What Causes Periodic Paralysis?
What is Periodic Paralysis?
So much time is spent talking about spinal cord injuries and the resulting paralysis the periodic paralysis often gets overlooked. Periodic paralysis (or sometimes called temporary paralysis) is caused by a genetic mutation and is passed from parent to child. Periodic paralysis is relatively rare, and so it is often misdiagnosed and improperly treated. As the name suggests, periodic paralysis comes and goes depending on external factors in a person’s life. The nature of the condition makes it important to seek medical attention immediately as soon as signs of paralysis appear – often making it easier to diagnose and treat. Caused by a genetic mutation, it is inherited from at least one parent. However, many people carry the gene mutation without ever manifesting any symptoms – making it difficult to pinpoint the source. Types of Periodic Paralysis In the most common periodic paralysis, the ion channels of the skeletal muscle cell membranes malfunction and allow charged ions to pass through the membrane in and out of the cell. This movement of electrically charged ions causes the cells to depolarize and thus become unable to move. Some extremely rare forms of periodic paralysis are not caused by a malfunction in the muscle cell membrane. For example, paramyotonia congenital is caused by a nerve dysfunction rather than the muscle cell membrane, and Andersen-Tawil syndrome causes a disrupted potassium flow in the skeletal muscles. Periodic Paralysis Triggers While periodic paralysis is caused by a gene mutation, the symptoms are typically brought on by external factors. The most common triggers include:
- Temperature extremes
- Mental or emotional stress
- Strenuous physical activity
- High carbohydrate intake
- Extended hunger
Treating Periodic Paralysis The rarity of periodic paralysis means that it can be difficult to diagnose, but it can be properly identified with either DNA testing or a compound muscle amplitude potential test. The DNA test can be accurate but routine tests do not include the full range of 30+ possible gene mutations. The compound muscle amplitude potential test, when properly performed, results in accurate diagnosis in about 80% of cases. The specific treatment for periodic paralysis will vary depending on the type, but common treatments include:
- Lifestyle changes to limit triggers
- Carbonic anhydrase inhibitors
- Thiazide diuretics to control potassium retention
- Oral potassium chloride supplements in hypo-cases
- Avoiding potassium for hyper-cases
The effects of periodic paralysis vary depending on the severity of the case. In some people, the only result is minor muscle weakness, while in others there can be muscle damage that requires the use of assistive devices. When left untreated, periodic paralysis can lead to permanent damage – making proper diagnoses and treatment important as soon as symptoms begin to occur.