Signs usually develop within the first year or two of life.
Not all features may be present when the condition begins. In many cases, the condition is benign and self-limited, usually lasting a few months, but some cases may last for several years. The cause of this classic type of spasmus nutans, is unknown. This type disappears spontaneously without treatment. Because many children with signs resembling those of spasmus nutans have underlying brain tumors, immediate neurologic evaluation and careful monitoring of infants and children with nystagmus is imperative.