• The effects of botulinum A toxin injections for the treatment of facial spasm were analyzed for 22 patients. Sixteen patients had unoperated on essential blepharospasm, three had essential blepharospasm with residual spasm following previous surgical treatment, and three had unoperated on hemifacial spasm. Treatment was effective for most patients, but transient, with the mean interval of relief of spasm after the first injections being ten weeks. The injection of botulinum toxin reduced the maximum lid force by about 10%. While side effects were common, they were generally mild and well tolerated. No cumulative effect of botulinum toxin was evident in those receiving three series of injections. There is no significant difference in either the interval free of spasm or the rate of lid-force recovery following any of three sequential injections of increasing doses of botulinum toxin.
Frueh BR, Felt DP, Wojno TH, Musch DC. Treatment of Blepharospasm With Botulinum ToxinA Preliminary Report. Arch Ophthalmol. 1984;102(10):1464-1468. doi:10.1001/archopht.1984.01040031184014