Recurrent laryngeal nerve paralysis and the non-malignant thyroid

Informed Consent for Intraoperative Neural Monitoring in Thyroid and Parathyroid Surgery - Consensus Statement of the International Neural Monitoring Study Group

In the past decade, the use of intraoperative neural monitoring (IONM) in thyroid and parathyroid surgery has been widely accepted by surgeons as a useful technology for improving laryngeal nerve identification and voice outcomes, facilitating neurophysiological research, educating and training surgeons, and reducing surgical complications and malpractice litigation. Informing patients about IONM is not only good practice and helpful in promoting the efficient use of IONM resources but is indispensable for effective shared decision making between the patient and surgeon. The International Neural Monitoring Study Group (INMSG) feels complete discussion of IONM in the preoperative planning and patient consent process is important in all patients undergoing thyroid and parathyroid surgery. The purpose of this publication is to evaluate the impact of IONM on the informed consent process before thyroid and parathyroid surgery and to review the current INMSG consensus on evidence-based consent. The objective of this consensus statement, which outlines general and specific considerations as well as recommended criteria for informed consent for the use of IONM, is to assist surgeons and patients in the processes of informed consent and shared decision making before thyroid and parathyroid surgery.

Peculiar anatomic variation of recurrent laryngeal nerve and EMG change in a patient with right substernal goiter and pre-operative vocal cord palsy-case report

We report a patient with right substernal goiter and preoperative vocal cord palsy (VCP). During dissection, an anatomic variation of the recurrent laryngeal nerve (RLN) and a prolonged EMG were detected by intraoperative neuromonitoring (IONM). Symmetrical vocal cord movement was recorded one month after surgery. The potential for recovery of vocal cord function is high after surgical treatment of a thyroid tumor with preoperative VCP. An IONM enables early localization of the RLN position. To the best of our knowledge, this case of prolonged EMG in an abnormal acquired-ventral RLN trajectory is the first reported in the literature.

[Thyroid tumors in the adult revealed by unilateral laryngeal paralysis]

GOAL

To analyze the characteristic of thyroid tumor associated with ipsilateral unilateral laryngeal paralysis (ULP) in the adult patient.

MATERIALS AND METHODS

Retrospective analysis of a cohort of 30 patients with ULP related to an ipsilateral thyroid tumor (group A) and comparison with a cohort of 99 patients in whom ULP revealed a non-thyroid tumor (group B).

RESULTS

Group A consisted of 66.6% of women with a mean age of 69 years. Comparison between both groups noted that female gender was more frequent in group A (66.6% vs. 17.1%, P<0.0001), and the underlying tumor was more frequently malignant in group B (89.9% vs. 43.4%, P<0.0001). Within group A, the incidence for recovery of laryngeal motion varied form 0% for malignant tumor to 50% for benign tumor. In patients with a benign thyroid tumor in whom recovery of laryngeal motion did not occur, the watch policy initiated allowed to detect a pathology (malignant tumor or neurological) explaining persistent ULP in 57% of cases.

CONCLUSION

The present series confirm that ULP in the face of thyroid tumor does not allow to distinguish formally between benign and malignant tumors and highlight the value of a long term watch policy in patients with benign thyroid tumor pathology in whom recovery of laryngeal mobility does not occur.

The basis of preoperative vocal fold paralysis in a series of patients undergoing thyroid surgery: the preponderance of benign thyroid disease

BACKGROUND

Preoperative vocal fold paralysis (VFP) is thought to be rare in patients with benign thyroid disease (BTD). In contrast with cases of malignancy, in which the recurrent laryngeal nerve (RLN) should be severed, in patients with BTD and VFP the RLN can be preserved without threatening patients' lives. This study investigates the clinical features that enable identification of patients who have VFP associated with BTD.

METHODS

Medical records of 187 consecutive patients who underwent thyroid surgery were retrospectively reviewed. The association between preoperative VFP and pathology (benign or malignant), clinical features, and treatment results of patients with BTD and VFP were analyzed.

RESULTS

Of the 187 patients, 145 patients had BTD and 8 of these cases (5.52%) had preoperative unilateral VFP. The prevalence of BTD with VFP was 4.3% (8/187). The other 42 patients had malignant thyroid disease and 4 of these cases (9.52%) had preoperative unilateral VFP. None of the aforementioned VFP was caused by previous thyroidectomy or surgery to the neck. Although the relative risk of VFP in patients with thyroid malignancy was 1.726 (9.52%/5.52%), there was no significant association between VFP and malignancy. Of the eight patients with BTD, benign fine-needle aspiration cytology or frozen sections, goiter with a diameter larger than 5 cm, cystic changes, and significant radiologic tracheo-esophageal groove compression were the common findings. During thyroidectomy, the RLN was injured but repaired in three patients. Two events occurred in patients who had severe RLN adhesion to the tumor caused by thyroidectomy performed decades ago. Two of the five patients without nerve injury recovered vocal fold function. The overall VFP recovery rate for patients with BTD and VFP was 25% (2/8).

CONCLUSIONS

Preoperative unilateral VFP is not uncommon in thyroid surgery. Obtaining information on laryngeal function is of extreme importance when planning surgery, especially contralateral surgery. Goiter with preoperative VFP is not necessarily an indicator of malignancy. Benign perioperative cytopathologic findings with typical radiographic compression strongly suggest that VFP is caused by BTD. If, during thyroidectomy, the RLN is carefully preserved, recovery of vocal fold function may still be possible.

The prevalence of undiagnosed thyroid disease in patients with symptomatic vocal fold paresis

OBJECTIVE

Vocal fold paresis has a multifactorial etiology and is idiopathic in many individuals. The incidence of thyroid-related neuropathy in the larynx has not been previously described. The purpose of this study was to evaluate the prevalence of previously undiagnosed thyroid disease in patients with laryngeal neuropathy and to compare this prevalence with that in a cohort of patients with a neurotologic neuropathy.

STUDY DESIGN AND SETTING

Case series with chart review; tertiary care, otolaryngology practice.

SUBJECTS AND METHODS

Charts of 308 consecutive patients with dysphonia and vocal fold paresis and 333 consecutive patients with sensorineural hearing loss, who presented for evaluation during a 3-year period, were reviewed.

RESULTS

One hundred forty-six of 308 (47.4%) patients with vocal fold paresis were diagnosed with concurrent thyroid disease, whereas 55 of 333 (16.5%) patients with sensorineural hearing loss were diagnosed with concurrent thyroid disease (P<0.001, Pearson chi-square = 92.896; degrees of freedom = 5). Thyroid diagnoses among those with vocal fold paresis included benign growths (29.9%), thyroiditis (7.8%), hyperthyroidism (4.5%), hypothyroidism (3.6%), and thyroid malignancy (1.6%).

CONCLUSIONS

Thyroid abnormalities are more prevalent in patients with dysphonia and vocal fold paresis than in patients with symptomatic sensorineural hearing loss, suggesting a greater association between previously undiagnosed thyroid abnormalities and laryngeal neuropathy than that between neurotologic neuropathy and thyroid disease.

Thyroid tumors with preoperative recurrent laryngeal nerve palsy: Clinicopathologic features and treatment outcome

BACKGROUND

The aim of this present study is to define the significance of recurrent laryngeal nerve palsy (RLNP) detected before surgery for thyroid diseases with regard to the incidence of malignancy, histopathologic distribution, extrathyroidal invasion, management, and prognosis.

METHODS

Six hundred and twenty-two patients underwent operation for various thyroid disease and were treated by the same surgeon. The study was confined to 16 (3%) patients who suffered from a thyroid tumor with preoperative RLNP.

RESULTS

Of these 16 patients, 1 had benign thyroid disease, while the other 15 had malignancy (94%). Among the 15 cancer patients, 14 had extrathyroidal invasion and needed more extensive surgical procedures than total thyroidectomy. The recurrent laryngeal nerve could be dissected from the thyroid neoplasm in 3 patients, 2 of whom experienced recovery of this nerve's function postoperatively.

CONCLUSIONS

Thyroid tumor associated with RLNP is strongly suggestive of malignancy. The RLN should be preserved if it has not been invaded by the tumor, because it offers a good chance of functional recovery postoperatively. Well-differentiated thyroid cancer accounts for only half of these patients who tend to present at an older age and feature a much higher incidence of upper aerodigestive tract invasion. The operations for these patients often are complex and should be performed by experienced surgeons. Radical excision of a resectable anaplastic or squamous cell carcinoma of the thyroid gland offers the chance, albeit small, of long-term survival in this study.

[Presymptomatic injury of the recurrent laryngeal nerve in benign thyroid disease: contribution of electromyography]

Diagnosis of recurrent laryngeal nerve palsy is usually possible through a clinical, laryngoscopical and electromyographical approach, but at a critical stage of the nerve injury. We observed four cases of benign thyroïd tumoral processes with a preoperative electromyographic examination showing neurogenic abnormalities in the thyroarytenoid muscle without any clinical symptoms. We presume that only laryngeal electromyography permits the diagnosis of mild, even asymptomatic laryngeal recurrent nerve injury. A recurrent laryngeal nerve palsy occurs in thyroid tumors, most often in malignant conditions, rarely in benign ones. Nevertheless early forms of nerve injury with benign thyroïd pathology could be underrated. Since the functional prognosis of symptomatic laryngeal nerve palsy is doubtful, laryngeal electromyography, through its ability to diagnose early nerve injury, provides helpful indications in thyroïd benign tumoral diseases for the therapeutic decision.

Management of the Recurrent Laryngeal Nerve in Suspected and Proven Thyroid Cancer

Vocal cord paralysis occurs with and without infiltration of the recurrent laryngeal nerve. Patients with no paralysis may have recurrent laryngeal nerve infiltration. We studied 262 patients with invasive thyroid carcinoma and an additional 480 patients that we operated on, and we offer an approach to the management of the recurrent laryngeal nerve during surgery for suspected or proven thyroid cancer. Because complete excision of papillary carcinoma with resection of the recurrent laryngeal nerve did not improve survival over incomplete excision, we recommend incomplete excision of papillary carcinoma infiltrating a functioning recurrent laryngeal nerve with postoperative I-131 and thyroid-stimulating hormone suppression. We observed (1) lymphoma and Reidel's thyroiditis causing paralysis with infiltration of the recurrent laryngeal nerve with recovery of function, (2) benign and malignant nodules causing paralysis without infiltration of the recurrent laryngeal nerve with recovery of function, and (3) infiltration of the recurrent laryngeal nerve without paralysis in lymphoma, Graves' disease, and thyroiditis. In surgery for a suspicious nodule with paralysis, identify the recurrent laryngeal nerve, resect it if it is infiltrated by carcinoma, and preserve it if not infiltrated or if infiltrated by any pathology besides carcinoma.

Relationship between vocal cord paralysis and benign thyroid disease

BACKGROUND

Vocal cord paralysis is generally associated with advanced thyroid malignancy. It may also be present in the setting of benign thyroid disease. This association may be incidental as well as causal.

METHODS

Retrospective review of cases with concurrent diagnosis of vocal cord paralysis and benign thyroid disease.

RESULTS

Eight cases found, all with documented vocal cord paralysis, by laryngoscopy. Four patients had nodular thyroid disease, but in two it was contralateral to the recurrent laryngeal nerve paralysis. The remaining patients had goiters of various sizes. Six patients were euthyroid, two on thyroid hormone replacement. Two patients were thyrotoxic: one had Graves' disease and the other had subacute thyroiditis.

CONCLUSIONS

Vocal cord paralysis can be the result of benign thyroid disease by such mechanisms as compression, stretching, or inflammation. Malignant thyroid disease should always be ruled out in structural thyroid abnormalities. Vocal cord paralysis can also be an incidental finding unrelated to thyroid abnormality.

Recurrent laryngeal nerve palsy secondary to benign thyroid disease

A recurrent nerve palsy occurring in the presence of a goitre is considered to be caused by thyroid malignancy until proven otherwise. Three cases are described in which benign thyroid disease resulted in recurrent laryngeal nerve paralysis. Recent haemorrhage was implicated histologically as the possible aetiology in all three cases. The importance of identifying and preserving the recurrent laryngeal nerve in the surgical management is highlighted.

Acute bilateral vocal fold paresis as a symptom of benign thyroid disease

A case of bilateral laryngeal nerve paralysis caused by a small goitre is reported. After thyroidectomy the return of vocal fold movements was observed. A review of the literature is presented. The possibility of acute airway distress caused by a slightly enlarged goitre is emphasized.

Benign thyroid adenoma causing recurrent laryngeal nerve palsy in a child

The standard teaching is that only malignant thyroid masses produce recurrent laryngeal nerve palsy. An unusual exception to this rule is reported.

Persistent vocal cord paralysis in subacute thyroiditis

We report a patient with subacute thyroiditis complicated by vocal cord paralysis; the paralysis has persisted after recovery from thyroiditis.