Tolerability of facial electrostimulation in healthy adults and patients with facial synkinesis.

PURPOSE: To evaluate optimal stimulation parameters with regard to discomfort and tolerability for transcutaneous electrostimulation of facial muscles in healthy participants and patients with postparetic facial synkinesis. METHODS: Two prospective studies were performed. First, single pulse monophasic stimulation with rectangular pulses was compared to triangular pulses in 48 healthy controls. Second, 30 healthy controls were compared to 30 patients with postparetic facial synkinesis with rectangular pulse form. Motor twitch threshold, tolerability threshold, and discomfort were assessed using a numeric rating scale at both thresholds. RESULTS: Discomfort at motor threshold was significantly lower for rectangular than for triangular pulses. Average motor and tolerability thresholds were higher for patients than for healthy participants. Discomfort at motor threshold was significantly lower for healthy controls compared to patients. Major side effects were not seen. CONCLUSIONS: Surface electrostimulation for selective functional and tolerable facial muscle contractions in patients with postparetic facial synkinesis is feasible.

Recovery of facial expressions using functional electrical stimulation after full-face transplantation.

BACKGROUND: We assessed the recovery of 2 face transplantation patients with measures of complexity during neuromuscular rehabilitation. Cognitive rehabilitation methods and functional electrical stimulation were used to improve facial emotional expressions of full-face transplantation patients for 5 months. Rehabilitation and analyses were conducted at approximately 3 years after full facial transplantation in the patient group. We report complexity analysis of surface electromyography signals of these two patients in comparison to the results of 10 healthy individuals. METHODS: Facial surface electromyography data were collected during 6 basic emotional expressions and 4 primary facial movements from 2 full-face transplantation patients and 10 healthy individuals to determine a strategy of functional electrical stimulation and understand the mechanisms of rehabilitation. A new personalized rehabilitation technique was developed using the wavelet packet method. Rehabilitation sessions were applied twice a month for 5 months. Subsequently, motor and functional progress was assessed by comparing the fuzzy entropy of surface electromyography data against the results obtained from patients before rehabilitation and the mean results obtained from 10 healthy subjects. RESULTS: At the end of personalized rehabilitation, the patient group showed improvements in their facial symmetry and their ability to perform basic facial expressions and primary facial movements. Similarity in the pattern of fuzzy entropy for facial expressions between the patient group and healthy individuals increased. Synkinesis was detected during primary facial movements in the patient group, and one patient showed synkinesis during the happiness expression. Synkinesis in the lower face region of one of the patients was eliminated for the lid tightening movement. CONCLUSIONS: The recovery of emotional expressions after personalized rehabilitation was satisfactory to the patients. The assessment with complexity analysis of sEMG data can be used for developing new neurorehabilitation techniques and detecting synkinesis after full-face transplantation.

Efficacy of Tape Feedback Therapy on Synkinesis Following Severe Peripheral Facial Nerve Palsy.

BACKGROUND: Mirror feedback rehabilitation is effective in preventing the development of oro-ocular synkinesis following severe facial palsy. However, we do not have effective maneuvers to prevent the deterioration of oculo-oral synkinesis. We developed a new method of biofeedback rehabilitation using tape for the prevention of oculo-oral synkinesis. OBJECTIVE: The aim of the present study was to investigate the efficacy of taping feedback rehabilitation. METHODS: Twelve consecutive patients with peripheral facial nerve palsy who developed synkinesis were divided into 2 groups. Six patients were treated with the new training method, and the remaining 6 patients were treated with conventional therapy as controls. In the experiment group, tape was placed around the mouth, and the patient was instructed to close the eyes so that no movements of the mouth would be perceived from sensations of the taped skin. After 4 weeks of training, facial movements were recorded and movie images were graded for mouth synkinesis using the revised Sunnybrook facial grading system by examiners blinded to patient grouping. RESULTS: Mouth corner contraction during eye closure was significantly weaker in the experimental group than in the control group. CONCLUSIONS: Our new feedback method could help prevent the deterioration of oculo-oral synkinesis.

Therapeutic strategies in post-facial paralysis synkinesis in pediatric patients.

UNLABELLED: Synkinetic movements comprise abnormal involuntary contractions of one or more facial muscle groups which follow the desired contraction of another facial muscle group. They are frequently encountered in patients with long standing facial paralysis and seriously affect their psychological status due to the impairment of their facial appearance, function and emotional expressivity. PATIENTS AND METHODS: Eleven pediatric patients (2 male and 9 female) presenting with post-facial paralysis synkinesis were included in the study. Mean age was 10.3±4 years and mean denervation time 72.5 months. RESULTS: Patients underwent the following types of treatment: --Cross facial nerve grafting (CFNG) and secondary microcoaptations with botulinum toxin injection which had an improvement of 100% (3 in the 3 grade synkinesis scale) (n=2). --Cross facial nerve grafting (CFNG) and secondary microcoaptations without botulinum toxin injection which had an improvement of 66%(2 in the 3 grade synkinesis scale) (n=5). --CFNG and direct muscle neurotization with (n=2) or without (n=1) botulinum toxin injection where the improvement was 33%. --Contralateral nasalis muscle myectomy was performed in one patient along with CFNG and secondary microcoaptations which resulted in 66% synkinesis improvement. Biofeedback was invariably undertaken by all patients. Postoperative improvement in eye closure and smile was also noted in the respective cases treated for synkinesis ranging from 25 to 50%, with all patients achieving optimum functional return. CONCLUSION: CFNG with secondary microcoaptations and botulinum toxin injections was found to be a very efficient surgical modality addressing post-facial palsy synkinesis with high improvement in facial function and symmetry. Facial neuromuscular re-education contributes considerably in the treatment.

Mirror biofeedback rehabilitation after administration of single-dose botulinum toxin for treatment of facial synkinesis.

OBJECTIVE: The efficacy of facial biofeedback rehabilitation with a mirror after administration of a single dose of botulinum A toxin on facial synkinesis was examined in patients with chronic facial palsy. STUDY DESIGN: Prospective clinical study. SETTING: University hospital. SUBJECTS AND METHODS: The present study includes 8 patients with Bell palsy and 5 with herpes zoster oticus showing facial synkinesis. A single dose of botulinum A toxin was used as the initial process of facial rehabilitation. Patients then continued a daily facial biofeedback rehabilitation with a mirror at home. They were instructed to keep their eyes symmetrically open using a mirror during mouth movements. The degree of oral-ocular synkinesis was evaluated by the degree of asymmetry of eye opening width during mouth movements (% eye opening). RESULTS: After administration of a single dose of botulinum A toxin, temporary relief of facial synkinesis was observed in all patients. Patients were then instructed to continue the facial biofeedback rehabilitation with a mirror for 10 months. The mean values of the percent of eye opening during 3 designated mouth movements that included lip pursing /u:/, teeth baring /i:/, and cheek puffing /pu:/ increased significantly after 10 months when the effects of botulinum A toxin had completely disappeared. CONCLUSION: These findings demonstrate that facial biofeedback rehabilitation with a mirror after administration of a single dose of botulinum A toxin is a long-lasting treatment of established facial synkinesis in patients with chronic facial palsy.

Efficacy of functional training of the facial muscles for treatment of incomplete peripheral facial nerve injury.

OBJECTIVE: To investigate the efficacy of functional training of facial mimic muscles for patients with incomplete peripheral facial nerve injury. METHODS: Ninety-two patients with 241 injured branches of incomplete peripheral facial nerve injury were divided into a treatment group and a control group. The treatment group consisted of 58 cases that received functional training of facial mimic muscles. The rest of the cases served as controls. Assessment parameters included the House-Brackmann grading system, a quantitative facial nerve function estimating system and electroneurography. According to the three assessments, the facial nerve injury was divided into four grades: normal, minor, moderate and severe. The treatment group started training facial mimic muscle activity 2 weeks after facial nerve injury. After follow-ups of 1 to 4 years, the outcomes were statistically analysed. RESULTS: In the minor facial nerve injury group, there was no significant difference in the time needed for initial recovery (Ti, the time needed for significant recovery of the facial nerve function after injury) and final recovery (Tf, the time point after which no further improvement of facial nerve function was obtained) between the two groups (P > 0.05). No adverse effect was found in these cases. In the moderate facial nerve injury group, the Ti and Tf of the treatment group were shorter than those of the control group (P < 0.05). One case had synkinesis. In the patients with severe facial nerve injury, the recovery rate of facial nerve function in the treatment group was higher than that of the control group and the sequelae were less. CONCLUSION: Functional training of facial mimic muscles cannot shorten the time of recovery for the patients with minor facial nerve injury but it can speed up the recovery and reduce the undesirable sequelae such as synkinesis and hemifacial spasm for the patients with moderate and severe facial nerve injury.

Management of synkinesis.

Facial synkinesis is one of the most distressing consequences of facial paralysis. Synkinesis refers to the abnormal involuntary facial movement that occurs with voluntary movement of a different facial muscle group. The pathophysiologic basis of facial synkinesis is likely multifactorial although the predominant mechanism appears to be aberrant regeneration of facial nerve fibers to the facial muscle groups after facial nerve injury. Patients experience hypertonic contractures and synkinetic movements such as eye closure with volitional movement of the mouth or midfacial movement during volitional or reflexive eye closure. Synkinesis can cause functional limitation with activities such as eating, drinking, smiling, and may even lead to social isolation. Evaluation of synkinesis is primarily subjective with facial grading scales such as the Sunnybrook scale. Objective measures of synkinesis using computerized video analysis show promise although no objective techniques are currently widely used. The most common therapeutic modalities for the treatment of facial synkinesis include (1) botulinum toxin type A (BTX-A) injections for selective chemodenervation of affected muscle groups and (2) facial neuromuscular retraining. Biofeedback using mirrors or electromyography has been used both for the treatment and prevention of facial synkinesis. Other treatment options include surgical therapies, such as selective neurolysis or myectomy, although these have been rendered nearly obsolete with the advent of BTX-A.

Neuromotor functions in Inuit preschool children exposed to Pb, PCBs, and Hg.

The aim of this study was to examine the effects of prenatal and postnatal chronic exposure to mercury (Hg), polychlorinated biphenyls (PCBs) and lead (Pb) on the neuromotor development of preschool children. The study population consisted of 110 preschool Inuit children from Nunavik (Canada). Blood Hg, PCBs and Pb concentrations were measured at birth (cord blood) and at the time of testing. Gross motor functions were evaluated and a neurological examination was performed. Fine neuromotor performance was assessed using quantitative measures of postural hand tremor, reaction time, sway oscillations, as well as alternating and pointing movements. Potential covariates were documented including demographic and familial characteristics, other prenatal neurotoxicants (alcohol, tobacco) and nutrients (selenium (Se), Omega-3 polyunsaturated fatty acids (n-3 PUFA)). Hierarchical multivariate regression analyses were performed, controlling for significant covariates. Gross motor development was not linked to prenatal exposures. However, significant associations were observed between blood Pb concentration at testing time and changes in reaction time, sway oscillations, alternating arm movements and action tremor. For some of these outcomes, neuromotor effects of Pb exposure are observed at blood concentrations below 10 microg/dl. Negative effects of PCBs on neuromotor development were not clearly observed, neither were the potential beneficial effects of n-3 PUFA and selenium. Tremor amplitude was related to blood Hg concentrations at testing time, which corroborate an effect already reported among adults.