Summary

Key words

facial palsy / defective healing / synkinesis / electromyography / biofeedback / rehabilitation

Submitted Accepted

October 01, 2012 April 22, 2013

Bibliography

DOI http://dx.doi.org/10.1055/s-0033-1345166 Online Publication: July 05, 2013 Laryngo-Rhino-Otol 2014; 93: 15-24 © Georg Thieme Verlag KG Stuttgart – New York ISSN 0935-8943

Correspondence address

Prof. Orlando Guntinas-Lichius Klinik und Poliklinik für Hals, Nasen- und Ohrenheilkunde Universitätsklinikum der FSU Jena Lessingstrasse 2 D-07740 Jena [email protected]

Translation from German to English

Anna Weigersdorfer

electromyographytraining.

Summary

Background: To date there is no standardized adjuvant therapy for the treatment of chronic facial palsy with defective healing (partial recovery). Therefore, no standard for the mimic exercise treatment with biofeedback exists. It also lacks an evaluation of the possibilities of a modern

(EMG-)

based

biofeedback

Material and methods: 8 patients with facial palsy offered their assistance: After they were instructed according to an exercise regimen, they tested at home various electrode types and various EMG biofeedback programs with- and without electrical stimulation for selective muscle activation, muscle relaxation, coordinated movements with the healthy side, as well as synchronic effort/relaxation with synkinetic muscle

Fabian Volk G et al. EMG Biofeedback Training at home … Laryngo-Rhino-Otol 2014; 93: 15-24

pairs. The feasibility and practical handling, as well as exercise intensity and compliance were evaluated. Results: Due to the facial skin movement by the mimic muscular system at the same time tiny muscles, only one electrode type and -size showed as appropriate to be used by the patients at home. A stepby-step treatment algorithm was developed to benefit of different EMG biofeedback programs, which enables the patients to treat the deficiencies of a defective healing (partial recovery) on their own. Conclusion: The worked out proposal for a standardized treatment algorithm of a defective healing with EMG biofeedback is the foundation for the evaluation of the efficiency, which is further described in the following clinical study:

Introduction

The most common type of acute facial palsy is the idiopathic (Bell’s) palsy, in which in most cases a damage of the nerve – without axonal damage, i.e. a non-degenerative damage, can be observed. These patients usually recover completely from the palsy [1]. However, rarely with idiopathic palsy, but regularly in cases of Ramsay Hunt Syndrome, traumatic and tumorous lesions, an anoxal damage, which results in Wallerian degeneration (degenerative damage) is the consequence. The lesion is seldom that strong, or another obstacle is present, which hinders a spontaneous regeneration, which would not allow any regeneration at all. The more common case is either spontaneous regeneration or a surgical reconstruction of the facial nerve (n. facialis). This type of regeneration always results in a defective healing [1, 2]. A defective healing is characterized by: A) Dyskinesia = changed (normally attenuated) mimic movements at voluntary use of the facial muscles; B) Synkinesis = non-voluntary and simultaneous mimic movements while the patient is voluntarily performing a different action; C) auto-paralysis syndrome = special type of synkinesis, in which the synkinetic activity is referring to the antagonistic muscles in the face. Then simultaneous activation of the antagonistic muscles results into no movement at all (auto palsy). Both, dyskinesia and synkinesis can result into D) hyperkinesis = excessive facial movement [1].

Although well established and evidence based therapies for facial palsy treatment exist, only a few systematic investigations for a defective healing therapy were carried out so far [3]. Due to insufficient data and the minor standardization of exercise methods, it can only be concluded by consensus, that the physical exercise treatment is helpful, apparently more in chronic than in acute palsy [4, 5]. An exercise treatment with mirror (mirror feedback) can be easily performed over a longer period by the patient alone and independently, and can already be standardized more easily [6]. Even better standardization and even more possibilities are available for muscle paralysis exercise treatment if the biofeedback training is carried out in an electromyographic (EMG-) based way (EMG biofeedback) [7]. There are only a few reports about the use of EMG biofeedback at patients with facial palsy [8-10]. Meanwhile the medical devices for the EMG biofeedback therapy have become significantly smaller and easier to handle for an exercise therapy at home. The improvements of computer animation allow feedback programs which are easy to understand. We have taken these facts as opportunity to develop a standardized exercise regimen with modern EMG biofeedback for patients with defective healing at chronic facial palsy.

Methodology

Patients During a prospective investigation a concept for adjuvant therapy with biofeedback training was developed together with chronical facial palsy patients. For this purpose, patients were approached during their weekly EMG-consultation hour in the ENT department of the University Clinic Jena for possible participation. These patients were chronical facial palsy patients (duration > 4 months) with defective healing, and who desired therapy. They should not have received any electrostimulation therapy or any EMG feedback therapy before. Defective healing was defined as a condition after acute facial palsy with incomplete recovery and the symptoms from attenuated arbitrary activity (hypokinesis) to strong arbitrary activity (hyperkinesis), and/or uncontrolled movements of the mimic muscles with arbitrary contraction of other mimic muscles (synkinesia). Forms of synkinesia were also present in the special type of auto paralysis. All


mentioned phenomena had to be demonstrated electromyographically. Within one year 7 patients agreed to participate in the study (see Tab. 1). Approval was obtained from the local ethical review committee. As we planned to test the adhesion of different electrode systems with very strong facial movements, additionally one patient with acute facial palsy joined this clinical study. This patient participated over the whole period until complete recovery.

Electrodes For facial use there is no recommendation for any electrode type. Due to the skin movements during the contraction of the mimic muscles the optimal electrode type must have a good adhesion, in contrary it should not have a too big contact surface, in order to stimulate the single individual mimic muscle precisely. Only those models were tested, which are approved for electrical stimulation. The following electrode types were tested: 1) Synapse electrodes for electrical stimulation (rectangular, 50X50 mm [2“x 2”]; Ambus A/S, Denmark); 2) Synapse electrodes for electrical stimulation (round, 32 mm [1 x 1/4”]; Ambus A/S, Denmark); 3) Plaquette disposable 4-disk electrodes (round, 20 mm, colour-coded cables, Technomed Europe, Netherlands); 4) Stimcom electrodes de stimulation (round, 30 mm; comepa, France); 5) ValuTrode neurostimulation electrodes (Model CF5000 with multi stick gel, round, 5 cm, [2”], Axelgaard, Denmark); 6) ValuTrode neurostimulation electrodes Model CF3200 with multi stick gel, round, 3,2 cm, [1,25”], Axelgaard, Denmark); 7) Pals platinum neurostimulation electrodes (Model J10R00 with multi stick gel, round, 2.5 cm [1”], Axelgaard, Denmark). The electrodes were tested with and without additional fixation of patch medical tape (Fixomull stretch, BSN medical, Germany). Alternatively, an evaluation was also made with additional fixation by an elastic band (Wandy Rubber Industrial Co. Ltd. Taipeh, Taiwan). The adhesion of the electrodes should be increased by this method.

EMG Biofeedback Programs The device applied was the electrotherapeutical medical device STIWELL med4 (Otto Bock Healthcare, Germany - in Austria sold by MED-EL,

Austria). This device has 4 individually adjustable stimulation channels and 2 measuring channels for the lead of the musculature. STIWELL med4 comprises a variety of electrical stimulation programs and EMG Biofeedback Programs. The object was 1) investigation of suitable programs for the treatment of a chronical facial palsy with defective healing 2) selection of optimal electrode types and 3) development of a therapy model with electrodes positioning, duration per therapy session and therapy frequency per week There was no explicit object to use the devices exclusively for an electrical stimulation of atrophied muscles for muscle build-up. The patients were thoroughly trained to operate the device. The first sessions took place in the clinic. Clear Biofeedback programs, as well as programs which combine EMG Biofeedback with electrical stimulation, were tested. Table 2 and table 3, as well as illustration 1 show a detailed overview of the tested exercise programs. The examined electrode position programs can be seen in illustration 2. Concerning the duration of the use, 4 parameters got examined: 1) The treatment was examined with a frequency from 2 days or 7 days per week. 2) The treatment took place 2 times or 3 times a day each time. 3) An EMG Feedback session had the duration of 20 minutes or 40 minutes. 4) During treatment with electrical stimulation programs the minimum necessary amperage and the maximum bearable amperage without any pain were examined in mA. Over a period from 4 to 17 months the patients tested the device with the different parameters mentioned above (Median: 11 months).

Patient questionnaire At the end of the study the patients completed a questionnaire regarding the operation of the device (complementary material).

Outcome

Patients The 7 patients’ age (5 women, 2 men) with chronical facial palsy ranged from 24 to 66 years (Median: 42 years) (Tab. 1). The duration of the palsy before the start of the study varied between 4 and 31 months (Median: 15 months). The defective healing occurred spontaneously with 5 patients and with 2 patients after reconstruction of the facial nerve through a hypoglossal facial nerve jump nerve-suture. All patients except for patient TC had electromyographically proofed synkinesis between the


upper and lower face. These 6 patients all had hypokinesis when closing their eyes (M. orbicularis oculi) and on lifting up their mouth corner (Mm. zygomatici) on the concerned side. Hyperkinesia with too strong basic tone of M. Orbicularis oculi could be observed with 3 patients.

Electrodes The most important results of the electrode testing are shown in illustration 3. The manufacturers have designed the surface electrodes primarily for the application at big muscles (back, extremities), i.e. for areas, where the electrode size and adhesion play a secondary role. Only the electrodes with a diameter of < 2.5 cm were appropriate for facial use. When using bigger electrodes, no insulated lead or stimulation of exactly one single mimic muscle could be guaranteed. However, the adhesive quality worsened as the electrodes got smaller. Here the peculiarity of the face came into play, as the facial skin, as carrier of the electrodes, was in constant movement. For this reason, the electrodes with a diameter of 2 cm had optimal specific stimulation and lead parameters, but they stayed only for a few minutes. Therefore, it was additionally attempted to fixate these electrodes with a tape (illustration 4a) or with a Velcro® fastener fixation band (illustration 4b, 5d). However, here the patient felt an unnatural external fixation of the mimic muscle. Moreover, only 1 patient was able to cope with the fixation at home without the help of a therapist. For this reason, ultimately the electrodes with a diameter of 2.5 cm without any further fixation showed as most appropriate.

Instruction and technical aspects The permanent communication with the patients and the final survey showed that the patients require detailed instructions regarding which programs at all to use in which way. Like other medical devices on the market, also this device was not specifically designed for the use in the face. There is no instruction in the device’s manual for the use in the face. Even after selection of the optimal electrodes the patients had difficulties to fixate them. The device’s display was well readable by the patients despite poor vision caused by the palsy. The patients preferred to look at the device’s display instead of connecting it to a computer monitor due to increased mobility. Moreover, the device could be used more quickly.

Exercise parameters The combination of electrodes’ adhesion exactly onto the targeted muscle together with the implementation

of specified movement- or relaxation exercises was easiest for the following muscles (in descending order): • M. frontalis • M. orbicularis oculi • M. orbicularis oris • M. zygomaticus (a differentiation between M. zygomaticus major and minor was not possible) Other mimic target muscles were not appropriate for reliable adhesion of the electrodes by the patients, who, at the same time, underwent special exercise treatment of the selected muscle. Only 1 out of 7 patients exceeded the treatment period of the daily exercise treatment (which implied 7 days per week): He performed the exercise for longer than 2 weeks. All patients were able to carry out the exercises 2 days per week. Only 2 patients were able to stand the exercise time of 40 minutes per unit for longer than 4 weeks. All patients were able to perform an exercise time of 20 minutes per unit. 3 patients with defective healing agreed to perform 3 exercise units per day. All patients were able to perform the exercise units 2 times per exercise day.

The various EMG Biofeedback Programs Principally all patients perceived the exercise with the EMG biofeedback as additional helpful support in comparison to mere biofeedback in front of the mirror, and wished the costs to be covered by their health insurance. None of the patients feared any adverse effect by exercising with the device. 6 out of 7 patients with defective healing subjectively perceived an improvement of their defective healing after completion of the study. A significant improvement – the measurements were based on the grading of the paresis – could not be detected in this small study cohort, neither by using Stennert’s specific index of defective healing, nor by using the Stennert Index, nor by the House-Brackmann scale. If the patients applied the EMG biofeedback, combined with electrostimulation to support an already arbitrarily initiated movement, a minimum current of 3-5 mA (Median: 4mA) was necessary. The maximum current used was from 7-12 mA (Median: 10mA). The pain, which became stronger with the increase of the current, was limited. Often a teethsurrounding pain was observed especially in the area of the mouth. For this reason, the exercise program with additional electrical stimulation (see table 2, exercises 5 and 6) was refused in the long run. Out of the 6 tested exercise programs (see table 2 for


overview), the following programs and orders were accepted for long-run treatment: A) To settle-in and to strengthen the self-perception of single muscles: Exercise 1 (muscle tension) and exercise 2 (muscle relaxation). B) For targeted, but not excessive strengthening of a muscle with synchronous guidance of the same muscle on the healthy, contralateral side: Exercise 3 (muscle symmetry). C) For targeted relief of synkinetic movements between 2 mimic muscles: Exercise 4 (muscle coordination).

Discussion

The present study has shown that an EMG Biofeedback training with a modern EMG Biofeedback device can appropriately support patients with defective healing of facial palsy when they exercise at home independently. The type of defective healing should be precisely analyzed beforehand. Adjusted to this analysis, the treating health practitioner shall prescribe to the patient exact exercise programs (see table 4). Indispensable prerequisite is, that the patient gets intensive training by a therapist beforehand, in order to be able to perform the exercise program successfully at home [11]. The exercise programs offered are dealing with the functionally most important aspects of defective healing, namely hypokinesis, hyperkinesis and synkinesis. The idea of usage of the EMG is not new. EMG helps the patient to facilitate the biofeedback training, as muscle response is earlier noticeable and more obvious than facial movement [12]. This can be especially helpful for patients, who have undergone facial nerve reconstruction at the hypoglossal nerve by a hypoglossal-facial-cross nerve suture. This helps the patient to understand and to find out which tongue movement is exactly needed to provoke a special facial movement [8]. Until now this method for facial nerve treatment has not become common, as: 1) First of all, remodeled EMG devices from the diagnostics had to be used, i.e. their application is too costly and not appropriate for home use. 2) For this reason the patients could be treated in only one center. 3) Although the next device generation could already provide an audio-visual feedback of the muscle activity, complex muscle coordination exercises were not possible [7, 8, 10, 13]. In the meantime the market provides smaller and even handier devices. (illustration 6), which enable complex exercise programs with animation especially used in the field of

sports medicine or for rehabilitation of stroke patients for home use [7]. Literature research has shown that the present study offers for the first time the application of complex multi-channel EMG biofeedback programs for use in the face. It must be emphasized that the offered exercise concept is not intending to apply electrical stimulation for muscle built. The role of electrical stimulation for facial palsy treatment is disputed, as some authors consider it as even counterproductive [14]. The electrical stimulation was tested exclusively to support a selfinitiated movement of the patient. This method however has not proved itself due to uncomfortable pain. The question is still unanswered whether electrical stimulation is appropriate for the treatment of defective healing. With the present study a standardized concept for EMG biofeedback exercise programs was established. We were able to show that the patients could be enabled and motivated to perform an exercise program independently and regularly at home. The patients of this study group profit from this treatment, however, the random sample was far too small. Besides, the purpose of this study was not to investigate the outcome. This study rather provides a good base for a future standardized clinical study with a larger patient population. An important reason why the efficiency of the adjuvant therapy at facial palsy could not be proofed by now is the lack of standardization, not the small amount of random samples [15]. By usage of the here developed algorithm it will be possible to investigate precisely to which extend the defective healing can be alleviated with the help of this EMG biofeedback concept, possibly also compared to a simple biofeedback in front of a mirror [6]. What is desirable is a further specific development of the electrodes. Even the electrode type selected in the end was a compromise. The requirements of the mimic muscles in the face are very different compared to other parts of the body because of the skin movements. For this reason a specialized further development by the industry is desired. As far as compliance is concerned for the operation of the EMG biofeedback device: It is the usage of the electrodes, which is primarily critical, not the device itself. The administration of botulinum toxin to treat synkinesis has proofed to be helpful. The injection with botulinum toxin into the m. orbicularis oculi at constantly hyperkintetic eye lid close or involuntary synkinetic movements at the lower face, e.g. when


eating, has shown to be especially effective [16, 17]. Moreover, the combination of botulinum toxin administration and simultaneous biofeedback training can help the patient with the exercises, especially in the beginning, when treating synkinesis [6]. A small study with 8 patients recently showed that a single injection of botulinum toxin into the m. orbicularis oculi, before starting the biofeedback training in front of a mirror, makes this training easier [6]. We would desire a comparable study of the here presented EMG biofeedback training without and with additional botulinum toxin therapy.

Résumé

practical handling, training intensity and compliance were evaluated. Results: Because of the mobility of the facial skin connected to the mimic muscles and the smallness of the muscles on the other hand, only one type of electrodes and one size was suitable. A stepwise treatment algorithm for the use of the different EMG biofeedback program was developed supporting the patient to specifically exercise deficits of defective healing at home. Conclusion: The proposed standardized algorithm to treat facial defective healing with EMG biofeedback is the basis for the evaluation of its efficacy in a subsequent clinical trial.

Additional material An exercise program with biofeedback for home usage was developed at a modern EMG-biofeedback medical device, in which diverse electrode types were tested. This study was made with the assistance of 7 patients suffering from chronic facial palsy with defective healing, as well as one patient having acute facial palsy. The basic principle is a step-by-step treatment algorithm to use different EMG biofeedback programs. This algorithm makes it easier for the patients to independently perform a well-directed treatment of the deficiencies of defective healing. This pilot study portrays a first step towards a standardized, adjuvant therapy of chronic facial palsy with defective healing.

The patient questionnaire (only in German language) can be found in the internet at ENT under: http://dx.doi.org/10.1055/s-0033-1345166

Literature: 1.

2.

Abstract

3.

EMG Biofeedback Training at Home for Patient with Chronic Facial Palsy and Defective Healing Background: There is no standard for the adjuvant treatment of patients with chronic facial palsy and defective healing. There is a lack of standard for mimic training programs with biofeedback technique. The advantages of modern EMG based biofeedback training have not been evaluated yet. Material and Methods: After detailed instruction 8 patients with facial palsy tested several types of electrodes and different EMG biofeedback programs without and with electrostimulation for selected mimic muscle activation, muscle relaxation, coordinated movements with the healthy contralateral side, as well as synchronous activation and relaxation of synkinetic muscle pairs at home. Feasibility,

4.

5.

6.

Fienkensiper M, Volk GF, Guntinas-Lichius O. Facial nerve disorders. Laryngol Rhinol Otol 2012; 91: 121-141 quiz 142 Volk GF, Pantel M, Guntinas-Lichius O. Modern concepts in facial nerve reconstruction. Head Face Med 2010; 6: 25 Heckmann JG, Lang C, Glocker FX, Urban P, Bischoff C, Weder B, Reiter G, Meier U, Guntinas –Lichius O. Die neue S2k AWMF Leitlinie zur idiopathischen Fazialisparese in kommentierter Kurzform. Laryngol rhinol Otol 2012; 686-692 Pereira LM, Obara K, Dias JM, Menacho MO, Lavado EL, Cardoso JR. Facial exercise therapy for facial palsy: systematic review and meta-analysis. Clin Rehabil 2011; 25: 649-658 Teixeira LJ, Valbuza JS, Prado GF. Physical therapy for Bell’s palsy (idiopathic facial paralysis). Cochrane Database Syst Rev 2011 CD006283 Azuma T, Nakamura K, Takahashi M, Ohyama S, Toda N, Iwasaki H, Kalubi B, Takeda N. Mirror biofeedback rehabilitation after administration of single-dose botulinum toxin for treatment of facial synkinesis.


7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

Otolaryngol Head Neck Surg 2012; 146: 40 – 45 Woodford H, Price C. EMG biofeedback for the recovery of motor function after stroke. Cochrane Database Syst Rev 2007 CD004585 Hammerschlag PE, Brudny J, Cusumano R, Cohen NL. Hypoglossal-facial nerve anastomosis and electromyographic feedback rehabilitation. Laryngoscope 1987; 97; 705709 Brach JS, VanSwearingen JM, Lenert J, Johnson PC. Facial neuromuscular retraining for oral synkinesis. Plast Reconstr. Surg 1997; 99: 1922-1931; discussion 1923-1932 Dalla Toffola E, Bossi D, Buonocore M, Montomoli C, Petrucci L, Alfonsi E. Usefulness of BFB/EMG in facial palsy rehabilitation. Disabil Rehabil 2005; 27: 809-815 Lindsay RW, Robinson M, Hadlock TA. Comprehensive facial rehabilitation improves function in people with facial paralysis: a 5year experience at the Massachussetts Eye and Ear Infirmary. Phys Ther 2010; 90: 391397 Balliet R, Shinn JB, Bach-y-Rita P. Facial paralysis rehabilitation: retraining selective muscle control. Int Rehabil Med 1982; 4: 6774 Ross B, Nedzelski JM, McLean JA. Efficacy of feedback training in longstanding facial nerve paresis. Laryngoscope 1991; 101: 744-750 Diels HJ. Facial paralysis: is there a role for a therapist? Facial Plast Surg 2000; 16: 361364 Cardoso JR, Teixeira EC, Moreira MD, Fávero FM, Fontes SV, Bulle de Oliveira AS. Effects of exercise on Bells’s palsy: systematic review of randomized controlled trials. Otol Neurotol 2008; 29: 557-560 Laskawi R. The use of botulinum toxin in head and face medicine: an interdisciplinary field. Head Face Med 2008; 4:5 Filipo R, Spahiu I, Covelli E, Nicastri M, Bertoli GA. Botulinum toxin in the treatment of facial synkinesis and hyperkinesis. Laryngoscope 2012; 122: 266 – 270


Table 1 Patient overview Patient GT

Gender M

Age (years) 24

Aetiology idiopathic

Paresis acute

SY

F

36

Vestibularis schwannoma surgery

chronic

RH

M

62

RM TC SC NH

F F F M

61 48 30 66

Otogenetic with otitis externa maligna Vestibularis schwannoma surgery Facelift surgery Idiopathic Meninges surgery

BD

F

36

Early Summer meningocephalitis vaccination - vaccination damage

Operative Rehabilitation none

HB 3

SI 0/6

Symptoms of defective healing Omitted

4

1/4

chronic

HFJA, upper eyelid weight none

4

2/5

chronic chronic chronic chronic

none none none HFJA

4 2 4 5

1/5 0/1 0/4 4/6

chronic

none

2

1/3

Incomplete eye closing, incomplete lifting of mouth corner, moderate synkinesis Incomplete eye closing, incomplete lifting of mouth corner, moderate synkinesis Severe synkinesis Incomplete closing of mouth moderate synkinesis Incomplete eye closing, incomplete lifting of mouth corner, moderate synkinesis Incomplete eye closing, severe synkinesis

Duration of the paresis (months) 0,3 16,4 2,5 4,8 14,5 4,3 23,4 31,2

HB = House Brackmann; SI = Stennert Index; HFJA = hypoglossal-facial- nerve - Jump-anastomosis - ULG = upper lid weight


Table 2 Overview of used biofeedback programs Exercise program

Method

Exercise 1: Muscle tension

EMG Biofeedback

EMG channels 1

Exercise 2: Relaxation training

EMG Biofeedback

1

Exercise 3: Myosymmetry

EMG Biofeedback

2

Exercise 4: Coordination training

EMG Biofeedback

2

In this exercise one muscle gets trained with muscle tension, at the same time muscle release is trained at another muscle. This exercise can be applied on the concerned side for treatment of synkinetic muscle pairs. It can also be applied bilaterally, in order to train the symmetric coordination.

Exercise 5: Muscle tension, EMG triggered 1 EMG

EMG Biofeedback with Electrostimulation

1

Exercise 6: Muscle tension and relaxation EMG triggered with 2 EMG

EMG Biofeedback with Electrostimulation

2

If the patient is already able to reproducibly tense a certain muscle until a certain EMG amplitude threshold, this program starts with electrostimulation after the threshold. The patient shall get motivated, as it demonstrates which extent of muscle contraction can be reached. This program increases the former program by another EMG channel. The electrostimulation (after exceeding the threshold) only starts if - at the same time - the derivation of another (synkinetic) muscle shows zero tension. With this program the tension of one muscle without tension of another muscle shall be exercised.

Comment The EMG derivation signals to the patient the degree of muscle tension. This program is suitable for special training and for strengthening of the muscle. The EMG derivation signals to the patient the degree of muscle tension. By this method the patient could control and exercise hyperkinetic muscles as well as involuntary synkinetic muscles. Simultaneous exercise of the paralyzed and healthy side, in order to demonstrate to the patient the muscle activity on both sides of the face.


Table 3 Overview of the different feasibility tests regarding the electrodes and programs Patient Electrode types * EMG Muscles Remarks Feedback *** Exercises ** GT 1 - 7, Band **** 1-6 F, OC, OR, Z SY 1, 3, 7 1-6 F, OC, OR, Z Electrostimulation painful from 10mA RH 3 - 7, Band **** 1-4 OC, OR, Z Electrostimulation painful from 10mA RM 1-7 1-6 F, OC, OR, Z Electrostimulation painful from 12mA TC 3, 6, 7 1-4 OC, OR, Z Electrostimulation painful from 8mA; electrostimulation with lower current strength only useful when hand is additionally used for help SC 2, 5 - 7 1-6 F, OC, OR, Z Electrostimulation painful from 10mA NH

3, 7, Band ****

1-4

OC, OR, Z

BD

3, 6, 7

1-6

F, OC, OR, Z

Facial skin was irritated at the electrode spots after frequent use -

Therapie duration per session (in minutes ) 20 or 40 20 or 40 20 or 40 20 or 40 20 or 40

Therapy frequency per day 2-3 2-3 2-3 2-3 2-3

Therapy frequency per week 7 days 2 or 7 days 2 or 7 days 2 or 7 days 2 or 7 days

Total duration of testing (months) 6 17 8 4 11

Improvement

20 or 40

2-3

2 or 7 days

12

Yes

20 or 40

2-3

7 days

11

Yes

20 or 40

2-3

7 days

12

No

Yes Yes Yes Yes Yes

*numbering according to method part; an exact description of the electrodes can be found in Ill. 3 ** numbering according Tab. 2 ***F = m. frontalis; OC = m. orbicularis oculi; OR = m. orbicularis oris; Z = m. zygomaticus ****additional fixation tested with elastic band (see Ill. 4b)


Table 4 Suggestion for biofeedback training series 1. Clinical study and EMG of facial muscles for electrophysiological description of defective healing 2. Determination of therapy methods and realistic therapy outcomes 3. Targets: 2-3 times per day exercise; 20 min per exercise unit, minimum 2 days per week 4. Instruction of device by treating physician, eventually with another therapist (speech therapy, physiotherapy or other) 5. Dependent of the muscles involved and the therapy targets: Exercise of the m. frontalis, m. orbicularis oculi, m. zygomaticus, m. orbicularis oris (in rare special cases also other muscles) with a program for targeted muscle tension, or targeted relaxation. 6. If the patient is able to successfully perform step 5, and if weakened muscles shall be trained: Exercise of the weakened muscles simultaneously with the healthy contralateral muscle with a program, which allows controlling the symmetry degree of the exercise. Possibly a treatment with botulinum toxin in order to weaken the healthy side can be helpful. 7. If the patient is able to successfully perform step 5, and if a synkinetic treatment is envisaged: Mutual exercise of synkinetic muscle pairs, so that one muscle gets activated and the other one is made to be relaxed. Possibly a treatment with botulinum toxin is helpful for unwanted synkinetic movements. 8. Monthly effectiveness check and consultation with the therapist for continuation of the exercise treatment.


muscle contraction with EMG trigger

muscle coordination

muscle symmetry

muscle release

muscle contraction muscle contraction and relaxation with EMG trigger Illustration 1: The 6 tested feedback programs showing examples for the movements and electrodes positions, as well as the corresponding display picture on the electrostimulation device.


Illustration 2: The different electrode positions shown on a model. The muscles were investigated individually, but also in combination of 2 muscles, as multi-channel investigations were possible: EMG from m. frontalis (blue); m. orbicularis oculi (green); m. zygomaticus (yellow); m. orbicularis oris (red).


Electrode type

Comment

Synapse electrodes for electrical stimulation (rectangular, 50X50 mm [2“x 2”]; Ambus A/S, Denmark)

Inappropriate for facial use as too big

Illustration

Synapse electrodes for electrical stimulation (round, 32 mm [1 x 1/4”]; Ambus A/S, Denmark)

Still quite big, insufficient adhesion in the face during movements

Plaquette disposable 4-disk electrodes (round, 20 mm, color-coded cables, Technomed Europe, Netherlands)

Suitable size and handling due to the colored cables, however insufficient adhesion after a few times usage in the face

Stimcom electrodes de stimulation (round, 30 mm; comepa, France)

Very short cables, insufficient adhesion even after a few times usage in the face

ValuTrode neurostimulation electrodes (Model CF5000 with multi stick gel, round, 5 cm, [2”], Axelgaard, Denmark)

Inappropriate for facial use as too big

ValuTrode neurostimulation electrodes Model CF3200 with multi stick gel, round, 3,2 cm, [1,25”], Axelgaard, Denmark)

Still very big, therefore inappropriate for facial use

Pals platinum neurostimulation electrodes (Model J10R00 with multi stick gel, round, 2.5 cm [1”], Axelgaard, Denmark)

Suitable size for most facial applications; multiple usages feasible if face had been previously washed with soap and water, if required. The adhesion gets improved by placing a plaster or adhesive tape, (e.g. Fixomull stretch from BSN medical Germany) on the plastic surface of the electrodes

Illustration 3: Tested electrode types and outcome of their application


Illustration 4: Additional fixation of the electrodes with a plaster a, or an elastic band b. Both methods support the adhesion of the electrodes, however they are perceived as constringent. The fixation of the plasters is time-consuming. Only some patients are able to apply these additional steps independently at home.


Illustration 5: Patients during testing of the feedback programs: a Patient after hypoglossal nerve facial nerve-suture on the right side 12 months ago, at testing of 2 electrode types with muscle contraction and muscle release exercise with synkinesis b and during exercise of coordinated symmetric contraction c patient with a 12-months old defective healing, without nerve reconstruction, during muscle contraction training with additional fixation of the electrodes with an elastic band; The little display on the device (see Ill. 1, right side and Ill. 6), can also get replaced. The device by plugging the device into a computer. This means enables the exercise to be performed with animation: This example shows a synkinesis exercise: The patient needs to make the balloons flying by contraction of muscle A, while muscle B remains relaxed, and the balloons need to stay on the ground


Illustration 6: The ectrotherapy device used for this study has an LCD display, a main switch, 4 buttons for the 4 different channels, as well as a wheel which enables to operate and adjust the different programs.
