4 Month Old Baby "Shaking Head & Hands"

[JacksParents]

Our 4 month old baby boy is otherwise healthy, but now in the last few weeks has been showing signs of what we wonder are infintile spasms.  Basically, during breastfeeding, typically just before his day nap or just before going to bed in the evening, will begin shaking his head rapidly side to side, and at the same time his hands (both) begn shaking rapidly.  This is disturbing to see, and lasts about 15-20 seconds.  We have tried arousing him duing the event, and does not see to work.  However, it is so upsetting, it is hard to tell for sure.  His eyes sometimes are open and sometimes are closed.  He continues his feeding afterwards, then goes to bed.  His sleep has been very poor.  We have a camera to watch him at night, and have noticed he is extremely unsettled during his sleep.  He lays on his back, and will roll his head from side to side, not as fast though as the above described spasm.  He will sleep only 10-30 minutes for naps during the day, and at night, sleeps from 7pm-midnight restlessly, but quietly, and then after midnight is continuously up every 1 hour for feedings until 6:30am.  We are all exhausted, and worried about this recent development.  There is a lot of discussion on the web about "normal" baby type movements due to immature neurological system, but there is a lot of info about infintile spasms too, which typically peak at 4-7 months of age.  Please comment.