Hemiparesis

Hemiparesis is a half-sided muscle weakness, half-sided loss of strength or partial half-sided paralysis. The word half-sided is sometimes replaced by unilateral (on one side of the body).
If the half-sided paralysis is complete, it is called hemiplegia or half-sided paralysis. See our pages for information about left sided paralysis or right sided paralysis.
Hemiparesis and hemiplegia can be accompanied by increased muscle tension and increased reflexes, which is called spasticity. See our spasticity page.
If muscle weakness occurs in all four limbs (both arms and legs), it is called tetraparesis. That happens in case of some brain disorders.

 

Causes

Both hemiparesis and hemiplegia are caused by forms of congenital  and non-congenital brain damage:

• stroke (CVA)
  
• traumatic brain injury
  
• meningitis
  
• inflammation of the brain (encephalitis)
  
• multiple sclerosis
  
• brain tumors
  
• being born prematurely and having too low birth weight
  
• developmental disorder
  
• cerebral palsy
  
• hydrocephalus 
  
• other diseases of the nervous system or brain

 

People with hemiparesis may have great difficulty moving their legs and arms.
They may have difficulty walking and also may have difficulty with balance.
This can make it more difficult to perform activities of daily living (ADL), such as washing, dressing, eating, reaching for objects and going to the toilet independently.

If the facial and/or neck muscles are affected, a person may have difficulty swallowing and may choke more often (dysphagia).

It may also be difficult to pronounce words properly due to reduced muscle control (dysarthria). A coordination disorder (ataxia) also occurs with hemiparesis. This is also called drunken gait because it resembles the clumsy movements and gait of a drunk person.
Which skills are lost depends on the area of the brain that is damaged in a person. The origin does not always have to be in the large hemispheres or in the brain, but can also be located in the pons or in the capsula interna.

 

The large hemispheres of the brain

The left hemisphere controls the muscles of the right half of the body.
Injury to the left hemisphere can therefore also cause right-sided muscle failure.
The right hemisphere controls the muscles of the left half of the body and injury in the right hemisphere can therefore cause left-sided muscle failure.

 

Hemiparesis right

There is injury to the left side of the affected person's cerebrum. The left side of a person's brain controls, among other things, speaking and language processing.
Possible problems:

• difficulty speaking
  
• difficulty understanding what others say
  
• difficulty telling left and right apart

More information about other consequences of injury in the
left hemisphere on our special page.

 

Hemiparesis left

There is injury to the right side of the affected person's cerebrum. The right side of the brain regulates learning processes, certain behaviors and non-verbal communication, among other things.
Possible problems:

• talking excessively
  
• short attention span
  
• memory problems

More information about other consequences of injury in the
right hemisphere on our special page.

 

Help

• A physiotherapist can help to optimize physical functions and prevent deformities as much as possible. The best results are achieved in the first phase after the brain injury.
  
• A speech therapist can help with the difficulty that arises when speaking and swallowing.
  
• An occupational therapist can help you find the right aids, relearn skills and learn to apply strategies. They can also help provide guidelines for activities and exercises.