А randomized comparative prospective 35-day clinical-instrumental trial of 30 patients with an ischemic hemispheric stroke hospitalized on the first day of disease was carried out. In addition to basic therapy, 16 patients of the main group were treated with the antioxidant power-normalizing drug cytoflavin used in dosage 20 ml/day intravenous in drops from the 1st to 10th day and 2 tablets twice a day from the 11th to 35th day. Fourteen patients of the comparison group received basic therapy only. Patient's state was assessed at 0-24 h and 5, 11, 21, 35 days of stroke. Assessment of neurological status (the Glasgow Coma Scale, the NIH stroke scale, a short version of MMSE), brain MRI (brain lesion volume), a study of antioxidant stress markers, assessment of functional outcome (the Barthel index and the modified Rankin scale) were conducted. The early active correction of power and free radical homeostasis by cytoflavin improved the dynamics of brain morphological changes and free-radical changes that was correlated with the activation of consciousness and reduction of neurologic deficit that resulted in the decrease of disability.