Objective To evaluate the effect of ultrasound-guided botulinum toxin A injection into the salivary glands in treating patients with sialorrhea attributable to brain damage.Methods Nine subjects with sialorrhea attributable to traumatic brain injury (n =5),cerebral infarction (n =3) and hypoxic ischemic encephalopathy (n =1) were recruited into the study.With the guidance of ultrasound,15 units (U) of botulinum toxin type A was injected into the highest and lowest points of the two parotid glands,and 20 U was injected into two points of both submandibular glands.The saliva flow rate and the severity and frequency of sialorrhea were recorded before the treatment and 1 week,4 weeks and 12 weeks later using the Drooling Scoring System (DSS).Results The saliva flow rate before treatment (0.49 ± 0.12 g/min) decreased significantly to 0.24 ± 0.08 g/min after 1 week,but then increased again to 0.28 ±0.12 g/min after 4 weeks and 0.34 ±0.11 g/min after 12 weeks.The average DSS severity score showed the same pattern:4.35 ± 0.48 initially 1.92 ± 0.37 after 1 week,1.92 ± 0.37 after 2 weeks and 2.32 ± 0.64 after 12 weeks.The DSS frequency score,however,remained significantly lower:3.56 ± 0.49 initially,2.01 ± 0.42 after 1 and 4 weeks and 2.28 ± 0.63 after 12 weeks.Conclusion Botulinum toxin type A can effectively improve the salivary secretion and sialorrhea attributable to brain damage.