Objective: The aim of this five-year longitudinal study was to investigate whether patients with increased blinking develop orbicularis oculi muscle spasms.
Methods: Eleven patients who initially manifested increased blinking alone were clinically and neurophysiologically re-evaluated five years later.
Results: By the five-year follow-up assessment, nine of the 11 patients had developed orbicularis oculi muscle spasms. The blink reflex recovery cycle became abnormal whereas somatosensory temporal discrimination, already abnormal at the first evaluation, did not significantly change.
Conclusions: Our longitudinal study demonstrates that increased blinking may precede blepharospasm and that an abnormal blink reflex recovery cycle reflects the development of orbicularis oculi muscle spasms.