Congenital myotonic squint, a deformity of the head of the neck deviating to the affected side due to a fibrous contracture of the sternocleidomastoid muscle on one side.
Etiology.
The etiology of congenital myotonic levator neck is still unknown. However, most scholars believe that abnormal intrauterine pressure or malposition of the embryo is the main cause of congenital myotonic leptomeningeal neck. The fetal malposition in the uterus or abnormal pressure on the uterine wall may cause pressure on one side of the neck and local blood circulation in the sternocleidomastoid muscle, resulting in ischemic fibrous degeneration of the muscle and causing oblique neck, and some scholars believe that the sternocleidomastoid muscle is embolized by the nutrient vessels, resulting in the degeneration of muscle fibers and forming oblique neck.
Difficult delivery and the use of forceps is one of the causes of myotonic rhomboid. This view has not been conclusively confirmed because it occurs more often in breech births, but examination of the local mass of the sternocleidomastoid muscle did not reveal signs of old hemorrhage.
It is thought that the occurrence of this condition is genetically related because of a clear family history in 1/5 of children with this condition, and it is often combined with other malformations such as congenital acetabular dysplasia.
Clinical manifestations.
After birth, the mother may find that the child’s head is tilted to the affected side, the face is rotated to the healthy side, and the jaw points to the healthy side of the shoulder. The head turning to the healthy side is obviously limited, and those with mild symptoms should be observed carefully to detect it. This symptom worsens as the child grows and develops.
A cervical mass is usually palpable after birth or within 2 weeks of birth and is located in the middle and lower sternocleidomastoid muscle, most often on the right side. The mass is pyknotic in shape, without pressure pain, and usually reaches its maximum size after 1 to 2 months, after which it gradually shrinks until it disappears completely.
If congenital myotonic squint is not treated effectively at an early stage, facial deformity will appear after 2 years of age. The main manifestation is facial asymmetry, the distance from the outer corner of the eye to the corner of the mouth is asymmetrical, the distance on the affected side is shortened and the healthy side grows. The affected side of the eye position plane is reduced, because both eyes are not on the same level, easy to produce visual fatigue and vision loss. The healthy side of the face is round and full, while the affected side is narrow and flat. The cervical spine may develop compensatory scoliosis. In addition, the whole face of the affected child, including the nose and ears, may also show asymmetric changes.
Treatment.
1.Non-surgical treatment
For children within half an age, non-surgical treatment can achieve satisfactory results. Therefore, once the diagnosis is made, treatment should be given as early as possible. The methods of non-surgical treatment include local hot compress, massage, and traction.
2.Surgical treatment
(1) Indications and contraindications for surgery
(1) Applicable to those who have failed to receive conservative treatment above the age of half a week;
(2) For people under 12 years old with obvious oblique neck deformity;
(3) Above 12 years old, if the facial deformity is not serious, surgery can be considered;
④For adults, since the deformity has existed for many years, not only the facial deformity will be more obvious after surgery, but also the vision will be changed due to the new position after surgery, so surgery is not recommended.
(2) Surgical methods
①Sternocleidomastoid excision is one of the more commonly used surgical methods. A transverse incision is made on the clavicle to reveal the sternal and clavicular heads of the sternocleidomastoid muscle, which are cut above the attachment point, and the surrounding fascial tissue is released.
②Sternocleidomastoid muscle partial excision For obvious neck masses, the masses of the sternocleidomastoid muscle can be excised.
③Total sternocleidomastoidectomy can be performed for adolescent patients if the entire sternocleidomastoid muscle is scarred.
④Lengthening of the sternocleidomastoid muscle is performed by cutting off the clavicular head of the sternocleidomastoid muscle and lengthening the sternal head in a “Z” shape. The advantages of this surgery include: correction of head and neck distortion, restoration of normal neck function; no destruction of the normal neck triangle body shape, avoiding other surgical methods that leave a concave deformity or abnormal flat deformity in the neck, and making the neck beautiful and symmetrical.
Some scholars believe that this procedure can be used in older children or those who have failed other surgeries. The method is to completely cut off the papillary side of the sternocleidomastoid muscle and the head side of the clavicle, and to extend the head side of the sternum in a “Z” shape.
(3) Postoperative treatment: In severe cases of oblique neck deformity and in uncooperative children, a head-neck-thorax cast should be used to maintain the position of the child after surgery.
Prevention.
Early detection, early diagnosis and early treatment should be carried out to prevent further damage to the child.