Chart Comparing Periodic Paralyses

This chart allows comparison of the forms of primary periodic paralysis, symptoms, clinical and cardiac signs, effect of potassium, triggers and therapies. 


Form Effect of K+ Age at onset Triggers Relieves Attack Length Myotonia? Hypertrophy Weakness between attacks EKG during attacks Therapies
Thyrotoxic HypoKalemic Periodic Paralysis  Relieves weakness At any age, 85% males; usually in 20–40 year–old Asians, Native Americans Hyperthyroidism (may be sub–clinical) ^ carbohydrate meal and exertion. K+, Treat thyroid condition Hours to days No No Yes During attacks ST depression, T wave flattens, U wave appears, sinus tachycardia Methimazole, Propranolol, K+, until anti–thyroid treatment, radio-iodine 131 or surgery

Hypokalemic Periodic Paralysis

Relieves weakness 1-25 years simple carbs, rest after exertion, sleep, strong emotion K+, mild exercise 1-72 hours only in eyelids Yes Yes, after age 35 ST depression, T flattens, U rises Diamox, K+, K+ sparing diuretics
Andersen-Tawil Syndrome Provokes weakness while relieving arrhythmia and/or weakness in some patients. At any age Varies from patient to patient, exercise, sleep, high K+ in some, low K+ in others. Varies from patient to patient. Varies No No Yes LQTc, ectopy, bigeminy, tachycardia, (in or out of attack) Varies, usually beta blockers + treatment for weakness
Hyperkalemic Periodic Paralysis Provokes weakness First decade Hunger, K+ in foods, rest after exercise, immobility Sugar, mild exercise 5 min – 12 hours In grip and exercised muscles Yes Yes T tall “tented”, R falls, QRS/PR increases, P gone K+ wasting diuretics, Diamox, Albuterol
Paramyotonia Congenita  (Pure form) Provokes weakness First two years Exercise, K+ Sugar, rest Minutes – days Face, eyes, jaw, hands. Worsens with cold and activity Yes May show signs of Hyperkalemia K+ wasting diuretics, Paxil, Mexiletine
Paramyotonia Congenita von Eulenburg Relieves weakness First two years Exercise, LOW K+ K+ rest Minutes – weeks May be absent at room temp. Yes Yes May show signs of hypokalemia Mexiletine, Paxil, K+
Acetazolamide– responsive Paramyotonia Congenita Provokes pain and stiffness, No weakness ? K+, activity Diamox ? Worse with Activity Yes ? ? Diamox
Myotonia Fluctuans Provokes stiffness, NO weakness   K+ ?   Mild, Varies     ? Diamox, K+ wasting diuretics
Myotonia Permanens Provokes severe myotonia ? K+ ? Constant Severe, continuous Marked ? ? Diamox, K+ wasting diuretics