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Spasmodic Dysphonia Evaluation and Botulinum Neurotoxin A Injection

last modified on: Fri, 09/15/2023 - 08:09

return to: Laryngeal Surgery (Benign Disease) Protocols

see: Botulinum neurotoxin preparationsCase example EMG guided laryngeal Botox InjectionCase Example Vocal Tremor Response to BotoxLaryngeal Movement Disorders Clinic (Neurolaryngology)Meige's SyndromeBotulinum neurotoxin treatment of salivary gland disorders

ADDUCTOR SPASMODIC DYSPHONIA

  1. Evaluation
    1. Voice clinic evaluation
      1. Otolaryngology
      2. Speech pathology (see Data Base Recording and Report Generation Voice Clinic)
      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 preceding 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).

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 - although many will use a percutaneous approach, see also: Case example - Transoral Videostrob Assisted PCA 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

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 - see also: Esophageal Speech without TEP compared to with TEP (Hoffman et al 1997)
    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.

REFERENCES

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).

Oromandibular dystonia: a clinical report. Schneider R, Hoffman HT. J Prosthet Dent. 2011 Dec;106(6):355-8.

Hoffman HT, Fischer H, VanDenmark D, Peterson KL, McCulloch TM, Karnell LH, Funk GF. Botulinum neurotoxin injection after total laryngectomy., Head & neck. 1997 March;19(2):92-7. PMID:9059865.