Great Plains Laboratory has information related to the benefits of a low oxalate diet in treating autism posted HERE.  This site also contains information on various supplements to help support the break down of oxalates that you may wish to discuss with your doctor.

Posted benefits include improvements in:

Fine/Gross motor

Receptive language

Expressive speech

Imitation/Social skills

Reduction of self-injurious behavior

Improved sleep

THIS CHART is incredibly helpful when watching oxalates. The second column indicates the oxalate content in common foods.