Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030552 (paresis)
 5,831 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of local cooling has been studied in 27 normal subjects, 8 cases of myotonia congenita, 5 of myotonic dystrophy and one of paramyotonia. Using the adductor pollicis we registered the compound muscle action potential, the isometric twitch force and the time to half relaxation, the maximum tetanic force and to time 3/4 relaxation. 1. In normal subjects the twitch force and maximum tetanic force decreased after cooling (Fig. 2). The amplitude of the action potential increased. 2. Myotonia congenita and myotonic dystrophy were not aggravated by cooling. Muscle force was reduced only in the same proportion as in normal subjects (Fig. 2). The myotonic after-contraction was made normal by cooling (Figs. 5 and 6). 3. In paramyotonia initial tonic stiffness with a pronouncedly prolonged twitch relaxation occured directly after cooling (Fig. 1 B). Paradoxical myotonia occured only after exercise and was accompained by increasing paresis (Figs. 3 and 8). The results indicate that exposure to cold has a specific effect on muscle function only in paramyotonia.
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PMID:Myotonia not aggravated by cooling. Force and relaxation of the adductor pollicis in normal subjects and in myotonia as compared to paramyotonia. 7 99

Four patients without symptoms of episodic hyperkalemic weakness from two families with paramyotonia congenita (Eulenburg) are described. 1. Maximum voluntary muscle contraction of the upper and lower arm was studied under isometric conditions at different temperatures. If the temperature was lowered stepwise, distinct paresis occured at 32--31 degrees C which increased with the amount of muscular effort. The upper arm muscles, however, developed weakness gradually after cooling. 2. During cooling of the resting muscle, the EMG showed dense spontaneous activity of the fibrillary type, which decreased again at about 30 degrees C. It can be assumed that in paramyotonia congenita cooling produces muscle cell membrane depolarization which at a critical level causes the firing of action potentials and finally muscular paresis. 3. Increasing muscular stiffness can be interpreted as abnormally slow muscular relaxation after isometric contraction. In the forearm muscles the time to 3/4 relaxation after cooling was about six times normal, in the upper arm muscles only two times normal. As an additional parameter the mechanical resistance to passive stretching of a muscle has been studied. This passive muscular tension increased simultaneously with the onset of weakness. 4. The close relation between weakness and stiffness suggest that both symptoms are caused by the same basic defect which is probably located in the sarcolemma. It is suggested that a defect of the sodium channel causes a cooling-dependent increase in sodium conductance. Raised intracellular sodium causes in the first place membrane depolarization, and in the second place depression of calcium reuptake through competition by sodium for calcium binding sites. This would explain muscle stiffness and delayed relaxation as well.
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PMID:Influence of temperature on isometric contraction and passive muscular tension in paramyotonia congenita (Eulenburg). 9 68

This study reports on clinical and electromyographical findings which were obtained from an examination of male dizygotic twins and their father, who all suffered on a paramyotonia congenita. A simple coldness test can be used to distinguish paramyotonia congenita from myotonia congenita. Systematic cooling of the muscle of subjects with paramyotonia congenita leads to muscle stiffness and paresis, and finally to paralysis. An electromyographic analysis was carried out at various degrees of coldness. More than 300 paramyotonic series of discharges were analysed in respect to duration, amplitude and frequency. The results showed that the paramyotonic series are more similar to those of dystrophia myotonica than those of myotonia congenita.
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PMID:[Paramyotonia congenita: clinical and electromyographical tests (author's transl)]. 82 44

Paramyotonia congenita (PC), first described in 1886 by Eulenberg, is characterized by cold and exercise-induced muscle stiffness and intermittent flaccid paresis not necessarily related to cold or myotonia. Several authors segregated a pure form of PC, which has no periodic paralysis, even after cold exposure. The existence of this phenotype has been debated in the literature. We describe electrophysiological and molecular genetic features of a patient with PC who had no history of periodic paralysis. Immersion in cold water or potassium load could not induce clinical paralysis. However, repetitive nerve stimulation and exercise test demonstrated a drop in compound muscle action potential amplitude. Genetic analysis revealed the substitution of valine for glycine on the human skeletal muscle sodium channel (SCN4A) gene. The G1306V mutation is rare in the classic form of PC, and moreover might be the first in pure paramyotonia.
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PMID:A case of paramyotonia congenita without periodic paralysis: electrophysiological and molecular genetic studies. 2044 32

Mutations of the skeletal muscle voltage-gated sodium channel (NaV1.4) are an established cause of several clinically distinct forms of periodic paralysis and myotonia. Focal paresis has sometimes already been described. We report a case with atypical clinical manifestation comprising paramyotonia and cold-induced persistent and focal paralysis. A 27-year-old woman presented with paramyotonia congenita since her childhood. She experienced during her childhood one brief episode of generalised weakness. At the age of 27, she experienced a focal paresis lasting for several months. The known mutation p.Val1293Ile was found in the muscle sodium channel gene (SCN4A). Channel inactivation is involved in most Na(+) channelopathies. Fast inactivation is known to be responsible for the myotonia phenotype. We hypothesise that the V1293I mutation may also alter the slow inactivation in specific conditions, for example, prolonged cold exposure or prolonged and intensive exercise. This observation broadens the spectrum of clinical manifestations of this sodium channel mutation.
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PMID:Focal and abnormally persistent paralysis associated with congenital paramyotonia. 2493 54