Ultrasound Guided Botulinum Toxin Injection for Sialorrhoea in Parkinson’s Disease; Evidence, Technique and Outcomes

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.

Evidence

Treatment Options

1. 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.

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

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

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

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

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.

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

Dr.Christopher Wilkinson, Dr.David King & Dr.Phil Duffey

Technique

Conclusion1.Sialorrhoea is a severely debilitating symptom for patients with PD2.A one-stop clinic offering USS-guided injection of botulinum toxin is a simple, safe and effective treatment option for sialorrhoea in PD3.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.

Outcomes

• 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

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

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

• 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

Complications

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

Injected Toxin

Needle

Parotid Gland

Submandibular intracapsular haematoma

Response to Treatment

Treatment Episodes

BTx Parotid – Submandibular Dose