头部疾病在中枢神经系统发育过程中影响中枢神经系统. 它们也可能影响大脑和颅骨的生长. 这些疾病会导致各种发育迟缓, 身体残疾的, 还有对孩子生命的威胁. 头性疾病开始于怀孕期间婴儿发育的早期. 它们也被称为神经发育障碍.

One of the most visible signs of a cephalic disorder is the unusual size or shape of a baby’s head.  Problems from these disorders are most likely when a baby’s head is much smaller or larger than the average for their age.

关于头部疾病的事实

这些疾病可轻可重. This depends on the parts of the brain and central nervous system affected. 许多头性疾病患者过着相对正常的生活. But some cephalic disorders are so severe that a baby will die within weeks or months of birth.

头部疾病的类型

有许多不同的头部疾病，包括:

• Anencephaly. This condition happens when the top of the neural tube doesn’t close as the baby develops during pregnancy. 大脑、头骨和头皮的主要部分都不见了. 剩下的脑组织经常暴露在外. 这些婴儿出生时失去知觉，耳聋和失明. 患有这种疾病的婴儿通常在出生后数小时或数天内死亡.

• Colpocephaly. The back part of the chambers of the brain (the occipital horns) are abnormally large. Babies with this condition have an unusually small head and an intellectual disability. Other symptoms may include muscle spasms, motor abnormalities, and seizures.

• Holoprosencephaly. As the baby develops during pregnancy, the brain grows into one single lobe instead of two. 严重程度有不同的等级. A baby may have very mild abnormalities and be able to lead a relatively normal life. 或者可能有严重的异常和功能受限. Many babies with the severe form of this disorder die before or soon after birth. Others may live, but may have severely deformed faces and severe cognitive and neurological impairment.

• Hydranencephaly. With this rare condition, the cerebral hemispheres of the brain are missing. 它们被脑脊液口袋所取代. 这些婴儿在出生时可能看起来很正常. 但几个月后，他们就会变得易怒. 它们不会沿着正常的时间线发展. Most of these children have severe neurological and cognitive impairment. 他们通常在几年内死亡.

• Hydrocephalus. This is not really a cephalic disorder, but it can cause a large head size in infants. With this condition, cerebrospinal fluid builds up in the ventricles of the brain. 儿童通常需要一根管子(分流)来排出多余的液体. The outcome depends on the cause of the hydrocephalus and how early therapy is started.

• Iniencephaly. This disorder combines the extreme backward bending of the baby’s head with severe spinal defects. 婴儿畸形的身体也可能使母亲的生命处于危险之中. 患有这种疾病的婴儿很少能活过几个小时.

• Lissencephaly. 在正常的大脑发育中, nerve cells (neurons) travel to the correct part of the nervous system and connect to each other. This and other related disorders happen when the brain neurons don’t end up in the correct place during development. 这会导致不寻常的大脑形成和极小的头部. 有一系列的神经功能障碍, from mild developmental delay to severe neurologic dysfunction and even death.

• Microcephaly. 在这种情况下，婴儿的头比正常情况小得多. Many children with smaller than average heads have normal intelligence and develop correctly. But this condition is common in many known disorders such as Down syndrome. 许多患有小头症的儿童可能有智力障碍, 还有脑瘫, 感觉障碍，包括视力问题, poor motor skills, 缺乏平衡和协调, 在思考和学习方面也有困难，这与孩子的年龄相符. Microcephaly is also a symptom of other birth defects such as lissencephaly and porencephaly.

• 大头畸形(又称巨脑畸形). 患有这种疾病的婴儿的头比正常人大得多. 这可能是因为大脑长得异常大. Experts believe this disorder may occur because normal cell production in the brain is disrupted. Children may have seizures, developmental delays, and other motor problems. (这种疾病不同于大头畸形, 脑肿大无相关脑缺陷的头部肿大. 它通常是遗传的，没有症状.) 

• Porencephaly. This disorder occurs when a pocket of cerebrospinal fluid forms in the baby’s brain during development. It is believed to be related to an infection or stroke, either during pregnancy or the newborn stage. Some children with this disorder have normal intelligence and few if any developmental problems. 其他人则有不同程度的运动或认知困难. The severity depends on the size of the cerebrospinal fluid-filled pockets, 以及它们在大脑中的位置. 

• Schizencephaly. This rare disorder happens when slits (clefts) form in one or both hemispheres of the brain. 症状取决于孩子有多少个唇裂, 如果它们在大脑的一侧或两侧. 有些患有这种疾病的人生活相对正常. Others may have severe developmental delays, motor delays or even paralysis, or seizures.

Symptoms

Symptoms vary depending on the type of cephalic disorder, but may include:

• 异常大或小的头

• 吞咽或进食困难

• Poor muscle tone

• Paralysis

• Seizures

• 手指或脚趾畸形

• Deformed face

• 发育迟缓身体能力或语言发育的迟缓

• Delayed growth

Diagnosis

进行诊断, 医疗保健提供者可能考虑症状和健康史, 给他的头骨和身体做个体检. You will often be referred to a specialist, such as a geneticist to help make a diagnosis. 医疗保健提供者也可以要求进行以下测试:

• Blood tests

• CT扫描或核磁共振扫描(核磁共振扫描通常显示更多细节)

诊断时通常考虑头部大小. A healthcare provider will use a measuring tape to measure the distance around your baby’s head (circumference). The tape is usually placed just above the eyebrows and around the widest part of the head. 这个数字与标准增长图表进行比较.

随着婴儿成长为蹒跚学步或幼儿，头部大小会发生变化. A child’s head size may be measured at every well visit or office visit to see if the head is changing shape. This usually continues until age 3, unless there is a reason to keep track past that age.

什么时候给孩子的医疗保健提供者打电话

一些头侧疾病从出生时就明显存在. Others are not. Call the healthcare provider if you have concerns about your child’s ability to meet developmental milestones. These include starting to roll over, crawl, walk, or speak at the expected age. Also call if you are concerned about the shape of your child’s face or head.

Treatment

治疗头性疾病取决于疾病的类型. 治疗方法包括:

• 运动理疗

• 语言治疗

• 治疗症状的药物，如抗癫痫药

• 分流以排出大脑中多余的液体

• 矫正颅骨或面部畸形的外科手术

• Comfort care

Prevention

头部疾病的真正原因尚不完全清楚. 专家认为基因可能是一个因素. 女性怀孕期间发生的事情也可能起作用. These can include having an infection or being exposed to toxic chemicals.

The best way to try to prevent cephalic disorders is to be as healthy as possible during pregnancy. 这意味着远离酒精、香烟和非法毒品. 吃多种健康的饮食也很重要. Getting enough folic acid has been shown to reduce the risk for certain birth defects, 包括一些头部疾病. But many women take good care of themselves during pregnancy and still give birth to a child with a cephalic disorder. Some of these disorders may be caused by intrauterine infection or an injury. 遗传条件也可能是一个因素. Genetic counseling may help you understand your risks in future pregnancies.