Symptoms and causes

Symptoms

Symptoms of functional neurologic disorders may vary, depending on the type of functional neurologic disorder, and they're significant enough to cause impairment and warrant medical evaluation. Symptoms can affect body movement and function and the senses.

Signs and symptoms that affect body movement and function may include:

  • Weakness or paralysis
  • Abnormal movement, such as tremors or difficulty walking
  • Loss of balance
  • Difficulty swallowing or feeling "a lump in the throat"
  • Seizures or episodes of shaking and apparent loss of consciousness (nonepileptic seizures)
  • Episodes of unresponsiveness

Signs and symptoms that affect the senses may include:

  • Numbness or loss of the touch sensation
  • Speech problems, such as inability to speak or slurred speech
  • Vision problems, such as double vision or blindness
  • Hearing problems or deafness

When to see a doctor

Seek medical attention for signs and symptoms listed above. If the underlying cause is a neurological disease or another medical condition, quick diagnosis and treatment may be important. If the diagnosis is a functional neurologic disorder, treatment may improve the symptoms and help prevent future problems.

Causes

The exact cause of functional neurologic disorders is unknown. Theories regarding what happens in the brain to result in symptoms are complex and involve multiple mechanisms that may differ, depending on the type of functional neurologic disorder.

Basically, parts of the brain that control the functioning of your muscles and senses may be involved, even though no disease or abnormality exists.

Symptoms of functional neurologic disorders may appear suddenly after a stressful event, or with emotional or physical trauma. Other triggers may include changes or disruptions in how the brain functions at the structural, cellular or metabolic level. But the trigger for symptoms can't always be identified.

Risk factors

Factors that may increase your risk of functional neurologic disorders include:

  • Having a neurological disease or disorder, such as epilepsy, migraines or a movement disorder
  • Recent significant stress or emotional or physical trauma
  • Having a mental health condition, such as a mood or anxiety disorder, dissociative disorder or certain personality disorders
  • Having a family member with a functional neurologic disorder
  • Possibly, having a history of physical or sexual abuse or neglect in childhood

Women may be more likely than men to develop functional neurologic disorders.

Complications

Some symptoms of functional neurologic disorders, particularly if not treated, can result in substantial disability and poor quality of life, similar to that caused by medical conditions or disease.