Hyperekplexia

Genetic disorder causing an exaggerated startle response

Hyperekplexia is a very rare neurologic disorder, classically characterised by a pronounced startle response to tactile or acoustic stimuli and an ensuing period of hypertonia. The hypertonia may be predominantly truncal, attenuated during sleep, or less prominent after one year of age.

This keyword could refer to multiple things. Here are some suggestions: