Year : 2005 | Volume
: 15 | Issue : 1 | Page : 17--18
Chiari III malformation - a case report
M Joshi, V Goswami, A Jain, R Agarawal, A Gupta
Department of Radiodiagnosis civil Hospital, Asarwa, Ahmedabad, India
32, Assistant professor quarters, civil hospital campus, Asarwa, Ahmedabad-380016
|How to cite this article:|
Joshi M, Goswami V, Jain A, Agarawal R, Gupta A. Chiari III malformation - a case report.Indian J Radiol Imaging 2005;15:17-18
|How to cite this URL:|
Joshi M, Goswami V, Jain A, Agarawal R, Gupta A. Chiari III malformation - a case report. Indian J Radiol Imaging [serial online] 2005 [cited 2020 Jul 12 ];15:17-18
Available from: http://www.ijri.org/text.asp?2005/15/1/17/28735
Chiari malformations are cerebellar anomalies which were first described more than 100 years ago by Dr. Hans Chiari. Four types of chiari malformation have been described. Their only commonality is that they all involve cerebellum. Otherwise there is neither anatomic or embryologic correlation. Here we present a case of chiari III malformation which is the most rare and severe form.
A CASE REPORT
Three and half months old female child presented with cleft palate and swelling in cervicooccipital region. First 4 female siblings born to the parents were absolutely normal. MRI of the brain was performed with 0.5 Tesla Philips Gyroscan using a dedicated head quadrature coil. Spin echo and fast spin echo sequences were used to obtain T1W, T2W, and FLAIR images in sagittal, coronal and axial planes. Plain study was performed. [Figure 1][Figure 2][Figure 3][Figure 4]
There was presence of posterior cervico occipital bone defect with posterior cervical vertebral agenesis with herniation of occipital lobes, cerebellum, meninges and CSF spaces through the defect. Herniated cerebellum showed dysgenesis. There was also hydrocephalus with hypogenesis of corpus callosum, prominent masa intermedia and tectal beaking. There was exaggerated cervical lordosis with downward displacement of brainstem and 4th ventricle into the cervical canal. There was no e/o syringohydromyelia of the cord .
Chiari III malformation is a rare and most severe form of chiari malformation (1,4). Infants with this anomaly are generally greatly neurologically compromised. Often the anomaly may be incompatible with life. This condition always comprises of high cervical and low occipital encephalocele,. Cases that do not involve the upper cervical spinal canal should not be classified as Chiari III malformation but simply as encephaloceles . Encephaloceles contain varying amounts of brain i.e. cerebellum, occipital lobes, ventricles and sometimes pons and medulla ,. Associated anomalies include petrous and clivus scalloping, over/undergrown cerebellar hemisphere, tonsillar herniation, deformed midbrain, hydrocephalus, dysgenesis of corpus callosum, posterior cervical vertebral agenesis, spinal cord syrinx ,.
Herniated lesion may be strikingly abnormal and often nonfunctioning because of necrosis, gliosis, fibrosis and the presence of heterotropias.
On USG, diagnosis can be made as early as 1st trimester. CT is sensitive in the depiction of the bony defect but less sensitive in demonstration of herniated sac's contents. MR demonstrates the sac's contents with much greater accuracy which is critical when surgery is contemplated. MR angiography can help screening for position of major dural sinuses and major cerebral arteries relative to encephalocele's contents. Treatment often is fraught with serious technical and ethical dilemmas. If surgery is undertake, the sac is excised and brain tissue is placed into the posterior fossa with dural graft and skin coverage.
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