10
Botulinum Toxins
• Botulinum toxin is not currently approved by the FDA for the treatment of
tremor.
• General side effects of botulinum toxins include rash, pain, stiffness,
cramping, hematoma, and paresthesia.
• Reports have shown efficacy of botulinum toxin for upper limb, head, and
voice tremor when the tremor is not responding to oral pharmacotherapies.
Table 5. Botulinum Toxins in Various Tremors
Area Comments
Upper Limb The greatest benefit has been shown to be between 6 and 16 weeks
after the injections. Hand weakness is the most common side effect
and is dose dependent. Focusing on the forearm wrist flexor instead of
the extensor muscles significantly reduces weakness.
Head It is important to distinguish ET from dystonic tremor. Botulinum
toxins have been shown to be beneficial for both dystonic and ET
head tremor in the majority of patients. The benefit usually occurs
after one week and continues for 8–12 weeks. The most common side
effects are dysphagia, headache and neck weakness.
Voice 50–60% of patients have been reported to improve with botulinum
toxin injections directed primarily at the vocal cord under
electromyographic guidance or direct visualization with endoscopy.
The most common side effects included weak voice, hoarseness, and
breathy voice, all of which can last for several weeks.
Management
