Today, I’m sitting in Littlest’s hospital room. It’s been ten days from the previous post, and he’s in yet another MRI. It’s been a whirlwind week, and since the last post was rather long, I decided to put the “rest of the story” about Littlest’s Spina Bifida in this post.
Spina Bifida: Chiari II Malformation
One of the things that is associated with Spina Bifida is a malformation of the brain called Arnold-Chiari malformation, or Chiari II malformation. Every SB patient (myelomeningocele) has Type II Chiari, because it’s a result of the spinal cord being pulled out from the spine in utero. This causes the cerebellum (balance, timing part) of the brain and the “tonsils” of the brainstem to be pulled down into the top of the neck. Littlest’s Chiari II is pretty severe, so this has resulted in something called symptomatic Chiari which basically means that he has symptoms (problems) from his brainstem/cerebellum being pulled down. His cervical spine is very tight, that doesn’t allow his CSF to cycle properly. His symptoms are gradual and slight loss of function in his arms, breathing difficulties, coordination problems (swallowing and hand-coordination), digression from developmental milestones he has already attained, and just general malaise.
Spina Bifida/Hydrocephalus: Hydromyelia
Because his CSF can’t cycle properly, it built up under the Chiari malformation and is causing pressure on the cervical and thoracic spine. This is called hydromyelia, and if left untreated, can cause damage to the spinal cord, resulting in a higher loss of function than they would otherwise have. Littlest’s hydromyelia is around his cervical (neck) and thoracic (shoulder to mid-back) spine; and his loss of function from that has included weakened grasp and poor hand control.
Hydrocephalus: Shunt Revisions
Because of the loss of function that Littlest was experiencing, the protocol for hydro/SB patients is to always revise the shunt first, to see if that may be causing the complications. On Tuesday (9/20), four months to the day after he had his shunt placed, Littlest underwent a revision. Dr. Woodward put the proximal end of his shunt catheter further into the ventricle, and changed the angle of access a little bit. She said that she expected a noticeable amount of improvement the next day, and sure enough, he had it. He was grabbing his toys, moving his arms and legs more than he had been, and acting all around happy. Today (Thursday), we noticed some marked digression again, which Dr. W had warned us would probably occur. She said that the fact that he did get better for a short time on Wednesday just confirmed that it was indeed symptomatic Chiari, and because of his digressions, she scheduled a Chiari decompression for Monday, Sept. 26.
Chiari II: Decompression
According to a website about Arnold Chiari Malformation, the decompression procedure:
…generally involves a linear incision at the back of the head and upper neck. A small part of the skull posterior to the foramen magnum is removed to effectively enlarge the opening, giving more room to the structures within. In many cases the posterior arch of the first cervical vertebrae is also opened to widen this space.
In most cases the dura, the leathery covering of the brain and spinal cord, is also opened in this area and expanded to improve the space within. This expansion, called a duraplasty, can be accomplished either with synthetic dura substitutes or sometimes with a piece of periosteum (the covering of the bone from the skull) from the patient.
Dr. W uses a synthetic graft, so that there is a lesser risk of the spinal cord adhering to the area where the surgery was performed. Littlest’s decompression will entail all three: the craniotomy (removal of part of the skull by the foramen magnum, the large opening at the base of the skull through which the spinal cord exits the skull), the laminectomy (removal of the posterior lamina on the C1 or C2 vertebrae), and the duraplasty.
9/30 EDIT: Littlest’s decompression did not included a craniotomy, Dr. W reserved that for down the road, since it wasn’t necessary this surgery, and will give him the potential for drastic relief should he need it down the road.