Chiari II malformation with spina bifida. Perinatoloji Dergisi 2011;19(2):105-106
- GATA Haydarpaşa Training Hospital Department of Obstetrics and Gynecology İstanbul TR
İsmet Gün, GATA Haydarpaşa Training Hospital Department of Obstetrics and Gynecology İstanbul TR,
Çıkar çakışması bulunmadığı belirtilmiştir.
Spina bifida is a developmental congenital disorder. Many individuals with spina bifida have an interrelated abnormality of the cerebellum, named the Chiari II malformation. In affected individuals, the back portion of the brain is displaced from the back of the skull down into the foramen magnum. It sometimes has actualized by non-communicating hydrocephalus secondary to obstruction of cerebrospinal fluid outflow. The aim of this presentation is to describe lack of lumbosacral protruding sacs in Chiari II malformations with spina bifida.
A 35-year-old woman was admitted to our clinic for routine pregnancy controls. Her regular antenatal visits were unremarkable up to 16 weeks. However, an ultrasound examination demonstrated Chiari II malformation with spina bifida accompanied by calvarium deformities (lemon sign), cerebellum deformity (banana sign), and a defect in the lumbar spine region with enlarged (Vp=10 mm) lateral ventricles. The couple was informed about Chiari II malformation with spina bifida and opted for the termination of pregnancy.
The neural tube is the embryonic structure that eventually develops into the brain and spinal cord and the tissues that enclose them. Infants born with spina bifida sometimes have an open lesion on their spine, where significant damage to the nerves and spinal cord has occurred. If the opening is large enough, this allows a portion of the spinal cord to protrude through the opening in bones. Chiari II malformation is usually associated with lumbar myelomeningocele. Chiari II malformation can be diagnosed prenatally through ultrasonography. There are four regions of the brain affected in Chiari malformation: the cerebellum, the brain stem, the ventricles, and the cerebrum. Chiari malformation can also involve defects in the base of the skull and in the bony part of the spine (lemon sign). Approximately 80 to 90% of the children with Chiari malformation also have hydrocephalus. One or more of the ventricles becomes enlarged because of the accumulation of cerebrospinal fluid (caused by obstruction of the fourth ventricle). Due to the displacement of the posterior fossa, cerebellum takes the shape of a banana (banana sign). Magnetic resonance imaging might be used to confirm the diagnosis.
Cases with mild-moderate ventriculomegaly, “banana” sign, and obliteration of cisterna magna view might not consistently comprise the typical lumbosacral protruding view. Lateral splaying of the lateral vertebral processes with widening of the spinal cord in coronal sections and V-sign in the lumbosacral region in axial views may suggest a diagnosis of Chiari II malformation with spina bifida.
Chiari II malformation, spina bifida, neural tube defect