Usually begins between six and eighteen months, and is often overlooked, because the symptoms of RS are just beginning and are somewhat vague. Parents and physicians may not notice the subtle slowing of development at first. The infant may have progressed and gained new skills, but at a slower rate or later date than expected. She maybe have a “floppy” body and a poor suck. Her development then slows down and seems stagnate. This stage usually lasts a few months, but can last more than a year. The infant may show less eye contact and have reduced interest in toys. She is often described and a “good” baby, calm and quite. There may be delays in some gross motor milestones, such as sitting, crawling, or pulling to stand. Gradually, her lack of attention is noticed and she may have non-specific hand movements. The rate of her head growth may be slower, but may not be significant enough to cause notice.
Begins from one to four years and usually lasts from weeks to months. A general developmental decline is seen with regression and loss of acquired skills. This stage can have a rapid onset or it can be more gradual as acquired finger and hand skills and spoken language are lost. Stereotyped hand movements begin and often include hand-to-mouth movements and clapping first. Movements which follow are most often mid-line hand wringing or hand washing. These hand movements persist while the girl is awake but disappear during sleep. Hands are sometimes clasped behind the back or held at the sides in a specific post, with random touching, grasping and releasing. Breathing irregularities may be noticed, and may include episodes of breath holding and hyperventilation (over breathing) associated with vacant spells. Puffing, air expulsion, or spitting may precede these. However, breathing is normal during sleep. Some girls appear autistic-like with loss of social interaction and communication. A lack of imitative or imaginative play is seen. General irritability and sleep irregularity may be seen, and some girls awaken with inappropriate laughing or crying spells. Periods of shakiness may be obvious, especially when they are excited. Gait patterns are unsteady with uncoordinated, jerky movements. Initiating motor movements can be difficult. Tooth grinding is common. Further slowing of head growth is usually noticed from three months to four years, when the girl’s head circumference growth rate decelerates on a percentile chart when compared with other children at the same age.
Usually begins from two to ten years following the rapid destructive period, and can last for many years. Regression is now over, and she reaches a stable period. Apraxia, motor problems, scoliosis, and seizures may be more prominent. However, improvement is seen in behavior with less irritability and crying, fewer autistic features and good eye contact. She shows more interest in her surroundings, and her alertness, attention span, and communication skills improve. Many girls with RS remain in Stage 3 for most of all of their lifetime.
Usually begins after age ten and is characterized by reduced mobility. Stage 4-A is used to describe those who once walked and stopped. Stage 4-B describes those who were never able to walk. In this stage, muscle weakness, rigidity, spasticity and scoliosis are prominent features which contribute to loss of movement skills. Feet are often swollen, cold, and bluish. However, there is no further decline in cognition, communication, or hand skills. Emotional contact and eye gaze are improved. Hand movements may decrease in frequency and intensity. Puberty begins at the expected age in most girls. In general, women with RS appear younger than their actual age.