Diplegia refers to symmetrical paralysis, usually affecting either the arms or the legs. It's the most common cause of paralysis in children, but can affect people of any age. Unlike other forms of paralysis, diplegia is highly unpredictable, and may get better, worse, or radically change with time.

What is Diplegia?

Diplegia is a symptom, not an illness unto itself. It can affect any symmetrical area of the body, including both sides of the face, both legs, or both arms. The severity varies quite a bit, and may change between sides. For example, a person with diplegia of the legs may have total paralysis in one leg, but only limited mobility in the other leg. Unlike other forms of paralysis, diplegia tends to change over time, and doesn't necessarily mean the full loss of function. Instead, people with diplegia have significant nervous system anomalies, but may maintain some functioning and sensation.

What Causes Diplegia?

It's impossible to diagnose the cause of diplegia based solely on symptoms, but knowing the location of the diplegia, as well as when it began, can help your physician rule in or out the most common causes. Some common causes of diplegia include:

  • Vascular disorders that limit blood flow to the area. Diplegia of the face is common during and after a stroke.
  • Infectious and toxic agents that damage nerves or muscles in the affected area. This can cause facial diplegia, and less commonly, may affect other areas of the body. Diplegia caused by infectious and toxic agents may be reversible if promptly treated.
  • Spinal cord and brain injuries. These injuries don't affect the paralyzed area. Instead, they impede the ability of the brain and spinal cord to send and receive signals to the affected area. Diplegia caused by brain and spinal cord injuries is usually permanent.
  • Cerebral palsy. Among children, this is the most common cause of diplegia, as well as the most common cause of other forms of paralysis. A related condition, spastic diplegia, may pair limited mobility with uncontrolled, unpredictable movements.

What Are the Symptoms of Diplegia?

The most obvious symptom of diplegia is absent or reduced mobility in symmetrical areas of the body. Other symptoms can include:

  • Changes in neurological functioning.
  • Uncontrolled muscle movements—known as spasticity.
  • Difficulty controlling the bladder or bowels.
  • Phantom pain.
  • Chronic pain.
  • Inability to feel the affected area.
  • Asymmetrical movements; for example, a person with facial diplegia may have a severely crooked smile, or only be able to raise one eyebrow.

Note that diplegia ranges from mild to severe, and symptoms can dramatically change with time.

How is Diplegia Treated?

Treatment for diplegia depends upon its cause, so a clear diagnosis is necessary. Your doctor may order blood work, imaging scans, genetic testing, and a range of other tests to evaluate the cause of diplegia, particularly if symptoms came on suddenly and did not follow an injury. Depending upon the cause of diplegia, treatment may include:

  • Antibiotics to treat an infection.
  • Surgery to address vascular issues.
  • Surgery on your brain or spinal cord.
  • Occupational and physical therapy to help your nervous system master working around the injury.

What is the Prognosis for Diplegia?

Diplegia is one of the most unpredictable forms of paralysis, so even severe cases may improve with time. Outcomes are ultimately dependent upon the cause of the diplegia, as well as the quality of care. Prompt medical intervention coupled with rehabilitative care offers the best hope for a full recovery, even in the most severe cases. In children with diplegia, symptoms often change dramatically in adolescence. Other factors, including overall health and other injuries, can also affect the course of diplegia.

Your doctor is the best source of information about how your diplegia might progress, but because diplegia is so variable, even the best doctors cannot fully predict outcomes.