Acquired Chiari-malformation after Ventriculoperitoneal Shunt for Hydrocepalus Associated with Neurocysticercosis

Acquired Chiari malformation is a term describing the low lying cerebellar tonsils subsequent to the documentation of a normal hind brain. It is radiograpnhically indistinguishable from Chiari-I type malformation. Ventricular and lumbar shunting are known predisposing factors in patients who develop such tonsilar descent. Managements of acquired Chiari malformations include ventriculoperitoneal(V-P) shunt. Ventriculoatrial(V-A) shunt or posterior fossa decompression after removal of lumboperitoneal(L-P) shunt. The authors recently have encountered a patient who developed an acquired chiari malformations after V-P shunt for hydrocephalus associatd with neurocysticercosis. This case of chiari malformation is presented as our report, together with pertinent literature review.

Analysis of Morphometric Characteristics of Lumbar adieles

During the past decade, internal fixation techniques for stabilization of spinal fracture, correction of spinal deformity and immobilization in degenerative spinal diseases have increased in general, pedicle screw fixation of the spine provides the three dimensionally rigid grip on each vertebra and minimizes the levels of spinal segment that is needed for proper fixation. But with the increasing use of pedicle screw, there is an increase in incidences of complication. Major complications of pedicle instrumentation are screw malposition, pedicle fracture, iatrogenic foraminal encroachment, injury to the facet joints or vessels, and mechanical failure. These complications may be associated with irreversible damage of both vertebral and neural elements. Therefore, full understanding and knowledge of vertebral morphology is essential for proper instrument fixation and avoidance of complications. A total of 500 pedicle measurements were made from L1 to L5 vertebra. Five morphometric parameters were studied, transverse pedicle width, transverse pedicle angle, depth to anterior cortex, sagittal pedicle width, sagittal pedicle angle. Measurements were done using both spinal computed tomography and simple lumbar X-rays. As for the results, the means of transverse pedicle width is 7.9-16.6mm, transverse pedicle angle is 8.3-29.1 degrees And depth to anterior cortex is 43.8-47.9mm. The results were compared with previous data.