The medical term for excessive eye twitching is hemifacial spasm (HFS) or ticconvulsif. This, essentially, is an involuntary contraction (or twitch) of the facial muscles, albeit on one side of the face. Hemifacial spasm is usually due to irritation of the facial nerve that controls the movement of muscles around the eyes, eyelids, mouth and lips.
In approximately 90% of cases, eye twitching starts near the eye before gradually progressing down the face. In the remaining 8% to 10% off patients, it begins near the chin and moves up towards the eye area. While the twitching is not painful, it can cause undue embarrassment and self-consciousness as it begins to interfere with normal facial expressions and vision.
Hemifacial spasm is a rare condition in the developed world with as few as 8 in 100,000 people being affected. In the UK alone, it is thought that there are 4,000 who suffer from hemifacial spasm. It typically manifests itself around 45 years of age and is slightly more common in women.
What causes hemifacial spasm?
Excessive eye twitching can be caused by an injury to the facial nerve which controls the facial muscles. It may also arise from a tumour or blood vessel which is pressing against the nerve. The compression causes the nerve to misfire and, thereby, causes the facial muscles to contract.
How is a diagnosis made?
Initially, a neurological examination needs to be carried out. An MRI scan is typically used to rule out other, more serious, conditions such as a brain tumour, aneurysm or brain arteriovenous malformation (AVM). An electromyogram (EMG) study of the face alongside a nerve conduction velocity (NVC) study to measure the nerve and muscle activity.
What Treatments Are Available?
There are a number of effective treatment options available. These include:
1. MedicationMuscle relaxants may be prescribed for mild cases of hemifacial spasm. However, they do cause some side effects including drowsiness, nausea, skin rashes or even dependence. Therefore, patients are carefully monitored and regular blood tests are taken to ensure that excessive levels do not enter into the bloodstream.
2.BoNT InjectionsBoNT (otherwise known as BoNT) can be carefully injected into the affected areas in order to paralysis the muscles. It is commonly used around the eyes, mouth and neck with patients reporting improvements within 3 days. The results can also last up to 3 months and the injections can be re-administered on a long-term basis, although its effectiveness can diminish over the years. This is due to the buildup of the antibodies. Side effects include temporary facial weakness, a drooping eyelid and eye sensitivity although many patients feel that the long-term results far outweigh them.
3.SurgeryWhen the facial spasms and eye twitching persists a surgical procedure called microvascular decompression can be performed. Here a sponge is inserted between the artery and the nerve to relieve nerve compression or pressure and ultimately stop the spasms. Whilat surgery always comes with a risk, the vast majority of patients report significant improvements and are able to return to their regular lifestyle as quickly as 2 months after the procedure