Four stages of Rett Syndrome have been suggested by scientists to describe how Rett syndrome presents itself over time.
Stage 1 is referred to as the ‘Early Onset ‘ stage. With a duration of months, the age group to whom it refers is from 6 to 18 months. This stage is usually overlooked as the symptoms of Rett syndrome (RTT) are just emerging and are somewhat vague. The affected infant may show less contact and a reduced interest in toys, and is often described as a “good” baby, being quite calm and placid. There may also be delays in reaching major movement milestones such as crawling or standing.
Stage 2 is called the ‘Rapid Destructive’ stage and can last from weeks to months. Children going through this stage can be as young as 1 year and as old as 4. Loss of purposeful hand use is usually apparent, and if talking, speech may cease. Repetitive hand movements begin to emerge and often include hand to mouth movements such as mid-line hand wringing or hand washing, and persist while the child is awake. Some children appear autistic-like because of their lack of social interaction and communication. Periods of shakiness may be obvious, especially when excited.
Stage 3 is termed the ‘Plateau’ stage. It begins in the pre-school or school years and, for some, most of their lifetime can be spent in this stage.
Apraxia (the brain experiences difficulty putting in place the usually automatic planning needed to perform voluntary movements) , movement problems and seizures, are more prominent. Improvement is seen in behavior with less irritability and crying, and less autistic features. The child shows more interest in surroundings, is more alert, attention span is better, and communication skills improve. Its almost as if the child has worked out how to partially get around the limitations that her body has placed upon her. In this stage, some lost skills might be regained, some may be acquired.
The ‘Late Motor Deterioration’ stage or Stage 4 of the syndrome begins when stage 3 ceases, be it at 5, 15, 25 years or older, and can be present for decades. Although eye gaze usually improves, mobility has reached the point where the individual is unable to walk. There is no further decline in cognition, communication or hand skills. Curvature of the spine is a common feature as is stiffness and dystonia (involuntary muscle spasms leading to body twisting, repetitive movement or abnormal posture). Repetitive hand movements and/or seizures may no longer be as frequent as in the past.