Codman Hakim VP shunt for normal pressure hydrocephalus

[Andy715]

My 83-year old father was diagnosed with normal pressure hydrocephalus.  The neurosurgeon recommended to place a shunt in the spinal cord to drain out excess CSF fluid to test to see if he gets better.  After the spinal cord shunt was placed, he immediately was able to walk faster, more alert and more capable to ask / answer questions and less urinary incontinence.  By the way, the spinal cord shunt was removed after a trial of 3 days (it collected about 90 ml CSF per day)

Because my father got better with the spinal cord shunt, the surgeon placed the Codman Hakim VP  Programmable Valve surgically 2 weeks ago.  After the surgery, father was more alert and more able to ask / answer questions.  However, his walking was still very limited, just like before the surgery.  The pressure setting for the shunt is at 120 mm h2o.  Why does the spinal cord shunt improve his symptoms while the Codman Hakim VP Valve didnt improve his walking ability ?  How long would it take to see improvement with his walking ?  What should the pressure setting be at ?

I really appreciate your reply to my questions.    Thanks very much for your help.

Andrew

[DrJerrelBoyer]

I am a neurosurgeon in Chicago.  It can take some time to achieve maximum results after shunting.  Also I am assuming that your father had an external lumbar drain.  These are difficult to really calibrate the pressure and drainage.  Therefore his actual pressures now may somewhat higher than they were with the lumbar drain.    Luckily his current valve is programmable and the pressures can be gradually lowered.  There is a risk of over drainage particularly in the elderly so this must be done slowly.  I hope this helps

Dr. Jerrel Boyer
Chicago Back Institute

[Dr_Nassim]

Thank you Andy, thank you Dr Boyer for your professional advice.

[Andy715]

Dear Dr. Boyer

Thanks very much for answering my question.  I really appreciate your expert advice.

Yes, my father did have an external lumbar drain prior to the Codman valve.  He responded
well with lumbar drain.  Father occasionally complains of headache after surgery .  I read that over drainage will cause headache.  If I may ask you another question, what test would you recommend prior to turning down the pressure to make sure there is no over drainage at current pressure setting ?  Thanks again.

Andrew