By : Busaba Sathornsumetee MD. Mettapracharak Hospital

1. Functional use of Botulinum
toxin A in Neuro-Ophthalmology
Busaba Sathornsumetee MD.
Mettapracharak Hospital
31 August 2012

2. Benign Essential
Blepharospasm

3. BEB
• Idiopathic focal dystonia
• Involuntary intermittent bilateral eyelid closure
• Women are affected more than men
• Usually begins in the 4th -6th decade of life

4. Involved muscles
• Orbicularis oculi
• Corrugator
• Procerus

5. Etiology
• Unknown
• No underlying causes
• Parkinson disease, lower pontine lesion

6. Symptoms
• Increased blinking (early)
• Difficulty in eyelid opening (early)
• Squeezing of the eyelids
• Photophobia, eye pain, dry eyes
• Functional blindness
• Disturb daily activity, cosmetic

7. Signs

8. Differential diagnosis
• Reflex blepharospasm
• Eyelid myokymia
• Early Hemifacial spasm
• Apraxia of eyelid opening

9. Meige syndrome
• BEB (often precede)
• Oromandibular dystonia
- Dystonia of lower face, jaw, neck

10. Management
• Conservative treatment
• Oral medication
• Botulinum toxin injection
• Myectomy

11. Botulinum toxin A for BEB
(FDA approved 1989)
(FDA approved 1989)
• Advise Risk & Benefit
• No contraindication for Botulinum toxin A injection
Neuromuscular disorder, Pregnancy-Lactation, Drug interaction
• May stop ASA 7 days (cosmetic issue)
• Cold pack for 5-10 mins (relieve pain & stop bleeding)

12. Potential adverse effects
• Effect of the toxin on adjacent non-target muscles
• Injection technique
• Mild & transient effects

13. Potential adverse effects
• Ptosis (7-11%)
• Lagophthalmos (5-12%)
• Symptomatic dry eyes
• Diplopia (<1%)
• Ecchymosis
• Lower facial weakness

14. Site of injection for BEB
- Orbicularis oculi (pretarsal part)
* subcutaneous injection
* medial & lateral area
* 2.5-5.0 unit (upper)
* 5.0-10.0 unit (lower)
- Corrugator & Procerus
* intramuscular injection
* 2.5-5.0 unit

15. Failure of botulinum toxin
• Inability of botulinum toxin to relieve squeezing
• Problem of eyelid opening
- Apraxia of eyelid opening (50%)
- Dermatochalasis, Brow ptosis

16. Apraxia of eyelid opening
• Inability to raise upper eyelid
• Often occur with BEB
• No eyelid squeezing , Elevation of eyebrow
• Botulinum toxin + upper myectomy + tightening levator M.

17. Hemifacial spasm

18. Hemifacial spasm
• Unilateral
• Dystonia of facial muscles
- Orbicularis oculi (precedes)
- Zygomaticus major
- Risorius
- Mentalis
• Normal ocular surface , Persist while sleeping

19. Hemifacial spasm
• The whole face on one side contracts
• Eyelid closure
• Elevation of corner of mouth

20. Etiology
• Hyperexcitability of the facial motor nucleus
- Idiopathic
- Ischemia or mass in pons (1%)
• Compression of the facial nerve near its exit from the
brainstem
- Tortuous AICA
- Dolichoectatic artery of the posterior circulation

22. Approach HFS
• History taking
Dizziness, vertigo, ataxia, facial numbness, hearing loss
Diplopia, facial palsy
• Examination
EOM, CN 5- 7- 8

23. Neuroimaging
• Brain MRI (เน้น brainstem) + MRA with/without GAD
• ตามตำาราแนะนำาให้ส่งทุก case
• ใน clinical practice จริงๆ มีหลากหลาย
- บางที่ส่งทุก case
- เลือกส่งในบาง case
มี neurological deficits อืนร่วม ไม่ตอบสนองต่อการรักษา
่

24. Management HFS
• Oral medications (same as for BEB)
• Chemodenervation with Botulinum toxin A
Duration of action tends to be longer than in BEB
• Microvascular decompression (craniotomy)

25. Microvascular decompression

26. Site for injection
• Orbicularis Oculi +/- Corrugator
• Zygomaticus Major (2.5-7.5 U)
• Risorius (some cases, 2.5 U)
• Mentalis (2.5-5 U)
(Intramuscular injection for lower face)
• ไม่แนะนำาให้ฉดบริเวณ Orbicularis Oris
ี

27. Potential adverse effects
• Same as BEB
• Asymmetric smile
• Drooping of the cheek and angle of mouth

28. How to decrease the adverse
effect ?
• Small dosage for Zygomaticus Major
• Avoid Orbicularis Oris
• Inject Botulinum toxin at Depressor Anguli Oris
(DAO) or contralateral Zygomaticus major
• Lower dose if secondary to facial palsy

29. Take home message
• BEB is often a chronic progressive condition
• Beware of other causes of treatment failure with botulinum toxin
• Keep brain MRI in mind for HFS
• Counselling is important before treatment

30. Thank you