Efficacy of gold weight implants in facial nerve palsy: quantitative alterations in blinking

Automated analysis of spontaneous eye blinking in patients with acute facial palsy or facial synkinesis

Although patients with facial palsy often complain of disturbed eye blinking which may lead to visual impairment, a blinking analysis is not part of routine grading of facial palsy. Twenty minutes of spontaneous eye blinking at rest of 30 patients with facial palsy (6 with acute palsy; 24 patients with facial synkinesis; median age: 58 years, 67% female), and 30 matched healthy probands (median age: 57 years; 67% female) was smart phone video recorded. A custom computer program automatically extracted eye measures and determined the eye closure rate (eye aspect ratio [EAR]), blink frequency, and blink duration. Facial Clinimetric Evaluation (FaCE), Facial Disability Index (FDI) were assessed as patient-reported outcome measures. The minimal EAR, i.e., minimal visible eye surface during blinking, was significantly higher on the paretic side in patients with acute facial palsy than in patients with synkinesis or in healthy controls. The blinking frequency on the affected side was significantly lower in both patient groups compared to healthy controls. Vice versa, blink duration was longer in both patient groups. There was no clear correlation between the blinking values and FaCE and FDI. Blinking parameters are easy to estimate automatically and add a functionally important parameter to facial grading.

[Nonspecific inflammatory reaction after implantation of palpebral implants]

PURPOSE

To identify the possible cause of an inflammatory reaction to a Russian-manufactured palpebral implant made of gold in the long term after surgery, and to determine the clinical and morphological changes in the tissues of the upper eyelid when the presence of the implant caused the inflammatory reaction.

MATERIAL AND METHODS

The results of 150 operations with placement of a palpebral implant were analyzed. In 12 cases, a nonspecific inflammatory reaction was revealed within 2 to 4 weeks after the operation, in 7 cases it necessitated explantation, in 5 cases the local long-term use of an ointment with a corticosteroid made it possible to avoid extrusion and explantation. Chemical microanalysis of the palpebral implant and fragments of the removed capsule was performed using scanning electron microscopy (SEM), as well as immunohistochemical (IHC), macro- and microscopic examination of the fragments of connective tissue capsule was carried out after removal of the palpebral implant.

RESULTS

The obtained data confirm the chemical purity of the implant, the absence of abnormal accumulation of metals in the tissues of the eyelid. IHC, macro- and microscopic examination of the presented fragments of the connective tissue capsule revealed signs characteristic of an inflammatory reaction to a foreign body.

CONCLUSION

Further research is needed to establish the factors and predictors for the development of inflammatory reactions to a foreign body and, in particular, to gold.

A Hybrid Bipolar Active Charge Balancing Technique with Adaptive Electrode Tissue Interface (ETI) Impedance Variations for Facial Paralysis Patients

Functional electrical stimulation (FES) is a safe, effective, and general approach for treating various neurological disorders. However, in the case of FES usage for implantable applications, charge balancing is a significant challenge due to variations in the fabrication process and electrode tissue interface (ETI) impedance. In general, an active charge balancing approach is being used for this purpose, which has limitations of additional power consumption for residual voltage calibration and undesired neurological responses. To overcome these limitations, this paper presents a reconfigurable calibration circuit to address both ETI variations and charge balancing issues. This reconfigurable calibration circuit works in two modes: An impedance measurement mode (IMM) for treating ETI variations and a hybrid charge balancing mode (HCBM) for handling charge balance issues. The IMM predicts the desired stimulation currents by measuring the ETI. The HCBM is a hybrid combination of electrode shorting, offset regulation, and pulse modulation that takes the best features of each of these techniques and applies them in appropriate situations. From the results, it is proved that the proposed IMM configuration and HCBM configuration have an optimal power consumption of less than 44 μW with a power ratio ranging from 1.74 to 5.5 percent when compared to conventional approaches.

Facial nerve paralysis: A review on the evolution of implantable prosthesis in restoring dynamic eye closure

Facial nerve paralysis (FNP) is a debilitating condition that leaves those affected with disfigurement and loss of function. The most important function of the facial nerve is protecting the eye through eye closure and blinking. A series of reanimation techniques have been reported to restore dynamic function in FNP, but the lack of a universally accepted method that is reliable and reproducible with immediate effect has led to the introduction of several implantable devices. Most of these devices have been applied to assist blinking; however, the delicate anatomy and unique mechanics of eye closure are difficult to replicate. Lid loading is the most frequently used implant today, which is a passive device that can aid in volitional eye closure but has a limited effect on blinking. Dynamic action can be achieved with active prostheses but achieving successful long-term function remains elusive. Device action must also be coupled with a real-time feedback mechanism in order to capture the natural variation in facial muscle movements. This review discusses all prostheses used for restoring eye closure and blinking to date and explores their relative merits.

Efficacy and safety of platinum chain and gold weight implants for paralytic lagophthalmos: a systematic review

BACKGROUND Surgery has been proposed as a treatment of paralytic lagophthalmos. However, no consensus has been reached on the best treatment. This study was aimed to investigate the efficacy and safety between platinum chain and gold weight implants to treat paralytic lagophthalmos. METHODS This study used all randomized controlled trials or observational studies (prospective or retrospective) using platinum chain and gold weight implants for paralytic lagophthalmos surgery that were published from 1990 to 2020 in the PubMed, Cochrane, and Google Scholar databases. Efficacy was indicated by the reduction of ≥3 in lagophthalmos, and safety was measured based on complications after surgery. RESULTS The efficacy of platinum chain and gold weight implants were 60–100% and 10–93.6%, respectively. The complications of platinum chain implant were 0–2.9% of extrusion and 0–3.3% of migration. However, gold weight implant had 0–13.3% of migration. CONCLUSIONS Both platinum chain and gold weight implants have similar efficacy to treat paralytic lagophthalmos. However, gold weight implant has a higher rate of complication.

Impact of early eyelid weight placement on the development of synkinesis and recovery in patients with idiopathic facial paralysis

Purpose

Determine the impact of upper eyelid weight placement at 3 months post onset of idiopathic facial paralysis (IFP) on the recovery of facial function in patients with lagophthalmos.

Methods

This is a retrospective review of patients with incomplete recovery of IFP-defined as a Sunnybrook Facial Grading Scale (FGS) score of less than 100, 3 months after onset. Only patients with FGS and Facial Clinimetric Evaluation (FaCE) scores recorded at 3 and 12 months were included. Patients were categorized into 3 groups: Group A, lagophthalmos with eyelid weight placement; Group B, lagophthalmos without eyelid weight placement; Group C, complete eye closure (CEC) without eyelid weight placement. The eye comfort domain and composite score of the FaCE questionnaire were analyzed. Voluntary eye closure, synkinesis with eye closure, overall synkinesis and the composite score of the FGS were also analyzed. Paired two-tailed t-test was used to evaluate the data comparing the 3 and 12 month FaCE and FGS scores within and between the 3 groups.

Results

The change in composite FGS score significantly increased from month 3 to month 12 in Group A as compared to Group B (37 vs 4.25, P = 0.01). While Group A had significantly lower eye comfort (-12.5, P = 0.01), voluntary eye closure (-1.75, P = 0.05) and overall FGS scores (-28.75, P = 0.04) at 3 months compared to those in Group C, there were no differences between these two groups at 12 month follow-up.

Conclusions

For patients with lagophthalmos at 3 months, early eyelid weight placement may lead to improved facial function at 12 months.

Recreation of eyelid mechanics using the sling concept✰

BACKGROUND

Paralytic lagophthalmos causes major functional, aesthetic and psychological problems in patients with facial paralysis. The Bionic Lid Implant for Natural Closure (BLINC) project aims to restore eyelid function using an implanted electromagnetic actuator combined with an eyelid sling. The authors performed a preliminary study using cadaveric heads to investigate the optimal application of an eyelid sling in various configurations around the orbit.

METHODS

The sling was tested in a cadaveric sheep head using 2 medial anchor points and 4 lateral ostectomy points. An impulse was generated using gravitational force to test each combination of medial and lateral sling insertion sites using weights between 10 and 50 g. Each generated blink was recorded and analysed. The final result was validated in a human cadaveric model.

RESULTS

The maximum amount of eye closure and closure speed displayed in sheep were 83.7 ± 9.4% of total closure and 70.6 ± 6.9 mm/s at a maximum force of 490 mN, respectively. The 2 inferior lateral attachments performed better at displacing the eyelid than the superior attachments. The position with the highest degree of eye-closure (improvement of 21.6%, p < 0.001) and speed (improvement of 30.4 mm/s, p < 0.001) was the combination of a posterior medial attachment and an inferior-posterior lateral attachment, which resulted in a near physiological closure in human cadaver.

CONCLUSION

Closure improved with an inferior lateral position due to increased force acting in the direction of closure. Posterior positioning increases force acting radially, towards the centre of eyelid movement. The latter directs the closure force to effectively move the eyelid around the curved globe.

Spontaneous Blinking Kinetics on Paralytic Lagophthalmos After Lid Load with Gold Weight or Autogenous Temporalis Fascia Sling

PURPOSE

To assess the upper eyelid kinematics during spontaneous blinking in unilateral paralytic lagophthalmos before and after upper eyelid load with gold weight (GW) or autogenous temporalis fascia (TF) sling.

DESIGN

Comparative case series.

SUBJECTS

Patients with long-standing unresolved unilateral facial palsy who underwent surgical treatment with GW (n = 8) or upper lid cerclage with TF (n = 10). The contralateral eyelid served as the control for each patient (control group).

METHODS

Preoperative and postoperative measurements of spontaneous blink kinematics with magnetic search coil and clinical assessment of lid margin position, lagophthalmos and ocular surface exposure, and determine amplitude, maximum velocity and main sequence of spontaneous blinks; relative amplitude of blinks to the pupil center; ocular surface exposure scores; magnitude of lagophthalmos and mid-pupil lid distances.

RESULTS

The mean (±SE) down-phase amplitude ratio between paralyzed and contralateral eyelids (blink gain) was 10.0% preoperatively for both groups and significantly increased to 29 ± 6% for the GW group (p < 0.05) and 23 ± 4% for the TF group (p < 0.05). At 6 months the gain was significant for the GW group only (32 ± 7%, p < 0.05). There was no effect on the maximum velocity of the blinks or the main sequence of paretic and contralateral blinks with either surgery. Both procedures lowered the lid margin increasing the number of blinks that reached the pupil center. At 6 months this effect was prominent only for the GW group. Exposure keratopathy scores and lagophthalmos decreased postoperatively especially in the GW group.

CONCLUSIONS

The beneficial effect of lid load surgeries result from a combination of a small increase on the spontaneous blink amplitude and a static effect due to the reduction of the distance between the lid margin and pupil center.

Effectiveness of the lower eyelid suspension using fascia lata graft for the treatment of lagophthalmos due to facial paralysis

PURPOSE

To evaluate of functional and cosmetic effectiveness of lower eyelid sling technique with fascia lata graft in patients with lagophthalmos due to facial paralysis.

MATERIAL AND METHOD

Ten patients with a mean age of 55.1 ± 19.77 years who underwent lower eyelid sling surgery with a fascia lata graft between September 2011 and January 2014 were included in this prospective study. Preoperatively and postoperatively patients were evaluated in terms of corneal epithelial defects, Schirmer's test, and tear break-up time (TBUT). Cosmetically, vertical eyelid aperture, margin reflex distances 1 and 2 (MRD1 and MRD2) and scleral show were evaluated preoperatively and postoperatively.

RESULTS

One patient had facial paralysis on the right side whereas the other 9 patients had facial paralysis on the left side. Preoperatively, 3 patients were detected with corneal ulcer, whereas 7 patients were detected with persistent corneal epithelial defects localized in the lower half of the cornea. In the 3 patients with preoperative corneal ulcer, the ulcer recovered with corneal opacity, whereas in the 7 patients with punctate epitheliopathy, postoperative corneal transparency was obtained.

DISCUSSION

Lower eyelid sling technique with fascia lata graft is an effective technique for the repositioning of the lower eyelid and preventing the corneal complications.

Facial synkinesia before and after surgical reanimation of the paralyzed face

BACKGROUND

Facial synkinesia is a common sequela of facial palsy, affecting 15 to 20 percent of patients. The rate of postoperative synkinesia after facial reanimation is not clearly established. The severity and type of synkinesia determine the degree of clinical relevance.

METHODS

One hundred sixty-seven patients with facial palsy were included in this retrospective cohort study. Three-dimensional video analysis of facial movements was performed preoperatively and 18 months after facial reanimation. The severity of synkinesia was rated subjectively on a four-degree severity scale. Objective three-dimensional analysis of synkinesia was performed on patients with 18-month follow-up times.

RESULTS

Preoperatively, 84.4 percent of patients were not affected by synkinesia, 9 percent presented with mild synkinesia, 4.2 percent presented with moderate synkinesia, and 2.4 percent presented with severe synkinesia. Postoperatively, 51 percent of all patients presented with facial synkinesia (41.8 percent mild, 17.3 percent moderate, and 1 percent severe synkinesia; some patients had more than one type). Patients treated with territorially differentiated gracilis muscle transplantation were most frequently affected (69.8 percent), followed by patients treated with gracilis muscle transplantation in combination with temporalis muscle transposition to the eye (51.8 percent). Oculo-oral synkinesia was the most frequent form of synkinesia.

CONCLUSIONS

After surgical reanimation of the paralyzed face, half of the patients presented with synkinesia. The majority of patients developed mild or moderate forms of synkinesia; therefore, the clinical relevance of synkinesia has to be seen in the context of total facial function. Because of the high prevalence of synkinesia, it should be documented and addressed in patients undergoing facial reanimation.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Trigeminal high-frequency stimulation produces short- and long-term modification of reflex blink gain

Reflex blinks provide a model system for investigating motor learning in normal and pathological states. We investigated whether high-frequency stimulation (HFS) of the supraorbital branch of the trigeminal nerve before the R2 blink component (HFS-B) decreases reflex blink gain in alert rats. As with humans (Mao JB, Evinger C. J Neurosci 21: RC151, 2001), HFS-B significantly reduced blink size in the first hour after treatment for rats. Repeated days of HFS-B treatment produced long-term depression of blink circuits. Blink gain decreased exponentially across days, indicating a long-term depression of blink circuits. Additionally, the HFS-B protocol became more effective at depressing blink amplitude across days of treatment. This depression was not habituation, because neither long- nor short-term blink changes occurred when HFS was presented after the R2. To investigate whether gain modifications produced by HFS-B involved cerebellar networks, we trained rats in a delay eyelid conditioning paradigm using HFS-B as the unconditioned stimulus and a tone as the conditioned stimulus. As HFS-B depresses blink circuits and delay conditioning enhances blink circuit activity, occlusion should occur if they share neural networks. Rats acquiring robust eyelid conditioning did not exhibit decreases in blink gain, whereas rats developing low levels of eyelid conditioning exhibited weak, short-term reductions in blink gain. These results suggested that delay eyelid conditioning and long-term HFS-B utilize some of the same cerebellar circuits. The ability of repeated HFS-B treatment to depress trigeminal blink circuit activity long term implied that it may be a useful protocol to reduce hyperexcitable blink circuits that underlie diseases like benign essential blepharospasm.

Innovation and translation efforts in wireless medical connectivity, telemedicine and eMedicine: a story from the RFID Center of Excellence at the University of Pittsburgh

Translational research has recently been rediscovered as one of the basic tenants of engineering. Although many people have numerous ideas of how to accomplish this successfully, the fundamental method is to provide an innovative and creative environment. The University of Pittsburgh has been accomplishing this goal though a variety of methodologies. The contents of this paper are exemplary of what can be achieved though the interaction of students, staff, faculty and, in one example, high school teachers. While the projects completed within the groups involved in this paper have spanned other areas, the focus of this paper is on the biomedical devices, that is, towards improving and maintaining health in a variety of areas. The spirit of the translational research is discovery, invention, intellectual property protection, and the creation of value through the spinning off of companies while providing better health care and creating jobs. All but one of these projects involve wireless radio frequency (RF) energy for delivery. The remaining device can be wirelessly connected for data collection.

A blink restoration system with contralateral EMG triggered stimulation and real-time artifact blanking

Patients suffering from facial paralysis are on the hazard of disfigurement and loss of vision due to loss of blink function. Functional-electrical stimulation (FES) is one possible way of restoring blink and other functions in these patients. A blink restoration system for uni-lateral facial paralyzed patients is described in this paper. The system achieves restoration of synchronized blink through processing the myoelectric signal of orbicularis oculi at the normal side in real-time as the trigger to stimulate the paralyzed eyelid. Design issues are discussed, including EMG processing, stimulating strategies and real-time artifact blanking. Two artifact removal approaches based on sample and hold and digital filtering technique are proposed and implemented. Finally, the whole system has been verified on rabbit models.

Lid loading for treatment of paralytic lagophthalmos

Lagophthalmos secondary to facial palsy is a most clinically important condition that requires effective and early treatment because prolonged corneal exposure may cause corneal lesions, ranging from corneal spots to corneal ulceration and finally blindness. Lid loading is the therapy used most commonly to treat the condition. This method was first described in 1950, modified in 1966, and popularized in 1974. Since its inception, only several reviews have referred to the technology, but they talked about only parts of this technology and did not provide information on the technology overall. This review discusses lid loading in detail. This method now often uses gold and platinum as the material for the implant and should be done as early as possible in those patients whose paralytic lagophthalmos has little chance of being reversed. This method has shown good clinical results and given patients a better perspective. Of course, this method has its intrinsic complications such as allergic reactions, extrusion, and migration. However, with modification of the implant and the surgical procedure, the complication rate has decreased. In conclusion, although lid loading cannot solve all the problems associated with the paralyzed eyelid, it is a simple, reversible, and effective way to treat paralytic lagophthalmos.

Spontaneous eyeblink activity

Spontaneous blinking is essential for maintaining a healthy ocular surface and clarity of vision. The spontaneous blink rate (SBR) is believed to reflect a complex interaction between peripheral influences mediated by the eye surface and the central dopaminergic activity. The SBR is thus extremely variable and dependent on a variety of psychological and medical conditions. Many different methods have been employed to measure the SBR and the upper eyelid kinematics during a blink movement. Each has its own merits and drawbacks, and the choice of a specific method should be tailored to the specific needs of the investigation. Although the sequence of muscle events that leads to a blink has been fully described, knowledge about the neural control of spontaneous blinking activity is not complete. The tear film is dynamically modified between blinks, and abnormalities of the blink rate have an obvious influence on the ocular surface.

Conditioned eyelid movement is not a blink

Based on kinematic properties and distinct substrates, there are different classes of eyelid movement described as eyeblinks. We investigate whether the eyelid movements made in response to a conditioned stimulus (CS) are a category of eyelid movements distinct from blinks. Human subjects received 60 trials of classical eyelid conditioning with a tone as the CS and electrical stimulation of the supraorbital branch of the trigeminal nerve as the unconditioned stimulus (UCS). Before and after training, reflex blinks were elicited with the UCS. The kinematics of conditioned responses (CRs) differed significantly from those of reflex blinks. The slope of the amplitude-maximum velocity function was steeper for reflex blinks than for CRs, and reflex blink duration was significantly shorter than CR duration. Unlike reflex blinks, for which maximum velocity was independent of blink duration, the maximum velocity of CRs depended on CR duration. These quantitative and qualitative differences indicated that CRs were a unique class of eyelid movements distinct from blinks and eyelid movements with vertical saccadic gaze shifts.

Palpebral spring in the management of lagophthalmos and exposure keratopathy secondary to facial nerve palsy

PURPOSE

To evaluate the use of a palpebral spring, a dynamic facial reanimation technique, in the management of lagophthalmos and exposure keratopathy secondary to facial nerve palsy.

METHODS

A palpebral spring was placed in 29 eyelids of 28 patients with symptomatic facial nerve palsy. Preoperative and postoperative symptoms, upper eyelid margin to midpupil distance, lagophthalmos, and exposure keratopathy were evaluated.

RESULTS

At an average of 83 months follow-up, preoperative symptoms improved or resolved in 26 (90%) eyes. The upper eyelid margin to midpupil distance decreased and lagophthalmos and exposure keratopathy significantly improved after palpebral spring placement (p < 0.001). After modification of the technique by suturing the spring to the anterior tarsal surface, rather than encasing the tip in a silicone tube and letting it ride freely, tension of the spring required adjustment in 4 eyes (27%). Dislocation of the spring from the tarsus without exposure through the skin was observed in 1 eyelid (7%). The spring was replaced because of loss of function secondary to metal fatigue in 5 eyelids (33%) after an average of 43 months. Exposure of the spring through the skin was observed in 2 eyelids (14%) and required spring removal from 1 eyelid and replacement of the spring in the other.

CONCLUSION

A palpebral spring is an effective treatment for lagophthalmos and exposure keratopathy in patients with facial nerve palsy who do not receive adequate relief from the static procedures of lower eyelid tightening and upper eyelid lowering. This technique significantly improved symptoms and signs in these patients while allowing some of the blink reflex.

Outcomes of periocular reconstruction for facial nerve paralysis in cancer patients

BACKGROUND

Facial nerve paralysis is a common event in patients with head and neck cancer or metastasis of cancer to the parotid region. The aim of this study was to evaluate the outcomes of periocular reconstruction for facial nerve paralysis in cancer patients.

METHODS

The medical records of all patients who had undergone periocular surgery for facial nerve paralysis between January of 1999 and December of 2003 were retrospectively reviewed. The outcome measures included the ocular symptoms and signs, improvement in symptoms of exposure keratopathy postoperatively, timing of periocular surgery in relation to radiotherapy, and surgical complications.

RESULTS

Preoperative symptoms included burning sensation (25 of 78 patients), difficulty with vision (30 of 78), frequent use of lubricating drops and ointments (52 of 78), and excessive tearing (37 of 78). The degree of lagophthalmos ranged from 1.5 to 12 mm (mean, 6.5 mm) preoperatively and from 0 to 4.5 mm (mean, 1.5 mm) postoperatively. Seventy-eight patients had gold weight placement; 72 of them also had lateral tarsorrhaphy, 56 had lower eyelid tightening via a lateral tarsal strip procedure in addition to the gold weight and lateral tarsorrhaphy, and 22 had brow elevation in addition to all the above-mentioned procedures. Four also required a medial tarsorrhaphy. All patients reported less dependence on lubricating drops and ointments after periocular surgery. Eighteen of 25 patients who had foreign body sensation as their main preoperative symptom experienced improvement after surgery. Forty-four patients had radiotherapy to the head and neck region. Twenty-seven patients completed radiotherapy before and 17 after periocular reconstruction. Complication rates were low and comparable in both preoperative and postoperative radiation groups.

CONCLUSIONS

Periocular reconstruction for facial paralysis results in improvement of exposure keratopathy and less dependence on lubricating drops and ointments. Complications are minimal and infrequent. The timing of external beam radiotherapy does not affect the outcomes of periocular surgery.

Electrical stimulation of the paralyzed orbicularis oculi in rabbit

Dysfunction of the seventh cranial nerve often results in facial paralysis and loss of the ability to blink the eye, which can lead to corneal scarring, diminished vision, and potential loss of the eye. This study investigated the potential of electrical stimulation of the orbicularis oculi muscle as a means of restoring blink function. An animal model of orbicularis paralysis was created by sectioning the seventh cranial nerve in rabbit. Twenty paralyzed and five normal rabbits were acutely implanted with a subcutaneous stimulating electrode near the margin of the upper eyelid. Biphasic current controlled stimulation pulses were delivered between implanted contacts at the medial and lateral edges of the eyelid. Strength-duration curves for lid twitch threshold were generated, and quantitative measurements of lid closure were made for systematically varied parameters including pulse amplitude, pulse width, number of pulses delivered, and duration of paralysis prior to stimulation. Normal rabbits achieved a greater degree of lid closure due to electrical stimulation than rabbits that had been surgically paralyzed. Of rabbits that had been paralyzed, those demonstrating evidence of at least partial reinnervation achieved a greater degree of lid closure than those demonstrating persistent denervation. Trains of 10 ms biphasic pulses delivered at 50 Hz were found to be the most effective means of eliciting lid closure for the range of parameters tested.

Ophthalmic Management of Facial Nerve Palsy: A Review

Facial nerve palsy affects individuals of all ages, races, and sexes. Psychological and functional implications of the paralysis present a devastating management problem to those afflicted, as well as the carriers. Since Sir Charles Bell's original description of facial palsy in 1821, our understanding and treatment options have expanded. It is essential that a multidisciplinary approach, encompassing ophthalmologists; Ear, Nose, and Throat surgeons; plastic surgeons; and psychologists work closely to optimize patient management in a staged approach. Although the etiology remains unknown, strong histological, cerebral spinal fluid, and radiological evidence suggests a possible association with herpes simplex virus in idiopathic facial nerve palsy (Bell's palsy). The use of steroids has been suggested as a means of limiting facial nerve damage in the acute phase. Unfortunately, no single randomized control trial has achieved an unquestionable benefit with the use of oral steroid therapy and thus remains controversial. In the acute phase, ophthalmologists play a pivotal role in preventing irreversible blindness from corneal exposure. This may be successfully achieved by using intensive lubrication, medical therapy (botulinum toxin), or surgery (upper lid weighting or tarsorraphy). Once the cornea is adequately protected and recovery deemed unlikely, longer term planning for eyelid and facial reanimation may take place in an individualized manner. Onset is sudden and management potentially lengthy. Physician empathy, knowledge, and experience are essential in averting long-term lifestyle and psychological discomfort for patients.

Communication between functional and denervated muscles using radiofrequency

OBJECTIVE

This article focuses on establishing communication between a functional muscle and a denervated muscle using a radiofrequency communications link. The ultimate objective of the project is to restore the eye blink in patients with facial nerve paralysis.

STUDY DESIGN AND SETTING

Two sets of experiments were conducted using the gastrocnemius leg muscles of Sprague-Dawley rats. In the initial tests, varying magnitudes of voltages ranging from 0.85 to 2.5 V were applied directly to a denervated muscle to determine the voltage required to produce visible contraction. The second set of experiments was then conducted to determine the voltage output from an in vivo muscle contraction that could be sensed and used to coordinate a signal for actuation of a muscle in a separate limb. After designing the appropriate external communication circuitry, a third experiment was performed to verify that a signal between a functional and a denervated muscle can be generated and used as a stimulus.

RESULTS

Voltages below 2 V at a 10-millisecond pulse width elicited a gentle, controlled contraction of the denervated muscle in vivo. It was also observed that with longer pulse widths, higher stimulation voltages were required to produce sufficient contractions.

CONCLUSION

It is possible to detect contraction of a muscle, use this to generate a signal to an external base station, and subsequently cause a separate, denervated muscle to contract in response to the signal.

SIGNIFICANCE

This demonstration in vivo of a signaling system for pacing of electrical stimulation of 1 muscle to spontaneous contraction of another, separate muscle, using radiofrequency communication without direct connection, may be used in numerous ways to overcome nerve damage.

Kinematics of electrically elicited eyelid movement

Electrical stimulation has demonstrated potential for reanimating eye blink following facial paralysis caused by damage to the seventh cranial nerve. This study investigated the kinematics of lid movement caused by electrical stimulation of the orbicularis oculi muscle in both normal rabbit and rabbit with surgically induced seventh nerve lesion.

Type IV hypersensitivity reactions to upper lid gold weight implants-is patch testing necessary?

AIMS

To report two cases of allergic reaction to upper lid gold weight implants in patients with facial nerve palsy and to identify the use of pre-implantation patch testing in predicting gold hypersensitivity.

METHODS

One patient who had a positive family history of gold allergy and had undergone previous gold dental restoration underwent patch testing with gold sodium thiosulphate. The gold weight from the same patient was analysed using scanning electron microscopy and energy dispersive X-ray analysis, which can detect surface impurities. Tissue obtained during surgery to remove the gold weight from the second patient was examined histologically.

RESULTS

Patch testing in the first patient gave a positive result. Analysis of the gold weight removed from the same patient confirmed 99.99% purity, and hence sensitivity to the gold itself was considered to be the cause of the inflammatory reaction. Histology of tissue taken from the eyelid of the second patient was consistent with type IV hypersensitivity.

CONCLUSION

A personal and family history of gold allergy should be looked for before upper eyelid gold weight implantation. Patch testing should be performed for patients where there is doubt about whether gold has been the specific cause of previous allergic reactions, for patients who have undergone previous dental restoration involving gold, or if there is a positive family history of gold allergy.

Botulinum Toxin for Aberrant Facial Nerve Regeneration: Double-Blind, Placebo-Controlled Trial Using Subjective Endpoints

BACKGROUND

Aberrant facial nerve regeneration syndrome is systematically studied by constructing a subjective questionnaire organized into pertinent domains (impairment of quality of life, social interactions, perception of self-appearance, visual function, and perception of problem severity) and by physical assessment of degree of involuntary palpebral fissure closure during routine facial movements using videotaping and a physicians' grading scale.

METHODS

The videotape measurements of corneal light reflex to upper lid margin distance and vertical palpebral distance were made during adynamic and active facial expression. Thirty-six patients were studied (six in an open-label pilot study design and 30 in a multicenter, double-blind, placebo-controlled trial). Botulinum toxin type A injections consistently suppressed the degree of involuntary eyelid movement associated with smiling, chewing, and puckering by each measurement and in both study designs.

RESULTS

In all subjective morbidity domains, improvement was demonstrated in the double-blind study design (quality of life, p < 0.05; social interaction, p < 0.001; personal appearance, p < 0.001; peripheral visual impairment, p < 0.01; and perception of severity, p < 0.05). Correlation between degrees of physical impairment was significant but low comparing degree of subjective impairment to direct videotaped measurements. Correlation was more significant comparing subjective scores to the physicians' grading scale assessment of degree of physical impairment.

CONCLUSIONS

Impairment in quality of life, social interactions, and self-assessment of appearance closely reflected the nature of the morbidity associated with palpebral fissure asymmetry associated with aberrant facial nerve regeneration. The physicians' grading scale best reflected subjective morbidity over direct videotaped measurements.

Ophthalmic management of facial nerve palsy

The ophthalmologist plays a pivotal role in the evaluation and rehabilitation of patients with facial nerve palsy. It is crucial to recognize and treat the potentially life-threatening underlying causes. The immediate ophthalmic priority is to ensure adequate corneal protection. The medium to long-term management consists of treatment of epiphora, hyperkinetic disorders secondary to aberrant regeneration and poor cosmesis. Patients should be appropriately referred for general facial re-animation. This review aims to provide a guide to the management of this complex condition.

Surgical management of seventh nerve paralysis and floppy eyelid syndrome

A seven-stage approach to the management of the paretic eyelid complex has been described. These stages include supportive care, planning and execution of general facial reanimation, lower eyelid and canthal resuspension or support, passive upper eyelid animation, dynamic lid animation, and soft tissue repositioning. A final stage, the epilogue, is described for the treatment of the synkinesis and hypertonicity that often develop. Recent developments in these areas are discussed. Floppy eyelid syndrome, first described by Culbertson and Ostler, is a syndrome of chronic papillary conjunctivitis in overweight patients with easily everted eyelids. The syndrome has now been associated with a variety of other conditions and findings. Surgical management with horizontal shortening of the floppy eyelids remains the mainstay of therapy.