Botulinum Neurotoxin A Injection

 return to: Laryngeal Surgery (Benign Disease) Protocols

see: Botulinum neurotoxin preparations

Case example EMG guided laryngeal Botox Injection

Case Example Vocal Tremor Response to Botox

 Laryngeal Movement Disorders Clinic (Neurolaryngology)

 Meige's Syndrome

 Botulinum neurotoxin treatment of salivary gland disorders

1. ADDUCTOR SPASMODIC DYSPHONIA
   1. Evaluation
      1. Voice clinic evaluation
         1. Otolaryngology
         2. Speech pathology (see Figure IIIB-1 (PDF))
         3. Speech physiology
         4. Videoendoscopy evaluation (fiberoptic transnasal)
            1. Quiet breathing
            2. Sniff 3 times rapidly
            3. Prolonged sniff 2 times
            4. Glide /i/
            5. Repeat the following
               1. Breathe - /i/- breathe
               2. /i/ 7 times
               3. /si/ 7 times
               4. /pi/ 7 times
               5. /mi/ 7 times
               6. /si-i/ 7 times
               7. /i-si/ 7 times
            6. Repeat the following sentences 2 different times
               1. We need meaning men
               2. She speaks pleasingly
               3. Peter will keep at the peak
            7. Count from 1 to 10 and from 80 to 90
            8. Say the days of the week
            9. Say the months of the year
      2. The differential diagnosis of spasmodic dysphonia includes:
         1. Spasmodic dysphonia (laryngeal dystonia - either isolated to the larynx or accompanied by other dystonias)
         2. Vocal tremor (may occur in isolation or co-exist with spasmodic dysphonia)
         3. Muscle tension dysphonia
         4. Glottic incompetence resulting strain and muscle tension secondarily to achieve glottic competence.
      3. When the diagnosis is questionable and the differential diagnosis includes muscle tension dysphonia, a trial of speech therapy may be warranted. This intervention may help to establish the diagnosis, to rule out the potential for significant improvement through a noninvasive approach, and to prepare the patient for post-injection voice therapy prior to treatment with Botox.
      4. Neurology evaluation as indicated (rule out associated dystonias). In the absence of other neurologic abnormalities on physical examination and history, the presence of an isolated laryngeal dystonia (spasmodic dysphonia) does not always require an evaluation by a neurologist.
      5. Psychological or psychiatric evaluation as indicated if a functional component related to psychiatric problems is detected.
         1. Kotby MD, Baraka M, El Sady SR, Ghanem M, and Shoeib R: Psychogenic stress as a possible etiological factor in non-organic dysphonia.International Congress Series 1240 (2003) 1251-1256 (International Federation of Otorhinolaryngological Societies (IFOS).
   2. Botulinum Neurotoxin A Injections
      1. First standard injection is 2.5 units per 0.1 cc, bilateral thyroarytenoid muscles; a smaller dose of 1.25 units per 0.1 cc for elderly, small-framed women or men (larger larynx, impact of paresis may be greater despite larger muscle size).
      2. If patient fails to respond within 2 weeks, re-inject (see Laryngeal EMG (Electromyography))protocol for instructions regarding needle placement).
      3. If first injection results in a good response, the second injection would be expected at 3 - 4 months; 2.5 units per 0.1 cc bilateral thyroarytenoid muscles; the patient's response is variable with injection required as infrequently as every 12 months.
      4. Subsequent doses are based on previous response. Doses lasting longer than 3 months may be increased if patient has not had any swallowing problems or breathiness.
      5. Injections done at intervals shorter than 6-8 weeks may be considered "boosters" and have additive effect to preceeding dose.
      6. Alternative injection sites (ie, unilateral thyroarytenoid, cricothyroid, strap muscles) are dependent on clinical picture, response to previous injections, and EMG results.
      7. Consider unilateral injection with higher dose than used for bilateral injection (10 to 15 units unilaterally).

2. ABDUCTOR SPASMODIC DYSPHONIA

   1. Evaluation
      1. Voice clinic evaluation
         1. Otolaryngology
         2. Speech pathology
         3. Speech physiology
         4. Videoendoscopy
      2. One month of speech therapy (as per above)
      3. Neurology evaluation (as per above)
      4. Psychological evaluation (as per above)
   2. Injection
      1. First injection: 2 separate sites of 1 posterior cricoarytenoid muscle on 1 side to a total dose between 3.75 to 10 units
      2. Second injection in contralateral side at separate time (typically 2 to 4 weeks later); titrate to response

3. CONSTRICTOR MUSCULATURE HYPERTONICITY FOLLOWING LARYNGECTOMY

   1. Evaluation
      1. Failure of tracheoesophageal puncture (TEP) speech and/or dysphagia symptoms following total laryngectomy. Need to confirm the absence of stricture or carcinoma recurrence - usually with transnasal fiberoptic esophagoscopy in clinic.
      2. Elevated TEP pressures and/or abnormalities on modified barium swallow suggestive of hypertonicity
      3. In the past, a trial of a lidocaine block was offered; now, in the absence of stricture or carcinoma and documentation (also through transnasal esophagoscopy) of a patent adequately positioned prosthesis, treatment with botulinum neurotoxin A is reasonable without a lidocaine trial.
   2. Injection
      1. First injection: between 50 and 100 units of Botox ® (at 2.5 units per 0.1 cc) are divided into three separate sites: cricopharyngeus, inferior constrictor, middle constrictor.
      2. Subsequent doses are based on previous response. Doses given 2 weeks apart are considered to be additive in the calculation of later dosages.

4. OROMANDIBULAR DYSTONIA - JAW OPENING VARIANT

   1. Evaluation
      1. Otolaryngology evaluation
      2. Neurology evaluation
   2. Injection
      1. First injection: 5 to 15 units per 0.1 to 0.3 cc into each lateral pterygoid and/or to anterior bellies of digastric muscles.
      2. Subsequent injections are based upon previous results and may be increased in duration. Doses given 2 weeks apart are considered to be additive for the purpose of calculation of subsequent injections.
      3. Speech and, to a lesser extent, swallowing morbidity may develop with velopharyngeal incompetence resulting from inaccurate placement of the Botox or its diffusion from the injection site.

5. BRUXISM

   < >IndicationsCerebral PalsyTreatmentBotox A to masseter muscles, temporalis muscle and possibly anterior belly of digastrictypical dose is 80 -100 units total injected into musclesSafetyReview of RCT trials have shown good safety profile at 1 month in cerebral palsy patientsIncrease rate of complications such as respiratory infections, bronchitis, falls, urinary incontinence (Albavera-Hernandex, et al; Clinical Rehab 2009; 23, 394-407)Oromandibular dystonia: a clinical report. Schneider R, Hoffman HT.
   J Prosthet Dent. 2011 Dec;106(6):355-8.