Bell's phenomenon asymmetry in both eyes

Introduction Asymmetry of the Bell phenomenon in both eyes is one of the symptoms of monocular double-upper palsy. Monocular double-upper muscle paralysis is characterized by asymmetrical Bell phenomenon in both eyes, and the eye is often poor or disappears. There are congenital and acquired differences, the real cause is not very clear. The pathological changes were mainly located in the anterior horn of the spinal cord. The motor cells were significantly reduced and degenerative. The residual nerve cells were pyknosis and nuclear lysis. The anterior root axis mutation was fine and the peripheral cells of the axons were swollen. The brainstem motor neuron degeneration is more common in the facial nerve, vagus nerve and hypoglossal nerve.

Cause

(1) Causes of the disease

Single eye double upper muscle paralysis has congenital and acquired nature, the real cause is not very clear.

(two) pathogenesis

Some people think that it may be part of the paralysis of the oculomotor nerve paralysis during the recovery process. In terms of congenitality, according to the anatomy of the oculomotor nerve, the oculomotor nucleus is raised from the top to the bottom of the nucleus of the diaphragm, the superior rectus and the inferior oblique nucleus, respectively. Straight muscle nucleus. During the mother's pregnancy, it may be interfered by certain factors, causing damage to the above-mentioned nerve nucleus and oculomotor nerves and oculomotor nerve palsy. Acquired people can cause oculomotor palsy due to trauma, brain inflammation, and tumors. Regardless of congenital or acquired nature, there is a certain order of recovery after oculomotor nerve paralysis. Generally, the recovery of the diaphragm is the earliest and fastest, followed by the medial rectus, the inferior rectus and the pupil sphincter, and the superior rectus and the lower The recovery of the oblique muscles is the latest or not, so it shows the characteristics of monocular double-upper muscle paralysis. Since the superior rectus muscle and the superior levator muscle are differentiated from one muscle, although the function of the levator muscle has been restored, the pseudo-sagging state is exhibited due to the pulling function of the superior rectus muscle. Mixed and true ptosis may be associated with incomplete or unrecoverable recovery of the nerve function that governs the superior diaphragm.

The pathological changes were mainly located in the anterior horn of the spinal cord. The motor cells were significantly reduced and degenerative. The residual nerve cells were pyknosis and nuclear lysis. The anterior root axis mutation was fine and the peripheral cells of the axons were swollen. The brainstem motor neuron degeneration is more common in the facial nerve, vagus nerve and hypoglossal nerve. The muscle pathology examination is shown in the auxiliary examination section below.

an examination

Related inspection

Eye and sacral area CT examination ophthalmologic examination

1. Eye position: In the first eye position, the affected eye has a downward oblique position, and the lower oblique degree is large, often combined with external strabismus. The lower slope is generally greater than 30 , and the external slope is mostly within 20 .

2. Eye movement: When the eye is in the first eye position and the two eyes move in the same direction, the upward movement of the superior rectus muscle and the inferior oblique muscle are obviously restricted. The same visual machine examination mainly showed that the upper left and upper right directions were higher than the affected eyes. The lower rectus muscle of the affected eye was not mechanically restricted, and the contraction of the superior rectus muscle and the inferior oblique muscle of the active contraction test was weak or completely weak.

3. The ptosis of the upper jaw: The eye is often accompanied by a true, false or mixed ptosis. Covering the eye with the eye, the eyelid sag disappears. At this time, the eyelid is more than the eye, which is the false ptosis; if the eye is gazing, the eyelid is improved and the normal cleavage height is still not reached. If the eye is smaller than the healthy eye, it is a mixed ptosis; if the eyelid sag is still not improved, it is a true ptosis.

According to the Hering rule, the nerve impulses from the brain are determined by the need to look at the eye. When the monocular double-upper palsy is paralyzed, the normal nerve impulses from the brain are suitable for healthy eyes, but this impulse is insufficient for impulsiveness of the double-upper palsy muscle of the affected eye, which cannot cause normal contraction and rotate backward, and at the same time The nerve impulse of the upper diaphragm is also small, so when the eye is gazing, the eye will appear ptosis. When covering the healthy eyes and gazing at the eyes, in order to maintain the gaze position of the paralyzed eyes, the brain must strengthen the nerve impulses of the double-upper muscles, and at the same time strengthen the nerve impulses of the upper jaw muscles. At this time, the ptosis disappears, so it is called fake. Sexually drooping, while healthy eyes receive strong nerve impulses, and their cleft palate is often greater than the affected eye.

4. Vision: Because of the slanting of the eye and the combination of external oblique and ptosis, the healthy eye is mostly gaze, so amblyopia often occurs, and about 50% of cases are accompanied by amblyopia.

5. Bell phenomenon: The phenomenon of Bell in both eyes is asymmetrical, and the eyes are often poor or disappear.

6. Lower jaw changes: Due to the pinching of the inferior rectus muscle, the fascia ligament is transmitted to the lower jaw, and the affected eye often appears to have wrinkles or deepening of the skin of the inferior temporal margin when looking down; or the lower jaw retracts.

Monocular double-rotating muscle paralysis is rare in clinical practice. According to its clinical features and necessary examinations, it is not difficult to diagnose such as video camera and traction test.

Differential diagnosis

It should be differentiated from the following extraocular muscle paralysis:

1. Separate superior rectus paralysis: The performance is that the eye is slanted when the eye is gazing, and the eye is oblique when the eye is gazing. The eye movement can be seen that the affected eye is insufficiently rotated upward and upward, and the direct antagonistic muscle (lower rectus muscle) of the contralateral eye partner muscle (inferior oblique muscle) or the ipsilateral eye is too strong, and the inner upper rotation is not limited. The same visual inspection showed that the upper eye position of the affected eye was significantly lower than that of the healthy eye. It can be combined with the ptosis, but it is mostly true.

2. Inferior oblique palsy: The eye position of the lower eye is low, the inward rotation of the affected eye is limited, the superior oblique muscle is too strong, and the Bielschowsky taro test is positive, that is, the eye is more oblique when the head is tilted to the healthy side. The external upturn is normal, without the ptosis.

3. Inferior oblique muscle and inferior rectus muscle adhesion syndrome: It is characterized by low eye position in the affected eye, and limited in the upper and lower upper and lower eyes of the affected eye. The rectus muscle has obvious resistance under the pull test. Not accompanied by ptosis.

4. Congenital ptosis: congenital ptosis is divided into light, moderate and severe according to the degree of ptosis. In addition to severe amblyopia, general congenital ptosis without strabismus, high refractive error and anisometropia rarely occur amblyopia. In addition, the congenital ptosis of the upper iliac muscle is weak, and will not disappear due to changing the gaze.

5. Bottom fracture: accompanied by extraocular muscle and surrounding tissue incarceration, manifested as vertical diplopia, limited eyeball upturn, traction test eyeball up, down and rotation are limited, orbital CT scan and X The flat film can detect the fracture site, shape, extent, and the presence or absence of sputum content.

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