foreign or spina bifida can be both open and or closed occult and it comes in many shapes and sizes as you can see from this slide um a variety of different abnormalities over the spinal midline when I think of open spina bifida I it's it for me it's a big dividing line between if the spinal cord is exposed versus all of the Spina Bifida occultyl lesions where the where the spinal cord is not um exposed and and what makes the difference between those two lesions they both have a local impact right they both can have an impact on the function of the lower extremities on the bowel bladder control sexual functioning but the difference is in an open lesion where the spinal cord in essence comes down and opens up like a flower and as you can see is attached to the skin here is that this lesion is is leaked taking spinal fluid and this happens very early in mother's pregnancy within the first three weeks of the pregnancy and that whole nervous system has many weeks with which it's going to develop and it's an abnormal situation for that brain and spinal cord to be developing when the bottom end of the spinal cord is exposed and leaking spinal fluid and the impact that it has on the developing nervous system is known as the Chiari tube and so I think of it as not only the wiring throughout the nervous system can be impacted but it also in essence you're you're letting the water out at the bottom end right and so these pictures that you see here are A sagittal slice through the brain and brain stem this is the brain stem in a splotch this is a splotch Mouse this is a typically developing Mouse and this black is the spinal fluid and so you can see when the tailbutt is closed you've got normal spinal fluid spaces in the brain this is the little romp encephalon this is the brain stem going into the cervical cord and you can see when you have a splotch Mouse where the bottom end is open as in spina bifida the CSF spaces are collapsed the romencephalon it hasn't developed yet but it has no room the posterior fossa is very small and the brain stem buckles onto the cervical cord and that is you know the the Chiari 2 not only I love to say not only is the house or the posterior fossa too small but the wiring is bad and we know that that's related to the development of the hydrocephalus or too much fluid in the brain and so again it's a big dividing line for me in spina bifida care between whether it's open or whether all of the closed lesions hey everyone Ryan rad here from neurosurgerytraining.org if you like that video subscribe and donate to keep our content available for medical students across the world