It's just occurred to me - I don't think I've ever head if William Shatner has a middle name. IMDB shows nothing there.
Nimoy's is Simon, DeForest is actually Kelley's middle name (Jackson DeForest Kelley is his full name), Doohan's is, amusingly, Montgomery (go figure
), Koenig's is Marvin and Takei's is Hosato. The only other one of the main original cast with a name anomaly (probably not an accurate word for it, but am at a loss for a better one) is Nichols, who was born Grace Nichols (also no listed middle name).
Not entirely uncommon - my paternal grandfather and uncle are both without middle names and I've met others over the years who claim the same. Don't know if it's a generational thing, but something of a curiosity nonetheless.
Nimoy's is Simon, DeForest is actually Kelley's middle name (Jackson DeForest Kelley is his full name), Doohan's is, amusingly, Montgomery (go figure

Not entirely uncommon - my paternal grandfather and uncle are both without middle names and I've met others over the years who claim the same. Don't know if it's a generational thing, but something of a curiosity nonetheless.