1. The document discusses various congenital anomalies of the central nervous system (CNS), including arachnoid cysts, neuroenteric cysts, craniosynostosis, encephalocele, Chiari malformations, Dandy-Walker malformations, aqueductal stenosis, neural tube defects, tethered cord syndrome, split cord syndrome, intracranial lipomas, and hypothalamic hamartomas. 2. It describes the phenotypes, genotypes, stages of CNS development, and types, symptoms, and treatments of each anomaly. 3. Key anomalies discussed in more depth include arachnoid cysts, craniosynostosis, encephalo

1. Congenital anomalies of the CNS DR.MAZIN M.K. BOUJAN 2011

2. INTRODUCTION Phenotype: the outer look. Genotype: the inner genetics. 1.Malformation=genetic=organ formation. 2.Deformity= environmental -Internal (more sever, no spontaneous recovery) e.g.: Meningomyelocele=spastic muscles=club feet. -External (might correct itself after the resolution of the force) e.g.: oligohydraminios(uterus force) leads to premature descent of the head and eventually coronal synostosis ). 3. disruption: tissue or organ destruction. (Hydrancephaly=necrosis). 4. a sequence= one primary defect leads to many secondary anomalies.

3. Neuroembryology Stages of embryonic development; Human embryo has 23 stages of development (each of 2-3 days long). Stage 8 to 23 is related to CNS development.

4. Stages of CNS development

5. Types of CNS anomalies Arachnoid cyst. Neuroenteric cysts. Craniosynostosis. Encephalocele. Chiari malformation. Dandy-Walker malformation. Aqueductal stenosis. Neural tube defects. Tethered cord syndrome. Split cord syndrome. Intracranial lipoma. Hypothalamic hamartoma.

6. 1.Arachnoid cyst 1.Intracranial: Usually asymptomatic discovered incidentally. Could be symptomatic. Symptoms: Increased ICP, seizure, or hemiparesis. Treatment: from shunting to excision. 2.intraspinal:almost always dorsal.

7. 2.Neuroenteric cysts Is a CNS cyst lined by endothelium resembling GIT or respiratory. Intraspinal: is the main location, usually anterior. Intracranial: few reported cases. Symptom: pain or myelopathy, meningitis(in the fistula type). Treatment: complete removal.

8. 3.Craniosynostosis. Congenital early closure of the sutures. Might occur postnataly by abnormal positioning (lazy lambdoid). Has many types according to the suture involved. Most well known: Sagittal=scaphocephaly. Unilateral Coronal= plegiocephaly. Bilateral coronal = brachycephaly. Treatment: indication for surgery is usually cosmetic.

9. 4.Encephalocele Is cranium bifidum usually a cyst in the occipital region. If only contains meningies=meningocele. If contain meningies and cerebral tissue = encephalocele. Another group is called basal encephalocele appear at the base of the skull and could be mistaken for a nasal polyp. Treatment: surgical excision and water-tight Dural suture.

10. 5.Chiari malformation Basically 4 types: Chiari I: caudal descent of the cerebellar tonsils to the cervical canal. Chiari II: caudal descent of the vermis, medulla and the 4th ventricle. Chiari III: rare, cerebellar herniation + encephalocele. Chiari IV: cerebellar hypoplesia. Treatment: surgical decompression of the posterior fossa.

11. 6.Dandy-Walker Malformation Atresia of foramen Magendie and luschka. Agenesis of the vermis. 4th ventricle communicated with a posterior fossa cyst. Treatment: shunt the posterior fossa cyst.

12. 7.Aqueduct stenosis Triventricular hydrocephalus. Normal size 4th ventricle. Congenital: malformation. Acquired: infection, neoplasm, arachnoids' cyst. Treatment: shunting.

13. 8.Spinal dysraphysm Spina bifida: types; Spina bifida occulta: an incidental finding of spinous process and lamina. Meningocele: 1+ cystic distention of the meningies. Myelomeningocele: 1+2+ spinal cord or cauda equina involvement. Treatment : for 2 and 3 repair, with or without shunt operation.

14. 9.Tethered cord syndrom Thick filumterminale with an abnormal low level conusmedularis. Presentation: Gait difficulty, visible muscle atrophy, sensory deficit, bladder dysfunction, scoliosis and kyphosis. Treatment: division of the filum.

15. 10.Split cord syndrom Type 1: 2 cords with 2 covering dura. Type 2(diplomyelia):2 cords within the same dura. treatment: untethering the cord

16. 11.Intracranial lipoma Usually in the midline above the corpus callosum. Discovered insidentaly, or cause seizure or hydrocephalus. Treatment : shunting the associated hydrocephalus. Direct surgery is rarely necessary.

17. 12.Hypothalamic hamartoma Masses of ectopic neural tissues. Presentation: seizure, behavioral disturbance, precocious puberty, mental retardation, and visual impairment. Surgical resection.

18. Good luck