Makindo Medical Notes

Related Subjects:Hyperkalaemia |ECG - Hyperkalaemia |Hypokalemia |Hyperkalaemic and Hypokalaemic Periodic Paralysis |Resuscitation - Advanced Life Support

This autosomal dominant disorder is caused by a mutation in the gene coding for a voltage-gated calcium channel. Patients typically experience generalised weakness after consuming a high-carbohydrate meal. Family history may include similar episodes in parents or siblings. A provocation test with oral glucose can help diagnose, and potassium supplementation is often used to alleviate attacks.

About

• Hypokalaemic Periodic Paralysis is the most common type of periodic paralysis syndrome.
• Inherited in an autosomal dominant manner, it is linked to a mutation affecting voltage-gated calcium channels.

Aetiology

• There is an association with thyrotoxicosis.
• More prevalent among individuals from Southeast Asia.

Precipitating and Relieving Factors

• Precipitating Factors:
  • Potassium-lowering diuretics (e.g., thiazides) can provoke weakness.
  • High-carbohydrate or high-sodium meals may trigger attacks.
  • IV glucose or IV saline can worsen the weakness.
• Relieving Factor: Potassium supplementation helps alleviate the weakness during an attack.

Clinical Features

• Episodes of generalised weakness following a large or carbohydrate-rich meal.
• Weakness can begin in the teenage years and often improves with age.
• Can involve bulbar muscles, potentially affecting swallowing.
• Weakness typically lasts several hours.
• Often occurs in the early morning or after rest following physical exertion.
• Family history may include similar episodes in parents or siblings.

Investigations

• Serum Potassium: Typically < 3.0 mmol/L during an attack.
• Genetic Testing: To confirm the specific gene mutation associated with the condition.

Management

• Diet: Low-carbohydrate and low-sodium diet to reduce risk of attacks.
• Exercise Precautions: Patients should be aware of the potential risks of intense exercise.
• Medications:
  • Acetazolamide can help reduce the frequency of attacks.
  • Potassium-sparing diuretics, such as triamterene and spironolactone, have been used in some cases.