Otology & Neurotology 35:1669Y1672 Ó 2014, Otology & Neurotology, Inc.
Yanagihara Facial Nerve Grading System as a Prognostic Tool in Bell’s Palsy Naohito Hato, Takashi Fujiwara, Kiyofumi Gyo, and Naoaki Yanagihara Department of Otolaryngology, Ehime University School of Medicine, Ehime, Japan
Objective: The aim of this study was to evaluate the accuracy of the Yanagihara facial nerve grading system in assessing the course of recovery and in determining the probability of a complete recovery of Bell’s palsy within 1 week after onset. Study Design: Retrospective study of patients at a single trial center. Setting: Tertiary referral center. Patients: Six hundred sixty-four patients with Bell’s palsy were assigned to three groups by degree of facial palsy using the Yanagihara 40-point system. Main Outcome Measure: The rate of recovered patients was assessed until 6 months after onset. Results: Ultimately, 151 (23.1%) patients were assessed with mild palsy, 286 (43.7%) with moderate palsy, and 217 (33.2%)
with severe palsy. The average Yanagihara score in the recovered patients was 15.7, whereas the score in the nonrecovered patients was 8.4. The rate of recovered patients in the mild group was 99.3%, that in the moderate group was 95.1%, and that in the severe group was 80.2%. These differences among the groups were significant (p G 0.05). Conclusion: The Yanagihara system was able to distinguish the probability of a complete recovery of the facial palsy within 1 week after the onset of palsy. We believe that the key point in improving the prognosis of Bell’s palsy is to diagnose the severity, using the Yanagihara system, and to treat it promptly to prevent progressive nerve degeneration. Key Words: Facial Grading SystemVYanagihara ScoreVYanagihara System. Otol Neurotol 35:1669Y1672, 2014.
Bell’s palsy is defined as an acute peripheral facial paralysis of unknown etiology, usually involving one side of the face. It is the most common cause of acute facial paralysis, and its reported incidence is 20 to 30 per 100,000 people annually (1). According to Peitersen (2), Bell’s palsy resolves spontaneously in 71% of patients. Unfortunately, more than 10% of Bell’s palsy patients do not recover normal facial movement after conventional conservative steroid treatment (3). The prognosis in Bell’s palsy depends on the severity of facial palsy: mild or moderate palsy tends to heal spontaneously, whereas severe palsy often fails to recover (4). Thus, the assessment of the degree of facial palsy is important in selecting therapeutic modalities. Electrical tests, such as the nerve excitability test, the maximal stimulation test, and electroneuronography, are reliable and valid methods for evaluating facial nerve function (5,6). However, they are insufficient before 1 week after the onset of palsy because Wallerian degeneration may not extend to the peripheral site of the facial nerve to be stimulated (7,8). Thus, there is a continuing need for a clinical tool that is easy to administer, provides a
quantitative score for reporting purposes, and is sensitive enough to assess the severity of the facial palsy within 1 week after the onset of palsy. Several grading systems for the assessment of facial nerve function using gross or regional scales have been proposed. The Yanagihara facial nerve grading system was developed in Japan as a representative regional scale, which was standardized in Japan and in some other countries for grading facial function (9). The Yanagihara system measures 10 separate aspects of different facial functions (Fig. 1). Each function is scored 0 (complete palsy), 2 (partial palsy), or 4 (nearly normal), giving a maximum score of 40 (Fig. 2). The score provides information on the grade of facial nerve dysfunction. The aim of this study was to evaluate the accuracy of the Yanagihara system in assessing the course of recovery and in determining the probability of a complete recovery of Bell’s palsy within 1 week after onset.
Address correspondence and reprint requests to Naohito Hato, M.D., Department of Otolaryngology, Ehime University School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan; E-mail: [email protected] The authors disclose no conflicts of interest.
Computerized data were collected from the Ehime University Facial Palsy Database, which prospectively collected consecutive patients’ data since January 1977 to December 2011. From the Ehime University Facial Palsy Database, we extracted
METHODS Trial Design and Patients
1669
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
1670
FIG. 1.
N. HATO ET AL.
Ten discrete facial expressive states evaluated in the Yanagihara system. Right face is paralyzed with severe Bell’s palsy.
patients who were diagnosed as having Bell’s palsy within 1 week after the onset. Patients with Bell’s palsy were retrospectively divided into three groups according to the Yanagihara score: a score lower than 10 was ‘‘severe,’’ a score of 12 to 20 was ‘‘moderate,’’ and a score higher than 22 was ‘‘mild.’’ All the patients with Bell’s palsy met the following criteria: older than 15 years, the degree of facial palsy was assessed using the Yanagihara system within 7 days after onset, treated conservatively with oral prednisolone (Takeda Pharmaceutical, Osaka, Japan) in gradually decreasing doses for about 10 days, and followed until complete recovery occurred or for more than 6 months in cases with poor prognoses. Facial palsy cases attributable to central nervous system disorders, neoplasms, otitis media, trauma, and Ramsay Hunt syndrome were excluded.
0 indicates no movement. As the Japanese Facial Nerve Study Group proposed in 1995, recovery from facial palsy was defined as a score higher than 36 points without accompanying facial contracture or synkinesis (10). The recovery rate, which is the number of recovered patients divided by the number of all patients, was assessed until 6 months after onset. One of six otolaryngologists, specialists in facial nerve practice, assessed the Yanagihara score in each patient.
Statistical Analysis The cumulative recovery rates in each group according to Yanagihara scores were examined with the Kaplan-Meier method, the W2 test, Student’s t test, and Fisher’s exact probability test. Data were analyzed using the SPSS software (version 19.0 for Windows; SPSS Inc., Chicago, IL, USA).
Outcome Measures Facial palsy was assessed using the Yanagihara system. Ten facial movements are allotted four points each for scoring, and facial function is evaluated by summing the scores. A total score of 40 points indicates normal facial movement, and a score of
FIG. 2.
RESULTS Between 1977 and 2011, 893 patients were diagnosed as having Bell’s palsy within 1 week after the onset. Of
Chart of the three-point scales of 10 expressive functions used for calculating facial paralysis score.
Otology & Neurotology, Vol. 35, No. 9, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
PROGNOSTIC VALUE OF THE YANAGIHARA SYSTEM TABLE 1.
1671
Characteristics of patients with Bell’s palsy Recovery (n = 596)
Characteristics Mean age (range) 48.2 (15Y88) Male, n (%) 282 (47.3) Yanagihara grading (score) Mean score 15.7 T 8.0 Mild, n (%) 196 (32.9) Moderate, n (%) 271 (45.5) Severe, n (%) 129 (21.6)
Nonrecovery (n = 58) 54.1 (18Y84) 25 (43.1) 8.4 T 5.5 3 (5.2) 20 (34.5) 35 (60.3)
them, 214 were excluded as lost to follow-up and 25 were excluded because they underwent facial nerve decompression surgery. Ultimately, 654 patients were included this study: 151 (23.1%) patients were assessed with mild palsy, 286 (43.7%) with moderate palsy, and 217 (33.2%) with severe palsy. Table 1 provides the characteristics of patients who recovered and who did not. No significant difference in age or gender was found between the groups. However, there were significant differences ( p G 0.01) in the severity of the facial palsy among the groups: the average Yanagihara score in the recovered patients was 15.7, whereas the score in the nonrecovered patients was 8.4. The rates of recovered patients in the mild, moderate, and severe groups were 99.3%, 95.1%, and 80.2%, respectively (Figs. 3, 4). Significant differences were noted among the groups ( p G 0.05). Early recovery, within 3 months after the onset of palsy, was evaluated further. The rate of early recovery patients in the mild group was 96.0%, that in the moderate group was 83.6%, and that in the severe group was 57.6%. These differences among the groups were also significant ( p G 0.05).
FIG. 3. Cumulative recovery rate of facial paralysis. The differences in the recovery rate between the three groups, mild, moderate, and severe palsy, as assessed by the Yanagihara system, were significant (p G 0.05) at 3 and 6 months after onset.
FIG. 4. Nonrecovery rate in each Yanagihara score within 1 week after onset.
DISCUSSION Grading systems for facial nerve function are divided into two major categories, gross and regional systems. We accept that a gross system is clinically useful because grading can be performed quickly without complex procedures and because a gross system provides a common ground for assessing facial function and comparing the results of therapy. Although several gross systems have been proposed, only the House-Brackmann (H-B) grading scale is widely used (11). Indeed, it has become the standard for reporting facial nerve outcome in several otolaryngology journals, including OtolaryngologyYHead and Neck Surgery and Otology & Neurotology. Gross systems, as first represented by that used by Botman and Jongkees (12), are designed to consider overall facial function and to describe the final outcome of the palsy. A gross system offers a simple procedure; however, facial palsy is a complex phenomenon. Thus, it is certain that there are patients for whom investigators reluctantly or with difficulty assign a single definite grade. In such clinical situations, bias caused by the nature of this choice may result in disagreement as to the appropriate grade and may result in different choices among different examiners. In addition, a gross system is insensitive to segmental palsy. The H-B grading scale was recently revised to address these weaknesses as the ‘‘Facial Nerve Grading System 2.0’’ (FNGS 2.0) by the Facial Nerve Disorders Committee in the United States (13). The FNGS 2.0 was modified as a regional system to provide reliable, reproducible, zone-specific information. Although there have also been many attempts at developing an accurate and reproducible regional scale for facial function, few have gained widespread acceptance. The Sunnybrook facial grading scale is popular and widely accepted in physical therapy; however, it requires subjective assessments of muscle tone in different regions of the face (14). The Yanagihara facial nerve grading system Otology & Neurotology, Vol. 35, No. 9, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
1672
N. HATO ET AL.
has also become popular; it requires subjective measurements of 10 separate facial functions. The Yanagihara system has practical advantages in that disturbances can be readily estimated from each expressive state without confusion, all muscular functions required for emotional facial expression are included, the functional importance of the circumocular and circumoral muscles is adequately emphasized, facial expressive functions recovering quickly and those recovering slowly from palsy are included equally, with balance, and the clinical importance of loss of facial tone is considered. Continued studies on the reliability and clinical utility of this system were carried out between l975 and 1980 by the Japanese Facial Nerve Study Group (15). The group subsequently accepted the Yanagihara 40-point system as the Japanese standard for reporting the grade of facial palsy. A strong correlation between Yanagihara scores and integrated electromyographic recordings has also been demonstrated (16). A recent objective assessment of facial palsy using computerized image analysis and Moire topography revealed that the Yanagihara score correlated closely with the objective score (17Y19). In this study, we retrospectively assessed the prognostic value of the Yanagihara facial nerve grading system within 1 week after the onset of Bell’s palsy. Only three gradings, mild palsy, assessed by a Yanagihara score higher than 22; moderate palsy, scored from 12 to 20; and severe palsy, scored lower than 10, were able to distinguish the probability of a complete recovery. Especially, 96% of the patients with mild palsy were certainly recovered within 3 months after the onset. Moreover, the Yanagihara system has the advantage that the severity of facial palsy can be assessed without requiring specialized equipment. Investigators can predict the course of recovery and determine the final outcome of the facial palsy when they become fully familiar with the Yanagihara system (20). Although the Japanese discussants were aware of the clinical value of the Yanagihara system, many of the nonJapanese invitees were unfamiliar with this system. In contrast to a gross system, a regional system requires both closer observation of the movement of each facial area and calculations to obtain a final score. However, once the examiner becomes familiar with the procedure, little time is needed to reach a final score. In the treatment of Bell’s palsy, assessment of the grade of palsy is important for deciding the appropriate therapeutic modality within the first week after onset because the recommended therapy differs somewhat according to disease severity. The prognosis of mild palsy is generally favorable, even without medication. Considering the cost and possible side effects, medication to prevent progressive nerve degeneration should be used only in patients with moderate or severe facial palsy. We believe that medical treatment within 1 week of the onset of palsy determines the outcome of facial palsy in most patients with Bell’s palsy.
CONCLUSION The Yanagihara facial nerve grading system was able to determine the probability of a complete recovery within 1 week after the onset of palsy. Although further prospective studies are necessary to fully evaluate the predictive value of the Yanagihara system, we believe that the key point in improving the prognosis of Bell’s palsy is to diagnose the severity, using the Yanagihara system, and to treat it promptly to prevent progressive nerve degeneration. REFERENCES 1. Yanagihara N. Incidence of Bell’s palsy. Ann Otol Rhinol Laryngol 1988;137(Suppl):3Y4. 2. Peitersen E. The natural history of Bell’s palsy. Am J Otol 1982;4:107Y11. 3. Salinas RA, Alvarez G, Daly F, et al. Corticosteroids for Bell’s palsy (idiopathic facial paralysis). Cochrane Database Syst Rev 2010;3:CD001942. 4. Hato N, Murakami S, Gyo K. Steroid and antiviral treatment for Bell’s palsy. Lancet 2008;371:1818Y20. 5. Adour KK. Current concepts on neurology: diagnosis and management of facial palsy. N Engl J Med 1982;307:348Y51. 6. Mantsopoulos K, Psillas G, Psychogios G, et al. Predicting the longterm outcome after idiopathic facial nerve paralysis. Otol Neurotol 2011;32:848Y51. 7. Tojima H, Aoyagi M, Inamura H, et al. Clinical advantages of electroneurography in patients with Bell’s palsy within two weeks after onset. Acta Oto-Laryngologica 1994;511(Suppl):147Y9. 8. Inamura H. Electroneurography (ENoG) for Bell’s palsy patients and its meaning in prognostic diagnosis. Facial N Res Jpn 1997; 17:16Y8. 9. Yanagihara N. Grading of facial palsy. In: Fisch U, ed. Proceedings of the Third International Symposium on Facial Nerve Surgery. Zurich, Switzerland: Kugler Medical Publications, 1976:533Y55. 10. Hato N, Matsumoto S, Kisaki H, et al. Efficacy of early treatment of Bell’s palsy with oral acyclovir and prednisolone. Otol Neurotol 2003;24:948Y51. 11. House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg 1985;93:146Y7. 12. Botman JWM, Jongkees LBW. The results of infratemporal treatment of facial palsy. Pract Otorhinolaryngol 1955;17:80Y100. 13. Vrabec JT, Backous DD, Djalilian HR, et al. Facial Nerve Grading System 2.0. Otolaryngol Head Neck Surg 2009;140:445Y50. 14. Ross BG, Fradet B, Nedzelski JM. Development of a sensitive clinical facial grading system. Otolaryngol Head Neck Surg 1996;114:380Y6. 15. Yanagihara N, Nishimura H, Hazama K, et al. On standard documentation on facial palsy. Jpn J Otol 1977;80:21Y7. 16. Yagi S, Ishikawa Y. Peripheral facial paralysis analyzed by integration of conventional EMG. Practica Otol 1980;73:1355Y61. 17. Kawamoto M, Isono M, Tanaka H, et al. Computerized quantitative analysis of facial motions: comparison with the Yanagihara’s system. Facial N Res Jpn 1995;15:81Y4. 18. Yuen K, Maeta M, Inokuchi I, et al. Evaluation of facial palsy by using the Moire topography index. Facial N Res Jpn 1995;15:91Y4. 19. Sawai N, Hato N, Hakuba N, et al. Objective assessment of the severity of unilateral facial palsy using OKAO Vision facial image analysis software. Acta Otolaryngol 2012;132:1013Y7. 20. Fujiwara T, Hato N, Gyo K, et al. Prognostic factors of Bell’s palsy: prospective patient collected observation study. Eur Arch Otorhinolaryngol 2014;271:1891Y5.
Otology & Neurotology, Vol. 35, No. 9, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
Yanagihara Facial Nerve Grading System as a Prognostic Tool in Bell’s Palsy Naohito Hato, Takashi Fujiwara, Kiyofumi Gyo, and Naoaki Yanagihara Department of Otolaryngology, Ehime University School of Medicine, Ehime, Japan
Objective: The aim of this study was to evaluate the accuracy of the Yanagihara facial nerve grading system in assessing the course of recovery and in determining the probability of a complete recovery of Bell’s palsy within 1 week after onset. Study Design: Retrospective study of patients at a single trial center. Setting: Tertiary referral center. Patients: Six hundred sixty-four patients with Bell’s palsy were assigned to three groups by degree of facial palsy using the Yanagihara 40-point system. Main Outcome Measure: The rate of recovered patients was assessed until 6 months after onset. Results: Ultimately, 151 (23.1%) patients were assessed with mild palsy, 286 (43.7%) with moderate palsy, and 217 (33.2%)
with severe palsy. The average Yanagihara score in the recovered patients was 15.7, whereas the score in the nonrecovered patients was 8.4. The rate of recovered patients in the mild group was 99.3%, that in the moderate group was 95.1%, and that in the severe group was 80.2%. These differences among the groups were significant (p G 0.05). Conclusion: The Yanagihara system was able to distinguish the probability of a complete recovery of the facial palsy within 1 week after the onset of palsy. We believe that the key point in improving the prognosis of Bell’s palsy is to diagnose the severity, using the Yanagihara system, and to treat it promptly to prevent progressive nerve degeneration. Key Words: Facial Grading SystemVYanagihara ScoreVYanagihara System. Otol Neurotol 35:1669Y1672, 2014.
Bell’s palsy is defined as an acute peripheral facial paralysis of unknown etiology, usually involving one side of the face. It is the most common cause of acute facial paralysis, and its reported incidence is 20 to 30 per 100,000 people annually (1). According to Peitersen (2), Bell’s palsy resolves spontaneously in 71% of patients. Unfortunately, more than 10% of Bell’s palsy patients do not recover normal facial movement after conventional conservative steroid treatment (3). The prognosis in Bell’s palsy depends on the severity of facial palsy: mild or moderate palsy tends to heal spontaneously, whereas severe palsy often fails to recover (4). Thus, the assessment of the degree of facial palsy is important in selecting therapeutic modalities. Electrical tests, such as the nerve excitability test, the maximal stimulation test, and electroneuronography, are reliable and valid methods for evaluating facial nerve function (5,6). However, they are insufficient before 1 week after the onset of palsy because Wallerian degeneration may not extend to the peripheral site of the facial nerve to be stimulated (7,8). Thus, there is a continuing need for a clinical tool that is easy to administer, provides a
quantitative score for reporting purposes, and is sensitive enough to assess the severity of the facial palsy within 1 week after the onset of palsy. Several grading systems for the assessment of facial nerve function using gross or regional scales have been proposed. The Yanagihara facial nerve grading system was developed in Japan as a representative regional scale, which was standardized in Japan and in some other countries for grading facial function (9). The Yanagihara system measures 10 separate aspects of different facial functions (Fig. 1). Each function is scored 0 (complete palsy), 2 (partial palsy), or 4 (nearly normal), giving a maximum score of 40 (Fig. 2). The score provides information on the grade of facial nerve dysfunction. The aim of this study was to evaluate the accuracy of the Yanagihara system in assessing the course of recovery and in determining the probability of a complete recovery of Bell’s palsy within 1 week after onset.
Address correspondence and reprint requests to Naohito Hato, M.D., Department of Otolaryngology, Ehime University School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan; E-mail: [email protected] The authors disclose no conflicts of interest.
Computerized data were collected from the Ehime University Facial Palsy Database, which prospectively collected consecutive patients’ data since January 1977 to December 2011. From the Ehime University Facial Palsy Database, we extracted
METHODS Trial Design and Patients
1669
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
1670
FIG. 1.
N. HATO ET AL.
Ten discrete facial expressive states evaluated in the Yanagihara system. Right face is paralyzed with severe Bell’s palsy.
patients who were diagnosed as having Bell’s palsy within 1 week after the onset. Patients with Bell’s palsy were retrospectively divided into three groups according to the Yanagihara score: a score lower than 10 was ‘‘severe,’’ a score of 12 to 20 was ‘‘moderate,’’ and a score higher than 22 was ‘‘mild.’’ All the patients with Bell’s palsy met the following criteria: older than 15 years, the degree of facial palsy was assessed using the Yanagihara system within 7 days after onset, treated conservatively with oral prednisolone (Takeda Pharmaceutical, Osaka, Japan) in gradually decreasing doses for about 10 days, and followed until complete recovery occurred or for more than 6 months in cases with poor prognoses. Facial palsy cases attributable to central nervous system disorders, neoplasms, otitis media, trauma, and Ramsay Hunt syndrome were excluded.
0 indicates no movement. As the Japanese Facial Nerve Study Group proposed in 1995, recovery from facial palsy was defined as a score higher than 36 points without accompanying facial contracture or synkinesis (10). The recovery rate, which is the number of recovered patients divided by the number of all patients, was assessed until 6 months after onset. One of six otolaryngologists, specialists in facial nerve practice, assessed the Yanagihara score in each patient.
Statistical Analysis The cumulative recovery rates in each group according to Yanagihara scores were examined with the Kaplan-Meier method, the W2 test, Student’s t test, and Fisher’s exact probability test. Data were analyzed using the SPSS software (version 19.0 for Windows; SPSS Inc., Chicago, IL, USA).
Outcome Measures Facial palsy was assessed using the Yanagihara system. Ten facial movements are allotted four points each for scoring, and facial function is evaluated by summing the scores. A total score of 40 points indicates normal facial movement, and a score of
FIG. 2.
RESULTS Between 1977 and 2011, 893 patients were diagnosed as having Bell’s palsy within 1 week after the onset. Of
Chart of the three-point scales of 10 expressive functions used for calculating facial paralysis score.
Otology & Neurotology, Vol. 35, No. 9, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
PROGNOSTIC VALUE OF THE YANAGIHARA SYSTEM TABLE 1.
1671
Characteristics of patients with Bell’s palsy Recovery (n = 596)
Characteristics Mean age (range) 48.2 (15Y88) Male, n (%) 282 (47.3) Yanagihara grading (score) Mean score 15.7 T 8.0 Mild, n (%) 196 (32.9) Moderate, n (%) 271 (45.5) Severe, n (%) 129 (21.6)
Nonrecovery (n = 58) 54.1 (18Y84) 25 (43.1) 8.4 T 5.5 3 (5.2) 20 (34.5) 35 (60.3)
them, 214 were excluded as lost to follow-up and 25 were excluded because they underwent facial nerve decompression surgery. Ultimately, 654 patients were included this study: 151 (23.1%) patients were assessed with mild palsy, 286 (43.7%) with moderate palsy, and 217 (33.2%) with severe palsy. Table 1 provides the characteristics of patients who recovered and who did not. No significant difference in age or gender was found between the groups. However, there were significant differences ( p G 0.01) in the severity of the facial palsy among the groups: the average Yanagihara score in the recovered patients was 15.7, whereas the score in the nonrecovered patients was 8.4. The rates of recovered patients in the mild, moderate, and severe groups were 99.3%, 95.1%, and 80.2%, respectively (Figs. 3, 4). Significant differences were noted among the groups ( p G 0.05). Early recovery, within 3 months after the onset of palsy, was evaluated further. The rate of early recovery patients in the mild group was 96.0%, that in the moderate group was 83.6%, and that in the severe group was 57.6%. These differences among the groups were also significant ( p G 0.05).
FIG. 3. Cumulative recovery rate of facial paralysis. The differences in the recovery rate between the three groups, mild, moderate, and severe palsy, as assessed by the Yanagihara system, were significant (p G 0.05) at 3 and 6 months after onset.
FIG. 4. Nonrecovery rate in each Yanagihara score within 1 week after onset.
DISCUSSION Grading systems for facial nerve function are divided into two major categories, gross and regional systems. We accept that a gross system is clinically useful because grading can be performed quickly without complex procedures and because a gross system provides a common ground for assessing facial function and comparing the results of therapy. Although several gross systems have been proposed, only the House-Brackmann (H-B) grading scale is widely used (11). Indeed, it has become the standard for reporting facial nerve outcome in several otolaryngology journals, including OtolaryngologyYHead and Neck Surgery and Otology & Neurotology. Gross systems, as first represented by that used by Botman and Jongkees (12), are designed to consider overall facial function and to describe the final outcome of the palsy. A gross system offers a simple procedure; however, facial palsy is a complex phenomenon. Thus, it is certain that there are patients for whom investigators reluctantly or with difficulty assign a single definite grade. In such clinical situations, bias caused by the nature of this choice may result in disagreement as to the appropriate grade and may result in different choices among different examiners. In addition, a gross system is insensitive to segmental palsy. The H-B grading scale was recently revised to address these weaknesses as the ‘‘Facial Nerve Grading System 2.0’’ (FNGS 2.0) by the Facial Nerve Disorders Committee in the United States (13). The FNGS 2.0 was modified as a regional system to provide reliable, reproducible, zone-specific information. Although there have also been many attempts at developing an accurate and reproducible regional scale for facial function, few have gained widespread acceptance. The Sunnybrook facial grading scale is popular and widely accepted in physical therapy; however, it requires subjective assessments of muscle tone in different regions of the face (14). The Yanagihara facial nerve grading system Otology & Neurotology, Vol. 35, No. 9, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
1672
N. HATO ET AL.
has also become popular; it requires subjective measurements of 10 separate facial functions. The Yanagihara system has practical advantages in that disturbances can be readily estimated from each expressive state without confusion, all muscular functions required for emotional facial expression are included, the functional importance of the circumocular and circumoral muscles is adequately emphasized, facial expressive functions recovering quickly and those recovering slowly from palsy are included equally, with balance, and the clinical importance of loss of facial tone is considered. Continued studies on the reliability and clinical utility of this system were carried out between l975 and 1980 by the Japanese Facial Nerve Study Group (15). The group subsequently accepted the Yanagihara 40-point system as the Japanese standard for reporting the grade of facial palsy. A strong correlation between Yanagihara scores and integrated electromyographic recordings has also been demonstrated (16). A recent objective assessment of facial palsy using computerized image analysis and Moire topography revealed that the Yanagihara score correlated closely with the objective score (17Y19). In this study, we retrospectively assessed the prognostic value of the Yanagihara facial nerve grading system within 1 week after the onset of Bell’s palsy. Only three gradings, mild palsy, assessed by a Yanagihara score higher than 22; moderate palsy, scored from 12 to 20; and severe palsy, scored lower than 10, were able to distinguish the probability of a complete recovery. Especially, 96% of the patients with mild palsy were certainly recovered within 3 months after the onset. Moreover, the Yanagihara system has the advantage that the severity of facial palsy can be assessed without requiring specialized equipment. Investigators can predict the course of recovery and determine the final outcome of the facial palsy when they become fully familiar with the Yanagihara system (20). Although the Japanese discussants were aware of the clinical value of the Yanagihara system, many of the nonJapanese invitees were unfamiliar with this system. In contrast to a gross system, a regional system requires both closer observation of the movement of each facial area and calculations to obtain a final score. However, once the examiner becomes familiar with the procedure, little time is needed to reach a final score. In the treatment of Bell’s palsy, assessment of the grade of palsy is important for deciding the appropriate therapeutic modality within the first week after onset because the recommended therapy differs somewhat according to disease severity. The prognosis of mild palsy is generally favorable, even without medication. Considering the cost and possible side effects, medication to prevent progressive nerve degeneration should be used only in patients with moderate or severe facial palsy. We believe that medical treatment within 1 week of the onset of palsy determines the outcome of facial palsy in most patients with Bell’s palsy.
CONCLUSION The Yanagihara facial nerve grading system was able to determine the probability of a complete recovery within 1 week after the onset of palsy. Although further prospective studies are necessary to fully evaluate the predictive value of the Yanagihara system, we believe that the key point in improving the prognosis of Bell’s palsy is to diagnose the severity, using the Yanagihara system, and to treat it promptly to prevent progressive nerve degeneration. REFERENCES 1. Yanagihara N. Incidence of Bell’s palsy. Ann Otol Rhinol Laryngol 1988;137(Suppl):3Y4. 2. Peitersen E. The natural history of Bell’s palsy. Am J Otol 1982;4:107Y11. 3. Salinas RA, Alvarez G, Daly F, et al. Corticosteroids for Bell’s palsy (idiopathic facial paralysis). Cochrane Database Syst Rev 2010;3:CD001942. 4. Hato N, Murakami S, Gyo K. Steroid and antiviral treatment for Bell’s palsy. Lancet 2008;371:1818Y20. 5. Adour KK. Current concepts on neurology: diagnosis and management of facial palsy. N Engl J Med 1982;307:348Y51. 6. Mantsopoulos K, Psillas G, Psychogios G, et al. Predicting the longterm outcome after idiopathic facial nerve paralysis. Otol Neurotol 2011;32:848Y51. 7. Tojima H, Aoyagi M, Inamura H, et al. Clinical advantages of electroneurography in patients with Bell’s palsy within two weeks after onset. Acta Oto-Laryngologica 1994;511(Suppl):147Y9. 8. Inamura H. Electroneurography (ENoG) for Bell’s palsy patients and its meaning in prognostic diagnosis. Facial N Res Jpn 1997; 17:16Y8. 9. Yanagihara N. Grading of facial palsy. In: Fisch U, ed. Proceedings of the Third International Symposium on Facial Nerve Surgery. Zurich, Switzerland: Kugler Medical Publications, 1976:533Y55. 10. Hato N, Matsumoto S, Kisaki H, et al. Efficacy of early treatment of Bell’s palsy with oral acyclovir and prednisolone. Otol Neurotol 2003;24:948Y51. 11. House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg 1985;93:146Y7. 12. Botman JWM, Jongkees LBW. The results of infratemporal treatment of facial palsy. Pract Otorhinolaryngol 1955;17:80Y100. 13. Vrabec JT, Backous DD, Djalilian HR, et al. Facial Nerve Grading System 2.0. Otolaryngol Head Neck Surg 2009;140:445Y50. 14. Ross BG, Fradet B, Nedzelski JM. Development of a sensitive clinical facial grading system. Otolaryngol Head Neck Surg 1996;114:380Y6. 15. Yanagihara N, Nishimura H, Hazama K, et al. On standard documentation on facial palsy. Jpn J Otol 1977;80:21Y7. 16. Yagi S, Ishikawa Y. Peripheral facial paralysis analyzed by integration of conventional EMG. Practica Otol 1980;73:1355Y61. 17. Kawamoto M, Isono M, Tanaka H, et al. Computerized quantitative analysis of facial motions: comparison with the Yanagihara’s system. Facial N Res Jpn 1995;15:81Y4. 18. Yuen K, Maeta M, Inokuchi I, et al. Evaluation of facial palsy by using the Moire topography index. Facial N Res Jpn 1995;15:91Y4. 19. Sawai N, Hato N, Hakuba N, et al. Objective assessment of the severity of unilateral facial palsy using OKAO Vision facial image analysis software. Acta Otolaryngol 2012;132:1013Y7. 20. Fujiwara T, Hato N, Gyo K, et al. Prognostic factors of Bell’s palsy: prospective patient collected observation study. Eur Arch Otorhinolaryngol 2014;271:1891Y5.
Otology & Neurotology, Vol. 35, No. 9, 2014
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