Oh wow, good to finally find others with the same issue!
I have been experiencing this over the past 2 months and until now I always thought that I bit my tongue during sleep. However the last time I experienced this was during a light nap and I conscious enough to realize my teeth were not to blame. Also, as per the previous comment, the location of the pain is too offset to be attributed to tongue biting.
The pain is indeed as though someone stuck a needle in your tongue - a needle with electric current running through it. I have jumped from sleep several times in shock due to the severity of the pain.
I also clench my jaws during sleep so I guess we all have this in common.
I'm 30 years old and the only change to my health has been the addition of Welbutrin to my daily dose of Paxil.
Anyone else taking any similar meds? I'm very interested to finding the cause and of course a solution to this problem!