Pediatric Movement Disorders - Chorea and Choreoathetosis

Examination

Mild chorea may be difficult to distinguish from normal restlessness. Therefore, it is important to assess whether the movements are controllable by the child and whether these movements are sustained or occur only in the doctor's office. It is important to note which parts of the body are involved. The speed and size of the movements determine whether this is most appropriately called chorea or ballism. For practical purposes, the distinction is often difficult to make; fortunately, this distinction is not usually helpful in diagnosis and treatment.

The effect of purposeful movements, such as reaching, speaking, or walking, must be assessed. Dystonia may cause excessive and apparently random movements. These movements are usually worsened with intentional, attempted movements and improve when the child is at rest. Ataxia may lead to an abnormal gait, with extra movements needed to compensate; however, the movements disappear when the child is steadied or seated.

The timing of the chorea is important. There are paroxysmal types that only occur with sudden movement, exercise, or when the child is under stress. The age of onset is also important. In particular, mild chorea may be normal during the first few years of life, so long as it is not worsening over time. It is important to determine whether there are particular foods that trigger the symptoms, or whether there are clues to a metabolic disorder. These clues include intolerance of certain foods or episodes of unexplained vomiting and lethargy.

Genetics of Chorea
There are several genetic causes of chorea. The history of other affected family members is critically important to determining the need for special testing. Since chorea may be caused by exposure to medications or toxins, it is also important to determine whether any such exposure is possible. One of the more common causes of chorea is Sydenham's chorea, which often follows a streptococcal infection. For this reason, a history of sore throat or flu symptoms that preceded the onset of chorea is important. This history is not necessarily diagnostic, since sore throats, flu symptoms, and even positive throat swabs or blood tests for streptococcal infection are common in children.