II. Epidemiology
- Prevalence: 1 in 100,000 (rare)
- Typical onset of symptoms before age 20 years
- More common in males
III. Causes
-
Genetic
- Autosomal Dominant disorder of Hypokalemia
- Most often related to a Sodium channel disorder, with a shifting of Potassium into tissues
- Acquired
IV. Risk Factors: Triggers
- Alcohol Abuse
- Corticosteroid use
- Insulin
- Renal disease
- Large Carbohydrate containing meals
- High salt intake
- Intense Exercise
- Glue sniffing
- Prolonged immobility
- Cold Weather
- Anesthetics
V. Symptoms
- Headaches
- Thirst
- Lethargy
- Generalized Muscle Weakness
- No associated pain
VI. Signs
- Slow progressive weakness (especially following triggers)
- Weakness lasts for hours to days
- Episodic muscular paralysis (lower extremities > upper extremities)
- Shoulder
- Pelvic girdle
- Other areas follow
- Muscle Strength normal between attacks
-
Deep Tendon Reflexes
- Diminished or absent
VII. Associated Conditions
-
Thyrotoxicosis
- Especially in young asian males, with onset after Exercise
VIII. Labs
- Consider extending evaluation to cover differential diagnosis as below
- Serum Electrolytes including Renal Function and Magnesium
- Serum Potassium with Hypokalemia during episode (normal between episodes)
- Hypomagnesemia may be associated with other causes of Hypokalemia
-
Thyroid Stimulating Hormone (TSH)
- Evaluate for Thyrotoxicosis
-
Genetic Testing
- Genetic outpatient testing if findings consistent with familial Hypokalemia
IX. Diagnostics
-
Electrocardiogram
- See Hypokalemia for related EKG changes
X. Differential Diagnosis
- See Hypokalemia Causes
- See Acute Motor Weakness Causes
XI. Management
- Replace Potassium IV in severe cases (oral Potassium in mild cases)
- See Potassium Replacement
- Exercise caution with replacement
- Replace Magnesium if low
- Avoid high Carbohydrate intake
- Avoid Excessive Salt Intake
XII. Complications
XIII. Prevention
- Carbonic anhydrase inhibitors (e.g. Acetazolamide)
- Potassium sparing Diuretics (e.g. Spironolactone)
XIV. References
- Candy and Herbert in Herbert (2020) EM:Rap 20(11): 8-9
- Claudius and Behar in Herbert (2019) EM:Rap 19(11):12-3
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Related Studies
| Definition (NCI) | A group of genetic neurological disorders caused by mutations in genes involved in the sodium and calcium channels in nerve cells. It is characterized by episodes of muscle paralysis in which the affected muscles become flaccid and the deep tendon reflexes disappear. Between the episodes the affected muscles usually work normally. |
| Definition (MSH) | A heterogenous group of inherited disorders characterized by recurring attacks of rapidly progressive flaccid paralysis or myotonia. These conditions have in common a mutation of the gene encoding the alpha subunit of the sodium channel in skeletal muscle. They are frequently associated with fluctuations in serum potassium levels. Periodic paralysis may also occur as a non-familial process secondary to THYROTOXICOSIS and other conditions. (From Adams et al., Principles of Neurology, 6th ed, p1481) |
| Definition (CSP) | heterogenous group of inherited disorders characterized by recurring attacks of rapidly progressive flaccid paralysis or myotonia; these conditions have in common a mutation of the gene encoding the alpha subunit of the sodium channel in skeletal muscle; frequently associated with fluctuations in serum potassium levels; periodic paralysis may also occur as a non-familial process secondary to thyrotoxicosis and other conditions. |
| Concepts | Disease or Syndrome (T047) |
| MSH | D010245 |
| ICD10 | G72.3 |
| SnomedCT | 54696002, 193241004, 155099000, 267714003, 267607008 |
| English | Familial Periodic Paralyses, Paralyses, Familial Periodic, Paralysis, Familial Periodic, Periodic Paralyses, Familial, Periodic Paralysis, Familial, familial periodic paralysis, familial periodic paralysis syndrome (diagnosis), familial periodic paralysis syndrome, Paralysis periodic, Paralyses, Familial Periodic [Disease/Finding], periodic familial paralysis, periodic paralysis familial, periodic paralysis, familial paralysis periodic, paralysis periodic, Familial periodic paralysis, Cavarre disease, Familial myoplegia, Familial recurrent paralysis, Myoplegic dystrophy, Periodic myotonia, Familial periodic paralysis (disorder), paralysis; periodic, periodic; paralysis, Familial periodic paralysis, NOS, Periodic paralysis, Familial periodic paralysis (disorder) [Ambiguous], Familial Periodic Paralysis |
| Dutch | paralyse periodiek, paralyse; periodiek, periodiek; paralyse, familiale periodieke paralyse, Familiale periodieke paralyse, Paralyse, familiale periodieke, Periodieke paralyse, familiale |
| French | Paralysie périodique, Paralysie périodique familiale, Paralysies périodiques familiales |
| German | Laehmung zeitweise, familiaere periodische Laehmung, Familiäre periodische Lähmungen, Lähmungen, familiäre periodische, Periodische Lähmungen, familiäre |
| Italian | Paralisi periodica, Paralisi periodica familiare |
| Portuguese | Paralisia periódica, Paralisia Periódica Normokalêmica, Paralisia periódica familiar, Paralisia Periódica Familiar, Paralisias Periódicas Familiares |
| Spanish | Parálisis periódica, parálisis familiar periódica (trastorno), parálisis familiar periódica, parálisis periódica familiar, parálisis periódica familiar (trastorno), mioplejía familiar, parálisis recurrente familiar, parálisis periódica I, Parálisis Periódica Normokalémica, enfermedad de Cavarre, mioplejía periódica, miotonía periódica, parálisis familiar recurrente, parálisis periódica familiar (concepto no activo), Parálisis periódica familiar, Parálisis Familiar Periódica, Parálisis Periódicas Familiares |
| Japanese | 周期性四肢麻痺, ｼｭｳｷｾｲｼｼﾏﾋ, ｶｿﾞｸｾｲｼｭｳｷｾｲﾏﾋ, 周期性麻痺-家族性, 周期性四肢麻痺-正常カリウム血性, 正常カリウム血性周期性麻痺, 家族性周期性麻痺, 四肢麻痺-正常カリウム血性周期性, 周期性四肢麻痺-家族性, 周期性麻痺-正常カリウム血性, 正常カリウム血性周期性四肢麻痺, 麻痺-家族性周期性, 麻痺-正常カリウム血性周期性, 四肢麻痺-家族性周期性, 家族性周期性四肢麻痺 |
| Swedish | Paralyser, familjära periodiska |
| Czech | paralýzy familiární periodické, Periodická obrna, Familiární periodická obrna |
| Finnish | Familiaaliset periodiset paralyysit |
| Russian | PARALICHI SEMEINYE PERIODICHESKIE, ПАРАЛИЧИ СЕМЕЙНЫЕ ПЕРИОДИЧЕСКИЕ |
| Polish | Porażenie okresowe rodzinne, Porażenie okresowe normokaliemiczne |
| Hungarian | Periódikus paralysis, Familiaris periódikus paralysis |
| Norwegian | Paralyse, familiær periodisk, Periodisk paralyse, familiær, Familiær periodisk paralyse |
Ontology: Hypokalemic periodic paralysis (C0238358)
| Definition (NCI) | An autosomal dominant inherited or genetic disorder characterized by irregular episodes of muscle weakness or paralysis which are always accompanied by low levels of potassium in the blood. |
| Definition (MSH) | An autosomal dominant familial disorder characterized by recurrent episodes of skeletal muscle weakness associated with falls in serum potassium levels. The condition usually presents in the first or second decade of life with attacks of trunk and leg paresis during sleep or shortly after awakening. Symptoms may persist for hours to days and generally are precipitated by exercise or a meal high in carbohydrates. (Adams et al., Principles of Neurology, 6th ed, p1483) |
| Concepts | Disease or Syndrome (T047) |
| MSH | D020514 |
| ICD10 | G72.3 |
| SnomedCT | 193241004, 240093008, 82732003, 54696002 |
| English | Famil.hypokalaem.period.paral., Hypokalaem periodic paralysis, FAMILIAL PERIODIC PARALYSIS <HYPOKALEMIC FORM>, periodic hypokalemic paralysis, FAMILIAL PERIODIC PARALYSIS HYPOKALEMIC FORM, Familial Hypokalemic Periodic Paralysis, Hypokalemic Periodic Paralysis, Familial, Hypokalemic Periodic Paralysis, Paralysis, Hypokalemic Periodic, Periodic Paralysis, Hypokalemic, Primary Hypokalemic Periodic Paralysis, Hypokalemic periodic paralysis (familial), Hypokalemic Periodic Paralysis [Disease/Finding], Periodic Paralysis- Hypokalemics, Periodic Paralysis Hypokalemic, Periodic Paralysis- Hypokalemic, hypokalaemic paralysis periodic, hypokalemic periodic paralysis, hypokalaemic periodic paralysis, hypokalemic paralysis periodic, periodic hypokalaemic paralysis, Westphall Disease, HYPOPP, HYPOKPP, HOKPP, Familial periodic paralysis (& [hypokalemic]), Familial periodic paralysis (& [hypokalaemic]) (disorder), Familial periodic paralysis (& [hypokalaemic]), Hypokalemic periodic paralysis (diagnosis), hypokalemic periodic paralysis syndrome, Hypokalemic periodic paralysis (disorder), Familial hypokalemic periodic paralysis, Periodic paralysis I, Familial hypokalaemic periodic paralysis, Hypokalaemic periodic paralysis, Familial hypokalemic periodic paralysis (disorder), Hypokalemic periodic paralysis, Hypokalemic familial periodic paralysis |
| Swedish | Hypokalemisk periodisk paralys |
| Czech | primární hypokalemická periodická paralýza, familiární hypokalemická periodická paralýza, hypokalemická periodická paralýza |
| Finnish | Hypokaleeminen periodinen halvaus |
| Russian | PARALICH GIPOKALIEMICHESKII PERIODICHESKII SEMEINYI, PARALICH GIPOKALIEMICHESKII PERIODICHESKII, ПАРАЛИЧ ГИПОКАЛИЕМИЧЕСКИЙ ПЕРИОДИЧЕСКИЙ, ПАРАЛИЧ ГИПОКАЛИЕМИЧЕСКИЙ ПЕРИОДИЧЕСКИЙ СЕМЕЙНЫЙ |
| Italian | Paralisi periodica ipocaliemica familiare, Paralisi periodica ipocaliemica primaria, Paralisi periodica ipocaliemica |
| Polish | Porażenie rodzinne hipokaliemiczne okresowe, Porażenie hipokaliemiczne okresowe |
| Japanese | 家族性低カリウム性周期性麻痺, 四肢麻痺-低カリウム性周期性, 低カリウム性周期性麻痺, 低カリウム血性周期性四肢麻痺, 低カリウム性周期性四肢麻痺, 原発性低カリウム性周期性麻痺, 四肢麻痺-低カリウム血性周期性, 四肢麻痺-周期性-低カリウム血性, 麻痺-低カリウム性周期性, 麻痺-原発性低カリウム性周期性, 麻痺-周期性-低カリウム性-原発性, 麻痺-周期性-低カリウム性-家族性, 麻痺-周期性-原発性低カリウム性, 麻痺-周期性-家族性低カリウム性, 麻痺-家族性低カリウム性周期性 |
| Norwegian | Hypokalemisk periodisk paralyse |
| Spanish | Parálisis Periódica Hipokalémica Primaria, Parálisis Periódica Hipokalémica Familiar, parálisis periódica hipocaliémica (trastorno), parálisis periódica hipocaliémica familiar (trastorno), parálisis periódica hipocaliémica familiar, parálisis periódica hipocaliémica, Parálisis Periódica Hipokalémica, Parálisis Periódica Hipopotasémica Familiar, Parálisis Periódica Hipopotasémica Primaria, Parálisis Periódica Hipopotasémica |
| Portuguese | Paralisia Periódica Hipokalêmica Familiar, Paralisia Periódica Hipokalêmica Primária, Paralisia Periódica Hipokalêmica, Paralisia Periódica Hipopotassêmica Familiar, Paralisia Periódica Hipopotassêmica, Paralisia Periódica Hipopotassêmica Primária |
| French | Paralysie périodique hypokaliémique, Maladie de Westphal, Paralysie périodique hypokaliémique de Westphal, Paralysie périodique primitive hypokaliémique de Westphal, Maladie de Westphall |
| German | Familiäre hypokaliämische Lähmung, Hypokaliämisch-periodische Lähmung, Lähmung, hypokaliämisch-periodische, Primäre hypokaliämische periodische Lähmung |
| Dutch | Familaire hypokaliëmische periodieke paralyse, Hypokaliëmische periodieke paralyse, Paralyse, hypokaliëmische periodieke, Periodieke paralyse, hypokaliëmische, Primaire hypokaliëmische periodieke paralyse |
