Facial muscle twitching refers to paroxysmal, irregular, involuntary contractions of the muscles on one side or both sides of the face. It is also known as facial myoclonus or hemifacial spasm. The facial muscles, also called mimetic muscles, originate from the skull and insert into the facial skin. Their contractions produce various facial expressions, primarily around the mouth, eyes, and nose.
The etiology of this disease is not yet clear, hence it is termed primary hemifacial spasm. It is mostly caused by pathological stimulation along the facial nerve pathway. In a small number of cases, it may result from atherosclerotic dilation of branches of the vertebrobasilar artery, compression by an aneurysm, demyelination following facial neuritis, or inflammation or tumors of the cerebellopontine angle.
Key Diagnostic Points
Clinically, it is more common in middle-aged women. Prior to onset, there may be no other symptoms or there may be a history of facial neuritis. The onset often begins with irregular twitching of the orbicularis oculi muscle, which gradually and slowly spreads to other muscles on one side of the face. Manifestations include paroxysmal and irregular twitching of the orbicularis oculi and the corner of the mouth, on one or both sides, lasting from seconds to several minutes. It can be aggravated by fatigue or mental stress and ceases after falling asleep. It mostly occurs on one side; bilateral involvement is rare.
Electromyography may show: fibrillation potentials and fasciculation potentials.
Treatment
## I. Acupoints and Acupuncture Techniques (Xuewei yu Zhenfa)
1. **Taiyang (EX-HN5)** (affected side): Located in the temporal region, in the depression about one horizontal finger-breadth posterior to the midpoint between the lateral end of the eyebrow and the outer canthus. Use a 30-gauge, 2-cun filiform needle. After routine local disinfection, insert the needle obliquely toward **GB8 (Shuaigu)** to a depth of about 1.8 cun. Needling sensation: distension and pain in the temporal region.
2. **Qianzheng (Extra point, affected side)**: Located 0.5 *cun* anterior to the earlobe, level with the midpoint of the earlobe. Use a 30-gauge, 2-*cun* filiform needle. After routine local disinfection, insert the needle toward the tip of the nose to a depth of approximately 1.8 *cun*. (This point should not be needled too deeply, as deep insertion may injure the parotid gland and the mandibular artery and vein.) **Needle sensation**: Local distension, heaviness, and pain.
3. ST2 (Sibai) (affected side): On the face, directly below the pupil when looking straight ahead, at the infraorbital foramen.
At the infraorbital foramen depression: Use a No. 30 filiform needle, 2 cun in length. Perform routine local disinfection, then insert perpendicularly into the infraorbital foramen to a depth of approximately 1.6 cun. Needling sensation: local distention and pain.
4. **ST4 (Dicang) on the affected side**: Located at the intersection of the lateral extension of the horizontal line at the mouth corner and the extension of the nasolabial groove. Using a 30-gauge 2-cun filiform needle, after routine local disinfection, insert obliquely toward ST6 (Jiache) to a depth of approximately 1.8 cun. Needle sensation: local distension and pain.
II. Methods
Acupuncture is performed on the affected side or bilaterally. The patient assumes a seated position. Needles are inserted into the prescribed acupoints and retained for 1 hour without manipulation, then withdrawn without twisting. Treatment is given once daily, with 10 sessions constituting one course of treatment. A 5-day rest period is taken before commencing the next course.
**Appendix: Stylomastoid Foramen Block**
Anterior Border Approach of the Mastoid Process
Prepare three 2 mL sterile syringes: one fitted with a 5-gauge dental sterile needle, one fitted with a 6-gauge intramuscular sterile needle containing 1 mL of 2% procaine, and another fitted with a 6-gauge intramuscular sterile needle containing 0.5 mL of 98% anhydrous alcohol, set aside for use.
**Method:** The patient is placed in a lateral recumbent position with the affected side uppermost. Locate the puncture point in the depression 1 cm anterior and superior to the tip of the mastoid process behind the ear (mastoid tip). After routine local disinfection, use an empty syringe fitted with a dental needle. First, insert the needle subcutaneously, then slowly advance it along the anterior wall of the mastoid process, directing it superiorly and posteriorly toward the ipsilateral cranium. When the facial nerve is reached, the patient will experience deep pain in the ipsilateral ear. The depth of insertion is generally 2.5–3 cm. Inject 0.3 mL of 2% procaine; if ipsilateral facial nerve palsy occurs after one minute, it confirms accurate stimulation of the facial nerve. Then inject 0.3 mL of absolute alcohol. During puncture, avoid excessive anterior angulation, as this may enter the external auditory canal; deep insertion may injure the carotid artery and vein, glossopharyngeal nerve, vagus nerve, sympathetic nerve, etc.
Posterior Border of Mastoid Process Approach
Preparation: same as before.
**Method:** The patient is placed in the lateral recumbent position with the affected side facing upward. The puncture point is located 1 cm above the tip of the mastoid process at the posterior root of the mastoid. After routine local disinfection, a dental needle attached to a syringe is used. The needle is inserted subcutaneously with the tip directed forward, horizontally and slightly inward, passing through the mastoid groove to reach the posterior margin of the stylomastoid foramen, at a depth of approximately 3–3.5 cm. When the facial nerve is punctured, a distending pain in the ipsilateral deep ear and parotid region will appear. First, 0.3 mL of 2% procaine is injected. If ipsilateral facial palsy develops, 0.3 mL of absolute alcohol is then injected. Avoid inserting too deeply to prevent complications.
【Remarks】
Acupuncture treatment for facial muscle twitching (面肌抽搐) requires a longer course of therapy and can yield certain effects. In milder cases, acupuncture may achieve a cure. For patients with a longer history and frequent twitching episodes, acupuncture can help reduce or relieve symptoms. Nerve block therapy may also be considered. However, extreme caution is necessary because this method carries significant risk and can easily lead to permanent facial nerve paralysis. Therefore, it should be used with great prudence. If a secondary lesion is present, the above treatments should be applied only after addressing the underlying cause, and they can still produce some results. For particularly refractory cases that do not respond to acupuncture or nerve block therapy, surgical intervention may be considered.