Acetyl co A represents Fat component, since the major source is fatty acid oxidation. Acetyl co A is completely oxidized in the TCA cycle in the presence of oxaloacetate. Pyruvate is mainly used up for Anaplerotic reactions to compensate for oxaloacetate concentration. Thus without carbohydrates (Pyruvate), there would be no anaplerotic reactions to replenish the TCA-cycle components. With a diet of fats only, the acetyl CoA from fatty acid degradation would not get oxidized and build up due to non functioning of TCA cycle. Thus fats can burn only in the flame of carbohydrates.
Because it has some selectivity for cerebral vasculature, nimodipine's main use is in the prevention of cerebral vasospasm and resultant ischemia , a complication of subarachnoid hemorrhage (a form of cerebral bleed ), specifically from ruptured intracranial berry aneurysms irrespective of the patient's post-ictus neurological condition.  Its administration begins within 4 days of a subarachnoid hemorrhage and is continued for three weeks. If blood pressure drops by over 5%, dosage is adjusted. There is still controversy regarding the use of intravenous nimodipine on a routine basis.