Motility of the central nervous system is characterized by which phenomenon?

• A. Inherent coiling and uncoiling of the neurons
• B. Rotation of the brain within the skull
• C. Migration of neural crest cells
• D. Random pulsations of brain tissue

Answer: (A)

The idea being tested is the inherent motility of the central nervous system. The brain and spinal cord have their own subtle, intrinsic motion within the craniosacral system, often described as a coiling and uncoiling of the neural tissue and its coverings as it moves relative to the surrounding membranes and CSF. This organized, rhythmic movement underlies the cranial rhythmic impulse that practitioners feel when evaluating or treating with cranial techniques. It’s not about a gross rotation of the brain inside the skull, nor about embryologic neural crest migration, nor about random pulsations; those don’t describe the intrinsic, coordinated motion of the CNS.