Biomaterial Database

Isaacs syndrome. 1984

T J Brown

Although Isaacs syndrome is known by several names including neuromyotonia and quantal squander, it bears some resemblence to other syndromes characterized by muscular stiffness such as stiff-man syndrome. The purpose of this paper is to examine pertinent clinical findings about Isaacs syndrome. A patient who presented cramping pain in both thighs and difficulty releasing his grip is described. Physical examination revealed myokymia in all four extremities, hyporeflexia, and hypertrophy of the thenar musculature. Electromyographic studied show continuous motor unit activity at rest. The patient was treated with phenytoin and showed almost complete symptom resolution over a 24-hour period. Clinical and electromyographic examinations in conjunction with the rapid response to phenytoin are diagnostic characteristics of Isaacs syndrome.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009127	Muscle Rigidity	Continuous involuntary sustained muscle contraction which is often a manifestation of BASAL GANGLIA DISEASES. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from MUSCLE SPASTICITY. (From Adams et al., Principles of Neurology, 6th ed, p73)	Cogwheel Rigidity,Extrapyramidal Rigidity,Gegenhalten,Nuchal Rigidity,Rigidity, Muscular,Catatonic Rigidity,Extensor Rigidity,Cogwheel Rigidities,Gegenhaltens,Muscular Rigidity,Rigidities, Cogwheel,Rigidity, Catatonic,Rigidity, Cogwheel,Rigidity, Extensor,Rigidity, Extrapyramidal,Rigidity, Muscle,Rigidity, Nuchal
D010672	Phenytoin	An anticonvulsant that is used to treat a wide variety of seizures. It is also an anti-arrhythmic and a muscle relaxant. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. The mechanism of its muscle relaxant effect appears to involve a reduction in the sensitivity of muscle spindles to stretch. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs.	Diphenylhydantoin,Fenitoin,Phenhydan,5,5-Diphenylhydantoin,5,5-diphenylimidazolidine-2,4-dione,Antisacer,Difenin,Dihydan,Dilantin,Epamin,Epanutin,Hydantol,Phenytoin Sodium,Sodium Diphenylhydantoinate,Diphenylhydantoinate, Sodium
D003937	Diagnosis, Differential	Determination of which one of two or more diseases or conditions a patient is suffering from by systematically comparing and contrasting results of diagnostic measures.	Diagnoses, Differential,Differential Diagnoses,Differential Diagnosis
D004576	Electromyography	Recording of the changes in electric potential of muscle by means of surface or needle electrodes.	Electromyogram,Surface Electromyography,Electromyograms,Electromyographies,Electromyographies, Surface,Electromyography, Surface,Surface Electromyographies
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D013577	Syndrome	A characteristic symptom complex.	Symptom Cluster,Cluster, Symptom,Clusters, Symptom,Symptom Clusters,Syndromes