Clinical advantages of electroneurography in patients with Bell's palsy within two weeks after onset

Task force of the Brazilian Society of Otology - evaluation and management of peripheral facial palsy

OBJECTIVE

To review key evidence-based recommendations for the diagnosis and treatment of peripheral facial palsy in children and adults.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on peripheral facial palsy were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 main parts: (1) Evaluation and diagnosis of facial palsy: electrophysiologic tests, idiopathic facial palsy, Ramsay Hunt syndrome, traumatic peripheral facial palsy, recurrent peripheral facial palsy, facial nerve tumors, and peripheral facial palsy in children; and (2) Rehabilitation procedures: surgical decompression of the facial nerve, facial nerve grafting, surgical treatment of long-term peripheral facial palsy, and non-surgical rehabilitation of the facial nerve.

CONCLUSIONS

Peripheral facial palsy is a condition of diverse etiology. Treatment should be individualized according to the cause of facial nerve dysfunction, but the literature presents better evidence-based recommendations for systemic corticosteroid therapy.

An electrophysiological prognostic diagnosis for facial palsy

Two electrophysiological tests for facial palsy-electroneurography (ENoG) and nerve excitability test (NET)-were reviewed. ENoG has advantages over NET in that it reflects the percentage of degenerated facial nerve fibers and can provide an accurate prognosis. However, as disadvantages, ENoG requires large, expensive equipment, and such supramaximal electrical stimulation can be quite painful for patients. NET is less painful due to weak stimulation with just enough current to meet the threshold, and the required equipment is compact and inexpensive to procure. However, it is impossible to calculate the percentage of degenerated nerve fibers, and NET is inferior to ENoG in terms of accurate prognostic prediction for facial palsy. The appropriate timing for both ENoG and NET is 7 to 10 days after the onset. While ENoG has proven more popular than NET because of its accuracy for prognostic prediction, we should not predict the prognosis of facial palsy based solely on the results of electrophyisiolgical examinations; a comprehensive evaluation including the facial muscle grading system is essential.

Endoscopic transcanal facial nerve decompression in Bell's palsy: A pilot study

PURPOSE

To explore the surgical effects of endoscopic facial nerve decompression in Bell's palsy.

MATERIALS AND METHODS

This retrospective study included 15 patients with Bell's palsy. All had grade VI (House-Brackmann grading system) complete unilateral facial paralysis before surgery and a >95% reduction in amplitude on electroneurography testing compared to the unaffected side. Their MRI results indicated perineural edema in the geniculate ganglion area. Endoscopic decompression surgery was performed soon after they presented at our hospital. The time between onset of facial paralysis and surgery ranged from 25 to 93 days. All patients had no relevant surgical history or ear diseases.

RESULTS

At 1-year follow-up, 13 of the 15 (87%) patients had recovered to normal or near-normal facial function (House-Brackmann grade I-II), and all patients had reached House-Brackmann grade III or lower facial function. No obvious air-bone gap or sensorineural hearing loss occurred after surgery, and there were no severe complications or synkinesis.

CONCLUSIONS

Endoscopic transcanal facial nerve decompression provides a less traumatic and improved exposure of the geniculate ganglion, and may also help prevent permanent severe facial sequela. Results of intraoperative facial nerve stimulation may be related to the length of time required for recovery. The optimal time of surgery after onset of paralysis needs to be investigated further, to identify a post-drug surgical therapy which may be more acceptable for patients. Patients' response to conservative treatments should be assessed as soon as possible so as not to delay surgery.

Role of Biomarkers as Prognostic Factors in Acute Peripheral Facial Palsy

Acute peripheral facial palsy (APFP), including Bell's palsy and Ramsay Hunt syndrome, is a disease that affects daily life through facial motor dysfunction, causing psychological problems. Various tests to evaluate prognosis have been studied; however, there are no validated predictive biomarkers to guide clinical decision making. Therefore, specific biomarkers that respond to treatment are required to understand prognostic outcomes. In this review, we discuss existing literature regarding the role of APFP biomarkers in prognosis and recovery. We searched the PubMed, EMBASE, and Cochrane Library databases for relevant papers. Our screening identified relevant studies and biomarkers correlating with the identification of predictive biomarkers. Only studies published between January 2000 and October 2021 were included. Our search identified 5835 abstracts, of which 35 were selected. All biomarker samples were obtained from blood and were used in the evaluation of disease severity and prognosis associated with recovery. These biomarkers have been effective prognostic or predictive factors under various conditions. Finally, we classified them into five categories. There is no consensus in the literature on the correlation between outcomes and prognostic factors for APFP. Furthermore, the correlation between hematologic laboratory values and APFP prognosis remains unclear. However, it is important to identify new methods for improving the accuracy of facial paralysis prognosis prediction. Therefore, we systematically evaluated prognostic and potentially predictive APFP biomarkers. Unfortunately, a predictive biomarker validating APFP prognosis remains unknown. More prospective studies are required to reveal and identify promising biomarkers providing accurate prognosis.

Steroids plus antiviral agents are more effective than steroids alone in the treatment of severe Bell's palsy patients over 40 years of age

Objective

The effectiveness of the combination of steroids and antiviral agents in the treatment of Bell’s palsy remains unclear. This study evaluated the therapeutic effect of combination therapy in severe Bell’s palsy patients and assesses specific conditions under which combination therapy is more effective than steroids alone.

Methods

From January 2005 to December 2019, the records of 1710 Bell’s palsy patients who visited Kyung Hee University Hospital were reviewed retrospectively. Of these, 335 (19.6%) patients were diagnosed with severe Bell’s palsy, with 162 patients treated with steroids alone and 173 patients treated with combinations of steroids and antiviral agents. The outcomes of treatment were assessed using the House–Brackmann (H-B) grade according to age, sex, hypertension, diabetes, and obesity.

Results

The favorable recovery rate was significantly higher in severe Bell’s palsy patients who were treated with combinations of steroids and antiviral agents than with steroids alone (78.0% vs. 66.7%, p = 0.020). Subgroup analysis showed that combination therapy resulted in significantly higher recovery rates than steroids alone in patients aged ≥40 years (77.5% vs. 64.1%, p = 0.023) and in those without hypertension (75.8% vs. 63.3%, p = 0.044) and diabetes (79.7% vs. 65.5%, p = 0.007).

Conclusion

Combination therapy with steroids and antiviral agents resulted in significantly higher favorable recovery rates than steroids alone in severe Bell’s palsy patients. Combination therapy was particularly more effective than steroids alone in patients aged ≥40 years and in patients without hypertension and diabetes.

Association between Initial Severity of Facial Weakness and Outcomes of Bell's Palsy

To establish whether clinical prognostic factor outcomes differed based on the initial severity of facial weakness and to determine the association between the initial severity of facial weakness and favorable outcomes. This retrospective cohort study analyzed all patients with Bell’s palsy who visited the outpatient clinic of our university hospital from 1 January 2005 through 31 January 2021. The primary outcome was the rate of recovery at 6 months, evaluated separately in patients with initial House–Brackmann (H-B) grades 3–4 and 5–6. Secondary outcomes included clinical factors associated with favorable outcomes stratified by the initial H-B grade. The rate of favorable recovery was higher in patients with initial H-B grades 3–4 than initial H-B grades 5–6 (82.9% vs. 68.2%, p < 0.001). Multivariable logistic regression analysis showed that age 19–65 years and good electromyography (EMG) results were prognostic of good outcomes in patients with initial H-B grades 3–4. In addition, good EMG results, controlled hypertension, and combination antiviral therapy were significantly prognostic of favorable outcomes in patients with initial H-B grades 5–6. Subgroup analysis interactions showed that combination antiviral therapy (OR: 3.06, 95% CI 1.62–5.78, p < 0.001) in initial H-B grades 5–6 were associated with more favorable outcomes at 6 months than with initial H-B grades 3–4. Our results showed that the proportion of patients who achieved favorable outcomes at 6 months and multiple clinical factors affecting favorable outcomes differed significantly among patients differing in initial severity of Bell’s palsy.

Evaluation of Factors Associated With Favorable Outcomes in Adults With Bell Palsy

Importance

Identification of the factors associated with improved facial nerve function after treatment of Bell palsy is important to provide patients with early and effective treatment.

Objective

To identify factors that are associated with improved treatment outcomes in patients with Bell palsy.

Design, Setting, and Participants

This retrospective cohort study included 1364 patients with Bell palsy treated at the outpatient clinic of the Department of Otolaryngology at the Kyung Hee University Hospital, Seoul, Republic of Korea, between January 1, 2005, and December 31, 2017. The medical records of patients admitted to this hospital for management of acute facial palsy were reviewed by 3 otolaryngologists with more than 20 years' experience in treating facial palsy.

Main Outcomes and Measures

Facial function at the initial and final visits were measured using the House-Brackmann (H-B) grading system, which is one of several analysis tools developed to quantify facial function and provide reproducible information. It is a widely accepted system for grading facial function in 6 steps, from normal (H-B grade I) to total paralysis (H-B grade VI).

Results

In total, 1364 patients with primary Bell palsy (718 [52.6%] women) and a mean (SD) age of 47.7 (16.7) years were enrolled. The overall rate of favorable outcome, which was defined as an H-B grade of I or II at the 6-month follow-up visit, was 80.6% (1099 of 1364 patients). Of 1099 patients who had a favorable outcome at 6 months, 343 (31.2%) were younger than 40 years. Of 1364 patients, 1053 (77.2%) had moderate facial dysfunction (H-B grade III or IV). No pathological spontaneous fibrillation activity (ie, good electromyography [EMG] results) was detected on EMG in 937 of 1364 patients (68.7%), 492 (36.1%) had controlled hypertension, and 673 (49.3%) were treated with oral corticosteroids alone. Multivariable analysis revealed that the following factors were associated with favorable outcome: age younger than 40 years (odds ratio [OR], 1.56; 95% CI, 1.09-2.22), an initial H-B grade of III or IV (OR, 2.62; 95% CI, 1.93-3.57), good EMG results after 2 weeks of treatment (OR, 3.38; 95% CI, 2.48-4.61), absence of diabetes (OR, 1.43; 95% CI, 1.04-2.36), and control of hypertension (OR, 1.64; 95% CI, 1.16-2.33).

Conclusions and Relevance

Multiple logistic regression analysis in this study suggests that multiple clinical factors are associated with favorable outcomes in patients with Bell palsy.

Facial paralysis: Clinical practice guideline of the Spanish Society of Otolaryngology

Bell's palsy is the most common diagnosis associated with facial nerve weakness or paralysis. However, not all patients with facial paresis/paralysis have Bell's palsy. Other common causes include treatment of vestibular schwannoma, head and neck tumours, iatrogenic injuries, Herpes zoster, or trauma. The approach to each of these conditions varies widely. The purpose of this guideline is to provide clinicians with guidance on the treatment and monitoring of patients with different causes of facial paralysis. We intend to draft a practical guideline, focusing on operationalised recommendations deemed to be useful in the daily management of patients. This guideline was promoted by the Spanish Society of Otolaryngology and developed by a group of physicians with an interest in facial nerve disorders, including at least one physician from each Autonomous Community. In a question and answer format, it includes 56 relevant topics related to the facial nerve.

Novel pre-therapeutic scoring system using patient and haematological data to predict facial palsy prognosis

OBJECTIVES

We describe a novel scoring system, the facial Palsy Prognosis Prediction score (PPP score), which we test for reliability in predicting pre-therapeutic prognosis of facial palsy. We aimed to use readily available patient data that all clinicians have access to before starting treatment.

DESIGN

Multicenter case series with chart review.

SETTING

Three tertiary care hospitals.

PARTICIPANTS

We obtained haematological and demographic data from 468 facial palsy patients who were treated between 2010 and 2014 in three tertiary care hospitals. Patients were categorised as having Bell's palsy or Ramsey Hunt's palsy.

MAIN OUTCOME MEASURES

We compared the data of recovered and unrecovered patients. PPP scores consisted of combinatorial threshold values of continuous patient data (eg platelet count) and categorical variables (eg gender) that best predicted recovery. We created separate PPP scores for Bell's palsy patients (PPP-B) and for Ramsey Hunt's palsy patients (PPP-H).

RESULTS

The PPP-B score included age (≥65 years), gender (male) and neutrophil-to-lymphocyte ratio (≥2.9). The PPP-H score included age (≥50 years), monocyte rate (≥6.0%), mean corpuscular volume (≥95 fl) and platelet count (≤200 000 /μL). Patient recovery rate significantly decreased with increasing PPP scores (both PPP-B and PPP-H) in a step-wise manner. PPP scores (ie PPP-B score and PPP-H score) ≥2 were associated with worse than average prognosis.

CONCLUSIONS

Palsy Prognosis Prediction scores are useful for predicting prognosis of facial palsy before beginning treatment.

A new electroneurography as a prognostic tool for marginal mandibular nerve paralysis after parotid gland surgery: A preliminary evaluation

OBJECTIVE

Marginal mandibular nerve paralysis is the most frequent complication of benign parotid tumor surgery and results in cosmetic deformity. The purpose of this study was to develop a new electroneurography method for marginal mandibular nerve paralysis using electroneurography (ENoG) and judge its usefulness for clinical practice.

METHODS

Twenty-seven patients who underwent surgery for benign parotid tumor were enrolled. We proposed and use the mandibular angle method, in which the recording electrode was placed on the skin above the depressor anguli oris muscle while the reference electrode was placed on the skin of the parietal region, and percutaneous electrical stimulation was applied to enclose the mandibular angle that could measure the function of the marginal mandibular nerve solely. Preoperative and postoperative ENoG values were compared in paralytic and non-paralytic patients.

RESULTS

The mean postoperative ENoG value (35.0%) was lower than the preoperative value (90.5%) in paralytic patients, whereas no difference was observed between preoperative (79.3%) and postoperative (69.5%) ENoG values in non-paralytic patients.

CONCLUSION

A new ENoG method (mandibular angle method) was thought to reflect marginal mandibular nerve injury and might be useful for determining the likelihood of paralysis.

Pretreatment Hematologic Findings as Novel Predictive Markers for Facial Palsy Prognosis

OBJECTIVE

To examine the relationship between prognosis of 2 different facial palsies and pretreatment hematologic laboratory values.

STUDY DESIGN

Multicenter case series with chart review.

SETTING

Three tertiary care hospitals.

SUBJECTS AND METHODS

We examined the clinical records of 468 facial palsy patients who were treated with an antiviral drug in combination with either oral or intravenous corticosteroids in participating hospitals between 2010 and 2014. Patients were divided into a Bell's palsy group or a Hunt's palsy group. We used the Yanagihara facial nerve grading system to grade the severity of facial palsy. "Recovery" from facial palsy was defined as achieving a Yanagihara score ≥36 points within 6 months of onset and having no accompanying facial contracture or synkinesis. We collected information about pretreatment hematologic findings, demographic data, and electrophysiologic test results of the Bell and Hunt group patients who recovered and those who did not. We then compared these data across the 2 palsy groups.

RESULTS

In the Bell's palsy group, recovered and unrecovered patients differed significantly in age, sex, electroneuronography score, stapedial muscle reflex, neutrophil rate, lymphocyte rate, neutrophil-to-lymphocyte ratio, and initial Yanagihara score. In the Hunt's palsy group, recovered and unrecovered patients differed in age, electroneuronography score, stapedial muscle reflex, monocyte rate, platelet count, mean corpuscular volume, and initial Yanagihara score.

CONCLUSIONS

Pretreatment hematologic findings, which reflect the severity of inflammation and bone marrow dysfunction caused by a virus infection, are useful for predicting the prognosis of facial palsy.

A novel muscle for electroneurography in peripheral facial palsy: occipitalis

Electroneurography (ENoG) is one of the most objective tests in grading the damage and prediction of prognosis in peripheral facial palsy (PFP). We aimed to determine temporal changes of ENoG recorded over occipitalis muscle in acute idiopathic PFP. Consecutive 21 patients with unilateral acute idiopathic PFP and age- and sex-matched 15 healthy volunteers were included in the study. Nasal and occipital ENoG values were recorded once in the control group and the same procedure was repeated daily between the second and eight days of the disorder in the PFP group. Occipital ENoG value began to increase on the third day while nasal ENoG value was still within the normal range (27.04 vs 7.69 %, p = 0.0001). In the fourth, fifth and sixth days, occipital ENoG value was significantly high compared to nasal ENoG value (p = 0.0001 for each day) whereas nasal and occipital ENoG values were very similar in the seventh and eighth days (p = 0.181 and p = 0.584, respectively). Our study presents further support for technical possibility of occipital ENoG which may reflect the degree of fiber degeneration earlier than the nasalis muscle in PFP.

Validity of late-term electroneurography in Bell's palsy

OBJECTIVE

To evaluate the validity of early (within 3 wk) and late-term (after 3 wk) electroneurography (ENoG) findings in Bell's palsy (BP) to predict the prognosis.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Patients with peripheral facial paralysis with no identified cause. All patients were given the same treatment.

INTERVENTION(S)

House Brackmann (HB) grading and ENoG.

MAIN OUTCOME MEASURES

The records of 38 patients with BP were retrospectively analyzed. This study included only those patients who had been followed up for at least 4 months on a regular basis or until complete recovery. ENoG was performed for orbicularis oculi and orbicularis oris muscles and degeneration ratio was calculated separately. Correlation between HB grading and ENoG findings, relationship between duration for maximum recovery and ENoG findings, and also initial HB grading and recovery rate were investigated.

RESULTS

Complete recovery rate was significantly higher in patients with HB grades I to III at initial examination. A significant correlation was found between HB grading and degree of ENoG degeneration at the 7th and 14th days of FP. Patients with degeneration less than 80% for orbicularis oculi and less than 65% for orbicularis oris had significantly better and faster recovery than those with higher level of degeneration (p < 0.05).

CONCLUSION

ENoG and HB grading during first to fourth weeks of BP are useful prognostic indicators. Serial ENoG examinations are recommended to predict the status of neural degeneration and the prognosis of the palsy. However, ENoG in late term may not be compatible with clinical facial function.

Clinical practice guideline: Bell's palsy

OBJECTIVE

Bell's palsy, named after the Scottish anatomist, Sir Charles Bell, is the most common acute mono-neuropathy, or disorder affecting a single nerve, and is the most common diagnosis associated with facial nerve weakness/paralysis. Bell's palsy is a rapid unilateral facial nerve paresis (weakness) or paralysis (complete loss of movement) of unknown cause. The condition leads to the partial or complete inability to voluntarily move facial muscles on the affected side of the face. Although typically self-limited, the facial paresis/paralysis that occurs in Bell's palsy may cause significant temporary oral incompetence and an inability to close the eyelid, leading to potential eye injury. Additional long-term poor outcomes do occur and can be devastating to the patient. Treatments are generally designed to improve facial function and facilitate recovery. There are myriad treatment options for Bell's palsy, and some controversy exists regarding the effectiveness of several of these options, and there are consequent variations in care. In addition, numerous diagnostic tests available are used in the evaluation of patients with Bell's palsy. Many of these tests are of questionable benefit in Bell's palsy. Furthermore, while patients with Bell's palsy enter the health care system with facial paresis/paralysis as a primary complaint, not all patients with facial paresis/paralysis have Bell's palsy. It is a concern that patients with alternative underlying etiologies may be misdiagnosed or have unnecessary delay in diagnosis. All of these quality concerns provide an important opportunity for improvement in the diagnosis and management of patients with Bell's palsy.

PURPOSE

The primary purpose of this guideline is to improve the accuracy of diagnosis for Bell's palsy, to improve the quality of care and outcomes for patients with Bell's palsy, and to decrease harmful variations in the evaluation and management of Bell's palsy. This guideline addresses these needs by encouraging accurate and efficient diagnosis and treatment and, when applicable, facilitating patient follow-up to address the management of long-term sequelae or evaluation of new or worsening symptoms not indicative of Bell's palsy. The guideline is intended for all clinicians in any setting who are likely to diagnose and manage patients with Bell's palsy. The target population is inclusive of both adults and children presenting with Bell's palsy. ACTION STATEMENTS: The development group made a strong recommendation that (a) clinicians should assess the patient using history and physical examination to exclude identifiable causes of facial paresis or paralysis in patients presenting with acute-onset unilateral facial paresis or paralysis, (b) clinicians should prescribe oral steroids within 72 hours of symptom onset for Bell's palsy patients 16 years and older, (c) clinicians should not prescribe oral antiviral therapy alone for patients with new-onset Bell's palsy, and (d) clinicians should implement eye protection for Bell's palsy patients with impaired eye closure. The panel made recommendations that (a) clinicians should not obtain routine laboratory testing in patients with new-onset Bell's palsy, (b) clinicians should not routinely perform diagnostic imaging for patients with new-onset Bell's palsy, (c) clinicians should not perform electrodiagnostic testing in Bell's palsy patients with incomplete facial paralysis, and (d) clinicians should reassess or refer to a facial nerve specialist those Bell's palsy patients with (1) new or worsening neurologic findings at any point, (2) ocular symptoms developing at any point, or (3) incomplete facial recovery 3 months after initial symptom onset. The development group provided the following options: (a) clinicians may offer oral antiviral therapy in addition to oral steroids within 72 hours of symptom onset for patients with Bell's palsy, and (b) clinicians may offer electrodiagnostic testing to Bell's palsy patients with complete facial paralysis. The development group offered the following no recommendations: (a) no recommendation can be made regarding surgical decompression for patients with Bell's palsy, (b) no recommendation can be made regarding the effect of acupuncture in patients with Bell's palsy, and (c) no recommendation can be made regarding the effect of physical therapy in patients with Bell's palsy.

Prognostic factors of Bell's palsy: prospective patient collected observational study

The purpose of this study was to evaluate various parameters potentially influencing poor prognosis in Bell's palsy and to assess the predictive value for Bell's palsy. A single-center prospective patient collected observation and validation study was conducted. To evaluate the correlation between patient characteristics and poor prognosis, we performed univariate and multivariate analyzes of age, gender, side of palsy, diabetes mellitus, hypertension, and facial grading score 1 week after onset. To evaluate the accuracy of the facial grading score, we prepared a receiver operating characteristic (ROC) curve and calculated the area under the ROC curve (AUROC). We also calculated sensitivity, specificity, positive/negative likelihood ratio, and positive/negative predictive value. We included Bell's palsy patients who attended Ehime University Hospital within 1 week after onset between 1977 and 2011. We excluded patients who were less than 15 years old and lost-to-follow-up within 6 months. The main outcome was defined as non-recovery at 6 months after onset. In total, 679 adults with Bell's palsy were included. The facial grading score at 1 week showed a correlation with non-recovery in the multivariate analysis, although age, gender, side of palsy, diabetes mellitus, and hypertension did not. The AUROC of the facial grading score was 0.793. The Y-system score at 1 week moderate accurately predicted non-recovery at 6 months in Bell's palsy.

Bell's palsy in children: relationship between electroneurography findings and prognosis in comparison with adults

OBJECTIVES

To investigate the correlation between electroneurography (ENoG) findings and the prognosis of Bell's palsy in children compared with adults.

METHODS

Twenty-two children and 92 adults with Bell's palsy who underwent ENoG between 8 days and 4 weeks from the onset of symptoms were retrospectively enrolled. The time to maximal recovery and rate of favorable recovery (House-Brackmann grade I or II) was assessed. Children (C) and adults (A) were further subdivided into low (<10%) or high (≧10%) subgroups according to their ENoG values (affected versus unaffected side) at initial evaluation. The numbers in each subgroup were as follows: C-low (n = 8), A-low (n = 21), C-high (n = 14), and A-high (n = 71).

RESULTS

Of the 22 children assessed, 2 of the 4 patients who showed a total loss of evoked potentials on the affected side (0% ENoG value) exhibited an unfavorable recovery. The remaining 20 patients achieved a favorable recovery eventually. Patients in group C-low reached a maximal recovery of facial movement significantly later than those in group C-high (p < 0.001). Time to maximal recovery of facial movement in group A-low was later than that in group C-low, although the difference was not statistically significant (p = 0.15). The patients in group A-high reached a maximal recovery significantly later than those in group C-high (p < 0.05).

CONCLUSION

Bell's palsy seems to recover earlier in children than adults when matched for severity. The presence of an identifiable response in ENoG, irrespective of its amplitude, may indicate a favorable recovery of facial movement in children.

Predictive value of postoperative electrophysiologic testing of the facial nerve after cerebellopontine angle surgery

Our objective was to assess the ability of postoperative electroneuronography (ENoG) and electromyography (EMG) to predict clinical facial function 1 year postoperatively in patients with facial paralysis and an intact facial nerve after cerebellopontine angle surgery. The study was a prospective, nonrandomized, uncontrolled clinical trial on an outpatient basis, at a tertiary care hospital. Primary eligibility criteria include: (1) cerebellopontine angle (CPA) surgery with anatomical preservation of facial nerve, (2) complete facial nerve paralysis; and (3) 1 year follow-up. ENoG and EMG were measured at 1 and 3 months postoperatively, House-Brackmann facial nerve grade at 1 year postoperatively. The Kendall coefficient of rank correlation demonstrated that the 1 and 3 month postoperative ENoG data were significant predictors of ultimate facial nerve outcome. Tracking multiple ENoG examinations in a single patient, over time was of little predictive value. EMG was a poor predictor of facial nerve outcome. In general, patients with delayed facial nerve paralysis had better ultimate facial function than patients with immediate paralysis. Postoperative ENoG, but not EMG was a statistically significant predictor of ultimate facial nerve outcome after CPA surgery. Patients with delayed facial paralysis had better outcomes than those with immediate facial paralysis.

Recovery of facial movement and facial synkinesis in Bell's palsy patients

OBJECTIVE

We examined the relationship between the time course of development of facial synkinesis in patients with Bell's palsy and the severity of facial nerve damage.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral center.

PATIENTS

Thirty-nine consecutive patients with Bell's palsy who developed synkinesis.

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURES

Subjects were divided into groups A (electroneurographic [ENoG] value, <10%; n = 31) and B (ENoG value, > or =10%; n = 8). Development of facial synkinesis was assessed based on the appearance of synkinetic potentials from the orbicularis oris muscle on the blink reflex test. Times to appearance of facial synkinesis in groups A and B were compared. The proportion of patients who developed facial synkinesis after complete recovery of facial movement was also assessed in 14 patients whose facial movement recovered completely.

RESULTS

The mean time to maximal recovery of facial movement was significantly longer in group A than in group B (p < 0.001), whereas the duration between the appearance of facial synkinesis and the onset of facial paralysis did not differ significantly between the 2 groups (p = 0.72). The proportion of patients who developed facial synkinesis after complete recovery of facial movement was significantly greater in group B than in group A (p = 0.015).

CONCLUSION

During the course of recovery from Bell's palsy, the patients with an ENoG value of 10% or greater have a higher risk of developing facial synkinesis after complete recovery of facial movement.

Reactivation of herpes simplex virus type 1 and varicella-zoster virus and therapeutic effects of combination therapy with prednisolone and valacyclovir in patients with Bell's palsy

OBJECTIVES

To determine whether reactivation of herpes simplex virus (HSV) type 1 or varicella-zoster virus (VZV) is the main cause of Bell's palsy and whether antiviral drugs bring about recovery from Bell's palsy.

STUDY DESIGN

Randomized, multicenter, controlled study.

METHODS

One hundred fifty patients with Bell's palsy were enrolled in this study. The patients were randomly assigned to a prednisolone group or a prednisolone-valacyclovir group, in whom virologic examinations for HSV-1 and VZV were performed by simple randomization scheme in sealed envelopes. The recovery rates among various groups were analyzed using the Kaplan-Meier method and the Cox proportional hazards model.

RESULTS

Reactivation of HSV-1, VZV, and both viruses was detected in 15.3%, 14.7%, and 4.0% of patients, respectively. There was no significant difference in recovery rates between the prednisolone group and the prednisolone-valacyclovir group, although recovery in the patients with HSV-1 reactivation tended to be higher in the prednisolone-valacyclovir group than in the prednisolone group. There was a significant difference in recovery among age groups and between individuals with complete and incomplete paralysis.

CONCLUSIONS

Reactivation of HSV-1 or VZV was observed in 34% of the patients with Bell's palsy. The effect of combination therapy with prednisolone and valacyclovir on recovery was not significantly higher than that with prednisolone alone.

A correlation study of endoneurial fluid pressure and electroneurography of the facial nerve

OBJECTIVE

The relationship between endoneurial fluid pressure (EFP) and electroneurography (ENoG) of the facial nerve was studied in order to evaluate the pathophysilogical basis of ENoG to serve as the criteria for decompression of the facial nerve.

METHODS

While the values of ENoG were recorded by an instrument for physiology on the normal and crushed facial nerves of guinea pigs, EFPs were measured at the same time by a servo-nulling micropipette system. After the elevated EFP was measured, the facial nerves were removed and then fixed properly for examination under the light and electron microscope in order to determine the differences from various periods after injury.

RESULTS

With the change of EFP in the facial nerve during the period from day 3 to the third week after crushed injury, the percentage of degenerated facial nerve fiber increased. There was a positive correlation between ENoG and EFP. The coefficient was 0.88 and 0.51 in the second and third week after crushed injury, respectively. Extensive edema in endoneurial and perivascular spaces of the facial nerve could be found at the early stage of injury, while proliferation of numerous Schwann cells appeared at the later stage.

CONCLUSION

The change of ENoG could reflect the value of EFP relatively within 3 weeks after crushed injury. Our data indicate that ENoG could be useful to evaluate the pathogenesis underlying facial palsy.

Electrodiagnostic studies in the management and prognosis of neuromuscular disorders

Prognosis remains a neglected aspect of modern medical care and research, behind diagnosis and treatment. The very term "electrodiagnosis" implies as much. Despite this, much has been published regarding the use and benefit of electrodiagnostic techniques in assessing prognosis and assisting in management of patients after the diagnosis has been established. This information is often hidden or otherwise not emphasized. This review summarizes the literature regarding the use of such techniques for prognosis and management of disorders of lower motor neurons, peripheral nerves, neuromuscular transmission, and muscle.

Bell's Palsy and Herpes Zoster Oticus

Normal facial movement is required for chewing, swallowing, speaking, and protecting the eye. Bell's palsy causes most cases of acute, unilateral facial palsy; infection with herpes simplex virus (HSV) type 1 may be its major cause. Varicella zoster virus (VZV) reactivation (Ramsay Hunt syndrome) is less common, but may appear without skin lesions in a form indistinguishable from Bell's palsy. Symptoms improve in nearly all patients with Bell's palsy, and most patients with Ramsay Hunt syndrome, but many are left with functional and cosmetic deficits. Steroids are frequently used to optimize outcomes in Bell's palsy, but proof of their effectiveness is marginal. Oral prednisone has been studied extensively, although some reports have suggested a higher recovery rate with intravenous steroids. Given the existing data, we support the use of oral prednisone in those patients with complete facial palsy, and no contraindications to their use (Fig. 1). In this author's opinion, the greatly increased cost and inconvenience of intravenous steroids cannot be justified by the data available. Antiviral agents may also be effective in treatment of Bell's palsy; HSV is susceptible to acyclovir and related agents. There have been few investigations of acyclovir treatment in Bell's palsy, but one controlled study showed added benefit when the drug was used with prednisone. The risk and cost of acyclovir is low enough that we support its use, with oral steroids, in those patients with complete facial paralysis. Several small studies have implied that oral acyclovir improves the outcome of facial palsy for patients with Ramsay Hunt syndrome. Although these studies do not prove efficacy, evidence for the benefits of antiviral agents in other forms of zoster is strong enough to recommend their use when the facial nerve is involved. VZV is less sensitive to acyclovir than HSV, so higher doses are recommended to treat Ramsay Hunt syndrome. Because some Ramsay Hunt syndrome patients with partial facial palsy do not fully recover, we recommend oral antiviral agents in all patients suspected of having zoster. There is weak evidence to suggest additional benefit of oral steroids in facial zoster, and their use can be supported in immunocompetent individuals. Facial nerve decompression surgery for Bell's palsy and herpes zoster oticus has experienced varying levels of enthusiasm over the years. Recent work implies that early, extensive decompression of the nerve through a middle fossa craniotomy may benefit patients at high risk for persistent deficits. However, until this procedure is subjected to a rigorous, controlled trial comparing it with maximal medical therapy, it is difficult to justify the very high costs and risk.

Electroneurographic facial muscle pattern in Bell's palsy

To study the electroneurographic facial muscle pattern in Bell's palsy over time, electroneurographic recordings in the frontalis, orbicularis oculi, nasalis, and mentalis muscle regions were performed early (mean, day 11) and 1 and 3 months after the onset of the condition in 30 consecutive patients. The correlation between facial muscle electroneurographic recordings over time was also calculated. An additional aim was to assess whether further prognostic information could be obtained by electroneurographic recordings in more than one facial region. The recovery pattern was similar in all 4 facial regions. Initially, the correlation between the facial recordings was weak (r = 0.20-0.27), but it was improved at follow-up examinations (r = 0.33-0.65). Favorable outcome in 23 of 24 patients (96%) could have been predicted by the initial nasalis and/or mentalis recordings. The gap between patients with favorable outcome and patients with unfavorable outcome increased when the average electroneurography values were calculated from 1, 2, and 4 muscle recordings (4%, 8%, and 15%, respectively). Our results indicate that in Bell's palsy, electroneurographic examination of more than one facial muscle region may add prognostic information and that the degree of degeneration is initially different in the nerve branches.

Variability of repeated facial nerve electroneurography in healthy subjects

BACKGROUND

Facial electroneurography is an objective measurement of a muscle compound action potential. The amplitude ratio between the paretic and the normal side is used as a basis for estimating the prognosis of facial palsy. According to Esslen, the difference of amplitudes in healthy subjects is only 3%. Twenty healthy test persons were investigated with the aim of 1. reproducing the published data on the left-right difference in normal test subjects and 2. determining whether the amplitude ratio is constant over time after repeated measurements.

STUDY DESIGN

Bilateral electroneurography was conducted on 20 healthy volunteers (age range, 23-36 y; 12 men, eight women). Two investigators performed four measurements at 1-week intervals on every subject.

RESULTS

Mean amplitude ratio was 32.5%. Repeated measurements on the same individual differed considerably-- from 0% to 80%. The 99% confidence interval computed from the data ranged from 26% to 39% amplitude ratio.

CONCLUSION

The symmetry of facial evoked compound potentials postulated by Esslen and Fisch is not supported by these data. As have other investigators, the authors found significant left-right differences in healthy subjects. Furthermore, they showed for the first time that the amplitude ratio is not constant in every individual at repeated measurements. In light of these data, prognosis of facial palsy based on electroneurographic data alone seems doubtful.