什麼是dandy walker?

Dandy Walker Syndrome是因胚胎時期後腦（Hind
brain）的發育異常而導致的腦部病變，主要出現的是
後顱窩的大型囊腫，而經常合併有水腦症
（Hydrocephalus）。Dandy Walker Syndrome常發生的
機率大約是25000分之一。就與水腦症發生關係而言，
約佔新生兒水腦患者的1~4%，通常女性患者稍多。事實
上，發生後顱窩的囊腫病變有多種，且與Dandy Walker
syndrome類似，故其命名方式也可能不盡相同。



正常的後顱窩構造主要包含小腦、腦幹及第四室。第四
腦室藉由大腦導水管（Aqueduct of Sylvius）與大腦
的腦室系統相連。所謂的典型（Classic）Dandy
Walker Syndrome便是指小腦不良發育，後顱窩形成巨
大水囊，這個水囊對周圍腦組織產生壓迫，使小腦天幕
（Tentorium）上提，以及腦水循環異常而致水腦症。



Dandy Walker syndrome病患通常併隨其他腦發育不
良，如 連接兩側大腦半球之corpus callosum喪失
（Agenesis）。除腦部外，其他器官發育異常比率也
高，約有30%病患可能出現如：唇顎裂（cleft lip，
palate ）、心臟異常（cardiac malformation）、骨
骼異常或呼吸道、泌尿道異常。



大部分的Classic Dandy Walker Syndrome病人因水腦
及顱內高壓而於一歲前診斷出來。從外觀而言，病患頭
圍增加、頭形明顯增大且前囪門（Anterior
fontanell）突出。病患可能因頸部肌肉無力以至頭部
支撐不良。



Dandy Walker syndrome患童約有20~30%可能有癲癇症
（Seizure）,智能發展遲緩是很常見的徵候。肢體及姿
勢協調異常及行走困難也很常見。




Dandy Walker syndrome患者大部分需要外科手術治
療。最常使用的手術方法是囊腔或腦室分流
（Diversion）手術。做法是將一含有壓力控制瓣
（Pressure controlled valve）導管的一端置入囊腔
或腦室內，將腦脊髓液（CSF）引流至腹膜腔或其他體
腔中。術前的MRI診斷對手術的選擇是很重要的，手術
醫師可藉由MRI影像判斷是先進行天幕上或後顱窩CSF引
流或是兩者需同時進行。



雖然，我們藉由腦水引流手術可改善病患症狀，但因疾
病的成因事先天性發展異常，這部份是無法手術矯治
的。病患協調異常、平衡不良、行走困難、學習障礙等
皆須長期仰賴小兒科、小兒神經科、小兒復健科、兒童
心智科等專科醫師長期密切進行追蹤及治療，使病童在
身心發展,教育及生活上能趨於正常。

What is Dandy-Walker Syndrome?
Dandy-Walker Syndrome is a congenital brain malformation involving the cerebellum (an area at the back of the brain that controls movement) and the fluid filled spaces around it. The key features of this syndrome are an enlargement of the fourth ventricle (a small channel that allows fluid to flow freely between the upper and lower areas of the brain and spinal cord), a partial or complete absence of the cerebellar vermis (the area between the two cerebellar hemispheres), and cyst formation near the internal base of the skull. An increase in the size of the fluid spaces surrounding the brain as well as an increase in pressure may also be present. The syndrome can appear dramatically or develop unnoticed. Symptoms, which often occur in early infancy, include slow motor development and progressive enlargement of the skull. In older children, symptoms of increased intracranial pressure such as irritability, vomiting, and convulsions, and signs of cerebellar dysfunction such as unsteadiness, lack of muscle coordination, or jerky movements of the eyes may occur. Other symptoms include increased head circumference, bulging at the back of the skull, problems with the nerves that control the eyes, face and neck, and abnormal breathing patterns. Dandy-Walker Syndrome is frequently associated with disorders of other areas of the central nervous system including absence of the corpus callosum (the connecting area between the two cerebral hemispheres, and malformations of the heart, face, limbs, fingers and toes.

You can find some other info from this site as well http://www.ninds.nih.gov/disorders/dandywalker/dandywalker.htm
hope this can help you out