Obliquus superior myokymia is an eye tremor that is very rare in this form. Therefore, it is often not recognized diagnostically. The symptoms are felt very intensely by those affected, although the prognosis of the disease is usually favorable.
What is obliquus superior myokymia?
Obliquus superior myokymia represents an extremely rare ocular condition in which microtremor occurs in the eye. The eye tremor occurs episodically and unilaterally and is often noticed only by the affected person. The eye movements can often only be detected with special equipment. However, the patient sees double images at the moment of the seizure. However, this form of eye tremor should not be confused with nystagmus. In a nystagmus, the organ of balance is damaged. Obliquus superior myokymia is caused by uncontrolled activity of the trochlear nerve. As the fourth cranial nerve, the trochlear nerve innervates the ocular obliquus superior muscle. This muscle is responsible for the lowering of the eye with its inward rolling. Obliquus superior myokymia is a benign eye condition, but it is extremely bothersome to the affected person.
Causes
The cause of obliquus superior myokymia is not yet fully known. It is thought to be due to compression of the trochlear nerve by the cerebral artery (posterior cerebral artery). However, this has not been conclusively proven to date. In the medical literature, the occurrence of obliquus superior myokymia has been described in lead poisoning and in adrenoleukodystrophy. Adrenoleukodystrophy is a hereditary neurological disorder. Simultaneous co-occurrence of obliquus superior myokymia with epilepsy has also been described. It is possible, however, that these disorders have nothing to do with the triggering of the eye tremor. Thus, a coincidental coincidence is also suspected. By means of MRI a neurological series of examinations was performed, which corroborated the assumption of a compression disorder of the trochlear nerve by the cerebral artery. According to the obtained results of this series of examinations, it is discussed whether obliquus superior myokymia can be called a neurovascular compression syndrome.
Symptoms, complaints, and signs
Obliquus superior myokymia is characterized by episodic eye tremor that is not even noticed by outside persons. However, the patients feel this fine, vertical and rotating tremor of the eyes very clearly. They feel the discomfort very intensely by the emergence of tilted double images and illusory movements. Overall, the attacks last only a few seconds. However, the attacks may repeat several times a day. After the attack ends, the findings return to normal. The eye tremor can sometimes be provoked by having the affected person look down. In this situation, however, the examiner can hardly see anything because the tremor is masked by many other normal physiological movements. However, when the affected person looks straight ahead again, there is a chance for the ophthalmologist to perceive the fine eye tremor after all, using special equipment. Overall, the course of the disease is benign. Only in rare cases paralysis occurs. However, further neurological disorders almost never occur.
Diagnosis and course of the disease
Obliquus superior myokymia could be diagnosed very easily if affected individuals were always taken seriously when describing their symptoms. Since there is nothing outwardly visible, they are often considered hysterical. However, these are very typical symptoms that would immediately lead an experienced physician to suspect obliquus superior myokymia. Using a slit lamp, the ophthalmologist can then detect the fine eye tremor during a provoked seizure.
Complications
Because of obliquus superior myokymia, affected individuals suffer from eye tremor. In most cases, patients do not recognize the tremor themselves, so this complaint can usually only be recognized and diagnosed by outsiders. As a rule, the affected persons thus appear bizarre and unnatural to other people.The eye tremor itself usually leads to visual problems due to obliquus superior myokymia and thus to double vision or strabismus. Veil vision can also occur due to obliquus superior myokymia and reduce the quality of life of the affected person. However, the tremor usually occurs only for a very short time and disappears again on its own. In some cases, paralysis of the eyes or the entire visual field may occur, so that the affected person may be limited in his or her daily life. Special complications or a serious course of the disease do not usually occur in obliquus superior myokymia. Treatment of obliquus superior myokymia can be done by taking medication. This can limit most of the symptoms. Complications do not occur. In some cases, however, surgical intervention is necessary. The life expectancy of the affected person is usually not affected by this disease.
When should you see a doctor?
In case of trembling of the eyelids, there is often an overload of the organism. If the symptoms reduce after a period of rest or a restful night’s sleep, no doctor is needed. If the tremor occurs during a tense and stressful phase of the person’s life, it should be further observed. In addition, it should be checked whether there is a deficiency symptom. If the symptoms are reduced as soon as everyday life returns to normal, freedom from symptoms often occurs after some time without medical treatment. If the eye tremor is persistent, very strong or occurs episodically, a doctor is needed. A clarification of the complaints should take place. A diagnosis will determine the need for treatment. If double vision or other limitations of vision occur, a doctor should be consulted. If there is an increased risk of accidents, dizziness or paralysis of the eyelid, the affected person needs help. In case of inner restlessness and nervousness as well as a general feeling of indisposition, a doctor should be consulted. If there are problems in coping with everyday life, a deficit in attention or disturbances in concentration, a visit to the doctor is advisable. If emotional irregularities or behavioral problems occur, the symptoms should be discussed with a doctor. Medical help should be sought for strabismus, facial paralysis, or withdrawal from social life.
Treatment and therapy
Treatment of obliquus superior myokymia is based on the patient’s subjective complaints. Often, the discomfort is felt to be very intense. There are cases of spontaneous healing. However, these are very rare. In case of severe discomfort, medications can be used. In this case, such drugs as carbamazepine or beta-receptor blockers are used. Carbamazepine is used for affective disorders (mania) or seizures, as well as neuralgia. Beta-receptor blockers such as propranolol or betaxolol inhibit the formation of adrenaline and noradrenaline. In addition to their use in cardiac arrhythmias, they are also used for anxiety disorders or tremor. Overall, however, when used for obliquus superior myokymia, the side effects of these drugs are greater than their benefits. Often, after months of drug treatment, there is no improvement in symptoms. In these cases, transection of the tendon of the superior oblique muscle may provide relief. However, this operation results in paralysis, but this can be satisfactorily corrected by further surgical procedures on the eye muscles. As a result, it is a defect healing, since the initial state cannot be completely restored. However, at present, this radical surgical intervention is the best way to prevent a recurrence of tremor. As an alternative to these treatment methods, the trochlear nerve can be relieved by a so-called microvascular decompression. In some cases, good success has been achieved with this. Microvascular decompression is a neurosurgical procedure in which abnormal contacts between certain cranial nerves and arteries are severed. This operation requires opening the skull and then eliminating the contact between the cranial nerve in question and the artery by interposing (placing in between) a cushion of muscle tissue or Teflon sponges. Success with obliquus superior myokymia has been good.This already indicates that this disease is caused by a pressure compression of the trochlear nerve. However, recurrences may occur due to slippage of the interposition device.
Outlook and prognosis
In rare cases, the prognosis for obliquus superior myokymia is good. It sometimes heals spontaneously on its own. However, in most cases, it does not. Therefore, it is rather the rule that the pronounced subjective complaints lead at least to a drug therapy. Either carbamazepine is used to stabilize the membrane, or treatment with beta-receptor blockers is considered. Considerable side effects are to be expected with both types of medication. Whether the presenting symptoms warrant them must be determined on a case-by-case basis. Often, there is no improvement in obliquus superior myokymia despite drug treatment. In this case, only surgical options remain. For example, transection and removal of the superior oblique tendon could be considered. This usually results in paralysis of the eye. However, this can also be corrected surgically. This requires one to several procedures on the eye muscles. However, if obliquus superior myokymia is not treated consistently, it usually leads to recurrence. This worsens the prognosis. An alternative treatment option is neurosurgical relief. Success can sometimes be achieved by microvascular pressure relief of the trochlear nerve. In addition, the success of this treatment suggests that obliquus superior myokymia may be caused by pressure on the nerve.
Prevention
To date, there is no known way to prevent obliquus superior myokymia.
Follow-up
Follow-up care for obliquus superior myokymia depends on the previous therapy and the actual cause of the disease. If symptomatic treatment is given, close monitoring of medication is recommended. The drugs are usually very rich in side effects and provide the desired effect only if the dosage is precisely adjusted. If the cause of the myocomia turns out to be overexertion or a deficiency, the same applies to aftercare as to therapy: symptom relief by minimizing causes. This means sufficient rest, enough sleep and relaxation. A balanced diet is also necessary to achieve symptom freedom in the long term. To avoid a recurring illness, various relaxation techniques such as meditation exercises can also be useful. If even a surgical intervention becomes necessary, a rest of the eyes afterwards is mandatory. Medical monitoring of healing is also important. In case of a neurological cause for obliquus superior myokymia, such as irritation of the trochlear nerve by a nearby vessel, surgery is usually advised. The prognosis for complete recovery after surgery is good. However, if muscle tremor recurs after successful surgery, this is often explained by reattachment of the nerve to a vessel. Further steps should then be discussed with the treating physician.
What you can do yourself
The eye tremor of obliquus superior myokymia can cause visual discomfort and strabismus. As long as the tremor occurs only temporarily for a short duration, people with the condition can cope quite well. However, when symptoms become more frequent, daily activities suffer. Patients should listen to their doctor’s advice when taking medication. In many cases, this can reduce the symptoms. The typical trembling of the eyelids may also indicate overwork. In this case, it is advisable to give the eyes a rest. Enough sleep and relaxation help to alleviate the discomfort. Nevertheless, those affected should monitor the symptoms closely. It is also possible that the eye tremor comes from a deficiency symptom. In this case, normalization of everyday life is necessary. Nevertheless, patients must expect that complete freedom from symptoms will not be achieved. The trembling feeling can be combated specifically by meditation exercises. However, in the case of severe and episodic seizures, those suffering from obliquus superior myokymia should definitely consult a physician. If there is a specific need for therapy, it is important to follow medical recommendations.In any case, an increased risk of accidents should be avoided. Therefore, in case of dizziness or paralysis of the eyelid, the way leads to the doctor’s office.
