An attempt to explain the mechanism of drop attacks.

We have investigated the possibility that a delay in long-loop (transcortical) reflexes might be responsible for the occurrence of drop attacks which occur in middle-aged women without disturbance of consciousness. We have not been able to confirm this suggestion. However, using simple Newtonian principles, we calculate how far the subject may fall before a long-loop reflex can be generated in the quadriceps muscle. We suggest that in some subjects tension cannot be generated sufficiently quickly to maintain the erect posture. This hypothesis provides a link between subjects who experience drop attacks due to overt muscle weakness and subjects without physical signs.