I. Overview
Facial muscle spasm (HFS) is a recurrent paroxysmal, involuntary twitching of one or both facial muscles (orbicularis oculi, expression muscles, orbicularis oris), aggravated by emotion or tension, and in severe cases, difficulty in opening the eyes, distorted corners of the mouth, and twitching-like murmurs in the ears.
It is more common in middle-aged and elderly people, with slightly more women than men, and the age of onset is trending younger. Although most facial muscle spasms are located on one side, bilateral facial muscle spasms are not uncommon.
Diagnosis
The diagnosis mainly depends on the clinical manifestations of atopy, and the related auxiliary examinations include: electrophysiological examination, imaging examination, and carbamazepine treatment test.
1.Electrophysiological examination includes electromyography (EMG) and abnormal muscle response (AMR) or called lateral spreading response (LSR) detection.
2, Imaging tests include CT and MRI to identify intracranial lesions that may be causing facial myoclonus.
3. Patients with facial myasthenia gravis are generally effective on carbamazepine treatment at the beginning of the disease (a small number of patients may appear ineffective).
Differential diagnosis
1, bilateral blepharospasm: manifested by recurrent episodes of involuntary eye closure of both eyelids, often with simultaneous onset of bilateral eyelids, the patient often shows difficulty in opening the eyes and reduced tears, with the prolongation of the disease, the symptoms are always confined to the bilateral eyelids.
2, Meijer syndrome: patients often start with recurrent episodes of involuntary eye closure of the eyelids bilaterally, but with the prolongation of the disease, there will gradually be involuntary twitching of the muscles below the eye fissures, manifesting as involuntary abnormal movements of the face bilaterally, and as the disease worsens, the scope of muscle spasm will gradually expand downward, even involving the muscles of the neck, extremities and trunk.
3, occlusal muscle spasm: spasm of unilateral or bilateral masticatory muscles, the patient may have different degrees of upper and lower jaw occlusion disorder, teeth grinding and mouth opening difficulties, trigeminal nerve motor branch lesion is one of the possible causes.
4. Posterior facial palsy: It is manifested as restricted movement of the ipsilateral facial expression muscles, involuntary twitching of the ipsilateral corners of the mouth and the conjoined movement of the corners of the mouth and eyelids, which can be identified based on the exact history of facial palsy.
Treatment
1.Medication: Commonly used drugs include carbamazepine, oxcarbazepine and Valium, etc. Alternative drugs are phenytoin sodium, clonidine, baclofen, topiramate, gabapentin and haloperidol, etc.
2.Botulinum toxin injection: commonly used drugs for injectable botulinum toxin type A.
3, microvascular decompression: indications include: the diagnosis of primary facial spasm is clear, secondary lesions are excluded by cranial CT or MRI; facial spasm symptoms are serious, affecting daily life and work, and the patient is strongly willing to operate; patients treated with drugs or botulinum toxin.
If there is poor efficacy, ineffectiveness, drug allergy or toxic side effects, active surgery should be performed; patients with recurrence after MVD can be operated again; patients with ineffectiveness after MVD can be considered for early reoperation if the first surgical decompression is considered insufficient and the postoperative AMR test is positive.
V. Complications
Common complications include: cerebral neurological dysfunction, cerebellar and brainstem injury, cerebrospinal fluid leakage, low intracranial pressure syndrome, other complications, etc.