CoQ10 or placebo will be given as a liquid once per day in the evening, by mouth or feeding tube. The CoQ10 dose will be 10 mg/kg with a maximum dose of 400 mg a day. Neither the subject nor the health care givers will know exactly when subjects are receiving CoQ10 or when subjects are receiving the placebo. However, subjects will receive CoQ10 for at least 6 months. At each visit the subject will be given a seven month supply of CoQ10, nutritional cocktail, and multivitamins to take home and they will be asked to bring back any unused medications at the next visit. At each visit subjects will be given a medication diary to record the time and date that they take the medications that will be provided. This diary should be returned to the study coordinator at the subject's scheduled visit. During the 12 month period that subjects are on the study, they will be expected to stop taking all medications and other supplements except for those provided by the study and those that the study doctor determines are medically needed. Except in the case of an emergency, the subject must contact the study doctor before taking any new medications or supplements. In the case of an emergency, subjects are required to inform the study doctor of the emergency and treatments as soon as possible.