The treatment and prognosis of the low grade glioma
will depend on the location and size of the tumor
and if it is exhibiting a mass effect on the other brain matter.
As far as the prognosis is concerned a childhood glioma has a better prognosis than the adult one.The slow onset of difficulty in speech and walking suggest towards mass effect or slowly developing Hydrocephalous which might need relief by a shunt.
I would suggest you to get in touch with a neurosurgeon who might be able to guide you and suggest surgical possibility .