A female infant stops meeting developmental milestones at age 12 months and then loses previously acquired skills. What prognosis should the clinician tell the parents?

A female infant stops meeting developmental milestones at age 12 months and then loses previously acquired skills. What prognosis should the clinician tell the parents?

• A. This is a temporary condition with full recovery expected.
• B. Physical and speech therapy will help to preserve functional abilities but do not improve skills.
• C. Intellectual development will not progress further.
• D. Cognitive development will be normal but motor skills will be lost.

Answer: (C)

When a girl who seemed to be developing normally up to about a year then loses previously acquired skills, think Rett syndrome, a neurodevelopmental disorder that affects cognitive and motor skills. In Rett syndrome, there is a period of apparently normal development followed by regression with loss of language and purposeful hand skills, the emergence of repetitive hand movements, deceleration of head growth, gait dysfunction, and often seizures. Importantly, the cognitive trajectory in Rett is not expected to resume progress after regression; once these skills are lost, intellectual development does not advance to prior levels. That is why the most accurate prognosis to convey is that intellectual development will not progress further. While therapies like physical and speech therapy can help maximize function and quality of life, they do not reverse the underlying cognitive decline.

When a girl who seemed to be developing normally up to about a year then loses previously acquired skills, think Rett syndrome, a neurodevelopmental disorder that affects cognitive and motor skills. In Rett syndrome, there is a period of apparently normal development followed by regression with loss of language and purposeful hand skills, the emergence of repetitive hand movements, deceleration of head growth, gait dysfunction, and often seizures. Importantly, the cognitive trajectory in Rett is not expected to resume progress after regression; once these skills are lost, intellectual development does not advance to prior levels. That is why the most accurate prognosis to convey is that intellectual development will not progress further. While therapies like physical and speech therapy can help maximize function and quality of life, they do not reverse the underlying cognitive decline.