Any injury to the CNS can take years to heal to an acceptable level. When I realized that I was losing my back muscles, I exercised by using a rowing machine. I eventually lost the use of all my paraspinal muscles but found that I had unwittingly increased the power of other muscles which took over the load.
One thing I used to do was to find out where the "top" was. I exercised until I thought I had "gone over the top", then remembered not to take my exercise that far in future. The CNS will repair at its own rate and cannot be forced by excessive exercising (despite what you see in movies).
Always bear in mind that Dr Kildares are figments of authors' imagination. In real life, Doctors know very little of the human nervous system and can only offer opinions.
Subtle cerebellar signs quickly disapppear due to central compensation, but that does not mean the problem has disappeared. Unless one has actually suffered from a neuro problem it is impossible to imagine what a neuro problem entails. Those very young, fit Doctors, can in reality have no idea at all what a neuro patient is suffering.