Craniofacial Muscles

16 Spastic Facial Muscle Disorders
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the drug history includes drugs which can cause tardive dystonia (Mauriello et al.
1998a ). Treatment consists of withdrawing the offending agent, sometimes combined
with the use of botulinum neurotoxin (BoNT) injections in refractory cases.
16.8 Treatment
Speci fi c treatment may be not necessary until patients with blepharospasm or other
cranial dystonia are disabled by the abnormal movements. Any potentially exacerbating
ocular disease such as dry eye or blepharitis must be treated fi rst. Dry eye
symptoms can be treated symptomatically with arti fi cial tears and punctal occlusion.
Tinted lenses also have been recommended to ameliorate photophobia in patients
with blepharospasm (Adams et al. 2006 ; Herz and Yen 2005 ) .
The treatment of choice in patients with debilitating blepharospasm, Meige’s
syndrome, and hemifacial spasm is localized injections of botulinum neurotoxin
type A ( BoNT / A ) around the eyelids to weaken the orbicularis oculi and other muscles
involved in eyelid closure and facial movements (Aramideh 1996 ; Aramideh
1995 ; Osako and Keltner 1991 ; Price and O’Day 1994 ; Defazio et al. 2002 ; Dutton
and Fowler 2007 ) . Greater than 90% of patients report a marked decrease in the
squeezing action of the eyelids and twitching in lower part of the face (Osako and
Keltner 1991 ; Elston 1987 ; Engstrom et al. 1987 ; Dutton and Buckley 1988 ;
Kennedy et al. 1989 ; Mauriello et al. 1996 ; Anderson et al. 1998b ). Some patients
with apraxia of eyelid opening bene fi t from BoNT injection depending on how
much of their eyelid closure is spastic. Most need higher doses of toxin and more
frequent injections.
16.8.1 BoNT Injection
BoNT injections were fi rst used to treat strabismus in 1977 by Alan Scott, a pediatric
ophthalmologist, (Dressler 2000 ) and subsequently used to treat blepharospasm in
the early 1980s by Frueh et al. ( 1984 ) and Scott et al. ( 1985 ) . Since then, BoNT has
been highly effective and well tolerated in the symptomatic treatment of a very
broad range of conditions involving either muscle hyperactivity such as blepharospasm
and hemifacial spasm, or cholinergic hyperactivity such as hyperhidrosis and
hypersalivation (Jankovic 2009 . Recently, BoNT has been approved for the treatment
of glabellar rhytids and chronic migraine headaches (Harrison 2003 ) .
The various strains of the anaerobic bacteria Clostridium botulinum produce
seven distinct serotypes of BoNT, of which fi ve are pharmacologically active in
humans (A, B, E, F, and G) and two are inactive (C and D) (Brin and Blitzer 1993 ) .
In all naturally occurring serotypes of BoNT (types A~G) and commercially available
BoNT preparations, the active neurotoxin (150 kDa; 100 kDa of a heavy chain;
and 50 kDa of a light chain) is noncovalently associated with a set of nontoxic and