Craniofacial Muscles

16 Spastic Facial Muscle Disorders
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lagophthalmos (5–12%), dry eye (7–10%), entropion, ectropion, epiphora, photophobia
(2.5%), and, less likely, diplopia (<1%) (Osako and Keltner 1991 ; Dutton
and Buckley 1988 ; Wutthiphan et al. 1997 ; Kalra and Magoon 1990 ) . These are all
due to the paralytic effects of the toxin and its deep penetration. They resolve spontaneously
as the effects of the BoNT wear off.
Contraindications for BoNT injections include pregnancy and lactation, allergies
to the drug, human serum albumin, or cow milk (due to lactose in Dysport ® ), uncooperative
patients, neuromuscular diseases, coagulopathies, infection in the injection
site, and use of medications such as quinine, calcium channel blockers, and
penicillamine or aminoglycoside antibiotics (Dutton and Buckley 1988 ; Hexsel and
Dal’forno 2003 ) .
16.8.1.1 Complications During Injection
(a) Pain : Slow injection with a fi ne, 30-gauge needle on a tuberculin syringe and
injection volume less than 0.1 mL per site are fairly helpful in reducing the
discomfort associated with injections. Some physicians prefer using a topically
applied anesthetic, such as Betacaine ® gel or EMLA ® cream before injection, or
ice compress before and after injection, while others do not use any sedatives or
local anesthesia (Soylev et al. 2002 ; Linder et al. 2002 ) .
Some patients feel more pain with injections around the corrugator supercilii
muscle because the skin at this location is thicker, and the supratrochlear nerve
is compressed by drug in fi ltration. Patients with a previous history of eyelid
surgery including myectomy tend to complain of more pain since the fi brotic
scar tissue is more dif fi cult to penetrate with a needle and is less expandable
compared to normal tissue. Slow injection of less volume with a higher concentration
is helpful in this situation.
(b) Ecchymosis / Hematoma : Any visible vessels underneath thin eyelid skin must
be avoided to reduce hematoma formation. If a hematoma occurs, compression
at the injection site should be applied for several minutes.
(c) Eyeball Perforation : Injection into the eyelids of controlled patients who move
their head vigorously and uncontrollably risk eyeball perforation. It is always
necessary to stabilize and hold the patient’s head still during the procedure.
16.8.1.2 Complications After Injection
(a) Erythema , Swelling : Erythema and swelling typically last for several days after
injection and slowly resolve.
(b) Blepharoptosis : Injections spreading from the upper eyelid injection sites to the
levator muscle can cause one of the most concerning complications, blepharoptosis.
In patients treated more than four times, the reported incidence of ptosis