Rare syndrome with peripheral nerve lesions
characterized by muscle stiffness, cramps, and continuous vibrating muscle
Hereditary Continuous Muscle Fiber Activity; Isaacs
Unclear; the role of autoimmunity, specifically
antibodies against the potassium channel-inducing hyperexcitability of the
peripheral nerve, has been advocated. Probably caused by mutations in the
potassium channel gene KCNA1 located on chromosome 12p13.
Characterized by muscular stiffness and cramping,
particularly in the limbs with continuous fine, vibrating muscle movements
Neuromuscular signs dominate the disease.
Progressive stiffness, cramping, weakness, and constant writhing movements
of the muscles under the skin persist during sleep or under general
anesthesia without muscle relaxant. Calf hypertrophy can be seen.
Electromyography (EMG) shows
specific anomalies (spontaneous discharges with rhythmical and continuous
firing). Muscle biopsies are abnormal. Clinical examination finds
hypertonia, spasticity, speech defect, ataxia, and sometimes seizures.
Hyperhidrosis and tachycardia, because of autonomic nervous system
involvement, are possible. Association with diaphragmatic hernia has been
Evaluate muscular dysfunction
(clinical, EMG), neurologic function (clinical, electroencephalogram (EEG)), and autonomic nervous
system involvement (clinical, heart rate variability).
Careful intraoperative positioning is
needed. Perioperative blood pressure monitoring is necessary because of
autonomic system dysregulation. Regional anesthesia is not contraindicated
but probably should be avoided or the benefit must be clearly established
because of peripheral nervous lesion (peripheral blocks) and autonomic
nervous system involvement (perimedullar blockade).
Consider interaction between
antiepileptic treatment and anesthetic drugs. Anesthetic drugs that are
suspected to induce dystonia should be used carefully (propofol).
Succinylcholine probably should be avoided because of muscular lesion and
potential risk of hyperkaliemic response.
Hallervorden-Spatz Disease: Characterized by dystonia (slow,
steady muscle contraction distorting limbs, neck, face, mouth, or trunk into
certain positions), muscular rigidity, and choreoathetosis. Muscle spasms
are present in more than 33% of patients affected with this rare
neurologic disorder. Other clinical features seen less often are dysarthria,
mental retardation, facial grimacing, dysphasia, muscle atrophy, and
Hereditary Spastic Paraplegia: Includes weakness, muscle spasms,
and stiffness of the legs. Leg muscles may contract or a heel deformity may
occur, making walking difficult. Dysphasia, dysphagia, exaggeration of
tendon reflexes, and general muscle weakness are symptoms of this autosomal
dominant or recessive transmitted disease.
Stiff Man Syndrome (Moersch-Woltman Syndrome): Characterized by progressive rigidity and
muscles spasms of the muscles of the neck, trunk, shoulders, and proximal
extremities. Caused by abnormal nerve activity most likely in the central,
rather than peripheral, nervous system. Electrical activity measured by the
EMG may begin in the spinal cord rather than the peripheral nerves.
Arimura K, Sonoda Y, Watanabe O, et al: Isaacs' syndrome as a potassium
channelopathy of the nerve. Muscle NerveSuppl 11:S55, 2002.
Hernandez-Palazon J, Tortosa-Serrano JA, Sanchez-Ortega JL, et al: Acquired
neuromyotonia (Isaacs' syndrome): Clinical characteristics and anesthesia
implications. Rev Esp Anesthesiol ...