Paralysis, periodic

When the pyrethrin concentration in a spray dosage was increased, the mean time for paralysis was reduced until it reached a minimum of 2.5 minutes and was then independent of concentration. This time was considered to represent the period required for diffusion through the cuticle to the site of action. 

Andersen s syndrome is a rare disorder characterized by periodic paralysis, cardiac arrhythmias, and dysmorphic features. 

Mutation of the human Cavl.l gene is associated with hypokalemic periodic paralysis. Deletion of the Cav1.3 gene leads to viable pups that are deaf and have cardiac arrhythmia at rest. Mutation of the human Cavl. 4 gene is associated with X-linked congenital stationary night blindness. 

Mutations of the NaVl. 4 channel gene cause various types of muscle diseases, including hyperkalemic periodic paralysis, paramyotonia congenita, myotonia fluctuans, acetazolamide-sensitive myotonia. Mutations disiupt inactivation and cause both myotonia (enhanced excitability) and attacks of paralysis (inexcitability resulting from depolarization). 

Hyperkalemic periodic paralysis AD 17q13 Sodium channel alpha subunit... 

Primary hyperkalemic periodic paralysis is usually first manifest in childhood. Attacks may last for a period of a few hours to several days, and the degree of muscle damage associated with the condition appears to increase with age and frequency of attacks. Vacuolation and dilatation of the SR is the most obvious form of damage, and it increases with age. 

A fall in serum is commonly associated with hypokalemic periodic paralysis. Primary hypokalemic paralysis is usually first expressed in children and young adults. Paralytic attacks may fluctuate with remarkable frequency, and there is a common diurnal variation in severity, with weakness especially bad in the morning and evening. The condition has an autosomal dominant pattern of inheritance caused by an abnormality in or close to locus lql3. The gene product is unknown. 

Secondary hypokalemic paralysis can be caused by almost any event that causes excessive loss. One particularly interesting secondary condition, however, is thyrotoxic periodic paralysis, seen most commonly in Chinese patients. 

The major mineralocorticoid, aldosterone, is secreted by cells of the zona glomerulosa. Primary hyperaldosteronism (Conn s syndrome) is associated with potassium depletion which is, in mm, responsible for the observed neuromuscular abnormalities seen in the disorder. These are similar to those seen in hypokalemic periodic paralysis (PP), with episodic and severe exacerbations of fixed muscle weakness. Muscle biopsy shows occasional muscle necrosis and vacuoles often these feamres are accompanied by mbular aggregates as in hypokalemic PP. All these changes can be attributed to the hypokalemia and not to excess aldosterone production per se. 

Riidel, R., Ricker, R. (1985). The primary periodic paralysis. Trends in Neurosci. 8,467-470, Zeviani, M., Servidei, S., Gellera, C., Bertini, E., Di Mauro, S.. Di Donato, S. (1989). An autosomal dominant disorder with multiple deletions of mitochondrial DNA starting at the D-loop. Nature (Lond.) 339, 309-311. 

Hyperkalemic periodic paralysis (MIM 170500) Sodium channel Skeletal muscle... 

Mutations of the sodium channel cause hyperkalemic periodic paralysis and paramyotonia congenital 720... 

Hypokalemic periodic paralysis is due to calcium channel mutations 721... 

Abnormal potassium channels in Andersen s syndrome cause more than periodic paralysis 721... 

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