Benign essential blepharospasm is characterized by abnormal repetitive movements 
of lid closure and spasm of the orbiculari oculi muscles. Modern theories 
postulate that this movement disorder originates by abnormal processing of 
afferent information with further disintegration of the sensorimotor neural 
program at central levels of the nervous system all of which is seen as dystonic 
movements in genetically susceptible people. Different investigations including 
neuroimagin, genetic and neurophysiological studies have discovered new findings 
on what structures are involved and how this abnormal movement is generated. 
Among these research is noteworthy the study of electrically elicited blink 
reflex. It consists of three responses called non-nociceptive (R1), nociceptive 
(R2) and ultranociceptive (R3). Such blink reflexes, mostly the ultranociceptive 
response (R3), seem to be very useful to understand more deeply the 
pathophysiology of this focal dystonia, to perform the functional 
endophenotyping and to do a more appropriate follow-up of this complex 
neurological problem.