Effect of Conventional Physiotherapeutic Techniques on Post-Operative Facial Palsy: A Case Study

Introduction

The parotid gland, together with the submandibular and sublingual glands, is the biggest of the three main paired salivary glands. It is situated in the retromandibular fossa, which is where this gland is typically found. The masseter muscle is its anterior boundary, the zygomatic arch is its superior border, and the sternocleidomastoid muscle is its posterior border. The parotid gland and the other salivary glands serve a crucial role in the oral cavity because they secrete saliva, which makes eating, swallowing, speaking, and digesting easier. The facial nerve runs through the body of the parotid gland where it divides into two main trunks - the cervico-facial and temporo-zygomatic branches, which further divide to form terminal branches creating a unique connection that necessitates close care during parotidectomies or other surgeries in the area.¹ Benign tumours account for about 80% of parotid gland tumours, with pleomorphic adenoma being the most common type. Surgical resection is the typical management strategy for neoplasms of the parotid gland. As the facial nerve runs through the glandular tissue of the parotid gland, identifying its location is critical during surgical procedures to prevent any nerve damage or injuries. Two types of surgeries are available depending on the location of the tumour. For superficial lobe tumours, superficial parotidectomy is recommended, while total parotidectomy is advised for tumours that arise from the deep lobe, in case of recurrent tumors, and to preserve the facial nerve in recurrent tumours. This information may aid clinicians in making decisions regarding treatment for parotid gland tumours.²

Physiotherapy is an effective method of aiding the rehabilitation process for patients who have undergone a parotidectomy. Physiotherapy can help alleviate symptoms and improve overall function and quality of life for patients. The specific objectives of physiotherapy following a parotidectomy may differ based on the individual patient needs and the extent of the surgical procedure. Research indicates that there are currently limited medical, surgical, or physiotherapy interventions available for treating post-operative facial nerve palsy.

Case Presentation

A 50 year old female patient reported with a complaint of painless swelling near left parotid area. Her first medical contact was with a general physician who referred her to a specialist. On evaluation with USG, she was diagnosed with a tumour in superficial lobe of left parotid gland. On histological examination, the diagnosis was confirmed as pleomorphic adenoma. She underwent left superficial parotidectomy. Modified Blair incision was made, the gland was dissected above the level of nerve. The patient withstood the procedure well but was diagnosed with post operative facial palsy. Since this condition was affecting her physically and socially, she was referred for physiotherapy to aid recovery. After collecting extensive details of history of presenting illness, a detailed neurological examination was performed. Patient’s chief complaints included inability to move the left side of the face, chewing from the left side along with jaw pain and spillage of water while drinking. The sensations of the face were intact except hypoesthesia near the suture site. Numerical Pain Rating Scale (NPRS) score for jaw pain was 0/10 at rest and 3/10 while chewing. A composite score of 45/100 was recorded for Sunnybrook Facial Grading Scale (SFGS) and Facial Disability Index (subjective) score was recorded as 128/200. In order to better grasp each framework component at a glance, the patient's difficulties were represented in International Classification of Functioning, Disability, and Health (ICF) framework.

Treatment Goals

Informed Consent Prior to examination and application of treatment, informed consent was taken from patient.

Intervention

The aetiology and degree of facial paralysis are quite variable and so is the treatment and its outcomes in India. The detailed evidenced interventions were applied based on different rationales and a four-week program was planned. Each session lasted 45 minutes. For the first two weeks, subject underwent five sessions per week, whereas in the next two weeks the subject received three sessions a week. Electrical stimulation was not a part of this protocol to avoid flaring of post-surgical inflammation and sensitivity.

1. Mime therapy³

Mime therapy, which is originally a form of art therapy was used. The following areas of a mime corporal analysis were used based on the rationales mentioned below.

-Breathing: Facial expression impairments relate to other areas of tension in the body. Breathing can help to reduce this tension. This was done at the beginning of the session for five minutes where diaphragmatic breathing was promoted.

-Auto massage of face and neck: This was given for 10 minutes to promote circulation.

-Articulation: Every movement, however complex, can be broken down into a series of single movements. The patient was taught to clearly and slowly pronounce vowels and consonants, each for 10 times, focussing on the position of lips.

-Expression: Mime can be used to enhance non-verbal communication. Reproducing facial expressions like happy, sad, angry, confused was practiced, each expression for five times.

All these exercises were aided with mirror biofeedback.

2. Kabat rehabilitation / facial proprioceptive neuromuscular facilitation (PNF) technique:⁴

It activates the weak muscles and helps initiate correct movement pattern. Here, the weaker side of the face is assisted during movements and the stronger side is resisted to facilitate movement through irradiation principle of proprioceptive neuromuscular facilitation (PNF). The muscles included for this rehabilitation were – Frontalis, Corrugator, Nasalis, Risorius and Platysma.

Each movement of muscle was repeated 10 times and mirror biofeedback was used.

3. Kinesio-taping for zygomaticus major, minor and frontalis muscle:⁵

Improves cutaneous sensory input and facilitates muscle contraction. It was given at the end of each session for two weeks, to be kept for a minimum of six hours.

4. Sensory re-education:⁶

Helps to blot out unpleasant sensations and to optimally tune into identifying sensations. In this case study, it was used to improve hypoesthesia caused by sutures around the suture site. Different texture profiles were used for 2-3 minutes in each session.

Home Exercise Protocol (HEP)

The patient was taught to do all exercises at home apart from taping. Ten repetitions of each exercise, two sets a day was advised. All exercises apart from taping and sensory re-education were part of Home Exercise Protocol (HEP).

Outcome Measures

Discussion

Facial asymmetry is a common complaint among patients, as it is considered an important factor in facial attractiveness and perceived good health, which can influence interpersonal interactions. In a retrospective analysis study by Siddiqui AH et al., it was noted that facial nerve paralysis is more common after superficial parotidectomy secondary to surgical trauma involving vasa nervosum.² Another study by Hui Y et al. found that hypoesthesia of the greater auricular nerve is a frequent consequence after parotidectomy, which can take almost an year to fully recover.⁷

In this case study, the International Classification of Functioning, Disability, and Health (ICF) was taken into consideration, as facial expression is a fundamental form of non-verbal communication. Patients may experience social isolation, feelings of inferiority, communication difficulties, and the appearance of being mentally impaired, all of which can negatively affect their quality of life. The patient's recovery after two weeks of intervention can be attributed to the careful selection and implementation of various intervention approaches that were based on the goals of the patient and supported by evidence.

According to the findings of Boschetti et al., it was observed that although patients tend to experience natural recovery over time, the implementation of Kabat therapy can expedite the process of facial muscle restoration. Specifically, the application of Kabat physical rehabilitation demonstrated significant enhancements in facial muscle tone on both the affected and the contralateral side, thereby yielding notable functional and aesthetic improvements among the patients under study.⁴ A study by SS Mishra and M Sayed discusses how Mime facial exercises result in a continuous increase in muscular tension followed by bilateral relaxation. This process increases facial circulation and coordination between the two halves of the face, allowing for symmetrical facial movements and emotions.⁸

Another study by Zai-Hui Sun supports the use of kinesio-taping (KT) by stating that KT can assist muscle contraction. When the direction of KT's tension matches the direction of muscle contraction, the recoil force of the KT can be transmitted to the fascia. This effect increases the excitability of the motor unit and induces the muscle spindle reflex. Strengthening the weak muscles help to realign structures around the face and modulate normal muscle activities.⁹

The use of sensory re-education is supported by the study conducted by Meyer RA, & Rath EM, which mentions how it assists the patient in realizing the maximum potential for recovery of sensory function.¹⁰

It should be noted that in this study, electrical stimulation was avoided to prevent post-surgical inflammation, and the subject could perform all exercises independently. This study is unique in that it incorporates different regimens based on rationales and focuses on dose-based physiotherapy, which is relatively rare for this condition.

In conclusion, there are currently no established management guidelines for post-operative facial nerve palsy, causing many physiotherapists to rely on their own experience to select treatment options. However, electrotherapeutic devices are commonly used in practice. This study provides evidence-based support for a non-electrical conventional treatment protocol, which can help physiotherapists across the nation to apply this protocol in clinical practice. By utilizing a dose-based physiotherapy approach, this study offers a unique and effective treatment option for patients suffering from post-operative facial nerve palsy, which can significantly improve their quality of life. Further research is needed to evaluate the long-term effectiveness of this treatment protocol and to develop standardized guidelines for managing post-operative facial nerve palsy.

Conflict of Interest

Nil