I would agree with the above:
I did an EEG only fellowship and I saw the writing on the wall. I think CNP only fellowships may be on their way out for what Thama said. EEG and EMG are both very highly "operator dependent", and you can get into trouble if the person doing/interpreting the study is not well versed in the technique. While I think that a CNP fellowship prepares you adequately to interpret or perform these studies the advantage lies in the context/interpretation.
I'm pretty lucky that I was able to take the Epilepsy board with my CNP-EEG fellowship, though and to be fair my fellowship was more geared towards epilepsy rather than purely CNP.