Ultrasound Guided Botulinum Toxin Injection for Sialorrhoea in Parkinson’s Disease; Evidence, Technique and Outcomes Dr.Christopher Wilkinson, Dr.David King & Dr.Phil Duffey Background

• Sialorrhoea: inability to control oral secretions, causing excess saliva in oropharynx.

• Parkinson’s Disease (PD) affects 120,000 people in the UK and up to 80% of patients suffer with sialorrhoea.

• Sialorrhoea may cause drooling, social embarrassment and severely affect quality of life. There are also concerns it may predispose to aspiration pneumonia.

• Established pharmacological treatments are often ineffective or poorly tolerated.

• USS-guided injection of botulinum toxin into the salivary glands is a highly effective treatment but is not widely offered in many centres.

• This treatment has been shown to decrease saliva production in up to 90% of patients and significantly improves quality of life.

• In our institution, a one-stop clinic is offered with a radiologist and physician working together. This provides a successful environment for symptom evaluation and the provision of USS-guided botulinum toxin injections.

Treatment Options

1.

2.

3.

4.

Anticholinergics: Block mACh receptors and decrease saliva production.

Poorly tolerated in the elderly due to side effects e.g. urinary retention, constipation and blurred vision. There are also concerns long-term treatment results in the production of neuro-fibrilllary tangles and causes neuro psychiatric problems.

Radiotherapy: some good reported success in limited trials but long term side effects are unknown, and not a realistic long-term treatment option.

Surgery: Neurectomy, salivary gland excision and duct ligation have varying success rates, but are invasive procedures and usually restricted to use in children.

Botulinum toxin: Ultrasound guided injection into the salivary glands. Inhibits cholinergic parasympathetic activity thereby reducing saliva production.

Ondo et al. Neurology 2004; 62:37-40

• Double blind, placebo controlled • 16 patients • Anatomical markers • Botulinum toxin B • Bilateral parotid and submandibular

Results

• Significant improvement in drooling rating, severity and frequency scales in botox group • Mild side effects e.g. dry mouth, neck pain diarrhoea and worsened gait.

Evidence

Porta et al. J Neurosurg Psych 2001; 70:538-540

• Open label trial • 10 patients • USS guided • Botulinum toxin A • Bilateral parotid and submandibular

Results

• 90% patients reported reduction in saliva production • No reported side effects or complications

Lipp et al. Neurology 2003; 61:1279-81

• Double blind, placebo controlled • 32 patients • Anatomical markers • Botulinum toxin A • Bilateral parotid injections

Results

• Mean saliva production decreased by 50% in botox group • No reported side effects or procedure related complications

Aspects of treatment requiring more research to determine optimum treatment parameters

•

Botulinum toxin A vs B • Initial injections into parotid vs submandibular.

• Optimum toxin dose • Optimum time between injections • Patient selection

Technique

Needle • High frequency linear probe, USS guided • Type A botulinum toxin (Dysport) diluted to 100 units per ml in 5ml syringe • Initial dose of 75 units into each parotid or submandibular gland. Dose increased gradually at each visit until optimum dose reached • Measured dose drawn up into 1ml syringe with 5cm 21G (green) needle attached Injected Toxin • Joint clinic with radiologist & neurologist • Patients self-book into clinic when treatment effect wears off • Effect of treatment assessed at each visit and dose adjusted accordingly • Typical frequency of visit = 3-6 months • Patients reviewed on a self referral basis and dose adjusted according to response Parotid Gland Treatment Episodes

Outcomes

• 28 patients • 24 male, 4 female • 115 treatment episodes • Mean treatment interval of 23 weeks Response to Treatment

Complications

• Complication rate <2% - all self limiting • 2 patients – intracapsular haematoma • 2 patients – haemato-sialorrhoea • 5 patients – xerostomia

Submandibular intracapsular haematoma BTx Parotid – Submandibular Dose

Conclusion

1.Sialorrhoea is a severely debilitating symptom for patients with PD 2.A one-stop clinic offering USS-guided injection of botulinum toxin is a simple, safe and effective treatment option for sialorrhoea in PD 3.More research into particular aspects of treatment is required to determine the factors required for optimum results

Reference: Sialorrhoea in Parkinson’s Disease: A Review, Chou et al., Movement Disorders (22) 16;2306-2313.