What is Rett syndrome? Rett syndrome is a childhood neurodevelopmental disorder characterized by normal early development followed by loss of purposeful use of the hands, distinctive hand movements, slowed brain and head growth, gait abnormalities, seizures, and mental retardation. It affects females almost exclusively.
The course of Rett syndrome, including the age of onset and the severity of symptoms, varies from child to child. Before the symptoms begin, however, the child appears to grow and develop normally. Then, gradually, mental and physical symptoms appear. Hypotonia (loss of muscle tone) is usually the first symptom. As the syndrome progresses, the child loses purposeful use of her hands and the ability to speak. Other early symptoms may include problems crawling or walking and diminished eye contact. The loss of functional use of the hands is followed by compulsive hand movements such as wringing and washing. The onset of this period of regression is sometimes sudden.
Another symptom, apraxia — the inability to perform motor functions — is perhaps the most severely disabling feature of Rett syndrome, interfering with every body movement, including eye gaze and speech.
Individuals with Rett syndrome often exhibit autistic-like behaviors in the early stages. Other symptoms may include toe walking; sleep problems; wide-based gait; teeth grinding and difficulty chewing; slowed growth; seizures; cognitive disabilities; and breathing difficulties while awake such as hyperventilation, apnea (breath holding), and air swallowing.
What are the stages of the disorder?
There are four stages of Rett syndrome. Stage I, called early onset, generally begins between 6 and 18 months of age. Quite frequently, this stage is overlooked because symptoms of the disorder may be somewhat vague, and parents and doctors may not notice the subtle slowing of development at first. The infant may begin to show less eye contact and have reduced interest in toys. There may be delays in gross motor skills such as sitting or crawling. Hand-wringing and decreasing head growth may occur, but not enough to draw attention. This stage usually lasts for a few months but can persist for more than a year.
Stage II, or the rapid destructive stage, usually begins between ages 1 and 4 and may last for weeks or months. This stage may have either a rapid or a gradual onset as purposeful hand skills and spoken language are lost. The characteristic hand movements begin to emerge during this stage and often include wringing, washing, clapping, or tapping, as well as repeatedly moving the hands to the mouth. Hands are sometimes clasped behind the back or held at the sides, with random touching, grasping, and releasing. The movements persist while the child is awake but disappear during sleep. Breathing irregularities such as episodes of apnea and hyperventilation may occur, although breathing is usually normal during sleep. Some girls also display autistic-like symptoms such as loss of social interaction and communication. General irritability and sleep irregularities may be seen. Gait patterns are unsteady and initiating motor movements can be difficult. Slowing of head growth is usually noticed during this stage.
Stage III, also called the plateau or pseudo-stationary stage, usually begins between ages 2 and 10 and can last for years. Apraxia, motor problems, and seizures are prominent during this stage. However, there may be improvement in behavior, with less irritability, crying, and autistic-like features. An individual in stage III may show more interest in her surroundings, and her alertness, attention span, and communication skills may improve. Many girls remain in this stage for most of their lives.
The last stage, stage IV — called the late motor deterioration stage — can last for years or decades and is characterized by reduced mobility. Muscle weakness, rigidity (stiffness), spasticity, dystonia (increased muscle tone with abnormal posturing of extremity or trunk), and scoliosis (curvature of the spine) are other prominent features. Girls who were previously able to walk may stop walking. Generally, there is no decline in cognition, communication, or hand skills in stage IV. Repetitive hand movements may decrease, and eye gaze usually improves.
I have a kid in class this year who has Rett Syndrome. For more information on it, please go to:
http://www.ninds.nih.gov/disorders/rett/detail_rett.htm
