Have botulinum toxins type A and type B a role in the management of Parkinson's Disease?

Abstract

Introduction : Management of cardinal signs of Parkinson's Disease (PD) is usually addressed in a satisfactory way by using Levodopa, dopaminoagonists and similar drugs. In selected cases Deep Brain Stimulation (DBS) can improve significantly patient's quality of life. Ancillary symptoms such as hyperlacrimation, hypersalivation and slowed swallowing, urinary problems, paradoxical dystonia determining stipsis or vescico-sphyncterial dissinergias, myofascial pain syndromes could be treated using Botulinum Toxin (BoNT) among other systemic drugs. BoNT Type A and Type B work on the synaptosomal and synaptobrevin proteins, respectively, exerting an anticholinergic effect which can be defined as: (1) muscular relaxation lasting 3–4 months, (2) eccrine glands’ production slowing lasting up to 10 months, (3) myofascial pain interference through intra- and extrafusal action over alpha and gamma fibers. Material and methods : A total number of 78 patients were treated. Thirty-one were male, average age was 64 (47–75). All of these patients have a long-term, ascertained levodopa treatment syndrome: levodopa dosages were 500 mg per day (average value: range 375–1250). In order to be included in the treatment series, patients were evaluated after being medicated at best with the currently accepted drugs. Injections were performed under electromyographic, echographic or CT scan guides. A detailed informed consent was signed by all the patients. Authors used BoNT/A (Allergan or Dysport) or Type B (Elan) using equivalent dosage. Results : For cholinergic glands BoNT/B appeared more potent in terms of effect. Twenty-one out of the 78 patients were injected into the tear glands (2 IU per gland), 10 into the salivary glands (45 IU per side), 9 into the sweat or seborrhoic glands (50–100 IU per region), 18 into dystonic muscles (50–80 IU per muscle), 2 into sural muscles in order to treat the “freezing” episodes (60–80 IU per muscle), while 8 patients were injected into the vescical detrusor (80–100 IU) and 10 patients were treated at the elevator ani (40 IU). No severe side effects were recorded and all the patients had temporary relief of the specific signs, lasting 3–4 months for voluntary muscles and 10–12 months for autonomic signs. Conclusions : The use of BoNT A or B appears useful for improving the quality of life. The procedure is safe and can address the temporary effect of BoNT because it is repeatable. A well-experienced center is necessary in order to pose the correct indication and to offer the adequate technical proficiency. Considering our results, BoNT injection appears to be a mandatory option for the treatment of patients affected with Parkinson's Disease.