Frey syndrome. A proposal for evaluating severity

Lipofilling after total parotidectomy: a useful option to prevent functional and aesthetic sequelae

Objective

Parotidectomy is the main treatment for parotid tumours, but its functional and aesthetic sequelae can be very disturbing for patients.

Methods

15 patients underwent total conservative parotidectomy, harvesting of a superficial musculoaponeurotic system (SMAS) flap and lipofilling between May 2014 and June 2020 for a benign parotid tumour. Aesthetic, functional sequelae and cosmetic results were assessed with the House-Brackmann scale, Luna-Ortiz's classification and a semiquantitative questionnaire. Lipofilling resorption was analysed by maxillofacial and neck MRI imaging at 2 years after surgery. The results were compared to a group of 21 patients who underwent total parotidectomy without harvesting a SMAS flap and lipofilling.

Results

No complications were observed. No facial defects were seen during follow-up. Post-operative MRI showed fat resorption was less than 20% in 12 patients and from 20 to 30% in 3 patients. Cosmetic satisfaction was 100% in all cases. Only 1 patient (6%) complained of Frey's syndrome.

Conclusions

Lipofilling is an excellent solution considering its efficacy, safety, simplicity, duration over time and economic costs. Donor site invasiveness is minimal, and reintervention is always possible. Face-lift incision and SMAS flap can improve aesthetic results and minimise the disfiguring impact of the surgical scar.

Frey's syndrome: A review of the physiology and possible role of neurotrophic factors

OBJECTIVES

Frey's syndrome (FS) describes the phenomenon of gustatory sweating and is a cause of significant social embarrassment for sufferers. It has been attributed to aberrant growth of parasympathetic salivatory fibers in the auriculotemporal nerve toward overlying sweat glands. However, the exact mechanism behind this growth is unknown. This review aims to expand and elucidate the theory of aberrant regeneration in FS.

METHODS

A review of the recent literature on nerve regeneration was conducted in order develop further insights into the etiology of both adult onset and pediatric FS.

RESULTS

Neurturin, a neurotrophic factor released by both salivary and sweat glands, was identified as a possible key player in the etiology of FS.

CONCLUSION

Further research into the role of neurturin could help to elucidate the pathogenic mechanisms underlying the condition and might reveal neurturin to be a potential target for pharmacological intervention.

LEVEL OF EVIDENCE

NA (Basic Science Review).

Prevention of Frey's Syndrome with the Use of Porcine Dermal Collagen Graft: Retrospective Analysis of 76 "Formal" Parotidectomies for Benign Pathologies

BACKGROUND

Frey's syndrome is a well-known complication of parotid surgery; its prevention may be achieved by the use of an interpositional barrier between the overlying flaps and the exposed parenchymal bed of parotid gland. The aim of this study was to retrospectively evaluate clinical outcomes with and without the interpositional placement of a porcine dermal collagen graft (PDCG) for prevention of syndrome occurrence.

METHODS

We conducted a 20-year retrospective study including the patients who had undergone "formal" (superficial, total, or subtotal) parotidectomies for benign pathologies. The inclusion criteria also involved patients that were (i) regularly monitored about clinical symptoms related to syndrome, and (ii) examined with Minor starch-iodine test. The severity of the diagnosed syndrome was retrospectively evaluated according to the grading score system of Luna-Ortiz. To assess group differences in terms of the extent of dissection in operating sites, we estimated the tumor and histological specimen volumes using the available dimensions.

RESULTS

We included 73 patients who had undergone 76 formal parotid surgeries. The surgical sites were divided into 2 groups: (1) Group A consisted of 44 sites that were reconstructed with a SMAS flap, and (2) Group B, comprised 32 sites where a PDCG was additionally applied as an artificial preventive barrier. At a mean follow-up of 26.3 months, a significantly lower incidence of clinically diagnosed Frey's syndrome was found after the use of dermal collagen interpositional barrier (P = .031). Specifically, subjective symptoms were reported at an incidence of 31.8% in Group A and 6.7% in Group B. Minor's test was positive at an incidence of 59.09% in Group A and 21.87% in Group B (P = .004, 95% CI). Severe Frey's syndrome was observed in 31.82% of the patients of Group A and in 3.12% of the patients of Group B (P = .002, 95% CI). Since there were no statistical significant differences between the volumes of the removed tumors and the excised histological specimens, the extent of dissection was not proved to influence the occurrence of Frey's syndrome in the compared groups.

CONCLUSION

Porcine dermal collagen is a safe, practical, and useful means for parotid reconstruction, since it seems to contribute in prevention of Frey's syndrome when increased amount of glandular tissue has to be removed. Additional randomized controlled studies with bigger samples are required to better assess the PDCG use in parotid surgery.

What is the best method for prevention of postparotidectomy Frey syndrome? Network meta-analysis

BACKGROUND

Prevention of Frey syndrome (FS) after parotidectomy using an interposition barrier has long been gaining a wide popularity; however, there is no clear evidence regarding which preventive technique is more effective. The aim of this network meta-analysis (NMA) is to answer the question: What is the best method for prevention of FS after parotidectomy?

METHODS

A comprehensive search of the PubMed, Embase, SCOPUS, and Cochrane library was conducted to identify the eligible studies. The outcome was the incidence of subjective Frey syndrome (SFS) and objective Frey syndrome (OFS). The Bayesian NMA accompanied with a random effects model and 95% credible intervals (CrIs) were calculated using GeMTC R package.

RESULTS

Thirty-four studies (n = 2987 patients) with five interventions, namely Alloderm (ADM), temporoparietal fascia (TPF), sternocleidomastoid muscle (SCM), superficial musculoaponeurotic system (SMAS), and free fat graft (FFG), were compared together and with no interposition barrier (NB). The results of NMA showed a statistically significant reduction in both SFS and OFS when ADM, TPF, SMAS, FFG, and SCM were compared with NB. No statistical differences were observed when comparing ADM, SCM, SMAS, FFG, and TPF. TPF ranked the best of all treatments (59.4%) and was associated with the least incidence of SFS; whereas ADM ranked the best of all treatments (61.1%) and was associated with the least incidence of OFS.

CONCLUSIONS

All interventions (TPF flap, ADM, FFG, SMAS, and SCM) were associated with a significant reduction in the incidence of FS when compared with NB. TPF and ADM showed the best outcome with the least incidence of SFS and OFS, respectively.

Extracapsular dissection versus partial superficial parotidectomy for the treatment of benign parotid tumours

The purpose of this study was to compare the complications of patients treated for a benign parotid tumour (BPT) by extracapsular dissection (ECD) vs. partial superficial parotidectomy (PSP). A comprehensive literature investigation was conducted by searching electronic databases. A systematic review and meta-analysis of comparative studies were performed to assess ECD and PSP for the treatment of BPTs with fixed-effects models. The outcomes analysed were transient or permanent facial nerve injury, Frey syndrome, recurrence rate, infection, and salivary fistula/sialocele. A total of 1641 patients from seven studies (1120 ECD-treated and 521 PSP-treated patients) were included in this meta-analysis. Transient facial nerve injury (odds ratio (OR)=0.28, 95% confidence interval (CI): 0.11-0.71; p=0.008) and Frey syndrome (OR=0.12, 95% CI: 0.03-0.48; p=0.003) were less prevalent in the ECD group. The rates of permanent facial nerve injury (OR=0.77, 95% CI: 0.35-1.70; p=0.520), recurrence rate (OR=0.17, 95% CI: 0.02-1.75; p=0.14), infection (OR=0.70, 95% CI: 0.07-6.67; p=0.76), and salivary fistula/sialocele (OR=0.40, 95% CI: 0.06-2.66; p=0.350) were similar in both groups. Although there was a trend that ECD showed a reduced risk for complications, the present results are not sufficient to conclude that ECD is more beneficial than PSP.

The Efficiacy of Sternocleidomastoid Muscle Flap on Frey's Syndrome via a Novel Test: Galvanic Skin Response

The aim of this study was to evaluate the effects of sternocleidomastoid (SCM) muscle flap on preventing Frey's syndrome by using, Galvanic skin responses (GSR). Fourty-three patients who underwent superficial parotidectomy were randomly divided into two groups and their GSR were recorded. SCM muscle flap was applied over the surgical area only in one group. Six months after the surgery, GSRs were remeasured. In addition, the patients completed a questionnaire regarding their complaints about clinical Frey's syndrome. Four patients had symptoms of clinical Frey's syndrome. Postoperative GSR measurements revealed no significant difference between two sides in flap group (p = 0.426) but higher in without flap group (p = 0.003). The patients with clinical Frey syndrome had significantly higher GSR values than the remaining patients. The SCM muscle flap was an effective method in preventing Frey's syndrome. Moreover, GSR test was highly sensitive and specific for diagnosis.

Free fat grafting in superficial parotid surgery to prevent Frey's syndrome and improve aesthetic outcome

Background:

Frey's syndrome and cosmesis are important considerations in parotid surgery. Placement of an interpositional barrier can prevent these complications; however, surgical technique and efficacy remain controversial.

Methods:

A prospective case series was collected comprising all patients undergoing primary superficial parotidectomy for benign pathology with abdominal free fat grafting between June 2007 and December 2010, performed by a single surgeon. A survey was also distributed to otorhinolaryngology consultants across Australia to assess current practice.

Results:

Twenty-eight patients were included. No patient had clinical symptoms of Frey's syndrome. Seventy-five per cent of patients were completely satisfied with their aesthetic outcome, 18 per cent scored 4/5 and the remaining 7 per cent (2 patients) scored 3/5. The survey revealed that 79 per cent of respondents did not use interpositional grafts.

Conclusion:

Abdominal free fat is ideal for grafting as it is an effective, safe, simple, accessible, fast and inexpensive method of providing an interpositional graft.

Frey's syndrome: diagnosis in geriatric dentistry

Frey's syndrome, is characterized by warmth, flushing and sweating of the face, most of time in the preauricular region, initiated by any gustatory stimulus. It is frequently related to parotid surgery. A case of Frey's syndrome in a 81-year-old female whose long-delayed clinical onset post-parotidectomy is presented.

Delayed Frey syndrome after closed treatment of condylar fracture

Frey syndrome is also known as auriculotemporal syndrome and gustatory sweating. It is characterized by the occurrence of hyperesthesia, flushing, and warmth or sweating over the distribution of the auriculotemporal nerve and/or greater auricular nerve while eating foods that produce a strong salivary stimulus. It is commonly seen as a complication of parotidectomy and open surgery of temporomandibular joint. It can also be caused by other forms of trauma, including blunt trauma, but rarely does it occur without trauma. The relation between fracture displacement of the condyle and Frey syndrome adds further support to the view of the intimate anatomic relationship of the auriculotemporal nerve with the capsule of the temporomandibular joint. However, despite the proximity of these structures and the high incidence of condylar fracture (25%-36% of mandibular fractures), Frey syndrome is rare after this type of fracture. Symptoms are sometimes delayed and can be very slight; often neither the patient nor the surgeon realizes their presence. The symptoms usually appear 5 weeks to 1 year after nerve damage.In this clinical report, we presented the delayed occurrence of Frey syndrome in a patient in 6 years after closed reduction of condylar fracture. One prospective study and 11 case reports describing the development of Frey syndrome after closed treatment of mandibular condyle fractures were found in the last 4 decades. Our clinical report participates to literature as a 12th case report.

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.

Lucja Frey--historical relevance and syndrome review

BACKGROUND

This article documents an objective review ofthe neuro-anatomical, diagnostic and clinical implications of the auriculotemporal syndrome (Frey's syndrome). The incidence of Frey's syndrome after parotidectomy as cited in the literature varies. It may also be a sequela to a variety of inflammatory, infective and traumatic aetiologies.

METHOD

An electronic search using the search engine Google, Medline and Pubmed was performed under 'Lucja Frey', 'Gustatory sweating', 'The auriculotemporal syndrome', 'Botulinum toxin'. Relevant papers were systematically reviewed from 1965 to present.

CONCLUSIONS

This disorder is important for ENT surgeons and allied specialties. We present the main surgical and cosmetic therapeutic strategies in the literature. We also discuss the fascinating life of Lucja Frey. As one of the first female academic neurologists in Europe, her career and life were tragically altered by the events of World War II.

Management of Frey syndrome

Almost all patients who undergo parotidectomy will to some extent develop Frey syndrome (auriculotemporal syndrome or gustatory sweating) after surgery, because of aberrant regeneration of cut parasympathetic fibers between otic ganglion and subcutaneous vessels. However, only the minority of these patients needs treatment. The syndrome consists of gustatory sweating, flushing, and warming over the preauricular and temporal areas. Thick skin flap and partial superficial parotidectomy are the most important techniques to minimize the risk of developing symptomatic Frey syndrome. Intracutaneous injection of botulinum toxin A is an effective, long-lasting, and well-tolerated treatment of Frey syndrome. If recurrence occurs, the treatment can be repeated.

Frey syndrome prevalence after partial parotidectomy

Introduction

Frey syndrome is a sequela observed after parotidectomy and the reported incidence varies enormously in the literature. Diagnosis is evaluated by presence of the classic triad of gustatory sweating, heating and flushing while feeding and documented by Minor starch-iodine test.

Aim

to evaluate the incidence of this syndrome in patients submitted to partial parotidectomy at Centro Otorrinolaringológico de Limeira, from 1994 to 2004, including presence of signs and symptoms and the surgical technique.

Material and method

fourteen patients undergoing partial parotidectomy with sternocleidomastoid muscle flap answered a questionnaire and were classified as positive or negative by Minor starch-iodine test in a clinical retrospective study.

Results

21% of the patients presented symptoms and positive iodine test.

Conclusion

only the patients presenting clinical symptoms had a positive test and the adopted surgical technique was efficient due to low incidence of the syndrome.

Treatment of gustatory sweating with low-dose botulinum toxin A: a case report

Frey's syndrome, gustatory sweating in the preauricular area, is an unpleasant phenomenon occurring during meals after surgery on the parotid gland. Recently, botulinum toxin A (BTX) has been shown to reduce the symptoms, but the variation in the reported doses is large.

OBJECTIVE

To quantify the effect of treatment with low-dose BTX in a case of Frey's syndrome over a period of 6 months.

MATERIAL AND METHODS

A 56-year-old woman was treated with 10 U Botox given as 20 single, intracutaneous injections of 0.5 U, one for each cm(2), 3 years after resection of the parotid gland. Before treatment and repeatedly during the 6-month period, the sweating was rated subjectively on a 100-mm visual analog scale (VAS) and by a severity index, and objectively by assessment of the extent of the involved skin area using Minor's iodine-starch test, staining the area of sweating dark.

RESULTS

The treatment decreased the involved area from 20 to 5 cm(2) and the VAS ratings from 98 to 8 mm. The index showed that treatment affected the sweating intensity, not the frequency. After the 6-month period the patient was still satisfied, but the involved skin area had increased; however, not entirely to pretreatment values.

CONCLUSIONS

The effect of BTX injections for gustatory sweating obtained in this case was comparable to results reported using higher doses. Low doses of BTX can therefore be used in the treatment of Frey's syndrome, but studies to clarify the dose-response relationship, in terms of both time-course and obtained effect, are needed.