Hypokalemic periodic paralysis: Difference between revisions
No edit summary |
Neil.m.young (talk | contribs) (Reformat with additions - BMP and other causes) |
||
| Line 1: | Line 1: | ||
==Background== | ==Background== | ||
*Autosomal dominant channelopathy<ref>June-Bum Kim, MD, PhD. Channelopathies. Korean J Pediatr. 2014 Jan;57(1):1-18 [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3935107/ Full Text]</ref> | *Autosomal dominant channelopathy<ref>June-Bum Kim, MD, PhD. Channelopathies. Korean J Pediatr. 2014 Jan;57(1):1-18 [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3935107/ Full Text]</ref> | ||
* | *Acquired hypokalemia from barium poisoning, hyperthyroidism, renal disorders, and GI losses<ref>Ahlawat SK and Sachdev A. Hypokalemic paralysis. Postgrad Med J. 1999; 75(882):193-197.</ref> | ||
*Most first attacks happen by age 16 | *Most first attacks happen by age 16 | ||
*There is no decrease in total body potassium. Blood potassium level is normal between attacks.<ref>Mount DB, Zandi-Nejad K. Disorders of potassium balance. In Taal MW, Chertow GM, Marsden PA, et al., eds. Brenner and Rector’s The Kidney. 9th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 17.</ref> | *There is no decrease in total body potassium. Blood potassium level is normal between attacks.<ref>Mount DB, Zandi-Nejad K. Disorders of potassium balance. In Taal MW, Chertow GM, Marsden PA, et al., eds. Brenner and Rector’s The Kidney. 9th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 17.</ref> | ||
== | ==Clinical Features== | ||
* | ===Symptoms=== | ||
* | *Muscle weakness or paralysis with associated hypokalemia (though potassium levels can be normal) | ||
* | *Sometimes painful though often painless | ||
* | *Weakness can be from hand to leg to complete paralysis | ||
* | ===History=== | ||
* | *Strenuous exercise | ||
* | *High carbohydrate meal | ||
* | *High sodium meals | ||
* | *Sudden changes in temperature | ||
*Emotional stress | |||
==Physical Exam== | *Attacks can last several hours to several days | ||
===Physical Exam=== | |||
*Reflexes are decreased or absent<ref name="Chinnery">Chinnery PF. Muscle diseases. In: Goldman L, Schafer AI, eds. Goldman’s Cecil Medicine. 24th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 429.</ref> | *Reflexes are decreased or absent<ref name="Chinnery">Chinnery PF. Muscle diseases. In: Goldman L, Schafer AI, eds. Goldman’s Cecil Medicine. 24th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 429.</ref> | ||
*Shoulders and hips, are involved more often than the arms and legs.<ref name="Chinnery"></ref> | *Shoulders and hips, are involved more often than the arms and legs.<ref name="Chinnery"></ref> | ||
| Line 24: | Line 23: | ||
*There should not be myoclonus or spasticity | *There should not be myoclonus or spasticity | ||
== | ==Differential Diagnosis== | ||
{{Weakness DDX}} | |||
==Diagnosis== | |||
*BMP | |||
===EKG Findings=== | |||
*Sinus bradycardia | *Sinus bradycardia | ||
*Electrocardiographic (ECG) signs of hypokalemia may be present but not always diagnostic<ref>Hypokalemic Periodic Paralysis. Periodic Paralysis International. http://hkpp.org/physicians/hypokalemic_pp</ref> | *Electrocardiographic (ECG) signs of hypokalemia may be present but not always diagnostic<ref>Hypokalemic Periodic Paralysis. Periodic Paralysis International. http://hkpp.org/physicians/hypokalemic_pp</ref> | ||
| Line 31: | Line 35: | ||
**Prolongation of the PR and QT intervals | **Prolongation of the PR and QT intervals | ||
== | ==Management== | ||
*Replace potassium appropriately - do not try to correct to normal level as once the muscles release potassium you will likely overcorrect | *Replace potassium appropriately - do not try to correct to normal level as once the muscles release potassium you will likely overcorrect | ||
*Long Term Treatment: | *Long Term Treatment: | ||
| Line 38: | Line 42: | ||
==Disposition== | ==Disposition== | ||
*Can be discharged from ED after potassium repletion and resolution of symptoms | *Can be discharged from ED after potassium repletion and resolution of symptoms | ||
*Consider admission if patient remains symptomatic | |||
==See Also== | ==See Also== | ||
*[[Hypokalemia]] | *[[Hypokalemia]] | ||
== | ==References== | ||
<references/> | <references/> | ||
[[Category:Neuro]] | [[Category:Neuro]] | ||
[[Category:FEN]] | [[Category:FEN]] | ||
Revision as of 13:57, 22 June 2015
Background
- Autosomal dominant channelopathy[1]
- Acquired hypokalemia from barium poisoning, hyperthyroidism, renal disorders, and GI losses[2]
- Most first attacks happen by age 16
- There is no decrease in total body potassium. Blood potassium level is normal between attacks.[3]
Clinical Features
Symptoms
- Muscle weakness or paralysis with associated hypokalemia (though potassium levels can be normal)
- Sometimes painful though often painless
- Weakness can be from hand to leg to complete paralysis
History
- Strenuous exercise
- High carbohydrate meal
- High sodium meals
- Sudden changes in temperature
- Emotional stress
- Attacks can last several hours to several days
Physical Exam
- Reflexes are decreased or absent[4]
- Shoulders and hips, are involved more often than the arms and legs.[4]
- There is flaccid paralysis rather than hypertonia
- There should not be myoclonus or spasticity
Differential Diagnosis
Weakness
- Neuromuscular weakness
- Upper motor neuron:
- CVA
- Hemorrhagic stroke
- Multiple sclerosis
- Amyotrophic Lateral Sclerosis (ALS) (upper and lower motor neuron)
- Lower motor neuron:
- Spinal and bulbar muscular atrophy (Kennedy's syndrome)
- Spinal cord disease:
- Infection (Epidural abscess)
- Infarction/ischemia
- Trauma (Spinal Cord Syndromes)
- Inflammation (Transverse Myelitis)
- Degenerative (Spinal muscular atrophy)
- Tumor
- Peripheral nerve disease:
- Neuromuscular junction disease:
- Muscle disease:
- Rhabdomyolysis
- Dermatomyositis
- Polymyositis
- Alcoholic myopathy
- Upper motor neuron:
- Non-neuromuscular weakness
- Can't miss diagnoses:
- ACS
- Arrhythmia/Syncope
- Severe infection/Sepsis
- Hypoglycemia
- Periodic paralysis (electrolyte disturbance, K, Mg, Ca)
- Respiratory failure
- Emergent Diagnoses:
- Symptomatic Anemia
- Severe dehydration
- Hypothyroidism
- Polypharmacy
- Malignancy
- Aortic disease - occlusion, stenosis, dissection
- Other causes of weakness and paralysis
- Acute intermittent porphyria (ascending weakness)
- Can't miss diagnoses:
Diagnosis
- BMP
EKG Findings
- Sinus bradycardia
- Electrocardiographic (ECG) signs of hypokalemia may be present but not always diagnostic[5]
- U waves in leads II, V-2, V-3, and V-4
- Progressive flattening of T waves and depression of ST segment
- Prolongation of the PR and QT intervals
Management
- Replace potassium appropriately - do not try to correct to normal level as once the muscles release potassium you will likely overcorrect
- Long Term Treatment:
- Should be initiated by primary physician but often includes eating a low carbohydrate diet and avoiding alcohol
- Medications to increase potassium: Acetazolamide, Spironolactone, Potassium tablets,
Disposition
- Can be discharged from ED after potassium repletion and resolution of symptoms
- Consider admission if patient remains symptomatic
See Also
References
- ↑ June-Bum Kim, MD, PhD. Channelopathies. Korean J Pediatr. 2014 Jan;57(1):1-18 Full Text
- ↑ Ahlawat SK and Sachdev A. Hypokalemic paralysis. Postgrad Med J. 1999; 75(882):193-197.
- ↑ Mount DB, Zandi-Nejad K. Disorders of potassium balance. In Taal MW, Chertow GM, Marsden PA, et al., eds. Brenner and Rector’s The Kidney. 9th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 17.
- ↑ 4.0 4.1 Chinnery PF. Muscle diseases. In: Goldman L, Schafer AI, eds. Goldman’s Cecil Medicine. 24th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 429.
- ↑ Hypokalemic Periodic Paralysis. Periodic Paralysis International. http://hkpp.org/physicians/hypokalemic_pp