Check Integrity of Potentially Corrupted Files

We recently experienced an issue with one of our hard drives and it had to be recovered using some disk utilities. The result of the restoration was as good as could be expected given the circumstances, but we're left with a quite a few files which are corrupted, namely they're now 0 byte length or only a few KB.

We need to quantify how many of these files are corrupt without having to manually open every single file. The files themselves are either Word, Excel or PDF files.

Is there any way to check the integrity of the files using software or some form of script which will penetrate all directories? I was thinking it may be possible to check the header of each file to ensure it looks good based on the abovefile types as all corrupted files just seem to contain garbaged text.