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Biomedical subjects

Andrew Blitzer

Publications and source records attributed to Andrew Blitzer.

16 recordsLinked to original sources
PubMed2006

Singer's dystonia: first report of a variant of spasmodic dysphonia.

OBJECTIVES: We discuss the phonatory characteristics of a previously undescribed focal laryngeal dystonia present in the singing voice. METHODS: We performed a retrospective chart review of 5 patients with singer's dystonia at a neurolaryngology referral center. RESULTS: Four patients reviewed demonstrated phonatory characteristics consistent with adductor spasmodic dysphonia present in their singing voice. One patient demonstrated abductor spasmodic dysphonia in the singing voice. Each patient initially exhibited normal connected speech in conversational voicing. The treatment protocol and outcome are discussed, including the use of botulinum toxin. CONCLUSIONS: Singer's dystonia is a previously undescribed neurologic disorder that should be understood by those who treat voice performers and voice disorders.

Adult↗
PubMed2005

Botulinum toxin A and B: a comparative dosing study for spasmodic dysphonia.

OBJECTIVE: The purpose of this study was to find the conversion factor, safety, and efficacy of type A to type B toxin for laryngeal muscles. METHODS: Thirty-two patients with adductor spasmodic dysphonia with stable doses of A toxin to manage their symptom were given type B toxin starting at a conversion of 1 U of BTX-A to 50 U of BTX-B. The patients were followed for 1 year, and doses adjusted according to response. RESULTS: The conversion factor was found to be 52.3 U:1 U. The onset of action of type B was more rapid (2.09 days vs 3.2 days [P = 0.028]), with a shorter duration of benefit (10.8 weeks vs 17 weeks [P = 0.002). The safety profile for A and B toxin appeared the same, with 3 patients receiving Myobloc reporting dry mouth. CONCLUSION: This study shows that a conversion factor of 52.3:1 Myobloc (BTX-B) to Botox (BTX-A) and that Myobloc is an effective alternative to Botox (BTX-A) for patients with spasmodic dysphonia.

Botulinum Toxins↗
PubMed2005

Dose response of topical anesthetic on laryngeal neuromuscular electrical transmission.

OBJECTIVES: Our purpose was to determine the effect of a dose response to decreasing concentrations of topical anesthetic upon laryngeal neuromuscular electrical transmission. METHODS: We performed a prospective study at a neurolaryngology referral center. Forty-three patients were divided into 5 groups. Each patient underwent laryngeal electromyography (EMG) of a thyroarytenoid muscle before and 60 seconds after topical laryngotracheal lidocaine hydrochloride, normal saline solution, or nothing was applied. The pretreatment and posttreatment measurements were recorded with the same indwelling EMG electrode. Group 1 (n = 12) received 4% lidocaine, group 2 (n = 9) received 2% lidocaine, and group 3 (n = 8) received 1% lidocaine. Group 4 (n = 5) received topical normal saline solution instead of lidocaine. A fifth group (group 5, n = 9) had 2 EMG recordings measured, each separated by 60 seconds, without topical anesthetic. RESULTS: Groups 1, 2, and 3 showed significant decreases in the maximum peak-to-peak amplitude of the EMG recording (48.5%, 49.7%, 44.7%, respectively). Groups 4 and 5 failed to show a significant change in peak-to-peak amplitude after 60 seconds. There was no dose response change in EMG with decreasing lidocaine concentrations. CONCLUSIONS: All concentrations of lidocaine administered in this study decreased the laryngeal neuromuscular electrical transmission as measured by laryngeal EMG. This group of patients did not exhibit any dose response to anesthetic concentration. This finding is clinically significant for both diagnostic and therapeutic uses of laryngeal EMG preceded by administration of topical anesthetic.

Anesthetics, Local↗
PubMed2004

Electromyography and the immobile vocal fold.

Laryngeal EMG has become a useful tool for the otolaryngologist in the four decades since the pioneering work of Faaborg-Anderson and Buchtal. It is able to distinguish between mechanical limitation and denervation in an immobile vocal fold. In the paralyzed vocal fold, it can guide workup by pointing to the site of the lesion. In the hands of a circumspect clinician, it can provide clinically valuable information regarding prognosis. Useful application of laryngeal EMG must rest on the basic fact that it isa qualitative test. Because of factors like sampling error, interfering signal from neighboring muscles, difficulties in needle placement, and our in-complete understanding of reinnervation physiology, the boundary between sophisticated, subtle interpretation and overreading is particularly difficult to distinguish. EMG diagnosis is based on patterns of abnormalities over time and, like other tests, requires interpretation in a clinical context. As in any such undertaking, there is no substitute for good judgment and experience. The most important benefit of clinical use of laryngeal EMG may be that it has catalyzed and broadened interest in laryngeal neurophysiology in the same way that stroboscopy has focused attention on the structure and function of the vocal fold lamina propria. The continuing refinement of electrodiagnostic approaches to the larynx that has resulted, including quantitative, single-fiber. and vector laryngeal EMG, and evolving methods of nerve conduction testing will continue to yield important insights into mechanisms of neural control that are likely to drive developments in the treatment of vocal fold paralysis in the future.

Action Potentials↗
PubMed2004

Noncosmetic uses of botulinum toxin.

In conclusion, botulinum toxin usage over the past 2 to 3 decades has expanded exponentially. Almost every discipline in medicine has found some therapeutic use for this toxin. Botulinum toxin has been shown to be safe, effective, and relatively easy to administer with proper training.

Botulinum Toxins, Type A↗
PubMed2003

Treatment of migraine headache with botulinum toxin type A.

Migraine is a common headache disorder with profound implications on patients' quality of life and the overall health care system. Traditional treatment options have been less than optimal and many migraine patients lack confidence in over-the-counter and prescribed medications. BTX-A has shown promise as an efficacious, well-tolerated, long-lasting preventive therapy. Completed placebo-controlled trials showed that BTX-A injections for migraine resulted in fewer headaches, reduced headache severity and duration, reduced migraine-associated symptoms, and reduced use of migraine medications. Because the administration of BTX-A is nonsystemic, reported adverse events have been rare and mild. Larger trials are currently underway to further evaluate BTX-A efficacy and to determine optimal dosing and injection sites. Based on the collective experience of clinicians in neurology, facial plastic surgery, and otolaryngology, as well as supporting evidence from completed and ongoing clinical trials and theorized mechanism of action, an effective BTX-A approach for treatment of migraine is emerging. With further refinement to its use as prophylactic therapy, BTX-A can potentially be a primary option for candidate migraine sufferers and prescribing clinicians.

Botulinum Toxins, Type A↗
PubMed2003

Laryngopharyngeal dysfunction from the implant vagal nerve stimulator.

OBJECTIVES/HYPOTHESIS: The objective of the study was to examine the side-effect profile of the vagal nerve stimulator. Vagal nerve stimulators have been used to treat intractable seizures in all age groups. They provide relief to the patient with a seizure disorder by decreasing the overall number and severity of seizure activities. Although significant complications are rare, many patients have some complaint, usually of their voice. STUDY DESIGN: A retrospective evaluation of four patients with intractable epilepsy. METHODS: Evaluation of charts and medical records and endoscopic examination of the larynx. RESULTS: In this small series, all four patients had implantation-related paresis. Three of the four appear to have side effects from device activation. CONCLUSIONS: Patients in whom a vagal nerve stimulator is placed can have adverse side effects. These can be related to the surgical manipulation of the vagus nerve, resulting in a temporary paresis of the vocal folds. A second set of side effects is related to the actual electrical stimulation of the device, and these side effects can directly affect the laryngeal musculature.

Adult↗
PubMed2003

Botulinum toxin management of adductor spasmodic dysphonia after failed recurrent laryngeal nerve section.

This study examined botulinum toxin type A (BTX-A) treatment of adductor spasmodic dysphonia patients who had previously undergone recurrent laryngeal nerve section that failed to control symptoms. Information was retrieved from records of patients treated by our group between 1984 and 1999. Complete records with standardized outcome measurements were available for 181 BTX-A injection sessions in 16 patients who had had nerve section. These were compared to previously published information regarding 4,621 sessions in 639 adductor spasmodic dysphonia patients also treated by our group. Treatment with BTX-A resulted in significant improvement in voice function in the studied patients (change, 38.2% +/- 24.5%; p < .0001). The onset of effect took place approximately 2.3 days after treatment, and the peak effect about 10.0 days after treatment. The therapeutic effect lasted 14.1 weeks on the average. These features were not significantly different from those observed in adductor spasmodic dysphonia patients as a whole. The incidence of complications was also comparable. However, lower baseline and peak posttreatment perceptions of voice function in the nerve section group were statistically significant (baseline, 45.6% +/- 23.0% versus 52.4% +/- 22.0%; peak, 83.8% +/- 16.4% versus 89.7% +/- 13.0%; both p < .001). We conclude that BTX-A is effective in the treatment of adductor spasmodic dysphonia in patients who have had recurrent nerve section. However, nerve section may adversely affect perceived voice function and may make botulinum toxin therapy less satisfactory. Because of this finding, and because of the unusual pathological features of the focal dystonias, irreversible means of treating adductor spasmodic dysphonia should be approached with caution.

Adolescent↗
PubMed2002

Other noncosmetic uses of BOTOX.

Botulinum toxin A has a wide variety of clinical applications, which are related by blockade of acetylcholine and often are related to abnormal muscle contractures. These applications include ocular disorders, disorders of the upper aerodigestive tract, dystonia and hemifacial spasm, cosmetic, gastrointestinal disorders, genitourinary disorders, management of pain, and use in autonomic nervous system disorders. Many of these diseases will be discussed with regard to their treatment with botulinum toxin compared to conventional treatments. Advantages and disadvantages of botulinum toxin use are delineated. General guidelines for adult and pediatric dosing will also be discussed.

Autonomic Nervous System Diseases↗
PubMed2002

Botulinum toxin type A (BOTOX) for treatment of migraine.

An open-label study and 2 double-blind, placebo-controlled studies have provided supporting evidence of botulinum toxin type A (BTX-A) as an effective, well-tolerated treatment for migraine. Observed durations of benefit were consistent with known properties of BTX-A. Findings suggest that response may vary by features of preinjection headaches, such as migraine frequency. The precise mechanism by which BTX-A provides pain relief is hypothesized to be related not only to acetylcholine inhibition but also to a blocking action on the parasympathetic nervous system. Additional studies that control factors likely to be related to response may lead to better understanding of the BTX-A effect on migraine and an optimal treatment protocol.

Blepharoptosis↗
PubMed2002

Swallowing and sensation: evaluation of deglutition in the anesthetized larynx.

To better characterize the role of laryngeal sensory systems in swallowing, we assessed 5 healthy adult volunteers via functional endoscopic evaluation of swallowing before and after bilateral superior laryngeal nerve block. The volunteers were tested multiple times with both liquid and puree consistencies. Laryngeal anesthesia resulted in a significantly higher (p < .05) incidence of premature spillage, pharyngeal residual, and laryngeal penetration with all consistencies, and a higher incidence of tracheal aspiration with liquid. Aspiration of puree was increased, but the difference did not achieve significance. These results contrast with those achieved by others with topical anesthesia, which caused little impairment. Other afferent modalities besides light touch, interrupted by superior laryngeal nerve block but not by topical anesthesia, may account for the difference. It is likely that this study underestimates the severity of clinical disability from afferent deficits, because of the short duration of the experimental deficit and the lack of associated comorbidities in the subjects. These findings have implications for clinical sensory testing and sensate flap reconstruction of pharyngeal defects.

Adult↗
PubMedDate not supplied

Botulinum toxin for masseter reduction in Asian patients.

Asian patients frequently seek aesthetic alteration of hypertrophic masseter muscles to reduce a prominent mandibular angle. Surgical reduction is common in Asia, but botulinum toxin offers a less invasive approach. This pilot study evaluated results of aesthetic lower face narrowing in 20 Asian patients. Initially, 25 U of botulinum toxin (5 U/0.1 mL) was injected at each inferior masseter border; an additional 25 U was injected per side as needed at 1-week intervals. Seven patients (35%) required only 1 injection; 10 (50%) required 2; and 3 (15%) required 3 injections. Maximum reduction was seen at 1 to 2 months; more prominent hypertrophy yielded the most impressive results. Maintenance reinjection took place at 6 to 8 months. Up to 12 months of follow-up is reviewed herein. Two patients (10%) complained of mild fatigue after vigorous chewing and 1 developed mild transient buccal weakness. Nineteen of 20 patients were satisfied.

Adolescent↗
PubMedDate not supplied

Facial anatomy.

Botulinum toxin acts at the neuromuscular endplate, which requires precise delivery of the drug to achieve a desired clinical result. A thorough understanding of the complex anatomic structures of the face and their effect on facial form and function, coupled with an appreciation of facial esthetics and the balanced muscle actions that produce resting and active facial form, will result in accurate and reproducible clinical effects. Utilizing some general anatomic principles in combination with specific individual facial features and variations will enable the physician to consistently find the optimum injection sites and combination of other therapies for desired outcomes.

Face↗
PubMedDate not supplied

Noncosmetic uses of botulinum toxin.

Since the introduction of botulinum toxin (BTX) as a therapeutic tool in the 1970s, the number of uses for this substance has increased exponentially. BTX's mechanism of action involves degrading the SNARE proteins blockading the release of acetylcholine into the neuromuscular junction. In many body systems, decrease of contractility, strength, and tension of certain muscle groups result in improved clinical outcomes. Applications now include cosmetic, gastroenterologic, otolaryngologic, genitourinary, neurologic, and dermatologic uses. In fact, BTX can be considered as a potential treatment in any situation involving inappropriate or exaggerated muscle contraction. Currently, the FDA has approved BTX-A (Botox) for treating glabellar lines, blepharospasm, strabismus, hemifacial spasm, cervical dystonia, and spasticity. With the addition of cosmetic applications to the FDA's approval list, the use of BTX has increased dramatically.

Botulinum Toxins, Type A↗