GENERAL PRINCIPLES Congenital abnormalities are among the leading causes of infant morbidity and mortality and fetal loss. The leading sites of congenital abnormalities are the skeleton, skin and brain. Congenital abnormalities of the CNS can be divided into developmental malformations and disruptions. Developmental malformations result from flawed development of the brain. This may be caused by chromosomal abnormalities and single gene defects that alter the blueprint of the brain or by imbalances of certain factors that control gene expression during development. Gene defects may be in the germline or develop after conception by spontaneous mutation or from the action of harmful physical or chemical agents. Some malformations are caused by multiple genetic and environmental factors acting in concert (multifactorial etiology). Disruptions result from destruction of the normally developed (or developing) brain caused by environmental or intrinsic factors such as fetal infection, exposure of the fetus to harmful chemicals, irradiation, and fetal hypoxia. For instance, holoprosencephaly, a condition in which the forebrain is not divided into two hemispheres, is a malformation. Hydranencephaly, in which massive destruction reduces the hemispheres into fluid-filled sacs, is a disruption. The line between malformation and disruption is sometimes blurred because an extrinsic factor (e.g. irradiation) may not only cause physical injury but may also damage genes that are important for development. In general, the pathological lesions of developmental malformations of the CNS are either midline or bilateral and symmetric and do not show gliosis. On the other hand, most disruptions are focal and asymmetric and are associated with gliosis and other reactive changes such as inflammation, phagocytosis and calcification. However, in disruptions occurring in the first trimester, these reactions are limited because the brain is immature. For these reasons, it is hard, sometimes, to distinguish malformation from disruption. This distinction carries important implications. Malformations carry a recurrence risk that can be calculated. Disruptions do not recur, unless the exposure recurs or continues. Exposure to teratogens, viral infections, etc., can occur throughout pregnancy. The timing of exposure is critical for both, malformations and disruptions. The earlier the exposure, the more severe the defect. For instance, fetal cytomegalovirus (CMV) infection before midgestation causes microcephaly and polymicrogyria. The most critical period for malformations and disruptions is the third to eighth week of gestation, during which most organs, including the brain, take form.
Q00-Q07Congenital malformations of the nervous system Q02Microcephaly Q02.-0Hydromicrocephaly Q02.-1Micrencephalon Q03Congenital hydrocephalusIncludes:hydrocephalus in newbornQ03.0Malformations of aqueduct of Sylvius Q03.1Atresia of foramina of Magendie and Luschka (Dandy Walker Syndrome) Q03.8Other congenital hydrocephalus Q03.80Congenital hydrocephalus in malformations classified elsewhere Q03.9Congenital hydrocephalus, unspecified Q04Other congenital malformations of brain Q04.0Congenital malformations of corpus callosum Q04.00Total agenesis of corpus callosum Q04.01Partial agenesis of corpus callosum Q04.02Agenesis with lipoma of corpus callosum Q04.08Other congenital malformation of corpus callosum Q04.1Arhinencephaly Q04.2Holoprosencephaly Q04.3Other reduction deformities of brain Q04.30Agyria Q04.31Lissencephaly Q04.32Microgyria Q04.33Pachygyria Q04.34Agenesis of part of brain , unspecified Q04.3x0Frontal Q04.3x1Temporal Q04.3x2Parietal Q04.3x3Occipital Q04.3x4Brain stem Q04.3x5Cerebellum hemispheres Q04.3x6Cerebellar vermis Q04.3x7Optic nerves Q04.3x8Thalamus or basal ganglia Q04.3x9Hypothalamus Q04.4Septo-optic dysplasia Q04.5Megalencephaly Q04.6Congenital cerebral cysts Q04.8Other specified congenital malformations of brain Q04.9Congenital malformation of brain, unspecified Q05Spina bifidaExcludes:Arnold-Chiari syndrome(Q07.0);spina bifidQ05.0Cervical spina bifida with hydrocephalus Q05.1Thoracic spina bifida with hydrocephalusSpina bifida:dorsal,thoracolumbar-with hydrocephalQ05.2Lumbar spina bifida with hydrocephalusLumbosacral spina bifida with hydrocephalusQ05.3Sacral spina bifida with hydrocephalus Q05.4Unspecified spina bifida with hydrocephalus Q05.5Cervical spina bifida without hydrocephalus Q05.6Thoracic spina bifida without hydrocephalus Q05.7Lumbar spina bifida without hydrocephalus Q05.8Sacral spina bifida without hydrocephalus Q05.9Spina bifida, unspecified Q06Other congenital malformations of spinal cord Q06.0Amyelia Q06.1Hypoplasia and dysplasia of spinal cord Q06.2Diastematomyelia Q06.3Other congenital cauda equina malformations Q06.4Hydromyelia Q06.8Other specified congenital malformations of spinal cord Q06.9Congenital malformation of spinal cord, unspecified Q07Other congenital malformations of nervous system Q07.0Arnold-Chiari syndrome Q07.8Other specified congenital malformations of nervous system Q07.9Congenital malformation of nervous system, unspecified
viwG_MasE01_ICD10NA_Q00-99_CongenitalChromosomal ICD 10DiseaseRemark Q03Congenital hydrocephalusIncludes:hydrocephalus in newborn Q03.0Malformations of aqueduct of Sylvius Q03.1Atresia of foramina of Magendie and Luschka (Dandy Walker Syndrome) Q03.8Other congenital hydrocephalus Q03.80Congenital hydrocephalus in malformations classified elsewhere Q03.9Congenital hydrocephalus, unspecified
viwG_MasE01_ICD10NA_Q00-99_CongenitalChromosomal ICD 10DiseaseRemark Q04Other congenital malformations of brain Q04.0Congenital malformations of corpus callosum Q04.00Total agenesis of corpus callosum Q04.01Partial agenesis of corpus callosum 04.02Agenesis with lipoma of corpus callosum Q04.08Other congenital malformation of corpus callosum Q04.1Arhinencephaly Q04.2Holoprosencephaly
Case # 104: MRI Brain, 11/11/92: Lobar Holoprosencephaly CC: Delayed motor development. Hx: This 21 month old male presented for delayed motor development, &quot;jaw quivering&quot; and &quot;lazy eye.&quot; He was an 8 pound 10 ounce product of a full term, uncomplicated pregnancy-labor-spontaneous vaginal delivery to a G3P3 married white female mother. There had been no known toxic intrauterine exposures. He had no serious illnesses or hospitalizations since birth. He sat independently at 7 months, stood at 11 months, crawled at 16 months, but did not cruise until 18 months. He currently cannot walk and easily falls. His gait is reportedly marked by left &quot;intoeing.&quot; His upper extremity strength and coordination reportedly appear quite normal and he is able to feed himself, throw and transfer objects easily. He knows greater than 20 words and speaks two-word phrases. No seizures or unusual behavior were reported except for &quot;quivering&quot; movement of his jaw. This has occurred since birth. In addition the parents have noted transient left exotropia. PMH: As above. FHx: Many family members with &quot;lazy eye.&quot; No other neurologic diseases declared. 9 and 5 year old sisters who are healthy. SHx: lives with parents and sisters. EXAM: BP83/67 HR122 36.4C Head circumference 48.0cm Weight 12.68kg(70%) Height 86.0cm(70%) MS: fairly cooperative. CN: Minimal transient esotropia OS. Tremulous quivering of jaw--increased with crying. No obvious papilledema, though difficult to evaluate due to patient movement. Motor: sat independently with normal posture and no truncal ataxia. symmetric and normal strength and muscle bulk throughout. Sensory: withdrew to vibration. Coordination: unremarkable in BUE. Station: no truncal ataxia. Gait: On attempting to walk, his right foot rotated laterally at almost 70degrees. Both lower extremities could rotate outward to 90degrees. There was marked passive eversion at the ankles as well. Reflexes: 2+/2+ throughout. Musculoskeletal: pes planovalgus bilaterally. COURSE: CK normal. The parents decided to forego an MRI in 8/90. The patient returned 12/11/92 at age 4 years. He was ambulatory and able to run awkwardly. His general health had been good, but he showed signs developmental delay. Formal evaluation had tested his IQ at 87 at age 3.5 years. He was weakest on tasks requiring visual/motor integration and fine motor and visual discrimination skills. He was 6 months delayed in cognitive development at that time. On exam, age 4 years, he displayed mild right ankle laxity on eversion and inversion, but normal gait. The rest of the neurological exam was normal. Head circumference was 49.5cm(50%) and height and weight were in the 90th percentile. Fragile X analysis and karyotyping were unremarkable.
Clinical History: The patient has nystagmus and diminished visual acuity. Findings: The axial flair image as well as the coronal T1 weighted MR image demonstrate absence of the septum pellucidum. The coronal T1 weighted image also demonstrates hypoplasia of the optic chiasm. The coronal T2 weighted image demonstrates hypoplastic optic nerves. Diagnosis: Septo-optic dysplasia. (de Morsier syndrome). Discussion: Patients with septo-optic dysplasia have hypoplastic optic nerves as well as a hypoplastic optic chiasm due to dysplasia of the optic pathways. The septum pellucidum may be completely (64%) or partially (36%) absent which results in a squared-off appearance of the frontal horns of the lateral ventricles. Other associated cerebral anomalies include schizencephaly which has been reported in 50% of patients as well as dysgenesis of the corpus callosum, olfactory, aplasia, gray matter, heterotopia, and cerebellar dysplasia. Septo-optic dysplasia is often considered in the spectrum of holoprosencephaly as representing the most minor form of holoprosencephaly. Clinical manifestations of septo-optic dysplasia are variable. Most typically, patients have nystagmus and diminished visual acuity, dwarfism secondary to division of growth hormone and thyroid stimulating hormone, and neurological defect. References: Chen CY, Zimmerman RA. Congenital Brain Anomalies. In: Neuroimaging Clinical and Physical Principles . Editors: Zimmerman RA, Gibby WA, Carmody RS. Springer-Verlag, New York; 2000:506. Congenital Disorders of the Brain and Spine. In: Neuroradiology: The
Congenital malformation of cns encephalocele
Congenital Malformation of CNS
ICD 10NA Congenital malformation <ul><li>Q00 Anencephaly and similar malformation </li></ul><ul><li>Q01 Encephalocele </li></ul><ul><li>Q02 Microcephaly </li></ul><ul><li>Q03 Congenital hydrocephalus </li></ul><ul><li>Q04 Other congenital malformations of brain </li></ul><ul><li>Q05 Spina bifida </li></ul><ul><li>Q06 Other congenital malformations of spinal cord </li></ul><ul><li>Q07 Other congenital malformations of nervous system </li></ul>
Q03Congenital hydrocephalus <ul><li>Q03.0 Malformations of aqueduct of Sylvius </li></ul><ul><li>Q03.1 Atresia of foramina of Magendie and Luschka (Dandy Walker Syndrome) </li></ul><ul><li>Q03.8 Other congenital hydrocephalus </li></ul><ul><ul><li>Q03.80 Congenital hydrocephalus in malformations classified elsewhere </li></ul></ul><ul><li>Q03.9 Congenital hydrocephalus, unspecified </li></ul>
Q04Other congenital malformations of brain <ul><li>Q04.0Congenital malformations of corpus callosum </li></ul><ul><ul><li>Q04.00Total agenesis of corpus callosum </li></ul></ul><ul><ul><li>Q04.01Partial agenesis of corpus callosum </li></ul></ul><ul><ul><li>04.02Agenesis with lipoma of corpus callosum </li></ul></ul><ul><ul><li>04.08Other congenital malformation of corpus callosum </li></ul></ul><ul><li>Q04.1Arhinencephaly </li></ul><ul><li>Q04.2Holoprosencephaly </li></ul>
Septo-optic Dysplasia (de Morsier Syndrome) <ul><li>Clinical History: The patient has nystagmus and diminished visual acuity. </li></ul><ul><li>Findings: The axial flair image as well as the coronal T1 weighted MR image demonstrate absence of the septum pellucidum. The coronal T1 weighted image also demonstrates hypoplasia of the optic chiasm. The coronal T2 weighted image demonstrates hypoplastic optic nerves </li></ul>