at 20 years old, presented at age 21 with bilateral exophthalmos, decreased function of extraocular muscles, and bilateral optic neuropathy. Oral administration of prednisone was begun immediately. Vision improved after four days of therapy, worsened when prednisone was tapered, and again improved when the high dose was reinstituted. Administration of edrophonium chloride (Tensiton) improved extraocular muscle function and ptosis.

Differential diagnosis of artial tachyarrhythmias.

Distinguishing between various supraventricular tachyarrhythmias requires careful study of atrial deflections and their morphology. Carotid sinus massage and administration of edrophonium chloride are additional helpful diagnostic tools.

Conversion of Atrial Flutter to Normal Sinus Rhythm after Intravenous Administration of Edrophonium Chloride

Carotid sinus stimulation or the administration of cholinergic drugs are known to convert paroxysmal atrial tachycardia to normal sinus rhythm. In atrial flutter usually only a slowing of the ventricular response, due to decreased atrioventricular conduction, is obtained, while the atrial flutter mechanism persists. A patient is described in whom the intravenous administration of 10 mg edrophonium chloride (Tensilon) resulted in the conversion of atrial flutter to normal sinus rhythm. Carotid sinus stimulation or the administration of cholinergic drugs are known to convert paroxysmal atrial tachycardia to normal sinus rhythm. In atrial flutter usually only a slowing of the ventricular response, due to decreased atrioventricular conduction, is obtained, while the atrial flutter mechanism persists. A patient is described in whom the intravenous administration of 10 mg edrophonium chloride (Tensilon) resulted in the conversion of atrial flutter to normal sinus rhythm.

The edrophonium tonogram test in myasthenia gravis.

The edrophonium (Tensilon) tonogram was devised to magnify the objective response of paretic extraocular muscles to a test dose of an antimyasthenic agent. While the intravenous administration of edrophonium chloride (Tensilon), as a rapid diagnostic procedure for myasthenia gravis is widely practiced, edrophonium tonography represents a sensitive refinement in recording the myasthenic response. In cases of subtle and confusing ophthalmoplegia, the value of this procedure may be of diagnostic significance. Derivatives of physostigmine had been used therapeutically by Walker^1,2and others,^3-6but the diagnostic value of a rapid test was not emphasized until Osserman and Kaplan⁷described the intravenous use of edrophonium. This analogue of neostigmine is a rapid anticurare agent whose maximum effect occurs within one minute. Breinin⁸has evaluated anticholinesterase and anticurare agents by use of electromyography. He suggests the occurrence in myasthenic patients of characteristic innervation patterns and drug response patterns. Kornblueth et