In young chicks this is known as wry neck or encephalomalacia, usually due to a vitamin E/selenium deficiency. Wry neck is also called torticolis and crook neck, and can be due to head injuries, brain inflammation, and from certain respiratory or Mareks disease. I would get some poultry vitamins and put them in the water. The most important vitamins to replace are E, thiamine or B1, and the mineral selenium which is found in egg, meats, fish, and nuts. Poultry Provita, and the ones below may be found in your local farm store. Some will also use PolyVisol baby vitamins (without iron) 2 drops given orally daily. Make sure that you are feeding chick starter grower feed, and you may need to wet the feed and help it eat to get enough. Here is some reading: http://www.browneggblueegg.com/Article/Crookneck/Crookneck.html