Chemotherapy and learning disabilites

[D-Winston]

    
      Re: Chemotherapy and learning disabilites
    


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Posted by CCF Neurology MD on October 17, 1997 at 11:29:51:

In Reply to: Chemotherapy and learning disabilites posted by D. Winston on October 01, 1997 at 00:40:13:

: I have an 11 year old survivor of neuroblastoma.  She underwent 2 years of chemo beginning at 9 months old.  She is has been diagnosed with ADD and tested (through her school system) for learning disabilities.  Have there been any studies done with children who have had chemo to determine possible differences in the way they process information, etc.
  Thanks for your time!
= Dear D. Winston, Chemotherapy given during the time frame you have described would affect predominately a subgroup of supportive cells of the brain, the oligodendrocytes, which are responsiable for supplying the myelin covering of axons of nerve cells. This myelin covering acts as an insulation so that signals of individual nerve cells can travel very efficiently down the axons allowing the nerve cells to communicate with one another. The lack of myelin would inhibit or may even block such communication between the nerve cells. Therefore during the time your child was on the chemotherapy this 'laying down of myelin' via the rapid growth of the oligodendroycytes would nave been disrupted. Once the chemotherapy was stopped, the oligodendrocytes would have restarted laying down the myelin but at a much slower rate since the critical time when they would normally do so would have been disrupted by the chemotherapy. The question arises if they were eventually 100% succesful or not. If not, there may be problems now in the ability of various nerve cells to communicate with one another. If these nerve cells are located in areas responsiable for learning, learning could be affected. However, the effect of the chemotherapy would be diffuse,in that no one population of oligodendrocytes would have been more affected than another. Therefore, one can only speculate on if the ADD seen in your child is related to the earlier exposure to chemptherapy.  One could recommend , if you wish to investgate this further, formal neuropsychological evaluation to evaluate for cognitive abnormaities. Imaging studies (i.e.MRI) would probably less useful unless they have not been done in the last several years and the diagnosis of ADD is new.  However, one would strongly advise that you discuss these issues with either your pediatrician, oncologist and/or pediatric neurologist on the need for further testing and if so, which one(s). It may also be beneficial to contact the National Attention Deficit Disorder at [phone]/ [phone][fax]/e-mail:***@**** www.add.org which may be able to supply additional information concerning your question(s).  "This information is provided for general education purposes only. Please consult your physician for diagnostic and treatment options of your specific medical conditions."