Follow-up colloid cyst with hydrocephalus

[Matthew]

History:
I'm a 33 year old male.  In Aug. 99, I had a quarter-size colloid cyst resected via a transcallasol route.  Subsequently, I developed diabetes insipidus and had to have a permanent VP shunt to control the hydrocephalus.  I do not have any disconnection deficits.  After developing some compensatory techniques during rehab to help overcome the less than average verbal scores on my neuropsychological battery, I returned to work full time as a software engineer after about 6 months.

My questions are 2-fold.  The first sets of questions are of a hindsight nature and the second of a looking forward preventive nature. The experienced and capable neurosurgeon ordered a pre-operative battery of tests by the neuro-optamaligist to ensure that my optic nerve and vision were not compromised.  He did not, however, order a pre-operative neuropsychological battery.  I felt that most of my verbal problems pre-dated the tumor as evident by my earlier schooling.  Do most neurosurgeons order a pre-operative neuropsychological battery?  Why or why not?

In addition, my neurosurgeon stated that the craniotomy had to be increased in size (the size of the flap was increased?) in order to find a route that could avoid the "huge dural venous lakes" (leaks? … blood vessels?) that were encountered upon removing the first flap.  In addition, the route ultimately chosen was through my dominant side causing hemiplegia for about a week.  Do most neurosurgeons order an angiogram to help in the placement of the flap?  Why or why not?

What portion of corpus callosum that can be sacrifice?

[CCF-Neuro-M.D.-JT]

1.A pre-op neuropscyhe test is very important in patients who will undergo neurosurgery to remove elegant parts of the brain, especially dominant hemisphere structures that include or border on speech/language/memory areas. A battery of testing is routinely ordered for patients with epilepsy, less commonly in tumors or vascular lesions in these high functioning areas to help the surgeon and patient determine how much is at risk if these areas are removed or damaged. It is not routinely ordered in cases such as yours.

2.Angiograms are not ordered routinely for bone flaps. Angiograms are important in patients with vascular problems such as strokes, aneurysms, arterial-venous malformations, and other arterial diseases to help doctors evalutate the vascular anatomy for diagnosis or intervention and repair.

3.Corpus callosotomy surgeries are sometimes done for epilepsy patients to prevent spread of seizures where they partially resect the structure or intentionally place holes there. Also, there are genetic syndromes in which patients are born without a corpus callosum at all. SO it's quite possible to live without one, but the patient of course is not neurologically normal.

[Matthew]

My neurosurgeon said the corpus callasum incision was about 3cm (in the anterior portion?) when they generally like to limit such a cut to 2 cm.  Is there a generally accepted size and position of the corpus callosum that can be sacrificed while still maintaining function?

I haven't seen my neurosurgeon in over a year.  However, I see my endo every 6 months for the DI.  He recently ordered a follow up MRI because I complained of slight lethargy more so than usual and he wanted to make sure the shunt was still working.  The report follows:

...
HISTORY - MRI BRAIN W/WO GADO: EVAL. NO RECURRENT HYDROCEPHALUS

Contrast MR of the brain

History: Follow-up colloid cyst with hydrocephalus

Sagittal and axial T1-weighted sequences were performed and axial T2-weighted sequences were performed. Contrast was administered, axial and coronal T1-weighted sequences were repeated.

Findings: There is a catheter extending into the ventricular system from a burr-hole in the right occipital region. There is no evidence of hydrocephalus. There is a focal area of abnormal high-signal intensity on the left side in the high convexity just in front of the central sulcus. Following administration of gadolinium there is a circular area of enhancement at the site of this abnormal signal intensity. There is no evidence of a mass-effect. The abnormal area enhancement may be the result of previous surgery.

Impression: Postoperative changes with probable enhancement in the operative site from surgery with the catheter extending into the ventricles with no evidence of hydrocephalus.
...

My endo said that this was good news.  I thought it was good news because there is no mass effect and no hydrocephalus but was a bit troubled by the "high signal intensity" area.  Is this just scar tissue?  Would you suggest that I inform my neurosurgeon of these images?  I don’t want to bother him if there’s not anything that can be done to correct it.

Finally, what other symptoms should I be on the look out for shunt malfunction?  Are most malfunctions caused by debris in the CSF that clogs the tubing?  Are there any vitamins or habits that I could take or adopt to maintain healthy CSF?  I know that the decadron all but practically stop dead in its tracks the excruciating headaches that I had been having prior to surgery.  

Thank you very much.

Matthew McCarty