Botox Ameliorates Sialorrhea

abstract & commentary

Synopsis: Sialorrhea lessened within 5 days of injection which improved patients an average of 61%, and maintained the benefit an average of 4.7 months.

Source: Porta M, et al. J Neurol Neurosurg Psychiatry. 2001; 70:538-540.

Injection of botulinum toxin has revolutionized the treatment of focal dystonia. Approved by the FDA in 1990, botulinum toxin injection is now the treatment of choice for patients with blepharospasm, torticollis, oromandibular dystonia, spasmodic dysphonia, and hemifacial spasm. The dramatic response to treatment and the safety of the procedure led investigators to apply this technique to a variety of other conditions, including bruxism, lower esophageal and rectal spasms, spasticity, tics, and hyperhidrosis.

Botulinum toxin exerts its effect by inhibiting the release of acetylcholine at the neuromuscular junction. In the last 2 years, several studies have shown that injection of toxin into the parotid gland is an effective treatment for patients with excess saliva. Excessive drooling or salivation usually accompanies neurologic conditions in which coordination of swallowing is impaired, including ALS, head trauma, cerebral palsy, and Parkinson’s disease. Among Parkinson patients followed at the Neurological Institute of New York, sialorrhea is a common complaint. In 5% of these patients, uncontrolled salivation becomes a major source of hygienic and psychosocial embarrassment. We have found that medical treatments for sialorrhea (typically anticholinergic drugs) are usually ineffective and poorly tolerated by older patients.

In this paper, Porta and colleagues describe their experience injecting botulinum toxin into the parotid and submandibular glands of patients with excessive sialorrhea. Ten patients were enrolled in this open-label study, 4 with ALS, 2 with Parkinson’s disease, and 1 each with primary sialorrhea, SSPE, cerebral palsy, and head trauma. Fifteen to 40 units of Botox (botulinum toxin type A) were injected into each parotid gland, and 10-15 units were injected into each submandibular gland. Porta et al defined the anatomy of the parotid and submandibular glands and the trajectory of the facial nerve using ultrasound. Patients rated their improvement using a visual analogue scale. Sialorrhea lessened within 5 days of injection which improved patients an average of 61%, and maintained the benefit an average of 4.7 months. There were no adverse events and side effects were minimal.

Comment by Steven Frucht, MD

This is a convincing study, showing that Botox is an effective treatment for patients with troubling sialorrhea. Ultrasound guidance is a useful tool to ensure optimal injection of the parotid gland, and it is probably required to inject the submandibular gland, which normally provides up to 70% of daily saliva production. The degree of improvement in sialorrhea is comparable to other studies, and the technique is well tolerated and safe. Fortunately, although the benefit remained only a bit longer than 4 months after injection, repeated injections appeared to sustain the improvement.

Unfortunately, a major limitation to this technique is the cost of the treatment. Botulinum toxin is extremely expensive, between $4 and $5 per unit, or $400 to $500 for an average sialorrhea injection. This does not include the injection fee. At present, Medicare and most managed care plans do not cover this procedure, and it is unclear whether or not physicians will be reimbursed if they perform it. This is unfortunate, as the technique effectively treats an often troubling symptom for which alternative treatments are not adequate.

Dr. Frucht is Assistant Professor of Neurology, Movement Disorders Division, Columbia-Presbyterian Medical Center, New York, NY.