Not quite true.

The disorder in ALS is of the corticospinal tract, not the NMJ, but both points are irrelevant in this case. The researchers are decoding cortical signals and translating them drive a mechanical prosthesis. Theoretically, anyone with an intact motor cortex (spinal cord injured patient, as you point out, but also for ALS) should be able to manipulate one of these things.

Pretty cool stuff, but we're years away from anything clinically useful coming out of this because compared to other medical conditions, the research dollars just aren't there (the number of people with diabetes dwarfs all the SCI and amputees easily). Also, we need to figure out a way to use these non-invasively (i.e. outside the head) to avoid the problems with infection and the ethics of justifying an experimental brain surgery on a human...

first of all, a complete resection of a infiltrative glioma is not possible, because frequently by the time they're diagnosed, they've already crossed the corpus callosum into the contralateral hemisphere (google butterfly glioma. and those are just the cells we can see with MRI. we already know there are micrometastases that are not visible by /any/ currently available clinical imaging modality)

theoretically, you could do a gross total resection (we do these all the time) and irradiate the surrounding parenchyma with white light to reduce the tumor burden due to micrometastases. of course, we could just find a slightly different form of EM radiation (like x-rays) that penetrate better than visible light and activate the nanoparticles that way.

interesting stuff.