Extraocular Muscle Trauma

Introduction to extraocular muscle trauma Indirect extramuscular muscle injury (injuriesofexternalmuscle) is caused by blunt external force or sharp injury to the eye or head, directly or indirectly damage the extraocular muscles and their innervation nerves, causing nerve paralysis or muscle disconnection, eye movement disorders, eye position deviation A strabismus in which the oblique or fusion function is broken and the symptoms of diplopia appear. basic knowledge Sickness ratio: 0.05% Susceptible people: no special people Mode of infection: non-infectious Complications: eyeball rupture

Cause of extraocular muscle trauma

Causes:

trauma.

Pathogenesis:

According to some statistics, about 15% of extraocular muscle paralysis in acquired paralytic strabismus is caused by trauma. Such extraocular muscle damage is common in the ankle or craniocerebral concussion injury and ankle penetrating injury. They can Direct damage to the extraocular muscles can also indirectly damage the motor nerves or nucleus of the extraocular muscles, causing dysfunction of the extraocular muscles they control, such as eyelid contusion, penetrating injury, direct tearing of nerves or muscles, and disconnection. Intraorbital hemorrhage, edema, compression of nerves, muscles, etc.; direct cutting and squeezing of broken bone fragments of humeral fractures; insertion of nerve muscles into fractures or into maxillary sinus or ethmoid sinus, and brain concussion injury to brainstem eyeballs Injury of motor nuclei; skull base fracture directly damages the motor nerve trunk; sharp instrument stabs the extraocular muscles, etc., can cause dysfunction of the extraocular muscles, and the extraocular muscle injury alone is almost invisible, often combined Eyelids, conjunctiva and even eyeball ruptures, orbital fractures and craniocerebral concussion injuries are common injuries or causes of extraocular muscle paralysis.

Extraocular muscle injury prevention

Mainly due to trauma, so pay attention to work safety and strengthen labor protection, to avoid the occurrence of trauma is crucial. Pay attention to personal protection and avoid unnecessary damage. In the event of trauma, please seek medical advice, confirm the diagnosis, and correct treatment and treatment to avoid the occurrence of secondary injury, and also avoid the occurrence of old injuries, and have an adverse impact on treatment and prognosis.

Extraocular muscle trauma complications Complications, eyeball rupture

Can be combined with eyelids, cornea, conjunctiva and even eyeball rupture and other parts of the body.

Extraocular muscle trauma symptoms Common symptoms Two eyes can not be eyeballs can not be free to move the eyeballs Distraction of the eye muscle paralysis eyeball invagination intracranial pressure increased edema internal bleeding ptosis diplopia

Types of extraocular muscles and nerve damage:

1. Direct damage to the extraocular muscles

(1) Extraocular muscle rupture: the rupture of the extraocular muscle may occur at the tendon, or in the muscle part of the muscle abdomen or even the equator of the eyeball; it may be partially broken or torn, or it may be completely disconnected, more common in Department of penetrating injury, caused by sharp objects such as knives, scissors, hooks, nails, glass fragments, etc., also belong to iatrogenic, such as rupture of the medial rectus muscle during pterygium resection; retinal detachment surgery Muscle slippage after suturing the suture; otolaryngology for maxillary sinus, ethmoid sinus or frontal sinus radical surgery through the wall to mistake the muscles, etc., this muscle break can also be seen in the eyelid contusion, after the extraocular muscle fracture occurs, Immediately appearing eye movement disorder, but due to conjunctival congestion, edema and swelling of the eyelids, it is often difficult to find, only after the edema absorption disappears, the eye appears diplopia, strabismus and eye movement disorder is detected, surgical exploration It is the only way to confirm the diagnosis.

(2) intramuscular hemorrhage: extraocular intramuscular hemorrhage can occur in eyelid contusion and direct injury of extraocular muscles. Hemorrhage originates from rupture of blood vessels in the iliac crest or rupture of blood vessels in the muscle. The intramuscular hemorrhage causes the extraocular muscles to become full of blood. Swelling, loss of contraction function and varying degrees of flaccidity, bleeding can be in the muscle abdomen, but also in the tendon, such as oblique muscle spasm bleeding is characterized by intermittent Brown superior oblique sheath syndrome and traction test positive, clinically differentiated Neurogenic paralysis and intramuscular hemorrhage are difficult and often identified during surgical exploration.

(3) extraocular muscle stagnation and incarceration: called restrictive strabismus, the common cause of incarceration or occlusion of extraocular muscles or surrounding soft tissue is bursting tibiofibular fracture, fracture of the at the base of the iliac crest is the inferior rectus muscle, inferior oblique muscle The inferior soft tissue incarceration penetrates into the fracture of the fracture, and even enters the maxillary sinus, causing the eyeball to not turn up; the fracture of the internal wall of the ankle causes the internal rectus muscle to be embedded, resulting in the inability of the eyeball to rotate and the external rotation is limited, and the eyeball is retracted when attempting to turn outward. And the cleft palate is reduced, called pseudo-Duane syndrome; the fracture of the apical wall can embed the superior rectus muscle or the superior oblique muscle, resulting in a downward movement of the eyeball. Most patients immediately have diplopia after injury, but also have edema in the eyelid. After disappearing, it was discovered that large fractures were often accompanied by eyeball retraction in addition to multiple extraocular muscles and surrounding soft tissue; or fracture fragments directly stabbed the extraocular muscles to cause fracture or intramuscular hemorrhage, small fractures or linear fractures. Because of intra-abdominal hemorrhage, edema oppresses the extraocular muscles and restricts eye movements. It is often improved within 3 weeks after injury. It can be diagnosed according to X-ray film and CT scan, fracture and tissue incarceration and positive traction test.

(4) eyeball displacement: eyelid trauma can cause the eyeball to shift forward and backward in the sac. The literature often reports traumatic ocular dislocation. This kind of ocular dislocation is caused by several fractures of the extraocular muscle or soft tissue in the iliac crest; Traumatic eyeball retraction is caused by severe sacral fracture; traumatic ocular protrusion has two reasons, one is intra-orbital hemorrhage and edema; the other is traumatic carotid cavernous sinus fistula, the eyeball shifts to one side Mostly, a group of extraocular muscles are mechanically restricted, and there are also ocular dyskinesias and diplopia. The position of the two eyes is asymmetrical due to the volume of the eyelids or supporting tissue changes, rather than caused by eye muscles and nerve damage. It is clinically called relative ophthalmoplegia.

(5) Damage to the pulley part: The upper oblique muscle dysfunction caused by the damage of the pulley part is rare in clinical practice, because it is caused by the protection of the upper edge of the sac, but it can also be seen in the upper part of the sputum. The damage of the pulley part caused by the puncture or the bruise of the table corner, and the cases of the iatrogenic block injury reported in the literature, such as the removal of the medial part of the upper sac, the frontal sinus, the ethmoid sinus surgery, etc. The damage of the pulley is mainly the disengagement or displacement.

(6) scar contraction and adhesion formation of extraocular muscles: eyelid contusion and penetrating injury can not only directly damage the extraocular muscles and their innervation nerves, but also scar contraction and adhesion after the injury, including extraocular muscles. To cause eye movement disorders, adhesions can occur at different locations, such as between the muscles or between the tendons and the eyeballs, between the muscles or their sheaths and the conjunctiva; between the sclera or between the muscles and the conjunctiva; or a large scar The tissue includes a fusion of extraocular muscles, sheath, intermuscular tissue and conjunctiva. Such adhesions can be seen in iatrogenic injuries, such as sputum tumor removal, decompression, extraocular muscle surgery, etc. The most simple way to identify adhesions is to pull the test.

2. Injury of the extraocular muscles

(1) Peripheral injury: also known as peripheral motor nerve injury or nerve trunk injury, trauma to the eyelid or head, can cause direct or indirect damage to one or several eye muscle motor nerves, injury in the ankle, such as the humerus The external force pushes into the iliac crest, often damages the nerve that innervates the lateral rectus muscle; the crest fracture can damage the oculomotor nerve that innervates the rectus muscle and lifts the diaphragm; the internal wall of the iliac crest or the humerus fracture may damage the inner part. The rectus muscle, the inferior rectus muscle, the oculomotor nerve of the inferior oblique muscle, and the trochlear nerve that innervates the superior oblique muscle, especially when the humeral fracture invades the supracondylar fissure, can damage the oculomotor nerve through the supracondylar fissure, the trochlear nerve, and exhibition Nerve and other motor nerves and trigeminal ocular branches and upper ocular veins cause supracondylar fissure syndrome. If the optic canal is involved, it can damage the optic nerve, causing the apical syndrome, skull fracture or brain parenchymal injury, and can cause eye movement. The nerve is involved in the injury, tearing, and breaking of the bone through the bone wall. In addition, the birth of the forceps, pelvic stenosis, and long labor period can also damage the extraocular muscle paralysis of the baby. Infant extraocular muscle One reason for paralysis can not be ignored.

In the peripheral motor nerve damage that governs the extraocular muscles, the most nerves are spread, accounting for about half, followed by the oculomotor nerves, and again the trochlear nerves.

1 nerve paralysis: because the nerve in the skull close to the tip of the humeral rock, through the supracondylar fissure into the iliac crest, and then slightly forward under the lateral rectus muscle, terminate in the muscle, so when the skull base fracture and sacral fissure or sputum When the lateral wall is damaged and fractured, and the forceps are injured, the gods are often injured. When the traumatic intracranial pressure is increased, the nerve paralysis can also occur, often unilaterally. The mechanism is that when the intracranial pressure is increased, the The nerve is compressed on the anterior cerebellar artery, or the brain stem moves down to the occipital foramen, and the nerve is pulled to make it paralyzed by the tip of the humeral rock. When the nerve is completely paralyzed, the eyeball has obvious internal oblique. The state can not be turned outwards, and there is a horizontal side-to-side double vision. When looking at the affected side, the complex image spacing increases, and the compensatory head position is deflected toward the affected side.

2 trochlear nerve paralysis: head trauma is a common cause of trochlear nerve injury, manifested as superior oblique muscle paralysis, eye position deflection is mainly external rotation and upward oblique and a little internal oblique, eye movement is insufficient for subtalar function, patient conscious Vertical ipsilateral double vision, in order to avoid double vision, the patient's head tilted to the healthy side, facing the healthy side, the mandible adduct, in order to maintain binocular monocular, Bielschowsky taro test positive is the main method to identify superior rectus paralysis.

3 oculomotor nerve paralysis: oculomotor innervation is applied to the diaphragm, the medial rectus, the superior rectus, the inferior rectus, the inferior oblique muscle, the pupil sphincter and the ciliary muscle. When the oculomotor nerve is completely paralyzed, it is characterized by ptosis. And the inner eye, the external muscle paralysis, due to the trochlear nerve, the nerve is normal, the eyeball is externally oblique and internal rotation and the pupil dilated, when the incomplete paralysis, the intraocular muscle is often affected to varying degrees, and the oculomotor nerve A single muscle paralysis of the muscles that are administered is less common.

(2) Nuclear injury: the nucleus that dominates the eye movement, located in the midbrain, the inferior colliculus, the third ventricle and the fourth ventricle, adjacent to the cerebral aqueduct, so when the head is traumatized, the external striking force is caused. The flow of liquid in the third ventricle causes the pressure around the front end of the cerebral aqueduct to increase, causing edema or plaque hemorrhage, causing extraocular muscle paralysis. The most likely to be affected is the III cranial nucleus, which is covered in the midbrain. Within the gray matter, it is widely distributed and close to each other. The damage often manifests as bilateral and incomplete extraocular muscle paralysis. The intraocular muscles are generally not affected. If it is unilateral and complete oculomotor nerve paralysis, it is not nuclear. Sexuality, the damage of the trochlear nerve nucleus is bilateral, which is characterized by rotational strabismus. The nucleus injury is often accompanied by facial nerve efferent fiber involvement. Clinically, it is not only manifested as external rectus paralysis, but also peripheral facial paralysis.

(3) supranuclear injury: mostly for the cerebral cortex and into the oculomotor, the trochlear, and the conduction path of the nucleus. The clinical manifestation is mainly bilateral bilateral dyskinesia, rather than the movement of one extraocular muscle. The disorder, which differs from nuclear or subnuclear lesions, is that there are no signs of diplopia.

Examination of extraocular muscle trauma

Because of the trauma, necessary laboratory tests such as blood routine, blood biochemistry, and cerebrospinal fluid must be performed.

X-ray and CT scan of the skull and eyelids, EEG, etc., can confirm the brain trauma and eye muscle trauma, other including vision, fundus, visual field, diplopia, eye position, eye movement, Hess screen, co-view Machine inspection, compensation head position, EMG, pull test, etc.

Diagnosis and differentiation of extraocular muscle trauma

diagnosis

The location diagnosis of traumatic extraocular muscle paralysis is difficult because the injury is complicated and often combined with other types of trauma, especially when two or more muscle paralysis is more difficult to locate. Cui Guoyi reported 43 cases of injury in 1989. The diagnosis and surgical experience of extraocular muscle paralysis, and reference to domestic and foreign literature, on the diagnosis and differential diagnosis are summarized as follows:

1. Learn more about the injury, including the skull, eyelid X-ray or CT scan, EEG, and non-surgical treatment of eye muscle paralysis.

2. Careful examination of eye conditions including vision, fundus, visual field, diplopia, eye position, eye movement, etc., after eye trauma caused by diplopia, strabismus and compensatory head position, should first find out whether it is one or more Muscle involvement is more important for vertical strabismus. The palpebral muscle is detected by the above method to determine which muscle damage is caused by double vision.

3. Secondary deviation Some mild extraocular muscle paralysis can be expressed as secondary skewness greater than primary skewness, and old paralytic strabismus with muscle contracture, there is a certain commonality, difficult to detect Paralyzed muscles, sometimes identifying two vertical muscles which are paralyzed muscles, are often difficult to perform, and need to be screened by Hess, or Bielschowsky's head test, Parks three-step test to identify.

4. Follow-up observation after extraocular muscle trauma to the obvious sharp injury, the injury site is clear, often can make a judgment, but after the injury to the extraocular muscle, the eyelid edema, can not blink the patient to disappear after the edema can be carried out Check, in the treatment and follow-up observations need to determine whether the condition is improving or continue to progress, the commonly used methods are Hess screen check and triple prism cover method and the same machine check.

Differential diagnosis

Extraocular muscle paralysis is mostly traumatic brain injury or blunt eye injury. Extraocular muscle separation is more common in perforated trauma or humeral fracture. In addition, when the extraocular muscle and surrounding soft tissue are incarcerated in the tibiofibular fracture, the traction test is Positive, need to be used for eyelid film or CT scan and other auxiliary examinations to distinguish.

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