The asymmetric facial skin perfusion distribution of Bell's palsy discovered by laser speckle imaging technology

Effects of acupuncture for Bell's palsy patients in the acute phase and its impact on facial nerve edema: a study protocol for a randomized, controlled trial

Background

Bell's palsy is an acute peripheral facial neuropathy, which is one of the most common causes of facial palsy of lower motor neurons. Facial nerve swelling is commonly observed in Bell's palsy. Acupuncture therapy has been widely used in the treatment of Bell's palsy. However, whether acupuncture can be effectively used in the acute stage is still controversial. There are no clinical trials conducted previously to evaluate the effect of acupuncture on facial nerve edema in Bell's palsy patients. The study aims to evaluate the potential efficacy of different acupuncture modalities on Bell's palsy patients in the acute phase, its effect on facial nerve edema, and to preliminarily explore its possible mechanism.

Methods and analysis

In this randomized, controlled trial, 165 Bell's palsy patients with unilateral onset within 3 days will be recruited and randomly assigned to either the electroacupuncture group (n = 33), the acupuncture group (n = 33), the sham acupuncture group (n = 33), the blank control group (n = 33), or the acupuncture control group (n = 33) in a 1:1:1:1:1 ratio. The participants will receive 4 weeks of treatment and 8 weeks of follow-up. The five groups of participants will receive the following treatments: A: Electroacupuncture + Medication (prednisone acetate tablets, mecobalamin tablets, and vitamin B1 tablets); B: Acupuncture + Medication; C: Sham Acupuncture + Medication; D: Medication only; and E: Acupuncture only. The primary outcome will be the effectiveness rate of different acupuncture modalities in improving facial nerve function after the intervention period. The secondary outcomes will be the recovery speed, the diameter of the facial nerve, the echo intensity and thickness of facial muscles, blood flow parameters of the facial artery, the serum inflammatory level, safety evaluation, and adverse events. Preliminary exploration of its mechanism of action occurs through inflammation and immune response. The difference between groups will be assessed using repeated measure analysis of covariance (ANCOVA) and trend chi-square.

Discussion

The trial will evaluate the efficacy and facial nerve edema of acupuncture for Bell's palsy patients in the acute phase and preliminarily explore its possible mechanism. The results thus may provide evidence for clinical application.

Clinical trial registration

https://www.chictr.org.cn/bin/project/edit?pid=133211, identifier ChiCTR2100050815.

Treatment of Peripheral Facial Paralysis After COVID-19 Infection With Traditional Chinese Medicine Therapies: A Case Report

Peripheral facial paralysis, characterized by facial expression and motor dysfunction of facial muscle groups, stems from lower motor neuron lesions of the facial nerve and can arise from various medical conditions such as viral infections, trauma, tumors, and autoimmune disorders, among others. It affects individuals across all age groups, from pediatric to geriatric populations. While many cases have no discernible cause, some are associated with infectious or non-infectious factors. Typically, most patients experience gradual recovery within one to three months following appropriate treatment in the acute phase, which may include inflammation control, antiviral therapy, reduction of neuroedema, and nerve nourishment. Although relatively rare, there have been few reports of peripheral facial paralysis following COVID-19 infection. Here, we present a case possibly linked to COVID-19: a 23-year-old male who reported numbness, facial asymmetry, and ear pain on the right side of his face persisting for five days after contracting COVID-19. Upon physical examination, peripheral facial paralysis of House-Brackmann grade IV was observed, prompting the initiation of traditional Chinese medicine (TCM) treatment. On the 10th day of treatment, acupoint catgut embedding was introduced as an adjunct therapy. Following four weeks of combined treatment, the patient's peripheral facial paralysis improved to grade I, and treatment was subsequently discontinued. TCM therapies, including acupuncture, electroacupuncture, plum blossom needle, moxibustion, acupoint catgut embedding, Chinese herbal medicine, etc., are safe and promising complementary treatments for the acute management of peripheral facial paralysis. However, additional large-scale, randomized controlled studies are needed to determine whether these interventions have a significant additive or synergistic effect on achieving full recovery in patients with peripheral facial paralysis.

Electroacupuncture and Transcutaneous Electrical Nerve Stimulation Induced Sensations in Bell's Palsy Patients: A Quantitative Current Intensity Analysis

Background

The intensity of electrical acupoint stimulation such as electroacupuncture (EA) and transcutaneous electrical nerve stimulation (TENS) is regulated by the observation of skin shivering or the participant’s comfort response. However, the specific intensity and spatial scope following EA or TENS stimulation are unclear.

Objective

This study aimed to test the stimulatory current intensities of lower and upper sensation thresholds in TENS- and EA-based treatment of Bell’s palsy patients. Also, the spatial scope of the stimulation at these current intensities was simulated and measured quantitatively.

Methods

A total of 19 Bell’s palsy patients were recruited. Six acupoints on the affected side of the face were stimulated by TENS and EA successively at 30-min intervals. During the stimulation, the current intensity was regulated gradually from 0 to 20 mA, and we simultaneously measured the lower (sensory) and upper (tolerability) sensations. After the treatment by TENS and EA, the modified Chinese version of the Massachusetts General Hospital Acupuncture Sensation Scales (C-MMASS) was applied to survey the de-qi sensations during stimulation. Additionally, we analyzed the correlation between current intensities and C-MMASS and comfort scores. Finite element models were established to depict the spatial distribution of electric field gradients at the lower and upper thresholds.

Results

The mean sensory and tolerability thresholds of TENS were 3.91–4.37 mA and 12.33–16.35 mA, respectively. The median sensory and tolerability thresholds of EA were 0.2 mA and 2.0–3.2 mA, respectively. We found a significant correlation between total C-MMASS scores and the current intensities at the tolerability threshold of TENS. The finite element model showed that the activated depths of TENS and EA at the lower threshold were 3.8 and 7 mm, respectively, whereas those at the upper threshold were both 13.8 mm. The cross-sectional diameter of the activated area during TENS was 2.5–4 times larger than that during EA.

Conclusion

This pilot study provided a method for exploring the current intensity at which the de-qi sensations can be elicited by TENS or EA. The finite element analysis potentially revealed the spatial scope of the electrical stimulation at a specific current intensity.

The research for the function evaluation of facial nerve and the mechanisms of rehabilitation training

BACKGROUND

Peripheral facial paralysis (PFP) is a common peripheral neural disease. Acupuncture treatment combined with PFP rehabilitation exercises is a routine method of PFP treatment. This article is to provide a new visual and objective evaluation method for exploring the mechanism and efficacy of acupuncture treatment on PFP, and develop an interactive augmented facial nerve function rehabilitation training system with multiple training models.

METHODS

This prospective and observational trial will recruit 200 eligible participants for the following study. In the trial, the laser speckle contrast analysis (LASCA) technology will be applied to monitor the microcirculation of facial blood flow during acupuncture, and real-time monitoring algorithms, data sampling, and digital imaging methods will be conducted by machine learning and image segmentation. Then, a database of patient facial expressions will be built, the correlation between surface blood flow perfusion volume and facial structure symmetry will be analyzed, combined with scale assessment and electrophysiological detection. In addition, we will also explore the objectivity and effectiveness of LASCA in the evaluation of facial paralysis (FP), and the changes in blood flow microcirculation before and after acupuncture treatment will be analyzed.

RESULTS

The standard image of the facial target area with facial nerve injury will be manually segmented by the convolutional neural network method. The blood flow images of the eyelid, cheek, and mandible of the patients' affected and healthy side will be compared and evaluated. Laser speckle blood flow symmetry Pr and its changes in FP condition evolution and prognosis outcome will be measured, and relevant characteristic signals values will be extracted. Finally, COX regression analysis method is conducted to establish a higher accuracy prediction model of FP with cross-validation based on laser speckle blood flow imaging technology.

CONCLUSIONS

We use modern interdisciplinary high-tech technologies to explore the mechanism of acupuncture rehabilitation training in PFP. And we will provide evidence for the feasibility of using the LASCA technique as a typing diagnosis of FP in the acupuncture rehabilitation treatment of PFP.

REGISTRATION NUMBER

ChiCTR1800019463.

Efficacy of Manipulative Acupuncture Therapy Monitored by LSCI Technology in Patients with Severe Bell's Palsy: A Randomized Controlled Trial

To determine if the effect of manipulative acupuncture monitored by laser speckle contrast imaging (LSCI) can improve facial blood perfusion in patients with severe Bell's palsy. This randomized, single-blind, controlled trial included 120 newly diagnosed patients (within 14 days) with severe Bell's palsy (House-Brackmann grading system (HBGS) ≥ grade IV). The patients were randomized (1 : 1) to receive either acupoints acupuncture combined with manipulations of twirling, lifting, and thrusting treatments (manipulative acupuncture) or acupoints acupuncture therapy alone (simple acupuncture). These treatments consisted of a total of 24 sessions, three times per week, and each treatment lasted for 30 min. Following 8 weeks of treatment and 6 months after the initial onset of facial palsy, facial nerve functioning was scored (HBGS) and clinical efficacy was measured. The patients' facial blood perfusion significantly improved following manipulative acupuncture assisted by LSCI compared with that at baseline (P < 0.01). At the conclusion of the 8-week treatment, both groups showed improvement; however, the recovery rate was significantly different (manipulative acupuncture 53.3% vs. simple acupuncture 33.9%, P < 0.05). Follow-up analysis at 6 months after the onset of facial palsy revealed a significantly higher recovery rate (91.7% vs. 78.0%; P < 0.05). In addition, the number of treatments in the observation group was less than that in the simple acupuncture therapy group (P < 0.05). Compared with simple acupuncture therapy, manipulative acupuncture therapy led to a more significant recovery rate in the treatment of severe Bell's palsy and required a shorter course of treatment. This trial was registered with ChiCTR1800019463.

Automatic Facial Paralysis Assessment via Computational Image Analysis

Facial paralysis (FP) is a loss of facial movement due to nerve damage. Most existing diagnosis systems of FP are subjective, e.g., the House-Brackmann (HB) grading system, which highly depends on the skilled clinicians and lacks an automatic quantitative assessment. In this paper, we propose an efficient yet objective facial paralysis assessment approach via automatic computational image analysis. First, the facial blood flow of FP patients is measured by the technique of laser speckle contrast imaging to generate both RGB color images and blood flow images. Second, with an improved segmentation approach, the patient's face is divided into concerned regions to extract facial blood flow distribution characteristics. Finally, three HB score classifiers are employed to quantify the severity of FP patients. The proposed method has been validated on 80 FP patients, and quantitative results demonstrate that our method, achieving an accuracy of 97.14%, outperforms the state-of-the-art systems. Experimental evaluations also show that the proposed approach could yield objective and quantitative FP diagnosis results, which agree with those obtained by an experienced clinician.

Fundamental supply of skin blood flow in the Chinese Han population: Measurements by a full-field laser perfusion imager

BACKGROUND

Skin blood flow is believed to link with many diseases, and shows a significant heterogeneity. There are several papers on basal cutaneous microcirculation perfusion in different races, while the data in Chinese is vacant.

OBJECTIVE

The aim was to establish the database of absolute fundamental supply of skin blood flow in the Chinese Han population.

METHODS

With a full-field laser perfusion imager (FLPI), the skin blood flow can be quantified. Cutaneous perfusion values were determined in 17 selected skin areas in 406 healthy participants aged between 20 and 80 years (mean 35.05 ± 11.33). Essential parameters such as weight, height were also measured and values of BMI were calculated. The perfusion values were reported in Arbitrary Perfusion Units (APU).

RESULTS

The highest cutaneous perfusion value fell on eyelid (931.20 ± 242.59 in male and 967.83 ± 225.49 in female), and pretibial had the lowest value (89.09 ± 30.28 in male and 85.08 ± 33.59 in female). The values were higher in men than women on the bank of fingertips, nose, forehead, cheek, neck and earlobe (P < .05). Perfusion values on stretch and flexion side of forearm had negative correlation with age (P = .01 and P = 4.88 × 10^-3 , respectively) in male. Abdomen was negatively correlated with BMI in both gender (P = .02, respectively).

CONCLUSIONS

Skin blood flow values vary with skin regions. There is a tendency to measure higher perfusion values in men than in women. And the values are irrelevant with age or BMI.