Botulinum Toxin Therapy for Nonmotor Aspects of Parkinson's Disease

The medical treatment of Parkinson's disease (PD) is symptomatic both in terms of motor and nonmotor aspects. The nonmotor symptoms therapy should be taken into account as many of them negatively influence the quality of life and are treatable. Botulinum neurotoxin (BoNT) offers effective treatment for drooling and bladder dysfunctions and alternative treatment for constipation and pain related to parkinsonism. BoNT for drooling is probably the best-documented therapy for nonmotor symptoms by clinical trials. Ultrasound-guided injections into parotid and submandibular glands can be recommended as the first line treatment, especially when anticholinergic oral medications are not indicated due to the risk of confusion, cognitive decline, or psychosis. BoNT therapy of constipation and neurogenic bladder is not so well evidenced and the latter indication is based on positive effects in clinical trials in multiple sclerosis and posttraumatic spine injuries. BoNT injections into the salivary glands or bladder are effective and safe with relatively low risk of complications. Authors reviewed the literature on the use of BoNT for all nonmotor aspects of PD, showed their position in guidelines and systematic reviews and gave the practical remarks on injection techniques and dosing.