Types of Channelopathy

Types of muscle channelopathy

There are 2 main groups of inherited muscle channelopathy, those associated with:

1. Stiffness → "Non-dystrophic myotonias"
   
   
2. Episodic weakness → "Periodic paralysis"

Non-dystrophic myotonia

• Patients with non-dystrophic myotonia have mainly stiffness of the muscles which is caused by myotonia.
• Myotonia happens when the muscle does not relax properly and this causes stiffness, cramping and sometimes pain. Some patients also experience weakness
  
  
• There are 2 main types of non-dystrophic myotonia depending on which gene is has a mistake in it:
  
  
  • Myotonia congenita
  • Paramyotonia congenita
    
    

To find out more about these conditions please click on the links above.

Periodic Paralysis

• Patients with familial periodic paralysis mainly have episodes of weakness.
• This can be weakness of the whole body from the neck down or of just a single arm of leg.
• Patients may also experience stiffness, fatigue or pain.
  
  
• Depending on the type of periodic paralysis that a patient has, attacks may be triggered by high or low potassium.
  
  
• There are 3 main types of familial periodic paralysis:
  
  
  • Hypokalaemic periodic paralysis
    
  • Hyperkalaemic periodic paralysis
    
  • Andersen-Tawil syndrome

To find out more about these conditions please click on the links above.