Effect of long-term electrical stimulation on motor recovery and improvement of clinical residuals in patients with unresolved facial nerve palsy

The application of neuroprosthesis in restoration of unilateral facial nerve paralysis: A scoping review

Facial nerve palsy can pose functional, psychosocial, and cosmetic issues for patients. Although various surgical techniques can improve facial functions and appearance for patients who do not fully recover following conservative management, they can be extensively invasive with limited restoration of facial movement and symmetry. Functional electrical stimulation (FES) is a technology that has been developed to stimulate paralyzed nerves or muscles and has 2 different applications in facial nerve palsy treatment: facial rehabilitation and neuroprosthesis. Our study focuses specifically on the neuroprosthesis application of FES, which uses signals from the healthy side of the face to stimulate the paralyzed side. This emerging neuroprosthetic technology is less invasive and holds promise in synchronizing facial movements. The purpose of our scoping review was to understand the landscape of the models that have been developed, as well as the outcomes of these studies in leading to facial movement on the paralyzed side. We found 22 studies in our review that each used varying methods for detecting facial movement from the healthy side and differing stimulation types and parameters, with each study describing successful stimulation of facial movement on the paralyzed side using healthy hemiface input.

Application of facial neuromuscular electrical stimulation (fNMES) in psychophysiological research: Practical recommendations based on a systematic review of the literature

Facial neuromuscular electrical stimulation (fNMES), which allows for the non-invasive and physiologically sound activation of facial muscles, has great potential for investigating fundamental questions in psychology and neuroscience, such as the role of proprioceptive facial feedback in emotion induction and emotion recognition, and may serve for clinical applications, such as alleviating symptoms of depression. However, despite illustrious origins in the 19th-century work of Duchenne de Boulogne, the practical application of fNMES remains largely unknown to today's researchers in psychology. In addition, published studies vary dramatically in the stimulation parameters used, such as stimulation frequency, amplitude, duration, and electrode size, and in the way they reported them. Because fNMES parameters impact the comfort and safety of volunteers, as well as its physiological (and psychological) effects, it is of paramount importance to establish recommendations of good practice and to ensure studies can be better compared and integrated. Here, we provide an introduction to fNMES, systematically review the existing literature focusing on the stimulation parameters used, and offer recommendations on how to safely and reliably deliver fNMES and on how to report the fNMES parameters to allow better cross-study comparison. In addition, we provide a free webpage, to easily visualise fNMES parameters and verify their safety based on current density. As an example of a potential application, we focus on the use of fNMES for the investigation of the facial feedback hypothesis.

Bell Palsy: Facts and Current Research Perspectives

Bell palsy is a non-progressive neurological condition characterized by the acute onset of ipsilateral seventh cranial nerve paralysis. People who suffer from this type of facial paralysis develop a droop on one side of their face, or sometimes both. This condition is distinguished by a sudden onset of facial paralysis accompanied by clinical features such as mild fever, postauricular pain, dysgeusia, hyperacusis, facial changes, and drooling or dry eyes. Epidemiological evidence suggests that 15 to 23 people per 100,000 are affected each year, with a recurrence rate of 12%. It could be caused by ischaemic compression of the seventh cranial nerve, which could be caused by viral inflammation. Pregnant women, people with diabetes, and people with respiratory infections are more likely to have facial paralysis than the general population. Immune, viral, and ischemic pathways are all thought to play a role in the development of Bell paralysis, but the exact cause is unknown. However, there is evidence that Bell's hereditary proclivity to cause paralysis is a public health issue that has a greater impact on patients and their families. Delay or untreated Bell paralysis may contribute to an increased risk of facial impairment, as well as a negative impact on the patient's quality of life. For management, antiviral agents such as acyclovir and valacyclovir, and steroid treatment are recommended. Thus, early diagnosis accompanied by treatment of the uncertain etiology of the disorder is crucial. This paper reviews mechanistic approaches, and emerging medical perspectives on recent developments that encounter Bell palsy disorder.

Efficacy of repetitive transcranial magnetic stimulation at different sites for peripheral facial paralysis: a prospective cohort study

Background

There are very few studies on transcranial magnetic stimulation (TMS) therapy for facial paralysis and no studies comparing the efficacy of central and peripheral TMS in the treatment of peripheral facial paralysis (PFP).

Purpose

To observe the therapeutic effect and security of central and peripheral repetitive transcranial magnetic stimulation (rTMS) on PFP.

Methods

Patients with unilateral onset of peripheral facial paralysis within 1 month were prospectively recruited, 97 patients with PFP were divided into the peripheral group, central group, and control group. The control group was given common treatment (drug therapy and acupuncture), and the peripheral and central groups received rTMS in addition to conventional treatment. After 2 weeks of treatment, the House-Brackmann (HB) grading scale, Sunnybrook facial grading system (SFGS), and modified Portmann scale (MPS) were used to evaluate the facial muscle function of patients in the three groups.

Result

After 2 weeks of rTMS treatment, the HBGS/SFGS/MPS scores of the three groups were significantly better than before (p < 0.05), and the mean change values of HBGS, SFGS, and MPS scores were significantly higher in participants in Peripheral Group (p < 0.001; p < 0.001; p = 0.003; respectively) and Central Group (p = 0.004; p = 0.003; p = 0.009; respectively) than in Control Group. But the mean change values of HBGS, SFGS, and MPS scores showed no significant differences in participants in the Peripheral Group than in the Central Group (p = 0.254; p = 0.139; p = 0.736; respectively) after 2 weeks of treatment (p > 0.05).

Conclusion

Our study shows that rTMS can be a safe and effective adjuvant therapy for patients with PFP. Preliminary studies have shown that both peripheral and central stimulation can effectively improve facial nerve function, but there is no significant difference in the efficacy of the two sites.

Effects of Electrical Stimulation on Facial Paralysis Recovery after Facial Nerve Injury: A Review on Preclinical and Clinical Studies

Various methods have been used to improve function and manage facial nerve injury. Although electrical stimulation therapy is frequently used to treat facial paralysis, its effects have been found to vary and no clear standards have been developed. The current review describes the results of preclinical and clinical studies evaluating the effectiveness of electrical stimulation therapy in promoting the recovery of a peripheral facial nerve injury. Evidence is presented showing the efficacy of electrical stimulation in promoting nerve regeneration after peripheral nerve injuries in both animal models and human patients. The ability of electrical stimulation to promote the recovery of facial paralysis was found to depend on the type of injury (compression or transection), the species of animal tested, the type of disease, the frequency and method of electrical stimulation, and the duration of the follow-up. Electrical stimulation, however, can also have potential negative outcomes, such as reinforcing synkinesis, including mistargeted axonal regrowth via inappropriate routes; excessive collateral axonal branching at the lesion site; and multiple innervations at neuromuscular junctions. Because of the inconsistencies among studies and the low quality of evidence, electrical stimulation therapy is not currently regarded as a primary treatment of facial paralysis in patients. However, understanding the effects of electrical stimulation, as determined in preclinical and clinical studies, is important for the potential validity of future research on electrical stimulation.

Selective Electrical Surface Stimulation to Support Functional Recovery in the Early Phase After Unilateral Acute Facial Nerve or Vocal Fold Paralysis

This article addresses the potential clinical value of surface electrical stimulation in the acute phase of denervation after the onset of facial nerve or recurrent laryngeal nerve paralysis. These two nerve lesions are the most frequent head and neck nerve lesions. In this review, we will work out several similarities concerning the pathophysiology features and the clinical scenario between both nerve lesions, which allow to develop some general rules for surface electrical stimulation applicable for both nerve lesions. The focus is on electrical stimulation in the phase between denervation and reinnervation of the target muscles. The aim of electrostimulation in this phase of denervation is to bridge the time until reinnervation is complete and to maintain facial or laryngeal function. In this phase, electrostimulation has to stimulate directly the denervated muscles, i.e. muscle stimulation and not nerve stimulation. There is preliminary data that early electrostimulation might also improve the functional outcome. Because there are still caveats against the use of electrostimulation, the neurophysiology of denervated facial and laryngeal muscles in comparison to innervated muscles is explained in detail. This is necessary to understand why the negative results published in several studies that used stimulation parameters are not suitable for denervated muscle fibers. Juxtaposed are studies using parameters adapted for the stimulation of denervated facial or laryngeal muscles. These studies used standardized outcome measure and show that an effective and tolerable electrostimulation of facial and laryngeal muscles without side effects in the early phase after onset of the lesions is feasible, does not hinder nerve regeneration and might even be able to improve the functional outcome. This has now to be proven in larger controlled trials. In our view, surface electrical stimulation has an unexploited potential to enrich the early therapy concepts for patients with unilateral facial or vocal fold paralysis.

Peripheral facial nerve palsy in children: clinical manifestations, treatment and prognosis

Background

Sudden onset of unilateral weakness of the upper and lower muscles of one side of the face is defined as peripheral facial nerve palsy. Peripheral facial nerve palsy is often idiopathic and sometimes it could be due to infectious, traumatic, neoplastic, and immune causes. This study aimed to report the clinical manifestation, evaluation, and prognosis in children with peripheral facial nerve palsy.

Methods

57 children under 18 years of age diagnosed with peripheral facial nerve palsy at Çukurova University, Balcalı Hospital, between January 2018 and September 2021, were included in the study.

Results

The mean age of the children at the time of diagnosis was 9.6 ± 7, 4 years. Thirty-two (56.1%) of the patients were female and 25 (43.9%) were male. A total of 57 patients were diagnosed with peripheral facial nerve palsy and categorized into many groups by etiology: idiopathic Bell’s palsy in 27 (47.5%), infectious in 11 (19.2%), traumatic in 6 (10.5%), and others (due to congenital, immune, neoplastic, Melkersson–Rosenthal syndrome, drug toxicity, and iatrogenic causes) in 13 (22.8%). Forty-six of the children achieved full recovery under oral steroids within 1–7 months. Four patients with acute leukemia, myelodysplastic syndrome, Mobius syndrome and trauma did not recover and two patients (schwannoma, trauma) showed partial improvement. Five patients could not come to follow-up control.

Conclusion

Peripheral facial nerve palsy is a rare condition in children with different causes. It could be idiopathic, congenital, or due to infectious, traumatic, neoplastic, and immune reasons. So, when a child presents with facial palsy, a complete clinical history and a detailed clinical examination are recommended. Giving attention to the red flag is very important. Peripheral facial nerve palsy in children is considered to have a good prognosis.

Functional Evaluation of Larynx Nerve Stimulator With EMG Acquisition Capability and Wireless Connectivity

Recently, an electrical stimulation of the paralyzed muscle, as a potential therapy for restoring function of a denervated muscle system, has been debated as an innovative treatment in the management of patients with laryngeal paralysis. Numerous studies in acute and chronic animal models have demonstrated that electrical stimulation of the paralyzed posterior cricoarytenoideus muscle (PCA) offers an approach to induce vocal fold abduction and restore ventilation through the glottis. The study aims to test applicability of the controlled opening of the rima glottides via direct electrical stimulation of the posterior cricoarytenoideus muscle. We developed for this purpose a novel instrument system for the controlled larynx nerve stimulation. An acute experiment on the 4 years old pig showed effectiveness of the engineered stimulator. The controlled opening of rima glottidis of both posterior cricoarytenoid muscles and afterwards of both PCA muscle contraction were observed as a result of the electrical stimulation with the applied current in the range of 0.1-3 mA and pulse width of 1 ms and 10 ms. Performed research indicates a large potential of the novel nerve stimulator for the human larynx stimulation.

Oral motor dysfunction after carotid endarterectomy: Challenges in diagnosing marginal mandibular nerve injury and effectiveness of rehabilitation

Carotid endarterectomy (CEA) is a frequently used surgical treatment for carotid artery stenosis. Cranial and peripheral nerve injuries are among the intraoperative complications. Diagnosing isolated injuries of the marginal mandibular branch of the facial nerve after CEA is challenging and leads to oral motor dysfunction that affects the patient's quality of life. Early diagnosis and treatment are valuable, since delayed diagnosis requires a surgical restoration of the affected nerve or muscle. In this article, we present a case of marginal mandibular nerve injury after CEA to increase the awareness on this complication and highlight the importance of rehabilitation for these cases, even in the chronic phase.

Efficacy of electrotherapy in Bell's palsy treatment: A systematic review

BACKGROUND

Up to now there is not enough evidence that supports the use of electrotherapy in the treatment of Bell's palsy.

OBJECTIVE

Through a systematic review, we aimed to verify whether the use of electrotherapy is effective for treating Bell's palsy or peripheral paralysis.

METHODS

Publications were searched in PubMed, EBSCO and Web of Science. The present systematic review included studies that analyzed the electrotherapy as a therapeutic method for treating individuals with Bell's palsy, in order to recover the function of facial muscles.

RESULTS

Seven studies involving a total of 131 cases and 113 controls were included in this systematic review. In the studies analyzed, patients received electrotherapy combined with other treatments such as hot-wet facial napkins, massages and muscle reeducation. Although the effect of electrotherapy alone was not evaluated, the use of electrotherapy combined with other treatments produced a significant improvement in the individuals evaluated.

CONCLUSIONS

Due to the diverse methodologies used and the small number of individuals included in the studies, we could not fully prove the efficacy of electrotherapy for treating Bell's Palsy. Future studies with larger samples and homogenous populations should be performed to obtain conclusive results.

Electrical stimulation of cranial nerves in cognition and disease

The cranial nerves are the pathways through which environmental information (sensation) is directly communicated to the brain, leading to perception, and giving rise to higher cognition. Because cranial nerves determine and modulate brain function, invasive and non-invasive cranial nerve electrical stimulation methods have applications in the clinical, behavioral, and cognitive domains. Among other neuromodulation approaches such as peripheral, transcranial and deep brain stimulation, cranial nerve stimulation is unique in allowing axon pathway-specific engagement of brain circuits, including thalamo-cortical networks. In this review we amalgamate relevant knowledge of 1) cranial nerve anatomy and biophysics; 2) evidence of the modulatory effects of cranial nerves on cognition; 3) clinical and behavioral outcomes of cranial nerve stimulation; and 4) biomarkers of nerve target engagement including physiology, electroencephalography, neuroimaging, and behavioral metrics. Existing non-invasive stimulation methods cannot feasibly activate the axons of only individual cranial nerves. Even with invasive stimulation methods, selective targeting of one nerve fiber type requires nuance since each nerve is composed of functionally distinct axon-types that differentially branch and can anastomose onto other nerves. None-the-less, precisely controlling stimulation parameters can aid in affecting distinct sets of axons, thus supporting specific actions on cognition and behavior. To this end, a rubric for reproducible dose-response stimulation parameters is defined here. Given that afferent cranial nerve axons project directly to the brain, targeting structures (e.g. thalamus, cortex) that are critical nodes in higher order brain networks, potent effects on cognition are plausible. We propose an intervention design framework based on driving cranial nerve pathways in targeted brain circuits, which are in turn linked to specific higher cognitive processes. State-of-the-art current flow models that are used to explain and design cranial-nerve-activating stimulation technology require multi-scale detail that includes: gross anatomy; skull foramina and superficial tissue layers; and precise nerve morphology. Detailed simulations also predict that some non-invasive electrical or magnetic stimulation approaches that do not intend to modulate cranial nerves per se, such as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS), may also modulate activity of specific cranial nerves. Much prior cranial nerve stimulation work was conceptually limited to the production of sensory perception, with individual titration of intensity based on the level of perception and tolerability. However, disregarding sensory emulation allows consideration of temporal stimulation patterns (axon recruitment) that modulate the tone of cortical networks independent of sensory cortices, without necessarily titrating perception. For example, leveraging the role of the thalamus as a gatekeeper for information to the cerebral cortex, preventing or enhancing the passage of specific information depending on the behavioral state. We show that properly parameterized computational models at multiple scales are needed to rationally optimize neuromodulation that target sets of cranial nerves, determining which and how specific brain circuitries are modulated, which can in turn influence cognition in a designed manner.

Can MRI quantify the volume changes of denervated facial muscles?

Could manual segmentation of magnetic resonance images be used to quantify the effects of transcutaneous electrostimulation and reinnervation of denervated facial muscle? Five patients with unilateral facial paralysis were scanned during the study while receiving a daily surface electrostimulation of the paralytic cheek region, but also after reinnervation. Their facial muscles were identified in 3D (coronal, sagittal, and axial) and segmented in magnetic resonance imaging (MRI) data for in total 28 time points over the 12 months of study. A non-significant trend of increasing muscle volume were detected after reinnervation. MRI is a valuable technique in the facial paralysis research.

Effect of pulse waveforms on movement amplitudes and perceived discomfort in electric muscle stimulation in unresolved facial nerve palsy

Studies on the effects of the pulse waveform used in electrical muscle stimulation on the activations and perceived discomfort of the waveform have been mainly executed on limb muscles with variable results, however, knowledge of these effects on facial muscles is currently lacking. We studied two waveforms, square wave and sinusoidal wavelet, for the activation of the frontalis muscle in 9 individuals with unresolved facial nerve palsy. Both waveforms produced a movement that was greater in amplitude compared with the maximal voluntary movement of the affected side in 8 participants and at least as great as the healthy side's maximal voluntary movement in 4 participants. Both waveforms were equally successful in producing movements, and there was no significant difference in perceived discomfort ratings between the two waveforms. These findings will be useful for the future development of neuroprosthetic applications for reanimating facial muscles using electrical stimulation. Trial registration: ClinicalTrials.gov NCT03496025, registration date March 19, 2018.

Neuromuscular electrical stimulation and shortwave diathermy in unrecovered Bell palsy: A randomized controlled study

BACKGROUND

Unrecovered Bell palsy is difficult to treat, because until now in literature there is not a gold standard. This study aimed to evaluate the effectiveness of neuromuscular electrical stimulation (NMES) and shortwave diathermy (SWD) therapy for chronic Bell palsy.

METHODS

After 5 months of conventional therapy, this 2-arm randomized controlled trial enrolled and randomly allocated 20 patients to a treatment group with NMES+SWD and supervised exercises (n = 10) or a sham group with supervised exercise alone (n = 10). The administration of NMES or sham NMES, as intervention, was performed 30 min/session, 5 sessions/wk, for 4 weeks. The primary outcome was assessed by Sunnybrook scale. The secondary outcomes were evaluated by the Kinovea©, a movement analysis software. All primary and secondary outcomes were measured at baseline (T0), at the end of 4-week treatment (T1).

RESULTS

At the end of 4-week treatment, the patients in the treatment group did not achieve better outcomes in resting symmetry, but we observed an increase of the perceived a significant improvement (P < .05) for symmetry of voluntary movements by the Sunnybrook subscale, with a score of 55.4 ± 9 compared to 46.4 ± 3.7 to control group and an increase in zygomatic muscle movement symmetry ratio (P < .05) by Kinovea©. No adverse events occurred in either group.

CONCLUSION

The improvements in the symmetry of voluntary movements demonstrated that combining diathermy with neuromuscular electrostimulation is valid and reliable in the treatment of chronic Bell palsy.

An Investigation of Neural Stimulation Efficiency With Gaussian Waveforms

OBJECTIVE

Previous computational studies predict that Gaussian shaped waveforms use the least energy to activate nerves. The primary goal of this study was to examine the claimed potential of up to 60% energy savings with these waveforms over a range of phase widths (50- [Formula: see text]) in an animal model.

METHODS

The common peroneal nerve of anaesthetized rats was stimulated via monopolar and bipolar electrodes with single stimuli. The isometric peak twitch force of the extensor digitorum longus muscle was recorded to indicate the extent of neural activation. The energy consumption, charge injection and maximum instantaneous power values required to reach 50% neural activation were compared between Gaussian pulses and standard rectangular stimuli.

RESULTS

Energy savings in the 50- [Formula: see text] range of phase widths did not exceed 17% and were accompanied by significant increases in maximum instantaneous power of 110-200%. Charge efficiency was found to be increased over the whole range of tested phase widths with Gaussian compared to rectangular pulses and reached up to 55% at 1ms phase width.

CONCLUSION

These findings challenge the claims of up to 60% energy savings with Gaussian like stimulation waveforms. The moderate energy savings achieved with the novel waveform are accompanied with considerable increases in maximal instantaneous power. Larger power sources would therefore be required, and this opposes the trend for implant miniaturization.

SIGNIFICANCE

This is the first study to comprehensively investigate stimulation efficiency of Gaussian waveforms. It sheds new light on the practical potential of such stimulation waveforms.

History of Cranial Nerve-Implanted Stimulators in Otolaryngology

This article aims to clearly understand the historical development of cranial nerve-implanted stimulators in otolaryngology. The authors also discuss cranial nerve history; initial theory of the functional concept of animal spirit; electrical nerve impulse theory; first electrical otolaryngology cranial nerve stimulation devices; and the development of implanted stimulators.

Mixed facial reanimation technique to treat paralysis in medium-term cases

Recent facial paralyses, in which fibrillations of the mimetic muscles are still detectable by electromyography (EMG), allow facial reanimation based on giving new neural stimuli to musculature. However, if more time has elapsed, mimetic muscles can undergo irreversible atrophy, and providing a new neural stimulus is simply not effective. In these cases function is provided by transferring free flaps into the face or transposing masticatory muscles to reinstitute major movements, such as eyelid closure and smiling. In a small number of cases, patients affected by paralysis are referred late - more than 18 months after onset. In these cases, reinnervating the musculature carries a high risk of failure because some or all of the mimetic muscles may atrophy irreversibly while axonal ingrowth is taking place. A mixed reanimation technique to address this involves a neurorrhaphy between the masseteric nerve and a facial nerve branch for the orbicularis oculi, to ensure a stronger innervation to that muscle, associated with the transposition of the temporalis muscle to the nasiolabial sulcus. This gives good symmetry in the rest of the midface, while smiling movement is achievable, but not guaranteed. This one-time facial reanimation is particularly indicated for those who refuse major free-flap surgery or when that may be risky, as in previously operated and irradiated fields. More extensive procedures based on utilizing a free flap to recover smiling, while adding a cross-face nerve graft to restore blinking, may be proposed for motivated patients. Between 2010 and 2015, five patients affected by complete unilateral facial palsy underwent this technique in the Maxillofacial Surgery Department, San Paolo Hospital (Milan, Italy). Symmetry of the middle-third of the face at rest and recovery of smiling was quite good. Complete voluntary eyelid closure was obtained in all cases. Combining temporalis flap rotation and a masseteric-to-orbicularis-oculi-facial-nerve branch neurorrhaphy seems to be a valid solution for those medium-term referred patients.

Surgical treatment of synkinesis between smiling and eyelid closure

Synkinetic movements are common among patients with incomplete recovery from facial palsy, with reported rates ranging from 9.1% to almost 100%. The authors propose the separation of the neural stimulus of the orbicularis oculi from that of the zygomatic muscular complex to treat eyelid closure/smiling synkinesis. This technique, associated with an anastomosis between the masseteric nerve and a central branch of the facial nerve, as well as with the use of a cross-facial nerve graft, resolves most of the spasms of the midface musculature, leading to a more relaxed tone when the mimic muscle is at rest and enhancing muscle excursion during voluntary and spontaneous smiling. Between 2011 and 2016, 18 patients affected by segmental paresis of the middle of the face underwent surgical treatment at the Maxillofacial Surgery Department of the San Paolo Hospital (Milan, Italy). Of these patients, 72.22% of cases with hypertone obtained partial to complete relaxation. Synkinesis was completely resolved in 83.33% of cases, and a significant improvement in facial movement was achieved in all patients. Neurorrhaphy of the masseteric nerve and the central branch of the facial nerve appears to produce favorable results. These initial data should be confirmed by further studies.

Unilateral Laryngeal Pacing System and Its Functional Evaluation

Goal. To establish a reliable instrumental system for synchronized reactivation of a unilaterally paralyzed vocal fold and evaluate its functional feasibility. Methods. Unilateral vocal fold paralysis model was induced by destruction of the left recurrent laryngeal nerve (RLN) in anesthetized dogs. With a micro controller-based electronic system, electromyography (EMG) signals from cricothyroid (CT) muscle on the ipsilateral side were recorded and used to trigger pacing of paralyzed vocalis muscles. The dynamic movement of vocal folds was continuously monitored using an endoscope, and the opening and closing of the glottis were quantified with customized imaging processing software. Results. The recorded video images showed that left side vocal fold was obviously paralyzed after destructing the RLN. Using the pacing system with feedback triggering EMG signals from the ipsilateral CT muscle, the paralyzed vocal fold was successfully reactivated, and its movement was shown to be synchronized with the healthy side. Significance. The developed unilateral laryngeal pacing system triggered by EMG from the ipsilateral side CT muscle could be successfully used in unilateral vocal fold paralysis with the advantage of avoiding disturbance to the healthy side muscles.

Electrical stimulation treatment for facial palsy after revision pleomorphic adenoma surgery

Surgery for pleomorphic adenoma recurrence presents a significant risk of facial nerve damage that can result in facial weakness effecting patients' ability to communicate, mental health and self-image. We report two case studies that had marked facial weakness after resection of recurrent pleomorphic adenoma and their progress with electrical stimulation. Subjects received electrical stimulation twice daily for 24 weeks during which photographs of expressions, facial measurements and Sunnybrook scores were recorded. Both subjects recovered good facial function demonstrating Sunnybrook scores of 54 and 64 that improved to 88 and 96, respectively. Neither subjects demonstrated adverse effects of treatment. We conclude that electrical stimulation is a safe treatment and may improve facial palsy in patients after resection of recurrent pleomorphic adenoma. Larger studies would be difficult to pursue due to the low incidence of cases.

Mime therapy for Ramsay Hunt syndrome: A case study

Background/Aim:

There are limited physiotherapy interventions and lack of significant outcome for Ramsay Hunt syndrome. This case report is the first to our knowledge that uses mime therapy as physiotherapy treatment for Ramsay Hunt syndrome.

Method:

A 53-year-old male patient received mime therapy along with electrical stimulation at two and half months post-diagnosis. The patient received electrical stimulation at the first week intervention as 30 minutes per session for 5 days a week and was discontinued at the third week intervention because the patient could not continue with facial muscle stimulation at home. Mime therapy was given three times a week for 13 weeks, with a total of 24 visits spread over 3 months.

Findings:

Facial symmetry was measured using the Sunnybrook Facial Grading System and severity of paresis was measured using the House-Brackmann scale throughout the course of treatment. House-Brackmann grades improved from grade V to grade II. Facial symmetry and synkinesis also improved. The facial disability index also showed improvement in both the physical function and social/wellbeing subscale components (Initial scores: physical subscale = 35/100; social/wellbeing subscale = 55/100. The final scores: physical subscale = 75/100; social/wellbeing subscale = 85/100).

Conclusions:

Overall, mime therapy was effective and benefits are stable for the short term. Therefore, mime therapy can be a good treatment choice for patients with Ramsay Hunt syndrome. Further research should include randomised controlled trials with a large sample size to prove its long-term effects.

A national survey of facial paralysis on the quality of life of patients with acoustic neuroma

OBJECTIVE

The aim of this survey was to objectively quantify the impact of facial palsy on the quality of life of acoustic neuroma patients.

METHODS

The Facial Clinimetric Evaluation (FaCE) Scale was emailed to all members of the British Acoustic Neuroma Association (BANA).

RESULTS

Of the 880 BANA members contacted, 398 (45.2%) responded, of which, 178 indicated that they had facial paralysis. Surgery for acoustic neuroma accounted for 80% of facial paralysis. Treatment received for facial palsy varied considerably, although 33% reported not receiving any treatment. The commonest single treatment modality wads facial electrical stimulation (41%), followed by facial physiotherapy (39%). The most common surgical procedures were to the eye lid (50%), followed by nerve graft (12%), forehead lift (10%), muscle sling (9%), and face lift (9%). The overall mean total FaCE Scale score was 54.8 (range, 10-100, standard deviation [SD] 21.2). Both facial movement and eye comfort domains had the lowest mean scores of 41.3 (SD, 29.9) and 41.2 (SD 32.6) respectively. The mean total FaCE Scale score of female respondents was statistically lower (p = 0.03) than males (52.6 (SD 21.2) versus 58.8 (SD 20.7) respectively), as were the difference in mean domain scores for facial comfort, eye comfort and social function. The mean total FaCE Scale scores of respondents aged below 40 years were the lowest. Younger patients had the lowest social function domain scores of all age groups.

CONCLUSION

Facial paralysis is a significant problem in patients with acoustic neuroma. Based on this survey, treatment for facial paralysis is often not offered and even when given, still leaves the patient with a significantly lowered quality of life. However, it should be remembered that this study has surveyed a skewed patient population and that overall, most acoustic neuroma patients do not suffer with facial paralysis.

Role of electrical stimulation added to conventional therapy in patients with idiopathic facial (Bell) palsy

OBJECTIVE

The aim of this study was to determine the efficacy of electrical stimulation when added to conventional physical therapy with regard to clinical and neurophysiologic changes in patients with Bell palsy.

DESIGN

This was a randomized controlled trial. Sixty patients diagnosed with Bell palsy (39 right sided, 21 left sided) were included in the study. Patients were randomly divided into two therapy groups. Group 1 received physical therapy applying hot pack, facial expression exercises, and massage to the facial muscles, whereas group 2 received electrical stimulation treatment in addition to the physical therapy, 5 days per week for a period of 3 wks. Patients were evaluated clinically and electrophysiologically before treatment (at the fourth week of the palsy) and again 3 mos later. Outcome measures included the House-Brackmann scale and Facial Disability Index scores, as well as facial nerve latencies and amplitudes of compound muscle action potentials derived from the frontalis and orbicularis oris muscles.

RESULTS

Twenty-nine men (48.3%) and 31 women (51.7%) with Bell palsy were included in the study. In group 1, 16 (57.1%) patients had no axonal degeneration and 12 (42.9%) had axonal degeneration, compared with 17 (53.1%) and 15 (46.9%) patients in group 2, respectively. The baseline House-Brackmann and Facial Disability Index scores were similar between the groups. At 3 mos after onset, the Facial Disability Index scores were improved similarly in both groups. The classification of patients according to House-Brackmann scale revealed greater improvement in group 2 than in group 1. The mean motor nerve latencies and compound muscle action potential amplitudes of both facial muscles were statistically shorter in group 2, whereas only the mean motor latency of the frontalis muscle decreased in group 1.

CONCLUSIONS

The addition of 3 wks of daily electrical stimulation shortly after facial palsy onset (4 wks), improved functional facial movements and electrophysiologic outcome measures at the 3-mo follow-up in patients with Bell palsy. Further research focused on determining the most effective dosage and length of intervention with electrical stimulation is warranted.

Electrical stimulation characteristics of denervated orbicularis oculi muscle

This research is to study the electrical stimulation characteristics of orbicularis oculi muscle and the characteristics of the mechanical contraction. We observed the stimulus current diffusion regularity and its relationship with mechanical contraction in the orbicularis oculi muscle using an electrode gathering line. Under different stimulus intensities of 2 or 4 mA, the closer the recording electrodes were to the stimulating electrode, the larger was the amplitude. When the recording electrode and stimulating electrode distance increased, the amplitude declined linearly with decreasing function. In addition, current conduction across the muscle fiber was studied. Under different stimulus intensities of 2 or 4 mA, it was found that the closer the recording electrodes were to the stimulating electrode, the larger was the amplitude. When the recording electrode and stimulating electrode distance increased, the amplitude declined linearly with decreasing function. The transverse current reached a maximum 4 mA range, and increasing the current intensity did not increase the propagation range. Under different stimulation intensities, the larger the stimulus intensity, the greater is the potential change and the faster is the attenuation. Longitudinal current, even in the range of 6 mm, can still record electrical activity. While a transverse current diffuser has a maximum range of 4 mm, increasing the current intensity does not increase the propagation range.

Homozygous hemoglobin S (HbSS) presenting with bilateral facial nerve palsy: a case report

BACKGROUND

Bilateral facial nerve palsy is a relatively rare presentation and often points to a serious underlying medical condition. Several studies have reported presentation of bilateral facial nerve palsy in association with Lyme disease, Guillain-Barre syndrome, systemic lupus erythematosus, human immunodeficiency virus, sarcoidosis, diabetes and Hanson disease. While unilateral facial nerve palsy is sometimes associated with hemiplegia in sickle cell patients, no case of bilateral facial nerve palsy have been reported in the literature.

CASE PRESENTATION

A 29-year-old black African woman who is a known homozygous haemoglobin S (HbSS) presented with bilateral facial nerve palsy. She had the said condition 2 months post delivery of her first child and reported for physiotherapy 3 months post incidence. The pre-treatment House Brackmann Facial Grading Scale (HBFGS) Scores were 3 for right side and 4 for left side. This patient was not on any medication for the facial palsy. After 4 sessions of combination therapy consisting of faradism, facial exercises and massage there was remarkable improvement in the neurological status of the facial muscles. The post treatment House Brackmann Facial Grading Scale score was 2 bilaterally.

CONCLUSION

Bilateral facial nerve palsy may be an initial presentation of sickle cell anemia patients in the absence of other overt clinical presentations. Therefore sickle cell anemia should be considered among others, in the differential diagnosis of bilateral facial nerve palsy. Furthermore, this case report has highlighted the important role of physiotherapy in the management of bilateral facial nerve palsy.

Comparative studies on the implantation of nano platinum black and pure platinum electrodes in the rabbit orbicularis oculi muscle

OBJECTIVE

To study the interactive influence of implanted nano platinum black electrodes (as compared with pure platinum electrodes) on rabbit orbicularis oculi muscle morphology and function.

METHODS

The influence of the two types of electrode on the orbicularis oculi muscle was monitored in a rabbit model of facial paralysis. Biological electric current and exciting current were administered to biological tissue, and morphological and functional changes were identified. Changes in orbicularis oculi muscle contraction, electrode configuration and performance associated with long-term electrical stimulation were observed over 28 days of implantation.

RESULTS

The nano platinum black electrode was superior to the pure platinum electrode in the following aspects: morphology and functionality, electrical excitation function of the orbicularis oculi muscle (as assessed by electromyography), muscle contraction function and biological tissue changes. Furthermore, the nano platinum black electrode features had good stability.

CONCLUSION

Microelectrode surface modification with nano platinum black can effectively increase the microelectrode surface area and improve electrode performance, and is associated with good tissue compatibility.

The neurologist's dilemma: a comprehensive clinical review of Bell's palsy, with emphasis on current management trends

Background

Recent advances in Bell’s palsy (BP) were reviewed to assess the current trends in its management and prognosis.

Material/Methods

We retrieved the literature on BP using the Cochrane Database of Systematic Reviews, PubMed, and Google Scholar. Key words and phrases used during the search included ‘Bell’s palsy’, ‘Bell’s phenomenon’, ‘facial palsy’, and ‘idiopathic facial paralysis’. Emphasis was placed on articles and randomized controlled trails (RCTs) published within the last 5 years.

Results

BP is currently considered the leading disorder affecting the facial nerve. The literature is replete with theories of its etiology, but the reactivation of herpes simplex virus isoform 1 (HSV-1) and/or herpes zoster virus (HZV) from the geniculate ganglia is now the most strongly suspected cause. Despite the advancements in neuroimaging techniques, the diagnosis of BP remains one of exclusion. In addition, most patients with BP recover spontaneously within 3 weeks.

Conclusions

Corticosteroids are currently the drug of choice when medical therapy is needed. Antivirals, in contrast, are not superior to placebo according to most reliable studies. At the time of publication, there is no consensus as to the benefit of acupuncture or surgical decompression of the facial nerve. Long-term therapeutic agents and adjuvant medications for BP are necessary due to recurrence and intractable cases. In the future, large RCTs will be required to determine whether BP is associated with an increased risk of stroke.

Facial reanimation by staged, split masseter muscle transfer

BACKGROUND

Facial paralysis of the lower face presents severe functional and aesthetic disturbance to patients. The gamut of facial paralysis correction is diverse and must be tailored to the patient. When nerve repair or free functional muscle transfer is unavailable, regional muscle transfer has become a staple in surgical management of facial paralysis. Previous masseter transfers relied on orbicularis oris attachment, which may be atrophic, adhered, or lengthened. Using fascia lata grafts, we describe the senior author's method of staged, split masseter transfer as a reliable method for reanimating the lower third of the face in appropriate candidates.

METHODS

The staged, split masseter muscle transfer is a 3-part repair. The first stage places a hemioral fascia lata graft to act as an anchor reinforcement. The second stage transfers the split masseter muscle, suturing to the fascia lata reinforced oral commissure. The third stage, a reefing procedure, is performed 6 to 10 months later under local anesthesia to reinforce attachments.

RESULTS

Six patients underwent the staged, split masseter muscle transfer. Mean age was 43 (15-67) years. Mean time to surgery from onset of deficit was 174 months (3 months to 65 years). All patients had significant improvement over preoperative symptoms. Symmetry was restored in repose. On movement, commissure excursion went from 0 to 6.67 mm in the superolateral vector. Of the 6 patients, 5 required an average of 1.5 outpatient revisions to achieve satisfactory results on average of 4.67 (4-127) months after the final stage.

CONCLUSIONS

The staged, split masseter transfer is useful for restoring subtle reanimation in patients presenting with facial paralysis. The staged, split masseter transfer provides bulk and restores both static and dynamic function. We present a case series demonstrating excellent long-term functional results.

Facial nerve damage following surgery for cerebellopontine angle tumours. Prevention and comprehensive treatment

Facial nerve (CN VII) palsy or even its transient paresis causes physical disability but is also a psychosocial problem. Immediately after vestibular schwannoma removal, different degrees of CN VII paresis occur in 20-70% of patients. Facial nerve paresis is observed in 10-40% after surgery of cerebellopontine angle meningiomas. Postoperative facial nerve weakness significantly reduces or completely withdraws with time in the majority of cases. However, even if prognosis for CN VII regeneration is good, proper management is needed because of the potential for serious ophthalmic complications. In this paper, the authors raise the issue of perioperative prophylaxis and comprehensive treatment of postoperative paresis of CN VII. Prophylaxis and treatment of ophthalmic complications are discussed. Current trends in the treatment of intraoperative loss of facial nerve continuity, management of facial paresis with good prognosis and dealing with facial palsy with no spontaneous recovery are also described in the paper.

Physical therapy for Bell's palsy (idiopathic facial paralysis)

BACKGROUND

Bell's palsy (idiopathic facial paralysis) is commonly treated by various physical therapy strategies and devices, but there are many questions about their efficacy.

OBJECTIVES

To evaluate physical therapies for Bell's palsy (idiopathic facial palsy).

SEARCH METHODS

We searched the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2011), MEDLINE (January 1966 to February 2011), EMBASE (January 1946 to February 2011), LILACS (January 1982 to February 2011), PEDro (from 1929 to February 2011), and CINAHL (January 1982 to February 2011). We included searches in clinical trials register databases until February 2011.

SELECTION CRITERIA

We selected randomised or quasi-randomised controlled trials involving any physical therapy. We included participants of any age with a diagnosis of Bell's palsy and all degrees of severity. The outcome measures were: incomplete recovery six months after randomisation, motor synkinesis, crocodile tears or facial spasm six months after onset, incomplete recovery after one year and adverse effects attributable to the intervention.

DATA COLLECTION AND ANALYSIS

Two authors independently scrutinised titles and abstracts identified from the search results. Two authors independently carried out risk of bias assessments, which , took into account secure methods of randomisation, allocation concealment, observer blinding, patient blinding, incomplete outcome data, selective outcome reporting and other bias. Two authors independently extracted data using a specially constructed data extraction form. We undertook separate subgroup analyses of participants with more and less severe disability.

MAIN RESULTS

For this update to the original review, the search identified 65 potentially relevant articles. Twelve studies met the inclusion criteria (872 participants). Four trials studied the efficacy of electrical stimulation (313 participants), three trials studied exercises (199 participants), and five studies compared or combined some form of physical therapy with acupuncture (360 participants). For most outcomes we were unable to perform meta-analysis because the interventions and outcomes were not comparable.For the primary outcome of incomplete recovery after six months, electrostimulation produced no benefit over placebo (moderate quality evidence from one study with 86 participants). Low quality comparisons of electrostimulation with prednisolone (an active treatment)(149 participants), or the addition of electrostimulation to hot packs, massage and facial exercises (22 participants), reported no significant differences. Similarly a meta-analysis from two studies, one of three months and the other of six months duration, (142 participants) found no statistically significant difference in synkinesis, a complication of Bell's palsy, between participants receiving electrostimulation and controls. A single low quality study (56 participants), which reported at three months, found worse functional recovery with electrostimulation (mean difference (MD) 12.00 points (scale of 0 to 100) 95% confidence interval (CI) 1.26 to 22.74).Two trials of facial exercises, both at high risk of bias, found no difference in incomplete recovery at six months when exercises were compared to waiting list controls or conventional therapy. There is evidence from a single small study (34 participants) of moderate quality that exercises are beneficial on measures of facial disability to people with chronic facial palsy when compared with controls (MD 20.40 points (scale of 0 to 100), 95% CI 8.76 to 32.04) and from another single low quality study with 145 people with acute cases treated for three months where significantly fewer participants developed facial motor synkinesis after exercise (risk ratio 0.24, 95% CI 0.08 to 0.69). The same study showed statistically significant reduction in time for complete recovery, mainly in more severe cases (47 participants, MD -2.10 weeks, 95% CI -3.15 to -1.05) but this was not a prespecified outcome in this meta analysis.Acupuncture studies did not provide useful data as all were short and at high risk of bias. None of the studies included adverse events as an outcome.

AUTHORS' CONCLUSIONS

There is no high quality evidence to support significant benefit or harm from any physical therapy for idiopathic facial paralysis. There is low quality evidence that tailored facial exercises can help to improve facial function, mainly for people with moderate paralysis and chronic cases. There is low quality evidence that facial exercise reduces sequelae in acute cases. The suggested effects of tailored facial exercises need to be confirmed with good quality randomised controlled trials.

Intrinsic and therapeutic factors determining the recovery of motor function after peripheral nerve transection

Insufficient recovery after peripheral nerve injury has been attributed to (i) poor pathfinding of regrowing axons, (ii) excessive collateral axonal branching at the lesion site and (iii) polyneuronal innervation of the neuromuscular junctions (NMJ). The facial nerve transection model has been used initially to measure restoration of function after varying therapies and to examine the mechanisms underlying their effects. Since it is very difficult to control the navigation of several thousand axons, efforts concentrated on collateral branching and NMJ-polyinnervation. Treatment with antibodies against trophic factors to combat branching improved the precision of reinnervation, but had no positive effects on functional recovery. This suggested that polyneuronal reinnervation--rather than collateral branching--may be the critical limiting factor. The former could be reduced by pharmacological agents known to perturb microtubule assembly and was followed by recovery of function. Because muscle polyinnervation is activity-dependent and can be manipulated, attempts to design a clinically feasible therapy were performed by electrical stimulation or by soft tissue massage. Electrical stimulation applied to the transected facial nerve or to paralysed facial muscles did not improve vibrissal motor performance and failed to diminish polyinnervation. In contrast, gentle stroking of the paralysed muscles (vibrissal, orbicularis oculi, tongue musculature) resulted in full recovery of function. This manual stimulation was also effective after hypoglossal-facial nerve suture and after interpositional nerve grafting, but not after surgical reconstruction of the median nerve. All these findings raise hopes that clinically feasible and effective therapies could be soon designed and tested.

Effects of electrical stimulation on House-Brackmann scores in early Bell's palsy

ABSTRACT Limited evidence may support the application of electrical stimulation in the subacute and chronic stages of facial palsy, yet some physiotherapists in South Africa have been applying this modality in the acute stage in the absence of published evidence of clinical efficacy. This preliminary study's aim was to determine the safety and potential efficacy of applying electrical stimulation to the facial muscles during the early phase of Bells palsy. A pretest posttest control vs. experimental groups design composed of 16 patients with Bell's palsy of less than 30 days' duration. Adult patients with clinical diagnosis of Bell's palsy were systematically (every second patient) allocated to the control and experimental groups. Each group (n = 8) was pretested and posttested using the House-Brackmann index. Both groups were treated with heat, massage, exercises, and a home program. The experimental group also received electrical stimulation. The House-Brackmann Scale of the control group improved between 17% and 50% with a mean of 30%. The scores of the experimental group ranged between 17% and 75% with a mean of 37%. The difference between the groups was not statistically significant (two-tailed p = 0.36). Electrical stimulation as used in this study during the acute phase of Bell's palsy is safe but may not have added value over spontaneous recovery and multimodal physiotherapy. A larger sample size or longer stimulation time or both should be investigated.

Application of isometric load on a facial muscle--the zygomaticus major

BACKGROUND

As an initial step to study facial muscle strengthening by loaded neuromuscular electrical stimulation, we examined the feasibility of applying load to the zygomaticus major, quantified the maximal isometric force of the muscle by volition and electrical stimulation, and compared the measured forces with the results of facial kinematic analysis and electrodiagnostic study.

METHODS

Eleven healthy subjects and two female patients with chronic unilateral facial palsy were enrolled. A custom made plastic bridge instrument with a centrally mounted load cell was attached at the mouth angle and to the skin overlying the zygomatic bone using double-sided adhesive tape to provide isometric resistance to skin movement during the muscle contraction.

FINDINGS

The force by maximal voluntary contraction of the zygomaticus major averaged 196.4 g force and the contraction force by maximally tolerated stimulation reached 60.1%, on average, of the force by maximal voluntary contraction in normal subjects. There was a significant correlation only between the force by maximally tolerated stimulation and the amplitude of compound muscle action potentials. The force by maximal voluntary contraction of the paralytic side in the patients showed 32.3% and 20.1% of the mean value of the normal subjects.

INTERPRETATIONS

This study demonstrates that an isometric load was possibly applied and a significant intensity of electrical stimulation could be tolerated and delivered to the isometrically loaded facial muscle. The isometric loading would be utilized for loaded facial neuromuscular electrical stimulation therapeutically and also for measurement of the force generation capacity of the zygomaticus major diagnostically.

Electrical stimulation of paralyzed vibrissal muscles reduces endplate reinnervation and does not promote motor recovery after facial nerve repair in rats

The outcome of peripheral nerve injuries requiring surgical repair is poor. Recent work has suggested that electrical stimulation (ES) of denervated muscles could be beneficial. Here we tested whether ES has a positive influence on functional recovery after injury and surgical repair of the facial nerve. Outcomes at 2 months were compared to animals receiving sham stimulation (SS). Starting on the first day after end-to-end suture (facial-facial anastomosis), electrical stimulation (square 0.1 ms pulses at 5 Hz at an ex tempore established threshold amplitude of between 3.0 and 5.0V) was delivered to the vibrissal muscles for 5 min a day, 3 times a week. Restoration of vibrissal motor performance following ES or SS was evaluated using the video-based motion analysis and correlated with the degree of collateral axonal branching at the lesion site, the number of motor endplates in the target musculature and the quality of their reinnervation, i.e. the degree of mono- versus poly-innervation. Neither protocol reduced collateral branching. ES did not improve functional outcome, but rather reduced the number of innervated motor endplates to approximately one-fifth of normal values and failed to reduce the proportion of poly-innervated motor endplates. We conclude that ES is not beneficial for recovery of whisker function after facial nerve repair in rats.

Cutaneous electrical stimulation treatment in unresolved facial nerve paralysis: an exploratory study

OBJECTIVE

The purpose of this study was to assess clinical and neurophysiological changes after 6 mos of transcutaneous electrical stimulation in patients with unresolved facial nerve paralysis.

DESIGN

A pilot case series of 10 consecutive patients with chronic facial nerve paralysis either of idiopathic origin or because of herpes zoster oticus participated in this open study. All patients received below sensory threshold transcutaneous electrical stimulation for 6 mos for their facial nerve paralysis. The intervention consisted of gradually increasing the duration of electrical stimulation of three sites on the affected area for up to 6 hrs/day. Assessments of the facial nerve function were performed using the House-Brackmann clinical scale and neurophysiological measurements of compound motor action potential distal latencies on the affected and nonaffected sides. Patients were tested before and after the intervention.

RESULTS

A significant improvement was observed in the facial nerve upper branch compound motor action potential distal latency on the affected side in all patients. An improvement of one grade in House-Brackmann scale was observed and some patients also reported subjective improvement.

CONCLUSIONS

Transcutaneous electrical stimulation treatment may have a positive effect on unresolved facial nerve paralysis. This study illustrates a possibly effective treatment option for patients with the chronic facial paresis with no other expectations of recovery.

Management of peripheral facial nerve palsy

Peripheral facial nerve palsy (FNP) may (secondary FNP) or may not have a detectable cause (Bell's palsy). Three quarters of peripheral FNP are primary and one quarter secondary. The most prevalent causes of secondary FNP are systemic viral infections, trauma, surgery, diabetes, local infections, tumor, immunological disorders, or drugs. The diagnosis of FNP relies upon the presence of typical symptoms and signs, blood chemical investigations, cerebro-spinal-fluid-investigations, X-ray of the scull and mastoid, cerebral MRI, or nerve conduction studies. Bell's palsy may be diagnosed after exclusion of all secondary causes, but causes of secondary FNP and Bell's palsy may coexist. Treatment of secondary FNP is based on the therapy of the underlying disorder. Treatment of Bell's palsy is controversial due to the lack of large, randomized, controlled, prospective studies. There are indications that steroids or antiviral agents are beneficial but also studies, which show no beneficial effect. Additional measures include eye protection, physiotherapy, acupuncture, botulinum toxin, or possibly surgery. Prognosis of Bell's palsy is fair with complete recovery in about 80% of the cases, 15% experience some kind of permanent nerve damage and 5% remain with severe sequelae.

Efficacy of electrical stimulation to increase muscle strength in people with neurological conditions: a systematic review

BACKGROUND AND PURPOSE

Weakness in partially paralysed muscles is a disabling impairment for people with neurological conditions. Strength training programmes are widely administered to address this impairment. There is a common belief that the effectiveness of strength training programmes can be enhanced by the addition of electrical stimulation. The purpose of this systematic review was to assess the efficacy of electrical stimulation for increasing voluntary strength in people with neurological conditions.

METHOD

Eligible randomized trials of electrical stimulation were identified by searches of computerized databases. The search yielded 11,267 abstracts, of which 60 were retrieved. Two assessors independently reviewed full text versions of these articles.

RESULTS

Eighteen studies satisfied the inclusion criteria. These studies involved participants with spina bifida (n = 1), cerebral palsy (n = 1), peripheral nerve lesion (n = 1), multiple sclerosis (n = 1), spinal cord injury (n = 3) and stroke (n = 11). The mean (SD) PEDro score for trial quality was 4.9 (1.0) out of 10. Meta-analyses of studies involving similar patients were not done because of insufficient data or lack of homogeneity. The results of all studies were analysed individually.

CONCLUSION

Several studies suggest a modest beneficial effect of electrical stimulation in patients with stroke. It is not clear whether patients with other types of neurological disabilities benefit from electrical stimulation in the same way.

Neuromuscular electrical stimulation in neurorehabilitation

This review provides a comprehensive overview of the clinical uses of neuromuscular electrical stimulation (NMES) for functional and therapeutic applications in subjects with spinal cord injury or stroke. Functional applications refer to the use of NMES to activate paralyzed muscles in precise sequence and magnitude to directly accomplish functional tasks. In therapeutic applications, NMES may lead to a specific effect that enhances function, but does not directly provide function. The specific neuroprosthetic or "functional" applications reviewed in this article include upper- and lower-limb motor movement for self-care tasks and mobility, respectively, bladder function, and respiratory control. Specific therapeutic applications include motor relearning, reduction of hemiplegic shoulder pain, muscle strengthening, prevention of muscle atrophy, prophylaxis of deep venous thrombosis, improvement of tissue oxygenation and peripheral hemodynamic functioning, and cardiopulmonary conditioning. Perspectives on future developments and clinical applications of NMES are presented.

Is there a role for ultrasound and electrical stimulation following injury to tendon and nerve?

Ultrasound (US) and electrical stimulation have been widely used in hand therapy to promote recovery after nerve and tendon injuries. There is support for the use of low-dosage continuous wave and pulsed US for carpal tunnel syndrome and tendonitis. Iontophoresis with dexamethasone sodium phosphate can relieve pain in acute elbow tendonitis, but there is no support for phonophoresis for any tendonitis. Animal model research supports the use of low-dosage US to improve the mechanical properties of the Achilles tendon when initiated immediately after tenorrhaphy. There are no studies available which have examined US applied to tendons in humans after repair. Electrical stimulation has been extensively studied in animal models after nerve axonotmesis and neurotmesis with nerve repair, with some support of enhancing recovery. There is a void in the literature on the use of electrical stimulation for humans after nerve transection and repair.