The use of botulinum toxins to treat hyperhidrosis and gustatory sweating syndrome

Sweating Disorders

PURPOSE OF REVIEW

This article reviews disorders of sweating, including hyperhidrosis and anhidrosis due to central or peripheral autonomic nervous system causes.

RECENT FINDINGS

Disorders of thermoregulation and sweating may manifest with hyperhidrosis or hypohidrosis/anhidrosis. Primary disorders of hyperhidrosis may significantly impact quality of life yet tend to be benign. Many sweating disorders present with compensatory hyperhidrosis due to areas of anhidrosis. Anhidrosis may occur due to either central or peripheral damage to the autonomic nervous system. The thermoregulatory control of sweating involves central pathways from the hypothalamus to the brainstem and then spinal cord as well as projections to peripheral structures, including the sympathetic chain ganglia, peripheral nerves, and eccrine sweat glands. Disruption at any point of this pathway may lead to impaired sweating. Characterization of sweating dysfunction helps localize different autonomic disorders to guide diagnosis and may allow for evaluation of treatment effect.

SUMMARY

Sweating dysfunction manifests in myriad ways, including essential hyperhidrosis, complete anhidrosis with heat intolerance, and compensatory hyperhidrosis due to anhidrosis, and often indicates involvement of underlying central or peripheral autonomic dysfunction.

Botulinum neurotoxin: Progress in negating its neurotoxicity; and in extending its therapeutic utility via molecular engineering. MiniReview

While the poisonous effects of botulinum neurotoxin (BoNT) have been recognized since antiquity, the overall actions and mechanisms of effects of BoNT have been elucidated primarily over the past several decades. The general utility of BoNT is described in the paper, but the focus is mainly on the approaches towards negating the toxic effects of BoNT, and on the projection of an engineered BoNT molecule serving as a Trojan Horse to deliver a therapeutic load for treatment of a host of medical disorders. The BoNT molecule is configured with a binding domain, a zinc-dependent protease with specificity primarily for vesicular proteins, and a translocation domain for delivery of the metalloprotease into the cytoplasm. The anti-toxin approaches for BoNT include the use of vaccines, antibodies, block of BoNT binding or translocation, inhibition of metalloprotease activity, impeded translocation of the protease/catalytic domain, and inhibition of the downstream Src signaling pathway. Projections of BoNT as a therapeutic include its targeting to non-cholinergic nerves, also targeting to non-neuronal cells for treatment of hypersecretory disorders (e.g., cystic fibrosis), and treatment of hormonal disorders (e.g., acromegaly). Still in the exploratory phase, there is the expectation of major advances in BoNT neuroprotective strategies and burgeoning utility of engineered BoNTs as therapeutics.

The effect of botulinum toxin B pretreatment to the blood flow in the microvascular anastomosis

BACKGROUND

Although multiple factors can lead to free flap failure, vessel-related accidents are the most important. Many methods have been developed (both intraoperative and postoperative) to prevent vessel-related complications. In this article, we study the effects of a "preoperative treatment" using botulinum toxin B that could enhance the velocity and blood flow of vascular pedicles and decrease vascular accidents.

METHODS

Ten Sprague-Dawley rats were pretreated with botulinum toxin type B at the perivascular area of the femoral vessel. Ten other rats were injected with saline as a control group. After 3 days, pedicle diameter and the peak mean frequency of blood in the pedicle were measured using laser Doppler flowmetry, and the peak mean blood velocity was calculated. We performed a "pedicle division and reanastomosis" operation to compare changes in vessel diameter and peak mean blood velocity.

RESULTS

Vessel diameter was significantly increased in the botox-pretreated group for both veins and arteries. A comparison of the deep femoral vein and artery blood velocities showed that the peak mean velocity was significantly higher in the botox group. The average increase in blood velocity was significantly larger in the botox group.

CONCLUSIONS

Botulinum toxin B is helpful by influencing the microvascular environment through an increase in the blood velocity of the pedicle.

Treatment of Frey's syndrome with botulinum toxin type B

OBJECTIVE

Frey's syndrome is a frequent sequela of parotidectomy, causing facial sweating and flushing because of gustatory stimuli. Although botulinum toxin type A has become first-line therapy for Frey's syndrome, some patients become resistant. In this study, we investigated whether another serotype, botulinum toxin type B, might be an effective alternative.

STUDY DESIGN

Case series with planned data collection.

SETTING

Otolaryngology department in a university hospital.

SUBJECTS AND METHODS

Seven patients aged 30 to 68 years, with severe Frey's syndrome, underwent the Minor test and had 80 U of botulinum toxin type B per cm(2) (mean total dose, 2354 U) injected intracutaneously in the mapped area of gustatory sweating. All patients were followed up for 12 months.

RESULTS

One month after treatment, six of the seven patients reported that gustatory sweating and flushing had resolved, and, in the remaining patient, these symptoms had decreased. The Minor test confirmed a significant improvement. The subjective benefits remained stable for six months in four patients and for nine months in the remaining three patients; 12 months after treatment, all patients still reported some improvement.

CONCLUSION

Botulinum toxin type B afforded symptomatic relief in a small sample of patients with Frey's syndrome and might be considered a potential alternative to botulinum toxin type A.

Evolution of neurotoxins: from research modalities to clinical realities

In the 1950s, the discovery of anti-nerve growth factor, an immunotoxin stunting sympathetic neural development, signaled the advent of neurotoxins as research modalities. Other selective neurotoxins were discovered in rapid succession. In the 1960s, 6-hydroxydopamine and 6-hydroxydopa were shown to destroy noradrenergic and dopaminergic nerves. Excitotoxins (glutamate, aspartate, and analogs) were discovered in the 1970s. DSP-4 [N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine] proved to be selective for noradrenergic destruction, while 5,6- and 5,7-dihydroxytryptamines were relatively selective for serotonin neurons. Additional neurotoxins were discovered, but it was MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) that predominated neurotoxicity research in the 1980s. Eventually, Clostridium botulinum neurotoxin (BoNT), discovered as a "poisonous" principle in the late 1800s, resurfaced in purified and standardized forms as a clinically useful drug. Neurotoxins represent chemical tools, useful not only for discerning neuronal mechanisms and animal modeling of neurological disorders, but also for their use in medicine and potential as treatments for medical disorders. This unit reviews the early discovery of neurotoxins, describes categories of neurotoxins, and finally characterizes their usefulness--first as research tools, and eventually as clinical therapeutic agents.

Sustained benefit lasting one year from T4 instead of T3-T4 sympathectomy for isolated axillary hyperhidrosis

INTRODUCTION

Level T4 video-assisted thoracoscopic sympathectomy proved superior to T3-T4 treatment for controlling axillary hyperhidrosis at the initial and six-month follow-ups of these patients.

OBJECTIVE

To compare the results of two levels of sympathectomy (T3-T4 vs. T4) for treating axillary sudoresis over one year of follow-up.

METHODS

Sixty-four patients with axillary hyperhidrosis were randomized to denervation of T3-T4 or T4 alone and followed prospectively. All patients were examined preoperatively and were followed postoperatively for one year. Axillary hyperhidrosis treatment was evaluated, along with the presence, location, and severity of compensatory hyperhidrosis and self-reported quality of life.

RESULTS

According to patient reports after one year, all cases of axillary hyperhidrosis were successfully treated by surgery. There were no instances of treatment failure. After six months, compensatory hyperhidrosis was present in 27 patients of the T3-T4 group (87.1%) and in 16 patients of the T4 group (48.5%). After one year, all T3-T4 patients experienced some degree of compensatory hyperhidrosis, compared to only 14 patients in the T4 group (42.4%). In addition, compensatory hyperhidrosis was less severe in the T4 patients (p < 0.01). Quality of life was poor before surgery, and it improved in both groups at six months and one year of follow-up (p = 0.002). There were no cases of mortality, no significant postoperative complications, and no need for conversion to thoracotomy in either group.

CONCLUSION

Both techniques were effective for treating axillary hyperhidrosis, but the T4 group showed milder compensatory hyperhidrosis and greater patient satisfaction at the one-year follow-up.

Different formulations of botulinum toxin type A have different migration characteristics: a double-blind, randomized study

OBJECTIVE

Different formulations of botulinum toxin type A (BoNTA) are not identical and may behave differently in clinical practice. The reportedly lower incidence of adverse effects with one formulation (from Allergan, Ltd.) relative to another (from Ipsen, Ltd.) may be due to differences in the degree of migration of the neurotoxin-protein complex from its injection site. A double-blind, randomized, within-subject pilot study was performed to compare the migration characteristics of each formulation.

METHODS

Twelve healthy volunteers were randomly assigned to receive three 0.1 mL intradermal injections in their forehead: 4 U BoNTA (Allergan) on one side, 12 U BoNTA (Ipsen) on the contralateral side, and saline in the center. At day 14, Minor's iodine starch test was performed, and the subjects walked around a hot room to induce sweating. The appearance of each forehead was documented using Canfield photography and the area of each anhidrotic halo calculated using software.

RESULTS

Overall, the area of anhidrosis was significantly larger with BoNTA (Ipsen) than BoNTA (Allergan) - mean +/- SD of 2.7 +/- 0.78 cm(2) vs. 1.8 +/- 0.65 cm(2) (P = 0.005) - with the area of anhidrosis being greater with BoNTA (Ipsen) than BoNTA (Allergan) in 11 of the 12 subjects. Across all subjects, the area of anhidrosis was greater with BoNTA (Ipsen) than BoNTA (Allergan) by a mean of 77%.

CONCLUSIONS

BoNTA (Ipsen) migrates more than BoNTA (Allergan) under the conditions described. The lower potential of BoNTA (Allergan) to migrate promotes more precise localization of clinical effects, thereby helping to optimize the risk/benefit ratio.

Botulinum neurotoxin: evolution from poison, to research tool--onto medicinal therapeutic and future pharmaceutical panacea

Botulinum neurotoxin (BoNT), for more than a hundred years, has been a recognized poisonous principle in spoiled food. As its chemical structure became unraveled, and as more knowledge was gained over its mechanism of toxicity, it became clear that BoNT had the potential to act therapeutically as a targeted toxin that could inactivate specific nerve populations, and thus achieve a therapeutic goal. BoNT has evolved over the past 25 years into a viable therapeutic, now being a first line treatment for dystonia, overtly altering the course of progression of this disorder. BoNT is used for hyperhidrosis and gustatory sweating syndrome, alleviation of pain, as a treatment for overactive bladder, achalasia and anal fissure; and it has gained popularity as a cosmetic aid. Many other possible uses are being explored. The greatest potential for BoNT may lie in its being a molecular Trojan Horse - able to carry a specific enzyme or specific drug to the inside of a cancer or other type of cell while bypassing other cells and thereby having little or no ill effect. BoNT's pharmaceutical potential is boundless.

The use of botulinum toxin in head and face medicine: an interdisciplinary field

Background

In this review article different interdisciplinary relevant applications of botulinum toxin type A (BTA) in the head and face region are demonstrated.

Patients with head and face disorders of different etiology often suffer from disorders concerning their musculature (example: synkinesis in mimic muscles) or gland-secretion.

This leads to many problems and reduces their quality of life. The application of BTA can improve movement disorders like blepharospasm, hemifacial spasm, synkinesis following defective healing of the facial nerve, palatal tremor, severe bruxism, oromandibular dystonias hypertrophy of the masseter muscle and disorders of the autonomous nerve system like hypersalivation, hyperlacrimation, pathological sweating and intrinsic rhinitis.

Conclusion

The application of botulinum toxin type A is a helpful and minimally invasive treatment option to improve the quality of life in patients with head and face disorders of different quality and etiology. Side effects are rare.

The role of botulinum toxin in the management of head and neck cancer patients

PURPOSE OF REVIEW

In this review article different relevant applications of botulinum toxin type A are demonstrated in patients with head and neck cancer.

RECENT FINDINGS

Patients with head and neck cancers of different etiologies often suffer from disorders concerning their musculature (for example, synkinesis in mimic muscles) or gland secretion in the head and neck region. This leads to many problems and reduces their quality of life. The application of botulinum toxin type A can improve movement disorders like synkinesis following reconstructive surgery in patients with cancers of the parotid gland, spasms of the pharyngo-esophageal musculature following laryngectomies and disorders of the autonomous nerve system like hypersalivation, hyperlacrimation and pathological sweating.

SUMMARY

The application of botulinum toxin type A is a helpful and minimally invasive treatment option in different functional disorders improving the quality of life in patients with head and neck cancers of different etiologies. Side effects are rare.

Primary cultures of embryonic chicken neurons for sensitive cell-based assay of botulinum neurotoxin: implications for therapeutic discovery

Botulinum toxin is an exceedingly potent inhibitor of neurotransmission across the neuromuscular junction, causing flaccid paralysis and death. The potential for misuse of this deadly poison as a bioweapon has added a greater urgency to the search for effective therapeutics. The development of sensitive and efficient cell-based assays for the evaluation of toxin antagonists is crucial to the rapid and successful identification of therapeutic compounds. The authors evaluated the sensitivity of primary cultures from 4 distinct regions of the embryonic chick nervous system to botulinum neurotoxin A (BoNT/A) cleavage of synaptosomal-associated protein of 25 kD (SNAP-25). Although differences in sensitivity were apparent, SNAP-25 cleavage was detectable in neuronal cells from each of the 4 regions within 3 h at BoNT/A concentrations of 1 nM or lower. Co-incubation of chick neurons with BoNT/A and toxin-neutralizing antibodies inhibited SNAP-25 cleavage, demonstrating the utility of these cultures for the assay of BoNT/A antagonists.

A randomized trial of T3-T4 versus T4 sympathectomy for isolated axillary hyperhidrosis

INTRODUCTION

Video-assisted thoracic sympathectomy (VATS) is one minimally invasive definitive treatment for axillary hyperhidrosis. Different techniques exist for controlling axillary sudoresis, but they are temporary and have high cost. This study was conducted to compare the initial results from sympathectomy using two distinct levels for treating axillary sudoresis: T3-T4 vs T4.

METHODS

Sixty-two patients with axillary hyperhidrosis were prospectively randomized for denervation of T3-T4 or T4 alone. All patients were examined preoperatively and were followed-up at 1 and 6 months postoperatively. Evaluated were the axillary hyperhidrosis treatment, the presence, location, and severity of compensatory hyperhidrosis, and the quality of life.

RESULTS

All the patients said that their axillary hyperhidrosis was successfully treated by the surgery after 6 months. There was no treatment failure. Compensatory hyperhidrosis was present in 29 patients (90.6%) of the T3-T4 group and in 17 T4 patients (56.7%) after 1 month. After 6 months, all the T3-T4 patients presented some degree of compensatory hyperhidrosis vs 13 T4 patients (43.3%). The severity of the compensatory hyperhidrosis was also lower in the T4 patients (P < . 01). The quality of life was poor in both groups before the surgery, and was equally improved in both groups after 1 and 6 months of follow-up. There were no deaths or significant postoperative complications nor a need for conversion to thoracotomy.

CONCLUSION

Both techniques are effective for treating axillary hyperhidrosis, but the T4 group presented milder compensatory hyperhidrosis and had a greater satisfaction rate.