Periodic Paralysis Begins before Third Decade of Life
All different instances of periodic paralysis arecharacterized by episodes of muscle weakness. It is normal to maintain strengthbetween attacks of paralysis. Some forms of paralysis may also be associatedwith fixed weakness which usually occurs in later stages of the medicalcondition. In most cases of periodic paralysis patients commonly getaffected by the symptoms before they reach their third decade of life.
Causes of Periodic Paralysis
Periodic paralysis is a rather peculiar medicalcondition which is triggered by mutations in certain genes which are in chargeof the function and development of some ion channels located in the musclemembranes in the human body. For those who do not know, ion channels pierce themuscle membrane and make it possible for the ions to move into /out of the cells. Inmost cases, periodic paralysis is an inherited type of medical condition,but in some families it may not be that obvious. Some people may carry themutated gene but show no symptoms at all.
Several Types of Periodic Paralysis
There are various different types of periodic paralysis butthe most commonly occurring ones include the Andersen-Tawil syndrome,thyrotoxic periodic paralysis, paramyotonia congenital, hypokalemic periodicparalysis and hyperkalemic periodic paralysis. Andersen-Tawil syndrome is aspecific type of medical condition which can easily trigger cardiacarrhythmia, have different dysmorphic features and is blamed for periodic paralysis. Other commonsymptoms which may be sometimes associated with this type of medicalcondition include scoliosis, fifth finger clinodactyly, micrognathia, lowset ears, hypertelorism and short stature. Episodes of weakness basically last forhours and sometimes even days. Andersen –Tawil syndrome night be involved withventricular arrhythmia and prolonged QT intervals. There are also certain typesof ECG abnormalities which may also be present in some cases and these includetorsades de pointes, prominent U waves, ventricular tachycardia,supraventricular tachycardia, ventricular bigeminy and PVC. Some rare cases ofAndersen-Tawil syndrome are a reason behind sudden cardiac death, cardiacarrest, syncopal episodes and palpitations. Another common type of periodicparalysis is thyrotoxic periodic paralysis. It usually occurs in adults between 20 and 40 years of age. The episodes of weakness are mostly proximal and in some cases they may affect the bulbar muscles and therespiratory muscles. Attacks sometimes last for several days.
Another common type of periodic paralysis is known by thename paramyotonia congenita. This is an inherited type of autosomal dominantdisorder which usually gets precipitated by cold temperatures and physicalactivity. The abnormalities associated with this type of periodic paralysis are usuallypresent in the muscles of the hands, tongue and the face. Some rare cases mayalso have the muscles of the lower limbs affected as well. Every third case ofparamyotonia congenital is also associated with muscle hypertrophy. Myotoniaitself usually does not last for more than couple of minutes in the most severecases, but weakness associated with this dreadful medical condition may lastfor days in other patients. In the majority of patients, the ingestion ofpotassium only worsens the symptoms, which is completely contrary to thepopular belief. Hypokalemic periodic paralysis is divided into twodifferent types and these include calcium channel mutation and sodiumchannel mutation. Severe cases of hypkalemic periodic paralysis usually affectchildren in their early childhood while milder cases may occur as late as inthe third decade of a person’s life. Weakness episodes generally comprise slightweakness but on the other hand some cases may involve severe generalizedweakness. Complex and harsh attacks usually occur in the morning and in many cases theymay be provoked or triggered by certain factors such as the lack ofsleep, menstruation, various types of infections, stress and several differentsorts of medications including corticosteroids, insulin and beta agonists. Mildattacks can be monomelic, partial or unilateral and they usually affect only one group of muscles. They may last for up to three days in some cases.During the attack, the patient may experience a decreased urinary output due tothe accumulation of water in the muscles. Under certain circumstances the condition is involved withpermanent muscle weakness and hypertrophy of the calves. The same can be saidfor proximal muscle wasting. One of themost commonly observed types of periodic paralysis is hyperkalemic periodicparalysis which usually develops in children younger than 10 years. The mostcommonly reported symptoms include a sense of stiffness and heaviness in the muscles and aweakness which spreads from the lower limbs to the upper ones. Another common symptomwhich may be associated with hyperkalemic periodic paralysisi is thelagging of the upper eyelid on downward gaze. This type of paralysis usuallydoes not involve the respiratory muscles, while the attacks do not last formore than 4 hours.