Keywords
facial paralysis - synkinesis - botulinum toxins-type A - physical therapy modalities
- surgery - plastic
Introduction
The constant agonistic-contraction and antagonistic-relaxation within groups of skeletal
muscles, prevents the stiffening of actin-myosin cross-bridges that could result in
reduced movement. However, in facial palsy when there is a prolonged period of inactivity
followed by chronic overactivity within the facial muscles, thixotropy, the formation
of tight cross-bridges between the actin and myosin filaments of the muscle fibers
causing stiffness of the muscle, is thought to occur.[1] This phenomenon was first described in the levator palpebrae superioris muscles
by Aramideh et al as a contributory factor in the development of lagophthalmos in
peripheral facial palsy.[2] Regular passive stretching has been shown to reduce thixotropy and reoptimize the
agonist-antagonistic balance and muscle function.[3] This forms the initial basis of specialist facial rehabilitation following chronic
lower motor neuron facial paralysis, for example, Bell's palsy.
Multimodal facial rehabilitation in the management of facial palsy includes a combination
of treatment modalities. Patients are psychologically screened given the known impact
of facial palsy on psychological health[4] and offered care as appropriate.[5] Patients with acute paralysis are given flaccid management advice including education
on facial nerve recovery, cheek taping, facial massage,[6] eye lid stretching, and eye protection strategies. They are also taught to minimize
contralateral hyperkinesis with education, stretching, and relaxation techniques.
If paralysis fails to resolve patients are offered static or dynamic surgical reanimation
as appropriate. Patients with urgent eye issues are referred to the oculoplastics
team for consideration of platinum eyelid weight surgery and other corrective procedures
as required.[7]
As recovering patients move into paresis, they commence movement reeducation work
in therapy. This incorporates muscle release work due to stiffness following prolonged
inactivity, education on normal facial anatomy, physiology, and function and coordinated
movement practice retraining.[8] Many patients with prolonged recovery go on to develop synkinesis.[9] This is managed primarily in facial therapy with muscle release techniques, relaxation
work, and neuromuscular retraining.[10] Some patients are also offered chemodenervation[4] to reduce synkinetic muscle activity. Those recalcitrant to both facial therapy
and chemodenervation, may be offered synkinesis surgery in the form of selective neurolysis
and myectomy.[11] See [Fig. 1] for an overview of interventions offered in facial palsy management.
Fig. 1 A schematic illustration of the facial therapy pathway which patients in our cohort
followed.
In this article, we set out to determine whether (1) a multimodal treatment approach
had a significant benefit on recovery in facial palsy and (2) whether earlier presentation
to therapy has greater benefit in terms of rehabilitation.
Methods
A retrospective case review of 75 patients (n = 75) was conducted at our facial palsy center over a 7-year period of follow-up
(2013–2020). Patients were included if they had completed a course of specialist facial
therapy rehabilitation, been discharged from this treatment arm, and had complete
documentation. This study adheres to the STROBE (Strengthening The Reporting of OBservational
Studies in Epidemiology) guidelines, conforms to the Helsinki guidelines on ethics,
and was registered with and approved by the institutional review team from the Research
and Development Department at The Queen Victoria Hospital NHS Foundation Trust prior
to being conducted (IRB No.1286).
Our standardized multidisciplinary clinic management process was followed for all
patients attending our facial palsy service. Patients were initially screened by the
psychological therapy team to determine their mental status, given the known impact
of facial palsy on psychological health.[4] Patients were then assessed by the multidisciplinary team. The facial muscles must
have a neural supply if neuromuscular retraining is to be successful.[12] Those with chronic flaccid paralysis lasting beyond 18 months who have no therapy
management potential[12] were given flaccid management advice, psychological therapy as required, and surgical
reanimation as appropriate. Patients with urgent eye issues were referred for ophthalmology
assessment and management as required. Patients who had potential for recovery (e.g.,
paretic and synkinetic patients) were referred on for rehabilitation with the specialist
facial therapy team.
Seventy-five patients (n = 75) fulfilled the inclusion criteria for specialist facial therapy. To elicit the
effect timing of facial therapy has on outcomes, the cohort was divided into four
subsets. Group I (who presented within 6 months post-palsy), group II (between 6 and
12 months post-palsy), group III (between 1 and 2 years post-palsy), and group IV
(late presentations beyond 2 years post-palsy). Seventy percent of patients recover
spontaneously within 3 months whereas deficits of varying magnitude persist in the
remaining 30%.[13] Due to the potential for acute facial palsy to recover spontaneously within the
first 12 weeks following neuropraxia, group I patients' results were omitted from
final analysis; however, their results and management strategies have been included
for reference. Patients with prolonged recovery beyond 6 months are not expected to
recover spontaneously, indeed if paralysis persists beyond 3 months the patient will
almost certainly experience residual effects (synkinesis).[12]
[14] Studies exploring prognosis after facial palsy have reported that the more severe
paralysis is even at 1 month, the more likely nonrecovery is.[15] Following development of synkinesis improvements in a patient's condition can be
attributed to appropriate specialist rehabilitation interventions as it is now understood
that the lack of observed movement is due to abnormal synchronization as opposed to
absent muscle activity.[12] It is important that rehabilitation is provided by specialists in facial therapy
as nonspecialist management may activate already overactive muscles and further reinforce
abnormal patterns causing deterioration rather than improvement.[16]
The included patients were seen by the specialist facial therapists, who depending
on the phase of recovery, treated them primarily as follows:
-
(1) Acute flaccid phase: massage, ipsilateral eyelid stretching, taping, and contralateral
cheek stretching.
-
(2) Paretic phase: trigger point release, passive stretches, and gentle centralized
movement reeducation.
-
(3) Synkinetic phase: muscle release techniques, relaxation training, and neuromuscular
retraining using surface electromyography feedback and synkinesis delinking exercises.
Within the synkinetic phase, those whose progress plateaued following facial therapy,
were chosen for chemodenervation[4] primarily to reduce the overactivity of ipsilateral synkinetic muscles although
patients extremely bothered by contralateral hyperkinesis were injected contralaterally
as required (see [Fig. 1] for an overview of the interventions offered). In instances of late presentation
to clinic post-onset, for example, patients in the synkinetic or paretic phases, their
treatment started at the point of presentation. Those recalcitrant to both facial
therapy and chemodenervation, were chosen for surgery in the form of selective neurolysis
and myectomy.[11] This treatment triage system was based on clinical parameters measured by the “East
Grinstead Grade of Stiffness (EGGS) scale” shown in [Table 1]. The EGGS scale is a descriptive scale which clinicians can use to support their
clinical reasoning when deciding which interventions a patient requires to best manage
their post-facial palsy sequelae.
Table 1
The East Grinstead Grade of Stiffness (EGGS) scale used in triaging treatment options
during nonflaccid facial palsy rehabilitation
|
EGGS
|
Description
|
Treatment required
|
|
I
|
Functional restoration of facial movements following specialist facial therapy alone
|
Long-term independent continuation of prescribed facial therapy program
|
|
II
|
Clinical improvement noted but plateau below level of functional restoration
|
Initiate chemodenervation alongside facial therapy followed by long-term independent
continuation of prescribed facial therapy program
|
|
III
|
Ongoing stiffness and pain despite facial therapy and chemodenervation
|
Selective neurolysis surgery followed by long-term independent continuation of prescribed
facial therapy program
|
The clinical outcomes of all patients were serially assessed by multiple assessors
with physical and psychosocial outcome measures. These included the clinician-graded
Facial Grading Scale (FGS) and House-Brackmann (HB) scores which were performed at
clinic review appointments. Although FGS and HB scores were not always performed by
an independent assessor the hospital facial palsy multidisciplinary team have been
audited in completion of these measures and found to have good inter- and intrarater
reliability. These measures can be used with good reproducibility by both novices
and experts, and by all professionals involved in the management of facial palsy.[17] Patient self-reported outcome measures (PROMs) were also used including the Facial
Disability Index (FDI)[18] and the Facial Clinimetric Evaluation (FaCE) scale.[19] These measures are completed by the patient rather than an assessor and both have
been shown to produce reliable and valid measurements[17]
[18]
[19] in patients with disorders of the facial motor system.
Statistical analyses of these outcome measures were compared pre- and posttherapy
between all subsets, using the two-way analysis of variance (ANOVA) test, to elicit
the benefits of multimodal therapy and the effect of timing of patient presentation
to therapy on patient outcomes and further treatment requirements. The chemodenervation
treatment arm was analyzed using one-way ANOVA with respect to (1) interval between
onset of facial therapy and chemodenervation initiation, (2) duration of chemodenervation,
(3) number of botulinum toxin injections, and (4) the maximum dose given during the
chemodenervation regime, while the correlation between the EGGS scale and time of
presentation, represented by the four subgroups was also assessed using one-way ANOVA.
Statistical significance was defined as p < 0.05 (GraphPad PRISM ver 8.0, USA).
Results
Of the 75 patients in this cohort, there was a female-to-male ratio of 3:1 (56 females
and 19 males). The mean age within the cohort was 54 years. While there is no female
preponderance in facial palsy per se, this suggests that females may be more likely
to pursue facial palsy treatment. The overall mean duration of treatment was 13.9
months (group I: 10 months, group II: 13.2 months, group III: 11.1 months, group IV:
20.1 months). As regards the proportion of this cohort (n = 75) requiring chemodenervation as part of their multimodal therapy regime, only
56 patients required it (75% of the cohort). The subset breakdown of patients requiring
chemodenervation was 92% (group I), 79% (group II), 71% (group III), and 92% (group
IV).
In terms of the facial stiffness scale (EGGS), the majority of the patients were grade
II requiring facial therapy and chemodenervation (71%) followed by 24% being grade
I requiring facial therapy only. The mean EGGS score (1–3) for each respective group
was as follows: group I: 1.5; group II: 1.76; group III: 1.77; and group IV: 2.07.
One-way ANOVA proved this to be statistically significant for increased stiffness
and treatment recalcitrance following delayed presentation to therapy with a p-value of 0.0016 (< 0.01). Only four patients (n = 4) or 5.3% of this entire cohort required surgical intervention for recalcitrant
synkinesis following facial therapy ± chemodenervation. Similarly, increasingly late
clinical presentations were associated with increased durations of chemodenervation
requirement (p = 0.0016; < 0.01), increased number of chemodenervation episodes (p = 0.0018; < 0.01), and increased dosage of botulinum toxin type A used per episode
(p = 0.0006; < 0.001). However, the “time” of presentation to therapy did not significantly
affect the interval between the onset of therapy and the initiation of chemodenervation
(p = 0.49; p = ns). These statistics are graphically depicted in [Fig. 2].
Fig. 2 (A–E) One-way analysis of variance (ANOVA) analysis of increasingly late clinical presentations
showing statistically increasing. (A) East Grinstead Grade of Stiffness (EGGS) scores. (B) Duration of chemodenervation required. (C) Number of chemodenervation episodes and (D) maximum dosage of botulinum toxin type A required. (E) Interval between onset of therapy and initiation of chemodenervation.
As shown in [Fig. 3], overall FGS significantly improved pre- and posttherapy in all groups (mean-standard
deviation, 60.13 ± 23.24 vs. 79.9 ± 13.01; confidence interval, –24.51 to –14.66,
p < 0.0001). However, this improvement slightly tapered in group IV (those presenting
at more than 2 years following onset of facial palsy), indicating an increasing proportion
of recalcitrant tightening in patients presenting to therapy more than 2 years after
onset. Further analysis of the components of FGS (namely volitional movement, resting
tone, and synkinesis), showed that multimodal therapy improved all domains of the
FGS statistically significantly (see [Figs. 4] and [5] for clinical images of patients showing improvement after multimodal therapy.).
Presenting for treatment earlier did not significantly improve volitional movement
and resting tone more than late presentation (p > 0.05). However, early presentation rather than late presentation was significant
(p < 0.0001) in reducing synkinesis, as shown in [Table 2].
Table 2
Component-wise breakdown of the effect of both time and facial therapy on the individual
components of the Facial Grading Scale, using the two-way ANOVA statistical analysis
(GraphPad PRISM ver 8.0)
|
FGS
|
Group
|
Pretherapy
|
Posttherapy
|
Statistical significance (two-way ANOVA)[a]
|
|
Mean
|
SD
|
Mean
|
SD
|
|
VM
|
I[a]
|
71.56
|
22.66
|
92
|
10.03
|
p < 0.05 (time effect)
p < 0.0001 (therapy effect)
|
|
II
|
60.80
|
18.03
|
78.69
|
15.80
|
|
III
|
65.85
|
12.92
|
81
|
10.42
|
|
IV
|
72.33
|
13.65
|
82.2
|
10.66
|
|
RS
|
I[a]
|
9.44
|
5.91
|
3.53
|
2.95
|
p < 0.05 (time effect)
p < 0.0001 (therapy effect)
|
|
II
|
12
|
3.68
|
6.15
|
4.16
|
|
III
|
11.54
|
3.76
|
4.38
|
3.20
|
|
IV
|
11.25
|
3.69
|
7.5
|
2.57
|
|
SS
|
I[a]
|
0.83
|
1.46
|
2.2
|
1.88
|
p < 0.0001 (time effect)
p < 0.0001 (therapy effect)
|
|
II
|
5.53
|
3.84
|
3.08
|
2.29
|
|
III
|
7.77
|
4.00
|
4.38
|
1.51
|
|
IV
|
8.04
|
2.99
|
3.45
|
1.39
|
Abbreviations: ANOVA, analysis of variance; FGS, Facial Grading Scale; RS, resting
symmetry; SD, standard deviation; SS, synkinesis score; VM, volitional movement.
Note: Group I (who presented within 6 months post-palsy), group II (between 6 and
12 months post-palsy), group III (between 1 and 2 years post-palsy), group IV (late
presentations beyond 2 years post-palsy).
a Group I (good prognosticators) was excluded from statistical analyses to minimize
the confounding factor of potential for natural recovery.
Fig. 3 In patients who started facial therapy, less than 2 years post-onset, a predictable
improvement in their mean Facial Grading Scale (FGS) was noted. However, beyond 24
months, the degree of improvement is slightly reduced as depicted graphically. This
is an indirect indicator that while muscle thixotropy may occur earlier on, beyond
2 years, muscle contracture may start setting in.
Fig. 4 Patient who presented 11 years post-onset right facial palsy due to Ramsay Hunt syndrome.
Improvement in synkinesis following specialist facial therapy only.
Fig. 5 Patient who presented 5 years post-onset right facial palsy following skull base
fracture. Improvement in synkinesis following multimodal treatment including specialist
facial therapy and chemodenervation.
Patients in group I were observed to have higher volitional movement scores than late
presenters, attributable to a higher proportion of these patients being in the good
prognostic subcohort; those showing initial signs of recovery within 1 month post-onset
with less likelihood of developing severe synkinesis.[18] The mean therapy scores in late presenters (group IV) eventually caught up with
early presenters (group I) but those in the latter group were more resistant to improvement
with those in group I exhibiting more than twice the increase in volitional activity.
This can likely be explained by the thixotropy effect on the facial muscles over time.
Similarly, the HB index showed a significant improvement in score pre- and post-facial
therapy but score improvements across groups II, III, and IV were not significantly
affected by time of presentation, probably due to the relative subjectivity of the
HB compared with the FGS.[19]
In terms of PROMs, both physical and social FDI scores were significantly improved
following therapy; however, only the physical score was affected by time of presentation
with early presenters (groups II and III) improving more than late presenters (group
IV). There was also statistically significant improvement in the FaCE scale scores
following our rehabilitation program but again improvements were not significantly
affected by time of presentation to therapy ([Table 3]).
Table 3
Two-way ANOVA statistical analysis (GraphPad PRISM ver 8.0) of the House-Brackmann
(HB), Facial Disability Index (FDI, physical and social subscores), and FaCE scoring
systems, the latter two representing patient-related outcome measures (PROMs)
|
Score
|
Group
|
Pretherapy
|
Posttherapy
|
Statistical significance (two-way ANOVA)[a]
|
|
Mean
|
SD
|
Mean
|
SD
|
|
HB
|
I[a]
|
3.33
|
1.50
|
1.87
|
0.64
|
p = 0.9273 (time effect)
p < 0.0001 (therapy effect)
|
|
II
|
3.07
|
0.83
|
2.15
|
0.80
|
|
III
|
2.78
|
0.82
|
2.00
|
0.00
|
|
IV
|
2.75
|
0.53
|
2.25
|
0.79
|
|
FDI-p
|
I[a]
|
67.78
|
21.84
|
91.43
|
13.36
|
p < 0.01 (time effect)
p < 0.0001 (therapy effect)
|
|
II
|
53.00
|
22.82
|
86.54
|
12.65
|
|
III
|
51.85
|
29.21
|
74.00
|
34.77
|
|
IV
|
61.04
|
24.32
|
81.67
|
11.13
|
|
FDI-s
|
I[a]
|
65.33
|
23.92
|
85.14
|
16.56
|
p = 0.30 (time effect)
p < 0.0001 (therapy effect)
|
|
II
|
59.47
|
22.37
|
79.08
|
11.33
|
|
III
|
59.92
|
33.53
|
74.86
|
23.97
|
|
IV
|
57.50
|
18.14
|
74.00
|
17.34
|
|
FaCE
|
I[a]
|
59.78
|
20.84
|
81.46
|
15.96
|
p = 0.3025 (time effect)
p < 0.0001 (therapy effect)
|
|
II
|
48.93
|
23.74
|
80.23
|
12.4
|
|
III
|
53.92
|
20.28
|
71
|
23.3
|
|
IV
|
47.63
|
14.43
|
69.95
|
17.31
|
Abbreviations: ANOVA, analysis of variance; FaCE, Facial Clinimetric Scale; FDI-p,
Facial Disability Index (physical); FDI-s, Facial Disability Index (social).
Note: Group I (who presented within 6 months post-palsy), group II (between 6 and
12 months post-palsy), group III (between 1 and 2 years post-palsy), group IV (late
presentations beyond 2 years post-palsy).
a Group I (good prognosticators) was excluded from statistical analyses to minimize
the confounding factor of potential for natural recovery.
Overall, the data illustrates the fact that a multidisciplinary approach is the key
element in recovery. This is illustrated in [Fig. 6], which shows statistically significant overall improvement in FGS scores before
and after multimodal therapy (unpaired Student's t-test; p < 0.0001). As stated previously good prognosticators (group I), who presented within
6 months of onset, were excluded from the data analyses, given that it was a confounding
factor. This is based on the fact that while 70% of patients completely recover by
6 months, the remaining 30% who have delayed recovery experience long-term sequelae
which will not spontaneously improve without intervention.[14] The evidence here suggests that earlier presentation to therapy for rehabilitation
can help better reduce stiffness and synkinesis long-term and that presentation to
therapy at any time will significantly improve both clinician-graded and patient-reported
outcomes, therefore improving patient's movement, comfort, and function.
Fig. 6 Overall improvement in Facial Grading Scale (FGS) scores comparing scores pre- and
postmultimodal treatment in this cohort (p < 0.0001).
Discussion
While the role of specialist facial therapy is being increasingly recognized as one
of the cornerstones of rehabilitation following facial palsy, its early acceptance
was limited by controversies regarding its efficacy. Nonspecialist physical therapy
was standardly provided; including inappropriate treatment options such as gross exercises,
which accounted for less successful objective outcomes. The key changes in the last
decade since the Cochrane review by Texeira et al[20] have been the multidisciplinary approach to facial rehabilitation and an appreciation
of the importance of facial therapy being delivered by trained specialist facial therapists.
There is recognition that psychosocial improvements are as important as physical improvements
in facial rehabilitation.[21] This has led to multimodal therapy,[22] based on a 360-degree assessment by psychologists, facial therapists, and surgeons,
followed by a step-by-step protocol as documented earlier.
In our practice, all patients are placed on a rehabilitation program starting with
psychological assessment. A high CORE score may initiate psychological therapy and
potentially preclude any surgical intervention until patients have completed psychological
intervention. Patients must also complete facial therapy prior to being considered
for any synkinesis surgery. Patients are reviewed approximately six times in therapy
over the course of up to 2 years to refine their independent therapeutic skills before
being discharged with the skill set to continue appropriate independent stretching,
relaxation, and neuromuscular retraining for as long as required.
Using serial FGS, FDI, FaCE, and Synkinesis Associated Questionnaire scores, patients
who are noted to have plateaued in term of their progress, receive tailored chemodenervation
programs based on our previous experience.[4]
[23] We find that low doses of botulinum toxin type A into specific synkinetic muscles,
given in a distributive dose, helps relax the sarcomere units, which then allows for
greater passive lengthening of these shortened muscles by repeated stretches. This
in turn affords patients an opportunity to work on coordinated movement pattern retraining
while their synkinesis is minimized and muscle length is optimized. Chemodenervation
treatment is tapered over time until treatment benefits plateau and the patient no
longer requires intervention.
Mean improvements in overall FGS scores, plotted against advancing time scales showed
that predictable increases in FGS were noted up to 24 months post-onset but beyond
this period, the degree of improvement, although still substantial, tapered. Analysis
of the FGS resting tone statistics between group III (12–24 months post-onset) and
group IV (> 24 months post-onset), reveals a 62% improvement in resting tone scores
of the former, as compared with a 33% improvement, in late presenters. This also concurs
with higher EGGS scores seen among late presenters; an indicator of progressive stiffening
over time which responds less well to therapeutic techniques in those that present
later to therapy.
Translating this clinically, we postulate that thixotropic/shortened muscles respond
better to stretching, rehabilitation, and chemodenervation in the early stages of
recovery (< 2 years) but beyond this timeline, muscle fibrosis and subsequent contracture
may set in, which is more resistant to therapy. Correlating this with the fact that
the overall mean duration of facial therapy treatment is 13 months versus 20.1 months
for those who presented beyond 2 years post-onset, it suggests that the facial muscles
and function in late presenters take comparatively longer to lengthen and improve
with facial therapy/chemodenervation as well as lengthening and improving to a lesser
degree.
In contrast to our experience, a study over a 20-year period from 1995 to 2016, showed
no benefit from the earlier institution of facial rehabilitation but this was based
purely on less specialist physiotherapy techniques.[24] We attribute our success in this regard, to the judicious use of highly trained
specialist facial therapists and multiple treatment arms where sequential timing and
therefore customized treatment, is paramount.
Moving forward, there remain questions unanswered regarding the cumulative benefits
of selective neurectomies in the EGGS III patient group, which our preliminary data
indicates is very effective. Histological evidence of muscle thixotropy and contracture
spectrums in these patients will also deepen our understanding of facial muscle recovery
following conditions like Bell's palsy. These are potential areas for future studies.
The coronavirus disease pandemic combined with increasing pressures upon NHS resources
in the U.K. has encouraged us to look for innovative ways to effectively deliver our
specialist facial therapy. We have therefore been working on a multidisciplinary online
group training program for patients with synkinesis and will be publishing the outcomes
for this group in due course. We hope that delivering our psychological therapy and
specialist facial therapy in this way will continue to provide patients with the significant
improvement in their physical and psychosocial outcomes that has been shown with our
one-to-one therapy provision.
In conclusion, the results of this study indicate that a multimodal approach to the
management of facial palsy is effective, even in those with chronically neglected
synkinesis, several years post-onset. In terms of latency periods between facial palsy
onset and treatment initiation, there is an advantage noted in earlier treatment,
particularly as regards synkinesis reduction, until beyond 2 years post-onset when
we postulate that muscle contracture begins to set in.
-
Access to specialist multimodal facial rehabilitation at any time post-onset improves
clinician and patient-reported outcomes even in chronic synkinesis.
-
After delayed recovery early access to rehabilitation (6–24 months post-onset) results
in reduced synkinesis.
-
Delayed facial therapy (2 years post-onset +) may result in increased treatment recalcitrance
and greater chemodenervation requirements.
