Study of Myobloc in the Treatment of Sialorrhea (Drooling) in Patients With Amyotrophic Lateral Sclerosis (ALS)

Inclusion Criteria: * Diagnosis of probable or definite ALS based on current World Federation of Neurology criteria * Between the ages of 21-85, inclusive * Sialorrhea refractory to treatment with at least two anticholinergic medications OR has been intolerant of anticholinergic medications due to side effects * Capable of giving informed consent * Must be able to attend all study visits Exclusion Criteria: * Patient has any uncontrolled significant medical, psychiatric or neurological disease (other than ALS) over the past 30 days * History of ongoing substance abuse * History of non-compliance with treatment in other experimental protocols * Cannot provide informed consent or comply with evaluation procedures * Has received any form of botulinum toxin in the past for any indication * Women who are pregnant, lactating, or of child bearing potential not using an adequate form of birth control * Currently being treated with coumadin * Forced vital capacity (FVC) \<40% of predicted unless the tidal volume is \> 600cc, as patients with significant bulbar weakness may show a falsely low FVC due to bulbar muscle spasticity