? HEMICORD

Q.All are true regarding diastematomyelia except

a.coronal clefting of spinal cord

b.80 % cases in female

c.45% cases in lumbar/lumbosacral area

d. the smaller hemicord often lies ventral to the larger hemicord

e.conus medullaris usually low

ANS----a

Diastematomyelia signifies a sagittal clefting of the spinal cord, conus medullaris, and/or filum terminale into two hemicords

The two hemicords are each narrower than normal  and nearly always (91%) reunite distally into a re-formed cord below the cleft . In 30% of cases the hemicords are grossly asymmetric in size. When the hemicords are asymmetric, the cord above and below the cleft is usually asymmetrically smaller on the side of the smaller hemicord, and the smaller hemicord often lies ventral to the larger hemicord. The filum terminale is usually-perhaps always-thickened and may itself tether the reunited cord. Hydromyelia is present in up to 50% of cases of diastematomyelia. It may affect the cord above the cleft and extend into one or both hemicords